diff --git a/src/tint/writer/hlsl/generator_impl.cc b/src/tint/writer/hlsl/generator_impl.cc
index b9a6675..72e02f0 100644
--- a/src/tint/writer/hlsl/generator_impl.cc
+++ b/src/tint/writer/hlsl/generator_impl.cc
@@ -1110,52 +1110,13 @@
         return EmitZeroValue(out, type);
     }
 
-    if (auto* mat = call->Type()->As<sem::Matrix>()) {
-        if (ctor->Parameters().size() == 1) {
-            // Matrix constructor with single scalar.
-            auto fn = utils::GetOrCreate(matrix_scalar_ctors_, mat, [&]() -> std::string {
-                TextBuffer b;
-                TINT_DEFER(helpers_.Append(b));
-
-                auto name = UniqueIdentifier("build_mat" + std::to_string(mat->columns()) + "x" +
-                                             std::to_string(mat->rows()));
-                {
-                    auto l = line(&b);
-                    if (!EmitType(l, mat, ast::StorageClass::kNone, ast::Access::kUndefined, "")) {
-                        return "";
-                    }
-                    l << " " << name << "(";
-                    if (!EmitType(l, mat->type(), ast::StorageClass::kNone, ast::Access::kUndefined,
-                                  "")) {
-                        return "";
-                    }
-                    l << " value) {";
-                }
-                {
-                    ScopedIndent si(&b);
-                    auto l = line(&b);
-                    l << "return ";
-                    if (!EmitType(l, mat, ast::StorageClass::kNone, ast::Access::kUndefined, "")) {
-                        return "";
-                    }
-                    l << "(";
-                    for (uint32_t i = 0; i < mat->columns() * mat->rows(); i++) {
-                        l << ((i > 0) ? ", value" : "value");
-                    }
-                    l << ");";
-                }
-                line(&b) << "}";
-                return name;
-            });
-            if (fn.empty()) {
-                return false;
-            }
-            out << fn << "(";
-            if (!EmitExpression(out, call->Arguments()[0]->Declaration())) {
-                return false;
-            }
-            out << ")";
-            return true;
+    // Single parameter matrix initializers must be identity constructor.
+    // It could also be conversions between f16 and f32 matrix when f16 is properly supported.
+    if (type->Is<sem::Matrix>() && call->Arguments().size() == 1) {
+        if (!ctor->Parameters()[0]->Type()->UnwrapRef()->is_float_matrix()) {
+            TINT_UNREACHABLE(Writer, diagnostics_)
+                << "found a single-parameter matrix constructor that is not identity constructor";
+            return false;
         }
     }
 
diff --git a/src/tint/writer/hlsl/generator_impl_constructor_test.cc b/src/tint/writer/hlsl/generator_impl_constructor_test.cc
index 700d94b..6a1d696 100644
--- a/src/tint/writer/hlsl/generator_impl_constructor_test.cc
+++ b/src/tint/writer/hlsl/generator_impl_constructor_test.cc
@@ -223,6 +223,24 @@
     EXPECT_THAT(gen.result(), HasSubstr("float2x3 tint_symbol = float2x3((0.0f).xxx, (0.0f).xxx)"));
 }
 
+TEST_F(HlslGeneratorImplTest_Constructor, EmitConstructor_Type_Mat_Identity) {
+    // fn f() {
+    //     var m_1: mat4x4<f32> = mat4x4<f32>();
+    //     var m_2: mat4x4<f32> = mat4x4<f32>(m_1);
+    // }
+
+    auto* m_1 = Var("m_1", ty.mat4x4(ty.f32()), mat4x4<f32>());
+    auto* m_2 = Var("m_2", ty.mat4x4(ty.f32()), mat4x4<f32>(m_1));
+
+    WrapInFunction(m_1, m_2);
+
+    GeneratorImpl& gen = Build();
+
+    ASSERT_TRUE(gen.Generate()) << gen.error();
+
+    EXPECT_THAT(gen.result(), HasSubstr("float4x4 m_2 = float4x4(m_1);"));
+}
+
 TEST_F(HlslGeneratorImplTest_Constructor, EmitConstructor_Type_Array) {
     WrapInFunction(Construct(ty.array(ty.vec3<f32>(), 3_u), vec3<f32>(1_f, 2_f, 3_f),
                              vec3<f32>(4_f, 5_f, 6_f), vec3<f32>(7_f, 8_f, 9_f)));
diff --git a/test/tint/expressions/type_ctor/mat2x2/explicit/identity/f32.wgsl b/test/tint/expressions/type_ctor/mat2x2/explicit/identity/f32.wgsl
index 7d23bcf..3249340 100644
--- a/test/tint/expressions/type_ctor/mat2x2/explicit/identity/f32.wgsl
+++ b/test/tint/expressions/type_ctor/mat2x2/explicit/identity/f32.wgsl
@@ -1 +1,7 @@
-let m = mat2x2<f32>();
+let m = mat2x2(mat2x2<f32>(0.0f, 1.0f,
+                           2.0f, 3.0f));
+
+fn f() -> mat2x2<f32> {
+    let m_1 = mat2x2(m);
+    return m_1;
+}
diff --git a/test/tint/expressions/type_ctor/mat2x2/explicit/identity/f32.wgsl.expected.glsl b/test/tint/expressions/type_ctor/mat2x2/explicit/identity/f32.wgsl.expected.glsl
index a496f95..98b5a53 100644
--- a/test/tint/expressions/type_ctor/mat2x2/explicit/identity/f32.wgsl.expected.glsl
+++ b/test/tint/expressions/type_ctor/mat2x2/explicit/identity/f32.wgsl.expected.glsl
@@ -4,4 +4,9 @@
 void unused_entry_point() {
   return;
 }
-const mat2 m = mat2(vec2(0.0f), vec2(0.0f));
+const mat2 m = mat2(vec2(0.0f, 1.0f), vec2(2.0f, 3.0f));
+mat2 f() {
+  mat2 m_1 = mat2(vec2(0.0f, 1.0f), vec2(2.0f, 3.0f));
+  return mat2(vec2(0.0f, 1.0f), vec2(2.0f, 3.0f));
+}
+
diff --git a/test/tint/expressions/type_ctor/mat2x2/explicit/identity/f32.wgsl.expected.hlsl b/test/tint/expressions/type_ctor/mat2x2/explicit/identity/f32.wgsl.expected.hlsl
index a38b32b..884de04 100644
--- a/test/tint/expressions/type_ctor/mat2x2/explicit/identity/f32.wgsl.expected.hlsl
+++ b/test/tint/expressions/type_ctor/mat2x2/explicit/identity/f32.wgsl.expected.hlsl
@@ -3,4 +3,9 @@
   return;
 }
 
-static const float2x2 m = float2x2((0.0f).xx, (0.0f).xx);
+static const float2x2 m = float2x2(float2(0.0f, 1.0f), float2(2.0f, 3.0f));
+
+float2x2 f() {
+  const float2x2 m_1 = float2x2(float2(0.0f, 1.0f), float2(2.0f, 3.0f));
+  return float2x2(float2(0.0f, 1.0f), float2(2.0f, 3.0f));
+}
diff --git a/test/tint/expressions/type_ctor/mat2x2/explicit/identity/f32.wgsl.expected.msl b/test/tint/expressions/type_ctor/mat2x2/explicit/identity/f32.wgsl.expected.msl
index 9076107..2397b00 100644
--- a/test/tint/expressions/type_ctor/mat2x2/explicit/identity/f32.wgsl.expected.msl
+++ b/test/tint/expressions/type_ctor/mat2x2/explicit/identity/f32.wgsl.expected.msl
@@ -1,5 +1,10 @@
 #include <metal_stdlib>
 
 using namespace metal;
-constant float2x2 m = float2x2(float2(0.0f), float2(0.0f));
+constant float2x2 m = float2x2(float2(0.0f, 1.0f), float2(2.0f, 3.0f));
+
+float2x2 f() {
+  float2x2 const m_1 = float2x2(float2(0.0f, 1.0f), float2(2.0f, 3.0f));
+  return float2x2(float2(0.0f, 1.0f), float2(2.0f, 3.0f));
+}
 
diff --git a/test/tint/expressions/type_ctor/mat2x2/explicit/identity/f32.wgsl.expected.spvasm b/test/tint/expressions/type_ctor/mat2x2/explicit/identity/f32.wgsl.expected.spvasm
index 849d656..8b08148 100644
--- a/test/tint/expressions/type_ctor/mat2x2/explicit/identity/f32.wgsl.expected.spvasm
+++ b/test/tint/expressions/type_ctor/mat2x2/explicit/identity/f32.wgsl.expected.spvasm
@@ -1,7 +1,7 @@
 ; SPIR-V
 ; Version: 1.3
 ; Generator: Google Tint Compiler; 0
-; Bound: 9
+; Bound: 18
 ; Schema: 0
                OpCapability Shader
                OpMemoryModel Logical GLSL450
@@ -9,13 +9,25 @@
                OpExecutionMode %unused_entry_point LocalSize 1 1 1
                OpName %m "m"
                OpName %unused_entry_point "unused_entry_point"
+               OpName %f "f"
       %float = OpTypeFloat 32
     %v2float = OpTypeVector %float 2
 %mat2v2float = OpTypeMatrix %v2float 2
-          %m = OpConstantNull %mat2v2float
+    %float_0 = OpConstant %float 0
+    %float_1 = OpConstant %float 1
+          %6 = OpConstantComposite %v2float %float_0 %float_1
+    %float_2 = OpConstant %float 2
+    %float_3 = OpConstant %float 3
+          %9 = OpConstantComposite %v2float %float_2 %float_3
+          %m = OpConstantComposite %mat2v2float %6 %9
        %void = OpTypeVoid
-          %5 = OpTypeFunction %void
-%unused_entry_point = OpFunction %void None %5
-          %8 = OpLabel
+         %11 = OpTypeFunction %void
+         %15 = OpTypeFunction %mat2v2float
+%unused_entry_point = OpFunction %void None %11
+         %14 = OpLabel
                OpReturn
                OpFunctionEnd
+          %f = OpFunction %mat2v2float None %15
+         %17 = OpLabel
+               OpReturnValue %m
+               OpFunctionEnd
diff --git a/test/tint/expressions/type_ctor/mat2x2/explicit/identity/f32.wgsl.expected.wgsl b/test/tint/expressions/type_ctor/mat2x2/explicit/identity/f32.wgsl.expected.wgsl
index 7d23bcf..27431a6 100644
--- a/test/tint/expressions/type_ctor/mat2x2/explicit/identity/f32.wgsl.expected.wgsl
+++ b/test/tint/expressions/type_ctor/mat2x2/explicit/identity/f32.wgsl.expected.wgsl
@@ -1 +1,6 @@
-let m = mat2x2<f32>();
+let m = mat2x2(mat2x2<f32>(0.0f, 1.0f, 2.0f, 3.0f));
+
+fn f() -> mat2x2<f32> {
+  let m_1 = mat2x2(m);
+  return m_1;
+}
diff --git a/test/tint/expressions/type_ctor/mat2x2/inferred/identity/f32.wgsl b/test/tint/expressions/type_ctor/mat2x2/inferred/identity/f32.wgsl
new file mode 100644
index 0000000..3b4c5e2
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat2x2/inferred/identity/f32.wgsl
@@ -0,0 +1,7 @@
+let m = mat2x2(mat2x2(0.0f, 1.0f,
+                      2.0f, 3.0f));
+
+fn f() -> mat2x2<f32> {
+    let m_1 = mat2x2(m);
+    return m_1;
+}
diff --git a/test/tint/expressions/type_ctor/mat2x2/inferred/identity/f32.wgsl.expected.glsl b/test/tint/expressions/type_ctor/mat2x2/inferred/identity/f32.wgsl.expected.glsl
new file mode 100644
index 0000000..98b5a53
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat2x2/inferred/identity/f32.wgsl.expected.glsl
@@ -0,0 +1,12 @@
+#version 310 es
+
+layout(local_size_x = 1, local_size_y = 1, local_size_z = 1) in;
+void unused_entry_point() {
+  return;
+}
+const mat2 m = mat2(vec2(0.0f, 1.0f), vec2(2.0f, 3.0f));
+mat2 f() {
+  mat2 m_1 = mat2(vec2(0.0f, 1.0f), vec2(2.0f, 3.0f));
+  return mat2(vec2(0.0f, 1.0f), vec2(2.0f, 3.0f));
+}
+
diff --git a/test/tint/expressions/type_ctor/mat2x2/inferred/identity/f32.wgsl.expected.hlsl b/test/tint/expressions/type_ctor/mat2x2/inferred/identity/f32.wgsl.expected.hlsl
new file mode 100644
index 0000000..884de04
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat2x2/inferred/identity/f32.wgsl.expected.hlsl
@@ -0,0 +1,11 @@
+[numthreads(1, 1, 1)]
+void unused_entry_point() {
+  return;
+}
+
+static const float2x2 m = float2x2(float2(0.0f, 1.0f), float2(2.0f, 3.0f));
+
+float2x2 f() {
+  const float2x2 m_1 = float2x2(float2(0.0f, 1.0f), float2(2.0f, 3.0f));
+  return float2x2(float2(0.0f, 1.0f), float2(2.0f, 3.0f));
+}
diff --git a/test/tint/expressions/type_ctor/mat2x2/inferred/identity/f32.wgsl.expected.msl b/test/tint/expressions/type_ctor/mat2x2/inferred/identity/f32.wgsl.expected.msl
new file mode 100644
index 0000000..2397b00
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat2x2/inferred/identity/f32.wgsl.expected.msl
@@ -0,0 +1,10 @@
+#include <metal_stdlib>
+
+using namespace metal;
+constant float2x2 m = float2x2(float2(0.0f, 1.0f), float2(2.0f, 3.0f));
+
+float2x2 f() {
+  float2x2 const m_1 = float2x2(float2(0.0f, 1.0f), float2(2.0f, 3.0f));
+  return float2x2(float2(0.0f, 1.0f), float2(2.0f, 3.0f));
+}
+
diff --git a/test/tint/expressions/type_ctor/mat2x2/inferred/identity/f32.wgsl.expected.spvasm b/test/tint/expressions/type_ctor/mat2x2/inferred/identity/f32.wgsl.expected.spvasm
new file mode 100644
index 0000000..8b08148
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat2x2/inferred/identity/f32.wgsl.expected.spvasm
@@ -0,0 +1,33 @@
+; SPIR-V
+; Version: 1.3
+; Generator: Google Tint Compiler; 0
+; Bound: 18
+; Schema: 0
+               OpCapability Shader
+               OpMemoryModel Logical GLSL450
+               OpEntryPoint GLCompute %unused_entry_point "unused_entry_point"
+               OpExecutionMode %unused_entry_point LocalSize 1 1 1
+               OpName %m "m"
+               OpName %unused_entry_point "unused_entry_point"
+               OpName %f "f"
+      %float = OpTypeFloat 32
+    %v2float = OpTypeVector %float 2
+%mat2v2float = OpTypeMatrix %v2float 2
+    %float_0 = OpConstant %float 0
+    %float_1 = OpConstant %float 1
+          %6 = OpConstantComposite %v2float %float_0 %float_1
+    %float_2 = OpConstant %float 2
+    %float_3 = OpConstant %float 3
+          %9 = OpConstantComposite %v2float %float_2 %float_3
+          %m = OpConstantComposite %mat2v2float %6 %9
+       %void = OpTypeVoid
+         %11 = OpTypeFunction %void
+         %15 = OpTypeFunction %mat2v2float
+%unused_entry_point = OpFunction %void None %11
+         %14 = OpLabel
+               OpReturn
+               OpFunctionEnd
+          %f = OpFunction %mat2v2float None %15
+         %17 = OpLabel
+               OpReturnValue %m
+               OpFunctionEnd
diff --git a/test/tint/expressions/type_ctor/mat2x2/inferred/identity/f32.wgsl.expected.wgsl b/test/tint/expressions/type_ctor/mat2x2/inferred/identity/f32.wgsl.expected.wgsl
new file mode 100644
index 0000000..cd44a0f
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat2x2/inferred/identity/f32.wgsl.expected.wgsl
@@ -0,0 +1,6 @@
+let m = mat2x2(mat2x2(0.0f, 1.0f, 2.0f, 3.0f));
+
+fn f() -> mat2x2<f32> {
+  let m_1 = mat2x2(m);
+  return m_1;
+}
diff --git a/test/tint/expressions/type_ctor/mat2x2/zero/f32.wgsl b/test/tint/expressions/type_ctor/mat2x2/zero/f32.wgsl
new file mode 100644
index 0000000..7d23bcf
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat2x2/zero/f32.wgsl
@@ -0,0 +1 @@
+let m = mat2x2<f32>();
diff --git a/test/tint/expressions/type_ctor/mat2x2/zero/f32.wgsl.expected.glsl b/test/tint/expressions/type_ctor/mat2x2/zero/f32.wgsl.expected.glsl
new file mode 100644
index 0000000..a496f95
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat2x2/zero/f32.wgsl.expected.glsl
@@ -0,0 +1,7 @@
+#version 310 es
+
+layout(local_size_x = 1, local_size_y = 1, local_size_z = 1) in;
+void unused_entry_point() {
+  return;
+}
+const mat2 m = mat2(vec2(0.0f), vec2(0.0f));
diff --git a/test/tint/expressions/type_ctor/mat2x2/zero/f32.wgsl.expected.hlsl b/test/tint/expressions/type_ctor/mat2x2/zero/f32.wgsl.expected.hlsl
new file mode 100644
index 0000000..a38b32b
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat2x2/zero/f32.wgsl.expected.hlsl
@@ -0,0 +1,6 @@
+[numthreads(1, 1, 1)]
+void unused_entry_point() {
+  return;
+}
+
+static const float2x2 m = float2x2((0.0f).xx, (0.0f).xx);
diff --git a/test/tint/expressions/type_ctor/mat2x2/zero/f32.wgsl.expected.msl b/test/tint/expressions/type_ctor/mat2x2/zero/f32.wgsl.expected.msl
new file mode 100644
index 0000000..9076107
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat2x2/zero/f32.wgsl.expected.msl
@@ -0,0 +1,5 @@
+#include <metal_stdlib>
+
+using namespace metal;
+constant float2x2 m = float2x2(float2(0.0f), float2(0.0f));
+
diff --git a/test/tint/expressions/type_ctor/mat2x2/zero/f32.wgsl.expected.spvasm b/test/tint/expressions/type_ctor/mat2x2/zero/f32.wgsl.expected.spvasm
new file mode 100644
index 0000000..849d656
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat2x2/zero/f32.wgsl.expected.spvasm
@@ -0,0 +1,21 @@
+; SPIR-V
+; Version: 1.3
+; Generator: Google Tint Compiler; 0
+; Bound: 9
+; Schema: 0
+               OpCapability Shader
+               OpMemoryModel Logical GLSL450
+               OpEntryPoint GLCompute %unused_entry_point "unused_entry_point"
+               OpExecutionMode %unused_entry_point LocalSize 1 1 1
+               OpName %m "m"
+               OpName %unused_entry_point "unused_entry_point"
+      %float = OpTypeFloat 32
+    %v2float = OpTypeVector %float 2
+%mat2v2float = OpTypeMatrix %v2float 2
+          %m = OpConstantNull %mat2v2float
+       %void = OpTypeVoid
+          %5 = OpTypeFunction %void
+%unused_entry_point = OpFunction %void None %5
+          %8 = OpLabel
+               OpReturn
+               OpFunctionEnd
diff --git a/test/tint/expressions/type_ctor/mat2x2/zero/f32.wgsl.expected.wgsl b/test/tint/expressions/type_ctor/mat2x2/zero/f32.wgsl.expected.wgsl
new file mode 100644
index 0000000..7d23bcf
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat2x2/zero/f32.wgsl.expected.wgsl
@@ -0,0 +1 @@
+let m = mat2x2<f32>();
diff --git a/test/tint/expressions/type_ctor/mat2x3/explicit/identity/f32.wgsl b/test/tint/expressions/type_ctor/mat2x3/explicit/identity/f32.wgsl
new file mode 100644
index 0000000..dff89c8
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat2x3/explicit/identity/f32.wgsl
@@ -0,0 +1,7 @@
+let m = mat2x3(mat2x3<f32>(0.0f, 1.0f, 2.0f,
+                           3.0f, 4.0f, 5.0f));
+
+fn f() -> mat2x3<f32> {
+    let m_1 = mat2x3(m);
+    return m_1;
+}
diff --git a/test/tint/expressions/type_ctor/mat2x3/explicit/identity/f32.wgsl.expected.glsl b/test/tint/expressions/type_ctor/mat2x3/explicit/identity/f32.wgsl.expected.glsl
new file mode 100644
index 0000000..b191a03
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat2x3/explicit/identity/f32.wgsl.expected.glsl
@@ -0,0 +1,12 @@
+#version 310 es
+
+layout(local_size_x = 1, local_size_y = 1, local_size_z = 1) in;
+void unused_entry_point() {
+  return;
+}
+const mat2x3 m = mat2x3(vec3(0.0f, 1.0f, 2.0f), vec3(3.0f, 4.0f, 5.0f));
+mat2x3 f() {
+  mat2x3 m_1 = mat2x3(vec3(0.0f, 1.0f, 2.0f), vec3(3.0f, 4.0f, 5.0f));
+  return mat2x3(vec3(0.0f, 1.0f, 2.0f), vec3(3.0f, 4.0f, 5.0f));
+}
+
diff --git a/test/tint/expressions/type_ctor/mat2x3/explicit/identity/f32.wgsl.expected.hlsl b/test/tint/expressions/type_ctor/mat2x3/explicit/identity/f32.wgsl.expected.hlsl
new file mode 100644
index 0000000..4a428a2
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat2x3/explicit/identity/f32.wgsl.expected.hlsl
@@ -0,0 +1,11 @@
+[numthreads(1, 1, 1)]
+void unused_entry_point() {
+  return;
+}
+
+static const float2x3 m = float2x3(float3(0.0f, 1.0f, 2.0f), float3(3.0f, 4.0f, 5.0f));
+
+float2x3 f() {
+  const float2x3 m_1 = float2x3(float3(0.0f, 1.0f, 2.0f), float3(3.0f, 4.0f, 5.0f));
+  return float2x3(float3(0.0f, 1.0f, 2.0f), float3(3.0f, 4.0f, 5.0f));
+}
diff --git a/test/tint/expressions/type_ctor/mat2x3/explicit/identity/f32.wgsl.expected.msl b/test/tint/expressions/type_ctor/mat2x3/explicit/identity/f32.wgsl.expected.msl
new file mode 100644
index 0000000..6e9320e
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat2x3/explicit/identity/f32.wgsl.expected.msl
@@ -0,0 +1,10 @@
+#include <metal_stdlib>
+
+using namespace metal;
+constant float2x3 m = float2x3(float3(0.0f, 1.0f, 2.0f), float3(3.0f, 4.0f, 5.0f));
+
+float2x3 f() {
+  float2x3 const m_1 = float2x3(float3(0.0f, 1.0f, 2.0f), float3(3.0f, 4.0f, 5.0f));
+  return float2x3(float3(0.0f, 1.0f, 2.0f), float3(3.0f, 4.0f, 5.0f));
+}
+
diff --git a/test/tint/expressions/type_ctor/mat2x3/explicit/identity/f32.wgsl.expected.spvasm b/test/tint/expressions/type_ctor/mat2x3/explicit/identity/f32.wgsl.expected.spvasm
new file mode 100644
index 0000000..0cecb54
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat2x3/explicit/identity/f32.wgsl.expected.spvasm
@@ -0,0 +1,35 @@
+; SPIR-V
+; Version: 1.3
+; Generator: Google Tint Compiler; 0
+; Bound: 20
+; Schema: 0
+               OpCapability Shader
+               OpMemoryModel Logical GLSL450
+               OpEntryPoint GLCompute %unused_entry_point "unused_entry_point"
+               OpExecutionMode %unused_entry_point LocalSize 1 1 1
+               OpName %m "m"
+               OpName %unused_entry_point "unused_entry_point"
+               OpName %f "f"
+      %float = OpTypeFloat 32
+    %v3float = OpTypeVector %float 3
+%mat2v3float = OpTypeMatrix %v3float 2
+    %float_0 = OpConstant %float 0
+    %float_1 = OpConstant %float 1
+    %float_2 = OpConstant %float 2
+          %7 = OpConstantComposite %v3float %float_0 %float_1 %float_2
+    %float_3 = OpConstant %float 3
+    %float_4 = OpConstant %float 4
+    %float_5 = OpConstant %float 5
+         %11 = OpConstantComposite %v3float %float_3 %float_4 %float_5
+          %m = OpConstantComposite %mat2v3float %7 %11
+       %void = OpTypeVoid
+         %13 = OpTypeFunction %void
+         %17 = OpTypeFunction %mat2v3float
+%unused_entry_point = OpFunction %void None %13
+         %16 = OpLabel
+               OpReturn
+               OpFunctionEnd
+          %f = OpFunction %mat2v3float None %17
+         %19 = OpLabel
+               OpReturnValue %m
+               OpFunctionEnd
diff --git a/test/tint/expressions/type_ctor/mat2x3/explicit/identity/f32.wgsl.expected.wgsl b/test/tint/expressions/type_ctor/mat2x3/explicit/identity/f32.wgsl.expected.wgsl
new file mode 100644
index 0000000..5c9282f
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat2x3/explicit/identity/f32.wgsl.expected.wgsl
@@ -0,0 +1,6 @@
+let m = mat2x3(mat2x3<f32>(0.0f, 1.0f, 2.0f, 3.0f, 4.0f, 5.0f));
+
+fn f() -> mat2x3<f32> {
+  let m_1 = mat2x3(m);
+  return m_1;
+}
diff --git a/test/tint/expressions/type_ctor/mat2x3/inferred/identity/f32.wgsl b/test/tint/expressions/type_ctor/mat2x3/inferred/identity/f32.wgsl
new file mode 100644
index 0000000..93c90e7
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat2x3/inferred/identity/f32.wgsl
@@ -0,0 +1,7 @@
+let m = mat2x3(mat2x3(0.0f, 1.0f, 2.0f,
+                      3.0f, 4.0f, 5.0f));
+
+fn f() -> mat2x3<f32> {
+    let m_1 = mat2x3(m);
+    return m_1;
+}
diff --git a/test/tint/expressions/type_ctor/mat2x3/inferred/identity/f32.wgsl.expected.glsl b/test/tint/expressions/type_ctor/mat2x3/inferred/identity/f32.wgsl.expected.glsl
new file mode 100644
index 0000000..b191a03
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat2x3/inferred/identity/f32.wgsl.expected.glsl
@@ -0,0 +1,12 @@
+#version 310 es
+
+layout(local_size_x = 1, local_size_y = 1, local_size_z = 1) in;
+void unused_entry_point() {
+  return;
+}
+const mat2x3 m = mat2x3(vec3(0.0f, 1.0f, 2.0f), vec3(3.0f, 4.0f, 5.0f));
+mat2x3 f() {
+  mat2x3 m_1 = mat2x3(vec3(0.0f, 1.0f, 2.0f), vec3(3.0f, 4.0f, 5.0f));
+  return mat2x3(vec3(0.0f, 1.0f, 2.0f), vec3(3.0f, 4.0f, 5.0f));
+}
+
diff --git a/test/tint/expressions/type_ctor/mat2x3/inferred/identity/f32.wgsl.expected.hlsl b/test/tint/expressions/type_ctor/mat2x3/inferred/identity/f32.wgsl.expected.hlsl
new file mode 100644
index 0000000..4a428a2
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat2x3/inferred/identity/f32.wgsl.expected.hlsl
@@ -0,0 +1,11 @@
+[numthreads(1, 1, 1)]
+void unused_entry_point() {
+  return;
+}
+
+static const float2x3 m = float2x3(float3(0.0f, 1.0f, 2.0f), float3(3.0f, 4.0f, 5.0f));
+
+float2x3 f() {
+  const float2x3 m_1 = float2x3(float3(0.0f, 1.0f, 2.0f), float3(3.0f, 4.0f, 5.0f));
+  return float2x3(float3(0.0f, 1.0f, 2.0f), float3(3.0f, 4.0f, 5.0f));
+}
diff --git a/test/tint/expressions/type_ctor/mat2x3/inferred/identity/f32.wgsl.expected.msl b/test/tint/expressions/type_ctor/mat2x3/inferred/identity/f32.wgsl.expected.msl
new file mode 100644
index 0000000..6e9320e
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat2x3/inferred/identity/f32.wgsl.expected.msl
@@ -0,0 +1,10 @@
+#include <metal_stdlib>
+
+using namespace metal;
+constant float2x3 m = float2x3(float3(0.0f, 1.0f, 2.0f), float3(3.0f, 4.0f, 5.0f));
+
+float2x3 f() {
+  float2x3 const m_1 = float2x3(float3(0.0f, 1.0f, 2.0f), float3(3.0f, 4.0f, 5.0f));
+  return float2x3(float3(0.0f, 1.0f, 2.0f), float3(3.0f, 4.0f, 5.0f));
+}
+
diff --git a/test/tint/expressions/type_ctor/mat2x3/inferred/identity/f32.wgsl.expected.spvasm b/test/tint/expressions/type_ctor/mat2x3/inferred/identity/f32.wgsl.expected.spvasm
new file mode 100644
index 0000000..0cecb54
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat2x3/inferred/identity/f32.wgsl.expected.spvasm
@@ -0,0 +1,35 @@
+; SPIR-V
+; Version: 1.3
+; Generator: Google Tint Compiler; 0
+; Bound: 20
+; Schema: 0
+               OpCapability Shader
+               OpMemoryModel Logical GLSL450
+               OpEntryPoint GLCompute %unused_entry_point "unused_entry_point"
+               OpExecutionMode %unused_entry_point LocalSize 1 1 1
+               OpName %m "m"
+               OpName %unused_entry_point "unused_entry_point"
+               OpName %f "f"
+      %float = OpTypeFloat 32
+    %v3float = OpTypeVector %float 3
+%mat2v3float = OpTypeMatrix %v3float 2
+    %float_0 = OpConstant %float 0
+    %float_1 = OpConstant %float 1
+    %float_2 = OpConstant %float 2
+          %7 = OpConstantComposite %v3float %float_0 %float_1 %float_2
+    %float_3 = OpConstant %float 3
+    %float_4 = OpConstant %float 4
+    %float_5 = OpConstant %float 5
+         %11 = OpConstantComposite %v3float %float_3 %float_4 %float_5
+          %m = OpConstantComposite %mat2v3float %7 %11
+       %void = OpTypeVoid
+         %13 = OpTypeFunction %void
+         %17 = OpTypeFunction %mat2v3float
+%unused_entry_point = OpFunction %void None %13
+         %16 = OpLabel
+               OpReturn
+               OpFunctionEnd
+          %f = OpFunction %mat2v3float None %17
+         %19 = OpLabel
+               OpReturnValue %m
+               OpFunctionEnd
diff --git a/test/tint/expressions/type_ctor/mat2x3/inferred/identity/f32.wgsl.expected.wgsl b/test/tint/expressions/type_ctor/mat2x3/inferred/identity/f32.wgsl.expected.wgsl
new file mode 100644
index 0000000..f0a3182
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat2x3/inferred/identity/f32.wgsl.expected.wgsl
@@ -0,0 +1,6 @@
+let m = mat2x3(mat2x3(0.0f, 1.0f, 2.0f, 3.0f, 4.0f, 5.0f));
+
+fn f() -> mat2x3<f32> {
+  let m_1 = mat2x3(m);
+  return m_1;
+}
diff --git a/test/tint/expressions/type_ctor/mat2x3/identity/f32.wgsl b/test/tint/expressions/type_ctor/mat2x3/zero/f32.wgsl
similarity index 100%
rename from test/tint/expressions/type_ctor/mat2x3/identity/f32.wgsl
rename to test/tint/expressions/type_ctor/mat2x3/zero/f32.wgsl
diff --git a/test/tint/expressions/type_ctor/mat2x3/identity/f32.wgsl.expected.glsl b/test/tint/expressions/type_ctor/mat2x3/zero/f32.wgsl.expected.glsl
similarity index 100%
rename from test/tint/expressions/type_ctor/mat2x3/identity/f32.wgsl.expected.glsl
rename to test/tint/expressions/type_ctor/mat2x3/zero/f32.wgsl.expected.glsl
diff --git a/test/tint/expressions/type_ctor/mat2x3/identity/f32.wgsl.expected.hlsl b/test/tint/expressions/type_ctor/mat2x3/zero/f32.wgsl.expected.hlsl
similarity index 100%
rename from test/tint/expressions/type_ctor/mat2x3/identity/f32.wgsl.expected.hlsl
rename to test/tint/expressions/type_ctor/mat2x3/zero/f32.wgsl.expected.hlsl
diff --git a/test/tint/expressions/type_ctor/mat2x3/identity/f32.wgsl.expected.msl b/test/tint/expressions/type_ctor/mat2x3/zero/f32.wgsl.expected.msl
similarity index 100%
rename from test/tint/expressions/type_ctor/mat2x3/identity/f32.wgsl.expected.msl
rename to test/tint/expressions/type_ctor/mat2x3/zero/f32.wgsl.expected.msl
diff --git a/test/tint/expressions/type_ctor/mat2x3/identity/f32.wgsl.expected.spvasm b/test/tint/expressions/type_ctor/mat2x3/zero/f32.wgsl.expected.spvasm
similarity index 100%
rename from test/tint/expressions/type_ctor/mat2x3/identity/f32.wgsl.expected.spvasm
rename to test/tint/expressions/type_ctor/mat2x3/zero/f32.wgsl.expected.spvasm
diff --git a/test/tint/expressions/type_ctor/mat2x3/identity/f32.wgsl.expected.wgsl b/test/tint/expressions/type_ctor/mat2x3/zero/f32.wgsl.expected.wgsl
similarity index 100%
rename from test/tint/expressions/type_ctor/mat2x3/identity/f32.wgsl.expected.wgsl
rename to test/tint/expressions/type_ctor/mat2x3/zero/f32.wgsl.expected.wgsl
diff --git a/test/tint/expressions/type_ctor/mat2x4/explicit/identity/f32.wgsl b/test/tint/expressions/type_ctor/mat2x4/explicit/identity/f32.wgsl
new file mode 100644
index 0000000..3d3f9c2
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat2x4/explicit/identity/f32.wgsl
@@ -0,0 +1,7 @@
+let m = mat2x4(mat2x4<f32>(0.0f, 1.0f, 2.0f, 3.0f,
+                           4.0f, 5.0f, 6.0f, 7.0f));
+
+fn f() -> mat2x4<f32> {
+    let m_1 = mat2x4(m);
+    return m_1;
+}
diff --git a/test/tint/expressions/type_ctor/mat2x4/explicit/identity/f32.wgsl.expected.glsl b/test/tint/expressions/type_ctor/mat2x4/explicit/identity/f32.wgsl.expected.glsl
new file mode 100644
index 0000000..41253c4
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat2x4/explicit/identity/f32.wgsl.expected.glsl
@@ -0,0 +1,12 @@
+#version 310 es
+
+layout(local_size_x = 1, local_size_y = 1, local_size_z = 1) in;
+void unused_entry_point() {
+  return;
+}
+const mat2x4 m = mat2x4(vec4(0.0f, 1.0f, 2.0f, 3.0f), vec4(4.0f, 5.0f, 6.0f, 7.0f));
+mat2x4 f() {
+  mat2x4 m_1 = mat2x4(vec4(0.0f, 1.0f, 2.0f, 3.0f), vec4(4.0f, 5.0f, 6.0f, 7.0f));
+  return mat2x4(vec4(0.0f, 1.0f, 2.0f, 3.0f), vec4(4.0f, 5.0f, 6.0f, 7.0f));
+}
+
diff --git a/test/tint/expressions/type_ctor/mat2x4/explicit/identity/f32.wgsl.expected.hlsl b/test/tint/expressions/type_ctor/mat2x4/explicit/identity/f32.wgsl.expected.hlsl
new file mode 100644
index 0000000..32b40f8
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat2x4/explicit/identity/f32.wgsl.expected.hlsl
@@ -0,0 +1,11 @@
+[numthreads(1, 1, 1)]
+void unused_entry_point() {
+  return;
+}
+
+static const float2x4 m = float2x4(float4(0.0f, 1.0f, 2.0f, 3.0f), float4(4.0f, 5.0f, 6.0f, 7.0f));
+
+float2x4 f() {
+  const float2x4 m_1 = float2x4(float4(0.0f, 1.0f, 2.0f, 3.0f), float4(4.0f, 5.0f, 6.0f, 7.0f));
+  return float2x4(float4(0.0f, 1.0f, 2.0f, 3.0f), float4(4.0f, 5.0f, 6.0f, 7.0f));
+}
diff --git a/test/tint/expressions/type_ctor/mat2x4/explicit/identity/f32.wgsl.expected.msl b/test/tint/expressions/type_ctor/mat2x4/explicit/identity/f32.wgsl.expected.msl
new file mode 100644
index 0000000..d4bd7df
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat2x4/explicit/identity/f32.wgsl.expected.msl
@@ -0,0 +1,10 @@
+#include <metal_stdlib>
+
+using namespace metal;
+constant float2x4 m = float2x4(float4(0.0f, 1.0f, 2.0f, 3.0f), float4(4.0f, 5.0f, 6.0f, 7.0f));
+
+float2x4 f() {
+  float2x4 const m_1 = float2x4(float4(0.0f, 1.0f, 2.0f, 3.0f), float4(4.0f, 5.0f, 6.0f, 7.0f));
+  return float2x4(float4(0.0f, 1.0f, 2.0f, 3.0f), float4(4.0f, 5.0f, 6.0f, 7.0f));
+}
+
diff --git a/test/tint/expressions/type_ctor/mat2x4/explicit/identity/f32.wgsl.expected.spvasm b/test/tint/expressions/type_ctor/mat2x4/explicit/identity/f32.wgsl.expected.spvasm
new file mode 100644
index 0000000..6766c86
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat2x4/explicit/identity/f32.wgsl.expected.spvasm
@@ -0,0 +1,37 @@
+; SPIR-V
+; Version: 1.3
+; Generator: Google Tint Compiler; 0
+; Bound: 22
+; Schema: 0
+               OpCapability Shader
+               OpMemoryModel Logical GLSL450
+               OpEntryPoint GLCompute %unused_entry_point "unused_entry_point"
+               OpExecutionMode %unused_entry_point LocalSize 1 1 1
+               OpName %m "m"
+               OpName %unused_entry_point "unused_entry_point"
+               OpName %f "f"
+      %float = OpTypeFloat 32
+    %v4float = OpTypeVector %float 4
+%mat2v4float = OpTypeMatrix %v4float 2
+    %float_0 = OpConstant %float 0
+    %float_1 = OpConstant %float 1
+    %float_2 = OpConstant %float 2
+    %float_3 = OpConstant %float 3
+          %8 = OpConstantComposite %v4float %float_0 %float_1 %float_2 %float_3
+    %float_4 = OpConstant %float 4
+    %float_5 = OpConstant %float 5
+    %float_6 = OpConstant %float 6
+    %float_7 = OpConstant %float 7
+         %13 = OpConstantComposite %v4float %float_4 %float_5 %float_6 %float_7
+          %m = OpConstantComposite %mat2v4float %8 %13
+       %void = OpTypeVoid
+         %15 = OpTypeFunction %void
+         %19 = OpTypeFunction %mat2v4float
+%unused_entry_point = OpFunction %void None %15
+         %18 = OpLabel
+               OpReturn
+               OpFunctionEnd
+          %f = OpFunction %mat2v4float None %19
+         %21 = OpLabel
+               OpReturnValue %m
+               OpFunctionEnd
diff --git a/test/tint/expressions/type_ctor/mat2x4/explicit/identity/f32.wgsl.expected.wgsl b/test/tint/expressions/type_ctor/mat2x4/explicit/identity/f32.wgsl.expected.wgsl
new file mode 100644
index 0000000..f31ac21
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat2x4/explicit/identity/f32.wgsl.expected.wgsl
@@ -0,0 +1,6 @@
+let m = mat2x4(mat2x4<f32>(0.0f, 1.0f, 2.0f, 3.0f, 4.0f, 5.0f, 6.0f, 7.0f));
+
+fn f() -> mat2x4<f32> {
+  let m_1 = mat2x4(m);
+  return m_1;
+}
diff --git a/test/tint/expressions/type_ctor/mat2x4/inferred/identity/f32.wgsl b/test/tint/expressions/type_ctor/mat2x4/inferred/identity/f32.wgsl
new file mode 100644
index 0000000..cc6f3fd
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat2x4/inferred/identity/f32.wgsl
@@ -0,0 +1,7 @@
+let m = mat2x4(mat2x4(0.0f, 1.0f, 2.0f, 3.0f,
+                      4.0f, 5.0f, 6.0f, 7.0f));
+
+fn f() -> mat2x4<f32> {
+    let m_1 = mat2x4(m);
+    return m_1;
+}
diff --git a/test/tint/expressions/type_ctor/mat2x4/inferred/identity/f32.wgsl.expected.glsl b/test/tint/expressions/type_ctor/mat2x4/inferred/identity/f32.wgsl.expected.glsl
new file mode 100644
index 0000000..41253c4
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat2x4/inferred/identity/f32.wgsl.expected.glsl
@@ -0,0 +1,12 @@
+#version 310 es
+
+layout(local_size_x = 1, local_size_y = 1, local_size_z = 1) in;
+void unused_entry_point() {
+  return;
+}
+const mat2x4 m = mat2x4(vec4(0.0f, 1.0f, 2.0f, 3.0f), vec4(4.0f, 5.0f, 6.0f, 7.0f));
+mat2x4 f() {
+  mat2x4 m_1 = mat2x4(vec4(0.0f, 1.0f, 2.0f, 3.0f), vec4(4.0f, 5.0f, 6.0f, 7.0f));
+  return mat2x4(vec4(0.0f, 1.0f, 2.0f, 3.0f), vec4(4.0f, 5.0f, 6.0f, 7.0f));
+}
+
diff --git a/test/tint/expressions/type_ctor/mat2x4/inferred/identity/f32.wgsl.expected.hlsl b/test/tint/expressions/type_ctor/mat2x4/inferred/identity/f32.wgsl.expected.hlsl
new file mode 100644
index 0000000..32b40f8
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat2x4/inferred/identity/f32.wgsl.expected.hlsl
@@ -0,0 +1,11 @@
+[numthreads(1, 1, 1)]
+void unused_entry_point() {
+  return;
+}
+
+static const float2x4 m = float2x4(float4(0.0f, 1.0f, 2.0f, 3.0f), float4(4.0f, 5.0f, 6.0f, 7.0f));
+
+float2x4 f() {
+  const float2x4 m_1 = float2x4(float4(0.0f, 1.0f, 2.0f, 3.0f), float4(4.0f, 5.0f, 6.0f, 7.0f));
+  return float2x4(float4(0.0f, 1.0f, 2.0f, 3.0f), float4(4.0f, 5.0f, 6.0f, 7.0f));
+}
diff --git a/test/tint/expressions/type_ctor/mat2x4/inferred/identity/f32.wgsl.expected.msl b/test/tint/expressions/type_ctor/mat2x4/inferred/identity/f32.wgsl.expected.msl
new file mode 100644
index 0000000..d4bd7df
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat2x4/inferred/identity/f32.wgsl.expected.msl
@@ -0,0 +1,10 @@
+#include <metal_stdlib>
+
+using namespace metal;
+constant float2x4 m = float2x4(float4(0.0f, 1.0f, 2.0f, 3.0f), float4(4.0f, 5.0f, 6.0f, 7.0f));
+
+float2x4 f() {
+  float2x4 const m_1 = float2x4(float4(0.0f, 1.0f, 2.0f, 3.0f), float4(4.0f, 5.0f, 6.0f, 7.0f));
+  return float2x4(float4(0.0f, 1.0f, 2.0f, 3.0f), float4(4.0f, 5.0f, 6.0f, 7.0f));
+}
+
diff --git a/test/tint/expressions/type_ctor/mat2x4/inferred/identity/f32.wgsl.expected.spvasm b/test/tint/expressions/type_ctor/mat2x4/inferred/identity/f32.wgsl.expected.spvasm
new file mode 100644
index 0000000..6766c86
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat2x4/inferred/identity/f32.wgsl.expected.spvasm
@@ -0,0 +1,37 @@
+; SPIR-V
+; Version: 1.3
+; Generator: Google Tint Compiler; 0
+; Bound: 22
+; Schema: 0
+               OpCapability Shader
+               OpMemoryModel Logical GLSL450
+               OpEntryPoint GLCompute %unused_entry_point "unused_entry_point"
+               OpExecutionMode %unused_entry_point LocalSize 1 1 1
+               OpName %m "m"
+               OpName %unused_entry_point "unused_entry_point"
+               OpName %f "f"
+      %float = OpTypeFloat 32
+    %v4float = OpTypeVector %float 4
+%mat2v4float = OpTypeMatrix %v4float 2
+    %float_0 = OpConstant %float 0
+    %float_1 = OpConstant %float 1
+    %float_2 = OpConstant %float 2
+    %float_3 = OpConstant %float 3
+          %8 = OpConstantComposite %v4float %float_0 %float_1 %float_2 %float_3
+    %float_4 = OpConstant %float 4
+    %float_5 = OpConstant %float 5
+    %float_6 = OpConstant %float 6
+    %float_7 = OpConstant %float 7
+         %13 = OpConstantComposite %v4float %float_4 %float_5 %float_6 %float_7
+          %m = OpConstantComposite %mat2v4float %8 %13
+       %void = OpTypeVoid
+         %15 = OpTypeFunction %void
+         %19 = OpTypeFunction %mat2v4float
+%unused_entry_point = OpFunction %void None %15
+         %18 = OpLabel
+               OpReturn
+               OpFunctionEnd
+          %f = OpFunction %mat2v4float None %19
+         %21 = OpLabel
+               OpReturnValue %m
+               OpFunctionEnd
diff --git a/test/tint/expressions/type_ctor/mat2x4/inferred/identity/f32.wgsl.expected.wgsl b/test/tint/expressions/type_ctor/mat2x4/inferred/identity/f32.wgsl.expected.wgsl
new file mode 100644
index 0000000..644d882
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat2x4/inferred/identity/f32.wgsl.expected.wgsl
@@ -0,0 +1,6 @@
+let m = mat2x4(mat2x4(0.0f, 1.0f, 2.0f, 3.0f, 4.0f, 5.0f, 6.0f, 7.0f));
+
+fn f() -> mat2x4<f32> {
+  let m_1 = mat2x4(m);
+  return m_1;
+}
diff --git a/test/tint/expressions/type_ctor/mat2x4/identity/f32.wgsl b/test/tint/expressions/type_ctor/mat2x4/zero/f32.wgsl
similarity index 100%
rename from test/tint/expressions/type_ctor/mat2x4/identity/f32.wgsl
rename to test/tint/expressions/type_ctor/mat2x4/zero/f32.wgsl
diff --git a/test/tint/expressions/type_ctor/mat2x4/identity/f32.wgsl.expected.glsl b/test/tint/expressions/type_ctor/mat2x4/zero/f32.wgsl.expected.glsl
similarity index 100%
rename from test/tint/expressions/type_ctor/mat2x4/identity/f32.wgsl.expected.glsl
rename to test/tint/expressions/type_ctor/mat2x4/zero/f32.wgsl.expected.glsl
diff --git a/test/tint/expressions/type_ctor/mat2x4/identity/f32.wgsl.expected.hlsl b/test/tint/expressions/type_ctor/mat2x4/zero/f32.wgsl.expected.hlsl
similarity index 100%
rename from test/tint/expressions/type_ctor/mat2x4/identity/f32.wgsl.expected.hlsl
rename to test/tint/expressions/type_ctor/mat2x4/zero/f32.wgsl.expected.hlsl
diff --git a/test/tint/expressions/type_ctor/mat2x4/identity/f32.wgsl.expected.msl b/test/tint/expressions/type_ctor/mat2x4/zero/f32.wgsl.expected.msl
similarity index 100%
rename from test/tint/expressions/type_ctor/mat2x4/identity/f32.wgsl.expected.msl
rename to test/tint/expressions/type_ctor/mat2x4/zero/f32.wgsl.expected.msl
diff --git a/test/tint/expressions/type_ctor/mat2x4/identity/f32.wgsl.expected.spvasm b/test/tint/expressions/type_ctor/mat2x4/zero/f32.wgsl.expected.spvasm
similarity index 100%
rename from test/tint/expressions/type_ctor/mat2x4/identity/f32.wgsl.expected.spvasm
rename to test/tint/expressions/type_ctor/mat2x4/zero/f32.wgsl.expected.spvasm
diff --git a/test/tint/expressions/type_ctor/mat2x4/identity/f32.wgsl.expected.wgsl b/test/tint/expressions/type_ctor/mat2x4/zero/f32.wgsl.expected.wgsl
similarity index 100%
rename from test/tint/expressions/type_ctor/mat2x4/identity/f32.wgsl.expected.wgsl
rename to test/tint/expressions/type_ctor/mat2x4/zero/f32.wgsl.expected.wgsl
diff --git a/test/tint/expressions/type_ctor/mat3x2/explicit/identity/f32.wgsl b/test/tint/expressions/type_ctor/mat3x2/explicit/identity/f32.wgsl
new file mode 100644
index 0000000..7a14231
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat3x2/explicit/identity/f32.wgsl
@@ -0,0 +1,8 @@
+let m = mat3x2(mat3x2<f32>(0.0f, 1.0f,
+                           2.0f, 3.0f,
+                           4.0f, 5.0f));
+
+fn f() -> mat3x2<f32> {
+    let m_1 = mat3x2(m);
+    return m_1;
+}
diff --git a/test/tint/expressions/type_ctor/mat3x2/explicit/identity/f32.wgsl.expected.glsl b/test/tint/expressions/type_ctor/mat3x2/explicit/identity/f32.wgsl.expected.glsl
new file mode 100644
index 0000000..49056fe
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat3x2/explicit/identity/f32.wgsl.expected.glsl
@@ -0,0 +1,12 @@
+#version 310 es
+
+layout(local_size_x = 1, local_size_y = 1, local_size_z = 1) in;
+void unused_entry_point() {
+  return;
+}
+const mat3x2 m = mat3x2(vec2(0.0f, 1.0f), vec2(2.0f, 3.0f), vec2(4.0f, 5.0f));
+mat3x2 f() {
+  mat3x2 m_1 = mat3x2(vec2(0.0f, 1.0f), vec2(2.0f, 3.0f), vec2(4.0f, 5.0f));
+  return mat3x2(vec2(0.0f, 1.0f), vec2(2.0f, 3.0f), vec2(4.0f, 5.0f));
+}
+
diff --git a/test/tint/expressions/type_ctor/mat3x2/explicit/identity/f32.wgsl.expected.hlsl b/test/tint/expressions/type_ctor/mat3x2/explicit/identity/f32.wgsl.expected.hlsl
new file mode 100644
index 0000000..049a998
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat3x2/explicit/identity/f32.wgsl.expected.hlsl
@@ -0,0 +1,11 @@
+[numthreads(1, 1, 1)]
+void unused_entry_point() {
+  return;
+}
+
+static const float3x2 m = float3x2(float2(0.0f, 1.0f), float2(2.0f, 3.0f), float2(4.0f, 5.0f));
+
+float3x2 f() {
+  const float3x2 m_1 = float3x2(float2(0.0f, 1.0f), float2(2.0f, 3.0f), float2(4.0f, 5.0f));
+  return float3x2(float2(0.0f, 1.0f), float2(2.0f, 3.0f), float2(4.0f, 5.0f));
+}
diff --git a/test/tint/expressions/type_ctor/mat3x2/explicit/identity/f32.wgsl.expected.msl b/test/tint/expressions/type_ctor/mat3x2/explicit/identity/f32.wgsl.expected.msl
new file mode 100644
index 0000000..9e216c8
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat3x2/explicit/identity/f32.wgsl.expected.msl
@@ -0,0 +1,10 @@
+#include <metal_stdlib>
+
+using namespace metal;
+constant float3x2 m = float3x2(float2(0.0f, 1.0f), float2(2.0f, 3.0f), float2(4.0f, 5.0f));
+
+float3x2 f() {
+  float3x2 const m_1 = float3x2(float2(0.0f, 1.0f), float2(2.0f, 3.0f), float2(4.0f, 5.0f));
+  return float3x2(float2(0.0f, 1.0f), float2(2.0f, 3.0f), float2(4.0f, 5.0f));
+}
+
diff --git a/test/tint/expressions/type_ctor/mat3x2/explicit/identity/f32.wgsl.expected.spvasm b/test/tint/expressions/type_ctor/mat3x2/explicit/identity/f32.wgsl.expected.spvasm
new file mode 100644
index 0000000..6679e29
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat3x2/explicit/identity/f32.wgsl.expected.spvasm
@@ -0,0 +1,36 @@
+; SPIR-V
+; Version: 1.3
+; Generator: Google Tint Compiler; 0
+; Bound: 21
+; Schema: 0
+               OpCapability Shader
+               OpMemoryModel Logical GLSL450
+               OpEntryPoint GLCompute %unused_entry_point "unused_entry_point"
+               OpExecutionMode %unused_entry_point LocalSize 1 1 1
+               OpName %m "m"
+               OpName %unused_entry_point "unused_entry_point"
+               OpName %f "f"
+      %float = OpTypeFloat 32
+    %v2float = OpTypeVector %float 2
+%mat3v2float = OpTypeMatrix %v2float 3
+    %float_0 = OpConstant %float 0
+    %float_1 = OpConstant %float 1
+          %6 = OpConstantComposite %v2float %float_0 %float_1
+    %float_2 = OpConstant %float 2
+    %float_3 = OpConstant %float 3
+          %9 = OpConstantComposite %v2float %float_2 %float_3
+    %float_4 = OpConstant %float 4
+    %float_5 = OpConstant %float 5
+         %12 = OpConstantComposite %v2float %float_4 %float_5
+          %m = OpConstantComposite %mat3v2float %6 %9 %12
+       %void = OpTypeVoid
+         %14 = OpTypeFunction %void
+         %18 = OpTypeFunction %mat3v2float
+%unused_entry_point = OpFunction %void None %14
+         %17 = OpLabel
+               OpReturn
+               OpFunctionEnd
+          %f = OpFunction %mat3v2float None %18
+         %20 = OpLabel
+               OpReturnValue %m
+               OpFunctionEnd
diff --git a/test/tint/expressions/type_ctor/mat3x2/explicit/identity/f32.wgsl.expected.wgsl b/test/tint/expressions/type_ctor/mat3x2/explicit/identity/f32.wgsl.expected.wgsl
new file mode 100644
index 0000000..06f3edf
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat3x2/explicit/identity/f32.wgsl.expected.wgsl
@@ -0,0 +1,6 @@
+let m = mat3x2(mat3x2<f32>(0.0f, 1.0f, 2.0f, 3.0f, 4.0f, 5.0f));
+
+fn f() -> mat3x2<f32> {
+  let m_1 = mat3x2(m);
+  return m_1;
+}
diff --git a/test/tint/expressions/type_ctor/mat3x2/inferred/identity/f32.wgsl b/test/tint/expressions/type_ctor/mat3x2/inferred/identity/f32.wgsl
new file mode 100644
index 0000000..d77e83b
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat3x2/inferred/identity/f32.wgsl
@@ -0,0 +1,8 @@
+let m = mat3x2(mat3x2(0.0f, 1.0f,
+                      2.0f, 3.0f,
+                      4.0f, 5.0f));
+
+fn f() -> mat3x2<f32> {
+    let m_1 = mat3x2(m);
+    return m_1;
+}
diff --git a/test/tint/expressions/type_ctor/mat3x2/inferred/identity/f32.wgsl.expected.glsl b/test/tint/expressions/type_ctor/mat3x2/inferred/identity/f32.wgsl.expected.glsl
new file mode 100644
index 0000000..49056fe
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat3x2/inferred/identity/f32.wgsl.expected.glsl
@@ -0,0 +1,12 @@
+#version 310 es
+
+layout(local_size_x = 1, local_size_y = 1, local_size_z = 1) in;
+void unused_entry_point() {
+  return;
+}
+const mat3x2 m = mat3x2(vec2(0.0f, 1.0f), vec2(2.0f, 3.0f), vec2(4.0f, 5.0f));
+mat3x2 f() {
+  mat3x2 m_1 = mat3x2(vec2(0.0f, 1.0f), vec2(2.0f, 3.0f), vec2(4.0f, 5.0f));
+  return mat3x2(vec2(0.0f, 1.0f), vec2(2.0f, 3.0f), vec2(4.0f, 5.0f));
+}
+
diff --git a/test/tint/expressions/type_ctor/mat3x2/inferred/identity/f32.wgsl.expected.hlsl b/test/tint/expressions/type_ctor/mat3x2/inferred/identity/f32.wgsl.expected.hlsl
new file mode 100644
index 0000000..049a998
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat3x2/inferred/identity/f32.wgsl.expected.hlsl
@@ -0,0 +1,11 @@
+[numthreads(1, 1, 1)]
+void unused_entry_point() {
+  return;
+}
+
+static const float3x2 m = float3x2(float2(0.0f, 1.0f), float2(2.0f, 3.0f), float2(4.0f, 5.0f));
+
+float3x2 f() {
+  const float3x2 m_1 = float3x2(float2(0.0f, 1.0f), float2(2.0f, 3.0f), float2(4.0f, 5.0f));
+  return float3x2(float2(0.0f, 1.0f), float2(2.0f, 3.0f), float2(4.0f, 5.0f));
+}
diff --git a/test/tint/expressions/type_ctor/mat3x2/inferred/identity/f32.wgsl.expected.msl b/test/tint/expressions/type_ctor/mat3x2/inferred/identity/f32.wgsl.expected.msl
new file mode 100644
index 0000000..9e216c8
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat3x2/inferred/identity/f32.wgsl.expected.msl
@@ -0,0 +1,10 @@
+#include <metal_stdlib>
+
+using namespace metal;
+constant float3x2 m = float3x2(float2(0.0f, 1.0f), float2(2.0f, 3.0f), float2(4.0f, 5.0f));
+
+float3x2 f() {
+  float3x2 const m_1 = float3x2(float2(0.0f, 1.0f), float2(2.0f, 3.0f), float2(4.0f, 5.0f));
+  return float3x2(float2(0.0f, 1.0f), float2(2.0f, 3.0f), float2(4.0f, 5.0f));
+}
+
diff --git a/test/tint/expressions/type_ctor/mat3x2/inferred/identity/f32.wgsl.expected.spvasm b/test/tint/expressions/type_ctor/mat3x2/inferred/identity/f32.wgsl.expected.spvasm
new file mode 100644
index 0000000..6679e29
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat3x2/inferred/identity/f32.wgsl.expected.spvasm
@@ -0,0 +1,36 @@
+; SPIR-V
+; Version: 1.3
+; Generator: Google Tint Compiler; 0
+; Bound: 21
+; Schema: 0
+               OpCapability Shader
+               OpMemoryModel Logical GLSL450
+               OpEntryPoint GLCompute %unused_entry_point "unused_entry_point"
+               OpExecutionMode %unused_entry_point LocalSize 1 1 1
+               OpName %m "m"
+               OpName %unused_entry_point "unused_entry_point"
+               OpName %f "f"
+      %float = OpTypeFloat 32
+    %v2float = OpTypeVector %float 2
+%mat3v2float = OpTypeMatrix %v2float 3
+    %float_0 = OpConstant %float 0
+    %float_1 = OpConstant %float 1
+          %6 = OpConstantComposite %v2float %float_0 %float_1
+    %float_2 = OpConstant %float 2
+    %float_3 = OpConstant %float 3
+          %9 = OpConstantComposite %v2float %float_2 %float_3
+    %float_4 = OpConstant %float 4
+    %float_5 = OpConstant %float 5
+         %12 = OpConstantComposite %v2float %float_4 %float_5
+          %m = OpConstantComposite %mat3v2float %6 %9 %12
+       %void = OpTypeVoid
+         %14 = OpTypeFunction %void
+         %18 = OpTypeFunction %mat3v2float
+%unused_entry_point = OpFunction %void None %14
+         %17 = OpLabel
+               OpReturn
+               OpFunctionEnd
+          %f = OpFunction %mat3v2float None %18
+         %20 = OpLabel
+               OpReturnValue %m
+               OpFunctionEnd
diff --git a/test/tint/expressions/type_ctor/mat3x2/inferred/identity/f32.wgsl.expected.wgsl b/test/tint/expressions/type_ctor/mat3x2/inferred/identity/f32.wgsl.expected.wgsl
new file mode 100644
index 0000000..e16eab4
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat3x2/inferred/identity/f32.wgsl.expected.wgsl
@@ -0,0 +1,6 @@
+let m = mat3x2(mat3x2(0.0f, 1.0f, 2.0f, 3.0f, 4.0f, 5.0f));
+
+fn f() -> mat3x2<f32> {
+  let m_1 = mat3x2(m);
+  return m_1;
+}
diff --git a/test/tint/expressions/type_ctor/mat3x2/identity/f32.wgsl b/test/tint/expressions/type_ctor/mat3x2/zero/f32.wgsl
similarity index 100%
rename from test/tint/expressions/type_ctor/mat3x2/identity/f32.wgsl
rename to test/tint/expressions/type_ctor/mat3x2/zero/f32.wgsl
diff --git a/test/tint/expressions/type_ctor/mat3x2/identity/f32.wgsl.expected.glsl b/test/tint/expressions/type_ctor/mat3x2/zero/f32.wgsl.expected.glsl
similarity index 100%
rename from test/tint/expressions/type_ctor/mat3x2/identity/f32.wgsl.expected.glsl
rename to test/tint/expressions/type_ctor/mat3x2/zero/f32.wgsl.expected.glsl
diff --git a/test/tint/expressions/type_ctor/mat3x2/identity/f32.wgsl.expected.hlsl b/test/tint/expressions/type_ctor/mat3x2/zero/f32.wgsl.expected.hlsl
similarity index 100%
rename from test/tint/expressions/type_ctor/mat3x2/identity/f32.wgsl.expected.hlsl
rename to test/tint/expressions/type_ctor/mat3x2/zero/f32.wgsl.expected.hlsl
diff --git a/test/tint/expressions/type_ctor/mat3x2/identity/f32.wgsl.expected.msl b/test/tint/expressions/type_ctor/mat3x2/zero/f32.wgsl.expected.msl
similarity index 100%
rename from test/tint/expressions/type_ctor/mat3x2/identity/f32.wgsl.expected.msl
rename to test/tint/expressions/type_ctor/mat3x2/zero/f32.wgsl.expected.msl
diff --git a/test/tint/expressions/type_ctor/mat3x2/identity/f32.wgsl.expected.spvasm b/test/tint/expressions/type_ctor/mat3x2/zero/f32.wgsl.expected.spvasm
similarity index 100%
rename from test/tint/expressions/type_ctor/mat3x2/identity/f32.wgsl.expected.spvasm
rename to test/tint/expressions/type_ctor/mat3x2/zero/f32.wgsl.expected.spvasm
diff --git a/test/tint/expressions/type_ctor/mat3x2/identity/f32.wgsl.expected.wgsl b/test/tint/expressions/type_ctor/mat3x2/zero/f32.wgsl.expected.wgsl
similarity index 100%
rename from test/tint/expressions/type_ctor/mat3x2/identity/f32.wgsl.expected.wgsl
rename to test/tint/expressions/type_ctor/mat3x2/zero/f32.wgsl.expected.wgsl
diff --git a/test/tint/expressions/type_ctor/mat3x3/explicit/identity/f32.wgsl b/test/tint/expressions/type_ctor/mat3x3/explicit/identity/f32.wgsl
new file mode 100644
index 0000000..9f57499
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat3x3/explicit/identity/f32.wgsl
@@ -0,0 +1,8 @@
+let m = mat3x3(mat3x3<f32>(0.0f, 1.0f, 2.0f,
+                           3.0f, 4.0f, 5.0f,
+                           6.0f, 7.0f, 8.0f));
+
+fn f() -> mat3x3<f32> {
+    let m_1 = mat3x3(m);
+    return m_1;
+}
diff --git a/test/tint/expressions/type_ctor/mat3x3/explicit/identity/f32.wgsl.expected.glsl b/test/tint/expressions/type_ctor/mat3x3/explicit/identity/f32.wgsl.expected.glsl
new file mode 100644
index 0000000..e99ac3c
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat3x3/explicit/identity/f32.wgsl.expected.glsl
@@ -0,0 +1,12 @@
+#version 310 es
+
+layout(local_size_x = 1, local_size_y = 1, local_size_z = 1) in;
+void unused_entry_point() {
+  return;
+}
+const mat3 m = mat3(vec3(0.0f, 1.0f, 2.0f), vec3(3.0f, 4.0f, 5.0f), vec3(6.0f, 7.0f, 8.0f));
+mat3 f() {
+  mat3 m_1 = mat3(vec3(0.0f, 1.0f, 2.0f), vec3(3.0f, 4.0f, 5.0f), vec3(6.0f, 7.0f, 8.0f));
+  return mat3(vec3(0.0f, 1.0f, 2.0f), vec3(3.0f, 4.0f, 5.0f), vec3(6.0f, 7.0f, 8.0f));
+}
+
diff --git a/test/tint/expressions/type_ctor/mat3x3/explicit/identity/f32.wgsl.expected.hlsl b/test/tint/expressions/type_ctor/mat3x3/explicit/identity/f32.wgsl.expected.hlsl
new file mode 100644
index 0000000..63eef11
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat3x3/explicit/identity/f32.wgsl.expected.hlsl
@@ -0,0 +1,11 @@
+[numthreads(1, 1, 1)]
+void unused_entry_point() {
+  return;
+}
+
+static const float3x3 m = float3x3(float3(0.0f, 1.0f, 2.0f), float3(3.0f, 4.0f, 5.0f), float3(6.0f, 7.0f, 8.0f));
+
+float3x3 f() {
+  const float3x3 m_1 = float3x3(float3(0.0f, 1.0f, 2.0f), float3(3.0f, 4.0f, 5.0f), float3(6.0f, 7.0f, 8.0f));
+  return float3x3(float3(0.0f, 1.0f, 2.0f), float3(3.0f, 4.0f, 5.0f), float3(6.0f, 7.0f, 8.0f));
+}
diff --git a/test/tint/expressions/type_ctor/mat3x3/explicit/identity/f32.wgsl.expected.msl b/test/tint/expressions/type_ctor/mat3x3/explicit/identity/f32.wgsl.expected.msl
new file mode 100644
index 0000000..d2eac15
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat3x3/explicit/identity/f32.wgsl.expected.msl
@@ -0,0 +1,10 @@
+#include <metal_stdlib>
+
+using namespace metal;
+constant float3x3 m = float3x3(float3(0.0f, 1.0f, 2.0f), float3(3.0f, 4.0f, 5.0f), float3(6.0f, 7.0f, 8.0f));
+
+float3x3 f() {
+  float3x3 const m_1 = float3x3(float3(0.0f, 1.0f, 2.0f), float3(3.0f, 4.0f, 5.0f), float3(6.0f, 7.0f, 8.0f));
+  return float3x3(float3(0.0f, 1.0f, 2.0f), float3(3.0f, 4.0f, 5.0f), float3(6.0f, 7.0f, 8.0f));
+}
+
diff --git a/test/tint/expressions/type_ctor/mat3x3/explicit/identity/f32.wgsl.expected.spvasm b/test/tint/expressions/type_ctor/mat3x3/explicit/identity/f32.wgsl.expected.spvasm
new file mode 100644
index 0000000..0386f4e
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat3x3/explicit/identity/f32.wgsl.expected.spvasm
@@ -0,0 +1,39 @@
+; SPIR-V
+; Version: 1.3
+; Generator: Google Tint Compiler; 0
+; Bound: 24
+; Schema: 0
+               OpCapability Shader
+               OpMemoryModel Logical GLSL450
+               OpEntryPoint GLCompute %unused_entry_point "unused_entry_point"
+               OpExecutionMode %unused_entry_point LocalSize 1 1 1
+               OpName %m "m"
+               OpName %unused_entry_point "unused_entry_point"
+               OpName %f "f"
+      %float = OpTypeFloat 32
+    %v3float = OpTypeVector %float 3
+%mat3v3float = OpTypeMatrix %v3float 3
+    %float_0 = OpConstant %float 0
+    %float_1 = OpConstant %float 1
+    %float_2 = OpConstant %float 2
+          %7 = OpConstantComposite %v3float %float_0 %float_1 %float_2
+    %float_3 = OpConstant %float 3
+    %float_4 = OpConstant %float 4
+    %float_5 = OpConstant %float 5
+         %11 = OpConstantComposite %v3float %float_3 %float_4 %float_5
+    %float_6 = OpConstant %float 6
+    %float_7 = OpConstant %float 7
+    %float_8 = OpConstant %float 8
+         %15 = OpConstantComposite %v3float %float_6 %float_7 %float_8
+          %m = OpConstantComposite %mat3v3float %7 %11 %15
+       %void = OpTypeVoid
+         %17 = OpTypeFunction %void
+         %21 = OpTypeFunction %mat3v3float
+%unused_entry_point = OpFunction %void None %17
+         %20 = OpLabel
+               OpReturn
+               OpFunctionEnd
+          %f = OpFunction %mat3v3float None %21
+         %23 = OpLabel
+               OpReturnValue %m
+               OpFunctionEnd
diff --git a/test/tint/expressions/type_ctor/mat3x3/explicit/identity/f32.wgsl.expected.wgsl b/test/tint/expressions/type_ctor/mat3x3/explicit/identity/f32.wgsl.expected.wgsl
new file mode 100644
index 0000000..4ed58da
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat3x3/explicit/identity/f32.wgsl.expected.wgsl
@@ -0,0 +1,6 @@
+let m = mat3x3(mat3x3<f32>(0.0f, 1.0f, 2.0f, 3.0f, 4.0f, 5.0f, 6.0f, 7.0f, 8.0f));
+
+fn f() -> mat3x3<f32> {
+  let m_1 = mat3x3(m);
+  return m_1;
+}
diff --git a/test/tint/expressions/type_ctor/mat3x3/inferred/identity/f32.wgsl b/test/tint/expressions/type_ctor/mat3x3/inferred/identity/f32.wgsl
new file mode 100644
index 0000000..d1792d1
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat3x3/inferred/identity/f32.wgsl
@@ -0,0 +1,8 @@
+let m = mat3x3(mat3x3(0.0f, 1.0f, 2.0f,
+                      3.0f, 4.0f, 5.0f,
+                      6.0f, 7.0f, 8.0f));
+
+fn f() -> mat3x3<f32> {
+    let m_1 = mat3x3(m);
+    return m_1;
+}
diff --git a/test/tint/expressions/type_ctor/mat3x3/inferred/identity/f32.wgsl.expected.glsl b/test/tint/expressions/type_ctor/mat3x3/inferred/identity/f32.wgsl.expected.glsl
new file mode 100644
index 0000000..e99ac3c
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat3x3/inferred/identity/f32.wgsl.expected.glsl
@@ -0,0 +1,12 @@
+#version 310 es
+
+layout(local_size_x = 1, local_size_y = 1, local_size_z = 1) in;
+void unused_entry_point() {
+  return;
+}
+const mat3 m = mat3(vec3(0.0f, 1.0f, 2.0f), vec3(3.0f, 4.0f, 5.0f), vec3(6.0f, 7.0f, 8.0f));
+mat3 f() {
+  mat3 m_1 = mat3(vec3(0.0f, 1.0f, 2.0f), vec3(3.0f, 4.0f, 5.0f), vec3(6.0f, 7.0f, 8.0f));
+  return mat3(vec3(0.0f, 1.0f, 2.0f), vec3(3.0f, 4.0f, 5.0f), vec3(6.0f, 7.0f, 8.0f));
+}
+
diff --git a/test/tint/expressions/type_ctor/mat3x3/inferred/identity/f32.wgsl.expected.hlsl b/test/tint/expressions/type_ctor/mat3x3/inferred/identity/f32.wgsl.expected.hlsl
new file mode 100644
index 0000000..63eef11
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat3x3/inferred/identity/f32.wgsl.expected.hlsl
@@ -0,0 +1,11 @@
+[numthreads(1, 1, 1)]
+void unused_entry_point() {
+  return;
+}
+
+static const float3x3 m = float3x3(float3(0.0f, 1.0f, 2.0f), float3(3.0f, 4.0f, 5.0f), float3(6.0f, 7.0f, 8.0f));
+
+float3x3 f() {
+  const float3x3 m_1 = float3x3(float3(0.0f, 1.0f, 2.0f), float3(3.0f, 4.0f, 5.0f), float3(6.0f, 7.0f, 8.0f));
+  return float3x3(float3(0.0f, 1.0f, 2.0f), float3(3.0f, 4.0f, 5.0f), float3(6.0f, 7.0f, 8.0f));
+}
diff --git a/test/tint/expressions/type_ctor/mat3x3/inferred/identity/f32.wgsl.expected.msl b/test/tint/expressions/type_ctor/mat3x3/inferred/identity/f32.wgsl.expected.msl
new file mode 100644
index 0000000..d2eac15
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat3x3/inferred/identity/f32.wgsl.expected.msl
@@ -0,0 +1,10 @@
+#include <metal_stdlib>
+
+using namespace metal;
+constant float3x3 m = float3x3(float3(0.0f, 1.0f, 2.0f), float3(3.0f, 4.0f, 5.0f), float3(6.0f, 7.0f, 8.0f));
+
+float3x3 f() {
+  float3x3 const m_1 = float3x3(float3(0.0f, 1.0f, 2.0f), float3(3.0f, 4.0f, 5.0f), float3(6.0f, 7.0f, 8.0f));
+  return float3x3(float3(0.0f, 1.0f, 2.0f), float3(3.0f, 4.0f, 5.0f), float3(6.0f, 7.0f, 8.0f));
+}
+
diff --git a/test/tint/expressions/type_ctor/mat3x3/inferred/identity/f32.wgsl.expected.spvasm b/test/tint/expressions/type_ctor/mat3x3/inferred/identity/f32.wgsl.expected.spvasm
new file mode 100644
index 0000000..0386f4e
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat3x3/inferred/identity/f32.wgsl.expected.spvasm
@@ -0,0 +1,39 @@
+; SPIR-V
+; Version: 1.3
+; Generator: Google Tint Compiler; 0
+; Bound: 24
+; Schema: 0
+               OpCapability Shader
+               OpMemoryModel Logical GLSL450
+               OpEntryPoint GLCompute %unused_entry_point "unused_entry_point"
+               OpExecutionMode %unused_entry_point LocalSize 1 1 1
+               OpName %m "m"
+               OpName %unused_entry_point "unused_entry_point"
+               OpName %f "f"
+      %float = OpTypeFloat 32
+    %v3float = OpTypeVector %float 3
+%mat3v3float = OpTypeMatrix %v3float 3
+    %float_0 = OpConstant %float 0
+    %float_1 = OpConstant %float 1
+    %float_2 = OpConstant %float 2
+          %7 = OpConstantComposite %v3float %float_0 %float_1 %float_2
+    %float_3 = OpConstant %float 3
+    %float_4 = OpConstant %float 4
+    %float_5 = OpConstant %float 5
+         %11 = OpConstantComposite %v3float %float_3 %float_4 %float_5
+    %float_6 = OpConstant %float 6
+    %float_7 = OpConstant %float 7
+    %float_8 = OpConstant %float 8
+         %15 = OpConstantComposite %v3float %float_6 %float_7 %float_8
+          %m = OpConstantComposite %mat3v3float %7 %11 %15
+       %void = OpTypeVoid
+         %17 = OpTypeFunction %void
+         %21 = OpTypeFunction %mat3v3float
+%unused_entry_point = OpFunction %void None %17
+         %20 = OpLabel
+               OpReturn
+               OpFunctionEnd
+          %f = OpFunction %mat3v3float None %21
+         %23 = OpLabel
+               OpReturnValue %m
+               OpFunctionEnd
diff --git a/test/tint/expressions/type_ctor/mat3x3/inferred/identity/f32.wgsl.expected.wgsl b/test/tint/expressions/type_ctor/mat3x3/inferred/identity/f32.wgsl.expected.wgsl
new file mode 100644
index 0000000..6bf1918
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat3x3/inferred/identity/f32.wgsl.expected.wgsl
@@ -0,0 +1,6 @@
+let m = mat3x3(mat3x3(0.0f, 1.0f, 2.0f, 3.0f, 4.0f, 5.0f, 6.0f, 7.0f, 8.0f));
+
+fn f() -> mat3x3<f32> {
+  let m_1 = mat3x3(m);
+  return m_1;
+}
diff --git a/test/tint/expressions/type_ctor/mat3x3/identity/f32.wgsl b/test/tint/expressions/type_ctor/mat3x3/zero/f32.wgsl
similarity index 100%
rename from test/tint/expressions/type_ctor/mat3x3/identity/f32.wgsl
rename to test/tint/expressions/type_ctor/mat3x3/zero/f32.wgsl
diff --git a/test/tint/expressions/type_ctor/mat3x3/identity/f32.wgsl.expected.glsl b/test/tint/expressions/type_ctor/mat3x3/zero/f32.wgsl.expected.glsl
similarity index 100%
rename from test/tint/expressions/type_ctor/mat3x3/identity/f32.wgsl.expected.glsl
rename to test/tint/expressions/type_ctor/mat3x3/zero/f32.wgsl.expected.glsl
diff --git a/test/tint/expressions/type_ctor/mat3x3/identity/f32.wgsl.expected.hlsl b/test/tint/expressions/type_ctor/mat3x3/zero/f32.wgsl.expected.hlsl
similarity index 100%
rename from test/tint/expressions/type_ctor/mat3x3/identity/f32.wgsl.expected.hlsl
rename to test/tint/expressions/type_ctor/mat3x3/zero/f32.wgsl.expected.hlsl
diff --git a/test/tint/expressions/type_ctor/mat3x3/identity/f32.wgsl.expected.msl b/test/tint/expressions/type_ctor/mat3x3/zero/f32.wgsl.expected.msl
similarity index 100%
rename from test/tint/expressions/type_ctor/mat3x3/identity/f32.wgsl.expected.msl
rename to test/tint/expressions/type_ctor/mat3x3/zero/f32.wgsl.expected.msl
diff --git a/test/tint/expressions/type_ctor/mat3x3/identity/f32.wgsl.expected.spvasm b/test/tint/expressions/type_ctor/mat3x3/zero/f32.wgsl.expected.spvasm
similarity index 100%
rename from test/tint/expressions/type_ctor/mat3x3/identity/f32.wgsl.expected.spvasm
rename to test/tint/expressions/type_ctor/mat3x3/zero/f32.wgsl.expected.spvasm
diff --git a/test/tint/expressions/type_ctor/mat3x3/identity/f32.wgsl.expected.wgsl b/test/tint/expressions/type_ctor/mat3x3/zero/f32.wgsl.expected.wgsl
similarity index 100%
rename from test/tint/expressions/type_ctor/mat3x3/identity/f32.wgsl.expected.wgsl
rename to test/tint/expressions/type_ctor/mat3x3/zero/f32.wgsl.expected.wgsl
diff --git a/test/tint/expressions/type_ctor/mat3x4/explicit/identity/f32.wgsl b/test/tint/expressions/type_ctor/mat3x4/explicit/identity/f32.wgsl
new file mode 100644
index 0000000..823be66
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat3x4/explicit/identity/f32.wgsl
@@ -0,0 +1,8 @@
+let m = mat3x4(mat3x4<f32>(0.0f, 1.0f, 2.0f, 3.0f,
+                           4.0f, 5.0f, 6.0f, 7.0f,
+                           8.0f, 9.0f, 10.0f, 11.0f));
+
+fn f() -> mat3x4<f32> {
+    let m_1 = mat3x4(m);
+    return m_1;
+}
diff --git a/test/tint/expressions/type_ctor/mat3x4/explicit/identity/f32.wgsl.expected.glsl b/test/tint/expressions/type_ctor/mat3x4/explicit/identity/f32.wgsl.expected.glsl
new file mode 100644
index 0000000..075d29b
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat3x4/explicit/identity/f32.wgsl.expected.glsl
@@ -0,0 +1,12 @@
+#version 310 es
+
+layout(local_size_x = 1, local_size_y = 1, local_size_z = 1) in;
+void unused_entry_point() {
+  return;
+}
+const mat3x4 m = mat3x4(vec4(0.0f, 1.0f, 2.0f, 3.0f), vec4(4.0f, 5.0f, 6.0f, 7.0f), vec4(8.0f, 9.0f, 10.0f, 11.0f));
+mat3x4 f() {
+  mat3x4 m_1 = mat3x4(vec4(0.0f, 1.0f, 2.0f, 3.0f), vec4(4.0f, 5.0f, 6.0f, 7.0f), vec4(8.0f, 9.0f, 10.0f, 11.0f));
+  return mat3x4(vec4(0.0f, 1.0f, 2.0f, 3.0f), vec4(4.0f, 5.0f, 6.0f, 7.0f), vec4(8.0f, 9.0f, 10.0f, 11.0f));
+}
+
diff --git a/test/tint/expressions/type_ctor/mat3x4/explicit/identity/f32.wgsl.expected.hlsl b/test/tint/expressions/type_ctor/mat3x4/explicit/identity/f32.wgsl.expected.hlsl
new file mode 100644
index 0000000..de62d39
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat3x4/explicit/identity/f32.wgsl.expected.hlsl
@@ -0,0 +1,11 @@
+[numthreads(1, 1, 1)]
+void unused_entry_point() {
+  return;
+}
+
+static const float3x4 m = float3x4(float4(0.0f, 1.0f, 2.0f, 3.0f), float4(4.0f, 5.0f, 6.0f, 7.0f), float4(8.0f, 9.0f, 10.0f, 11.0f));
+
+float3x4 f() {
+  const float3x4 m_1 = float3x4(float4(0.0f, 1.0f, 2.0f, 3.0f), float4(4.0f, 5.0f, 6.0f, 7.0f), float4(8.0f, 9.0f, 10.0f, 11.0f));
+  return float3x4(float4(0.0f, 1.0f, 2.0f, 3.0f), float4(4.0f, 5.0f, 6.0f, 7.0f), float4(8.0f, 9.0f, 10.0f, 11.0f));
+}
diff --git a/test/tint/expressions/type_ctor/mat3x4/explicit/identity/f32.wgsl.expected.msl b/test/tint/expressions/type_ctor/mat3x4/explicit/identity/f32.wgsl.expected.msl
new file mode 100644
index 0000000..86e4c2e
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat3x4/explicit/identity/f32.wgsl.expected.msl
@@ -0,0 +1,10 @@
+#include <metal_stdlib>
+
+using namespace metal;
+constant float3x4 m = float3x4(float4(0.0f, 1.0f, 2.0f, 3.0f), float4(4.0f, 5.0f, 6.0f, 7.0f), float4(8.0f, 9.0f, 10.0f, 11.0f));
+
+float3x4 f() {
+  float3x4 const m_1 = float3x4(float4(0.0f, 1.0f, 2.0f, 3.0f), float4(4.0f, 5.0f, 6.0f, 7.0f), float4(8.0f, 9.0f, 10.0f, 11.0f));
+  return float3x4(float4(0.0f, 1.0f, 2.0f, 3.0f), float4(4.0f, 5.0f, 6.0f, 7.0f), float4(8.0f, 9.0f, 10.0f, 11.0f));
+}
+
diff --git a/test/tint/expressions/type_ctor/mat3x4/explicit/identity/f32.wgsl.expected.spvasm b/test/tint/expressions/type_ctor/mat3x4/explicit/identity/f32.wgsl.expected.spvasm
new file mode 100644
index 0000000..8770c7b
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat3x4/explicit/identity/f32.wgsl.expected.spvasm
@@ -0,0 +1,42 @@
+; SPIR-V
+; Version: 1.3
+; Generator: Google Tint Compiler; 0
+; Bound: 27
+; Schema: 0
+               OpCapability Shader
+               OpMemoryModel Logical GLSL450
+               OpEntryPoint GLCompute %unused_entry_point "unused_entry_point"
+               OpExecutionMode %unused_entry_point LocalSize 1 1 1
+               OpName %m "m"
+               OpName %unused_entry_point "unused_entry_point"
+               OpName %f "f"
+      %float = OpTypeFloat 32
+    %v4float = OpTypeVector %float 4
+%mat3v4float = OpTypeMatrix %v4float 3
+    %float_0 = OpConstant %float 0
+    %float_1 = OpConstant %float 1
+    %float_2 = OpConstant %float 2
+    %float_3 = OpConstant %float 3
+          %8 = OpConstantComposite %v4float %float_0 %float_1 %float_2 %float_3
+    %float_4 = OpConstant %float 4
+    %float_5 = OpConstant %float 5
+    %float_6 = OpConstant %float 6
+    %float_7 = OpConstant %float 7
+         %13 = OpConstantComposite %v4float %float_4 %float_5 %float_6 %float_7
+    %float_8 = OpConstant %float 8
+    %float_9 = OpConstant %float 9
+   %float_10 = OpConstant %float 10
+   %float_11 = OpConstant %float 11
+         %18 = OpConstantComposite %v4float %float_8 %float_9 %float_10 %float_11
+          %m = OpConstantComposite %mat3v4float %8 %13 %18
+       %void = OpTypeVoid
+         %20 = OpTypeFunction %void
+         %24 = OpTypeFunction %mat3v4float
+%unused_entry_point = OpFunction %void None %20
+         %23 = OpLabel
+               OpReturn
+               OpFunctionEnd
+          %f = OpFunction %mat3v4float None %24
+         %26 = OpLabel
+               OpReturnValue %m
+               OpFunctionEnd
diff --git a/test/tint/expressions/type_ctor/mat3x4/explicit/identity/f32.wgsl.expected.wgsl b/test/tint/expressions/type_ctor/mat3x4/explicit/identity/f32.wgsl.expected.wgsl
new file mode 100644
index 0000000..4c6c2d0
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat3x4/explicit/identity/f32.wgsl.expected.wgsl
@@ -0,0 +1,6 @@
+let m = mat3x4(mat3x4<f32>(0.0f, 1.0f, 2.0f, 3.0f, 4.0f, 5.0f, 6.0f, 7.0f, 8.0f, 9.0f, 10.0f, 11.0f));
+
+fn f() -> mat3x4<f32> {
+  let m_1 = mat3x4(m);
+  return m_1;
+}
diff --git a/test/tint/expressions/type_ctor/mat3x4/inferred/identity/f32.wgsl b/test/tint/expressions/type_ctor/mat3x4/inferred/identity/f32.wgsl
new file mode 100644
index 0000000..b80dbc5
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat3x4/inferred/identity/f32.wgsl
@@ -0,0 +1,8 @@
+let m = mat3x4(mat3x4(0.0f, 1.0f, 2.0f, 3.0f,
+                      4.0f, 5.0f, 6.0f, 7.0f,
+                      8.0f, 9.0f, 10.0f, 11.0f));
+
+fn f() -> mat3x4<f32> {
+    let m_1 = mat3x4(m);
+    return m_1;
+}
diff --git a/test/tint/expressions/type_ctor/mat3x4/inferred/identity/f32.wgsl.expected.glsl b/test/tint/expressions/type_ctor/mat3x4/inferred/identity/f32.wgsl.expected.glsl
new file mode 100644
index 0000000..075d29b
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat3x4/inferred/identity/f32.wgsl.expected.glsl
@@ -0,0 +1,12 @@
+#version 310 es
+
+layout(local_size_x = 1, local_size_y = 1, local_size_z = 1) in;
+void unused_entry_point() {
+  return;
+}
+const mat3x4 m = mat3x4(vec4(0.0f, 1.0f, 2.0f, 3.0f), vec4(4.0f, 5.0f, 6.0f, 7.0f), vec4(8.0f, 9.0f, 10.0f, 11.0f));
+mat3x4 f() {
+  mat3x4 m_1 = mat3x4(vec4(0.0f, 1.0f, 2.0f, 3.0f), vec4(4.0f, 5.0f, 6.0f, 7.0f), vec4(8.0f, 9.0f, 10.0f, 11.0f));
+  return mat3x4(vec4(0.0f, 1.0f, 2.0f, 3.0f), vec4(4.0f, 5.0f, 6.0f, 7.0f), vec4(8.0f, 9.0f, 10.0f, 11.0f));
+}
+
diff --git a/test/tint/expressions/type_ctor/mat3x4/inferred/identity/f32.wgsl.expected.hlsl b/test/tint/expressions/type_ctor/mat3x4/inferred/identity/f32.wgsl.expected.hlsl
new file mode 100644
index 0000000..de62d39
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat3x4/inferred/identity/f32.wgsl.expected.hlsl
@@ -0,0 +1,11 @@
+[numthreads(1, 1, 1)]
+void unused_entry_point() {
+  return;
+}
+
+static const float3x4 m = float3x4(float4(0.0f, 1.0f, 2.0f, 3.0f), float4(4.0f, 5.0f, 6.0f, 7.0f), float4(8.0f, 9.0f, 10.0f, 11.0f));
+
+float3x4 f() {
+  const float3x4 m_1 = float3x4(float4(0.0f, 1.0f, 2.0f, 3.0f), float4(4.0f, 5.0f, 6.0f, 7.0f), float4(8.0f, 9.0f, 10.0f, 11.0f));
+  return float3x4(float4(0.0f, 1.0f, 2.0f, 3.0f), float4(4.0f, 5.0f, 6.0f, 7.0f), float4(8.0f, 9.0f, 10.0f, 11.0f));
+}
diff --git a/test/tint/expressions/type_ctor/mat3x4/inferred/identity/f32.wgsl.expected.msl b/test/tint/expressions/type_ctor/mat3x4/inferred/identity/f32.wgsl.expected.msl
new file mode 100644
index 0000000..86e4c2e
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat3x4/inferred/identity/f32.wgsl.expected.msl
@@ -0,0 +1,10 @@
+#include <metal_stdlib>
+
+using namespace metal;
+constant float3x4 m = float3x4(float4(0.0f, 1.0f, 2.0f, 3.0f), float4(4.0f, 5.0f, 6.0f, 7.0f), float4(8.0f, 9.0f, 10.0f, 11.0f));
+
+float3x4 f() {
+  float3x4 const m_1 = float3x4(float4(0.0f, 1.0f, 2.0f, 3.0f), float4(4.0f, 5.0f, 6.0f, 7.0f), float4(8.0f, 9.0f, 10.0f, 11.0f));
+  return float3x4(float4(0.0f, 1.0f, 2.0f, 3.0f), float4(4.0f, 5.0f, 6.0f, 7.0f), float4(8.0f, 9.0f, 10.0f, 11.0f));
+}
+
diff --git a/test/tint/expressions/type_ctor/mat3x4/inferred/identity/f32.wgsl.expected.spvasm b/test/tint/expressions/type_ctor/mat3x4/inferred/identity/f32.wgsl.expected.spvasm
new file mode 100644
index 0000000..8770c7b
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat3x4/inferred/identity/f32.wgsl.expected.spvasm
@@ -0,0 +1,42 @@
+; SPIR-V
+; Version: 1.3
+; Generator: Google Tint Compiler; 0
+; Bound: 27
+; Schema: 0
+               OpCapability Shader
+               OpMemoryModel Logical GLSL450
+               OpEntryPoint GLCompute %unused_entry_point "unused_entry_point"
+               OpExecutionMode %unused_entry_point LocalSize 1 1 1
+               OpName %m "m"
+               OpName %unused_entry_point "unused_entry_point"
+               OpName %f "f"
+      %float = OpTypeFloat 32
+    %v4float = OpTypeVector %float 4
+%mat3v4float = OpTypeMatrix %v4float 3
+    %float_0 = OpConstant %float 0
+    %float_1 = OpConstant %float 1
+    %float_2 = OpConstant %float 2
+    %float_3 = OpConstant %float 3
+          %8 = OpConstantComposite %v4float %float_0 %float_1 %float_2 %float_3
+    %float_4 = OpConstant %float 4
+    %float_5 = OpConstant %float 5
+    %float_6 = OpConstant %float 6
+    %float_7 = OpConstant %float 7
+         %13 = OpConstantComposite %v4float %float_4 %float_5 %float_6 %float_7
+    %float_8 = OpConstant %float 8
+    %float_9 = OpConstant %float 9
+   %float_10 = OpConstant %float 10
+   %float_11 = OpConstant %float 11
+         %18 = OpConstantComposite %v4float %float_8 %float_9 %float_10 %float_11
+          %m = OpConstantComposite %mat3v4float %8 %13 %18
+       %void = OpTypeVoid
+         %20 = OpTypeFunction %void
+         %24 = OpTypeFunction %mat3v4float
+%unused_entry_point = OpFunction %void None %20
+         %23 = OpLabel
+               OpReturn
+               OpFunctionEnd
+          %f = OpFunction %mat3v4float None %24
+         %26 = OpLabel
+               OpReturnValue %m
+               OpFunctionEnd
diff --git a/test/tint/expressions/type_ctor/mat3x4/inferred/identity/f32.wgsl.expected.wgsl b/test/tint/expressions/type_ctor/mat3x4/inferred/identity/f32.wgsl.expected.wgsl
new file mode 100644
index 0000000..46be1d3
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat3x4/inferred/identity/f32.wgsl.expected.wgsl
@@ -0,0 +1,6 @@
+let m = mat3x4(mat3x4(0.0f, 1.0f, 2.0f, 3.0f, 4.0f, 5.0f, 6.0f, 7.0f, 8.0f, 9.0f, 10.0f, 11.0f));
+
+fn f() -> mat3x4<f32> {
+  let m_1 = mat3x4(m);
+  return m_1;
+}
diff --git a/test/tint/expressions/type_ctor/mat3x4/identity/f32.wgsl b/test/tint/expressions/type_ctor/mat3x4/zero/f32.wgsl
similarity index 100%
rename from test/tint/expressions/type_ctor/mat3x4/identity/f32.wgsl
rename to test/tint/expressions/type_ctor/mat3x4/zero/f32.wgsl
diff --git a/test/tint/expressions/type_ctor/mat3x4/identity/f32.wgsl.expected.glsl b/test/tint/expressions/type_ctor/mat3x4/zero/f32.wgsl.expected.glsl
similarity index 100%
rename from test/tint/expressions/type_ctor/mat3x4/identity/f32.wgsl.expected.glsl
rename to test/tint/expressions/type_ctor/mat3x4/zero/f32.wgsl.expected.glsl
diff --git a/test/tint/expressions/type_ctor/mat3x4/identity/f32.wgsl.expected.hlsl b/test/tint/expressions/type_ctor/mat3x4/zero/f32.wgsl.expected.hlsl
similarity index 100%
rename from test/tint/expressions/type_ctor/mat3x4/identity/f32.wgsl.expected.hlsl
rename to test/tint/expressions/type_ctor/mat3x4/zero/f32.wgsl.expected.hlsl
diff --git a/test/tint/expressions/type_ctor/mat3x4/identity/f32.wgsl.expected.msl b/test/tint/expressions/type_ctor/mat3x4/zero/f32.wgsl.expected.msl
similarity index 100%
rename from test/tint/expressions/type_ctor/mat3x4/identity/f32.wgsl.expected.msl
rename to test/tint/expressions/type_ctor/mat3x4/zero/f32.wgsl.expected.msl
diff --git a/test/tint/expressions/type_ctor/mat3x4/identity/f32.wgsl.expected.spvasm b/test/tint/expressions/type_ctor/mat3x4/zero/f32.wgsl.expected.spvasm
similarity index 100%
rename from test/tint/expressions/type_ctor/mat3x4/identity/f32.wgsl.expected.spvasm
rename to test/tint/expressions/type_ctor/mat3x4/zero/f32.wgsl.expected.spvasm
diff --git a/test/tint/expressions/type_ctor/mat3x4/identity/f32.wgsl.expected.wgsl b/test/tint/expressions/type_ctor/mat3x4/zero/f32.wgsl.expected.wgsl
similarity index 100%
rename from test/tint/expressions/type_ctor/mat3x4/identity/f32.wgsl.expected.wgsl
rename to test/tint/expressions/type_ctor/mat3x4/zero/f32.wgsl.expected.wgsl
diff --git a/test/tint/expressions/type_ctor/mat4x2/explicit/identity/f32.wgsl b/test/tint/expressions/type_ctor/mat4x2/explicit/identity/f32.wgsl
new file mode 100644
index 0000000..44099e2
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat4x2/explicit/identity/f32.wgsl
@@ -0,0 +1,9 @@
+let m = mat4x2(mat4x2<f32>(0.0f, 1.0f,
+                           2.0f, 3.0f,
+                           4.0f, 5.0f,
+                           6.0f, 7.0f));
+
+fn f() -> mat4x2<f32> {
+    let m_1 = mat4x2(m);
+    return m_1;
+}
diff --git a/test/tint/expressions/type_ctor/mat4x2/explicit/identity/f32.wgsl.expected.glsl b/test/tint/expressions/type_ctor/mat4x2/explicit/identity/f32.wgsl.expected.glsl
new file mode 100644
index 0000000..899a25f
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat4x2/explicit/identity/f32.wgsl.expected.glsl
@@ -0,0 +1,12 @@
+#version 310 es
+
+layout(local_size_x = 1, local_size_y = 1, local_size_z = 1) in;
+void unused_entry_point() {
+  return;
+}
+const mat4x2 m = mat4x2(vec2(0.0f, 1.0f), vec2(2.0f, 3.0f), vec2(4.0f, 5.0f), vec2(6.0f, 7.0f));
+mat4x2 f() {
+  mat4x2 m_1 = mat4x2(vec2(0.0f, 1.0f), vec2(2.0f, 3.0f), vec2(4.0f, 5.0f), vec2(6.0f, 7.0f));
+  return mat4x2(vec2(0.0f, 1.0f), vec2(2.0f, 3.0f), vec2(4.0f, 5.0f), vec2(6.0f, 7.0f));
+}
+
diff --git a/test/tint/expressions/type_ctor/mat4x2/explicit/identity/f32.wgsl.expected.hlsl b/test/tint/expressions/type_ctor/mat4x2/explicit/identity/f32.wgsl.expected.hlsl
new file mode 100644
index 0000000..de0cb92
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat4x2/explicit/identity/f32.wgsl.expected.hlsl
@@ -0,0 +1,11 @@
+[numthreads(1, 1, 1)]
+void unused_entry_point() {
+  return;
+}
+
+static const float4x2 m = float4x2(float2(0.0f, 1.0f), float2(2.0f, 3.0f), float2(4.0f, 5.0f), float2(6.0f, 7.0f));
+
+float4x2 f() {
+  const float4x2 m_1 = float4x2(float2(0.0f, 1.0f), float2(2.0f, 3.0f), float2(4.0f, 5.0f), float2(6.0f, 7.0f));
+  return float4x2(float2(0.0f, 1.0f), float2(2.0f, 3.0f), float2(4.0f, 5.0f), float2(6.0f, 7.0f));
+}
diff --git a/test/tint/expressions/type_ctor/mat4x2/explicit/identity/f32.wgsl.expected.msl b/test/tint/expressions/type_ctor/mat4x2/explicit/identity/f32.wgsl.expected.msl
new file mode 100644
index 0000000..19ae099
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat4x2/explicit/identity/f32.wgsl.expected.msl
@@ -0,0 +1,10 @@
+#include <metal_stdlib>
+
+using namespace metal;
+constant float4x2 m = float4x2(float2(0.0f, 1.0f), float2(2.0f, 3.0f), float2(4.0f, 5.0f), float2(6.0f, 7.0f));
+
+float4x2 f() {
+  float4x2 const m_1 = float4x2(float2(0.0f, 1.0f), float2(2.0f, 3.0f), float2(4.0f, 5.0f), float2(6.0f, 7.0f));
+  return float4x2(float2(0.0f, 1.0f), float2(2.0f, 3.0f), float2(4.0f, 5.0f), float2(6.0f, 7.0f));
+}
+
diff --git a/test/tint/expressions/type_ctor/mat4x2/explicit/identity/f32.wgsl.expected.spvasm b/test/tint/expressions/type_ctor/mat4x2/explicit/identity/f32.wgsl.expected.spvasm
new file mode 100644
index 0000000..045b57c
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat4x2/explicit/identity/f32.wgsl.expected.spvasm
@@ -0,0 +1,39 @@
+; SPIR-V
+; Version: 1.3
+; Generator: Google Tint Compiler; 0
+; Bound: 24
+; Schema: 0
+               OpCapability Shader
+               OpMemoryModel Logical GLSL450
+               OpEntryPoint GLCompute %unused_entry_point "unused_entry_point"
+               OpExecutionMode %unused_entry_point LocalSize 1 1 1
+               OpName %m "m"
+               OpName %unused_entry_point "unused_entry_point"
+               OpName %f "f"
+      %float = OpTypeFloat 32
+    %v2float = OpTypeVector %float 2
+%mat4v2float = OpTypeMatrix %v2float 4
+    %float_0 = OpConstant %float 0
+    %float_1 = OpConstant %float 1
+          %6 = OpConstantComposite %v2float %float_0 %float_1
+    %float_2 = OpConstant %float 2
+    %float_3 = OpConstant %float 3
+          %9 = OpConstantComposite %v2float %float_2 %float_3
+    %float_4 = OpConstant %float 4
+    %float_5 = OpConstant %float 5
+         %12 = OpConstantComposite %v2float %float_4 %float_5
+    %float_6 = OpConstant %float 6
+    %float_7 = OpConstant %float 7
+         %15 = OpConstantComposite %v2float %float_6 %float_7
+          %m = OpConstantComposite %mat4v2float %6 %9 %12 %15
+       %void = OpTypeVoid
+         %17 = OpTypeFunction %void
+         %21 = OpTypeFunction %mat4v2float
+%unused_entry_point = OpFunction %void None %17
+         %20 = OpLabel
+               OpReturn
+               OpFunctionEnd
+          %f = OpFunction %mat4v2float None %21
+         %23 = OpLabel
+               OpReturnValue %m
+               OpFunctionEnd
diff --git a/test/tint/expressions/type_ctor/mat4x2/explicit/identity/f32.wgsl.expected.wgsl b/test/tint/expressions/type_ctor/mat4x2/explicit/identity/f32.wgsl.expected.wgsl
new file mode 100644
index 0000000..6ae1b50
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat4x2/explicit/identity/f32.wgsl.expected.wgsl
@@ -0,0 +1,6 @@
+let m = mat4x2(mat4x2<f32>(0.0f, 1.0f, 2.0f, 3.0f, 4.0f, 5.0f, 6.0f, 7.0f));
+
+fn f() -> mat4x2<f32> {
+  let m_1 = mat4x2(m);
+  return m_1;
+}
diff --git a/test/tint/expressions/type_ctor/mat4x2/inferred/identity/f32.wgsl b/test/tint/expressions/type_ctor/mat4x2/inferred/identity/f32.wgsl
new file mode 100644
index 0000000..45b9ed0
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat4x2/inferred/identity/f32.wgsl
@@ -0,0 +1,9 @@
+let m = mat4x2(mat4x2(0.0f, 1.0f,
+                      2.0f, 3.0f,
+                      4.0f, 5.0f,
+                      6.0f, 7.0f));
+
+fn f() -> mat4x2<f32> {
+    let m_1 = mat4x2(m);
+    return m_1;
+}
diff --git a/test/tint/expressions/type_ctor/mat4x2/inferred/identity/f32.wgsl.expected.glsl b/test/tint/expressions/type_ctor/mat4x2/inferred/identity/f32.wgsl.expected.glsl
new file mode 100644
index 0000000..899a25f
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat4x2/inferred/identity/f32.wgsl.expected.glsl
@@ -0,0 +1,12 @@
+#version 310 es
+
+layout(local_size_x = 1, local_size_y = 1, local_size_z = 1) in;
+void unused_entry_point() {
+  return;
+}
+const mat4x2 m = mat4x2(vec2(0.0f, 1.0f), vec2(2.0f, 3.0f), vec2(4.0f, 5.0f), vec2(6.0f, 7.0f));
+mat4x2 f() {
+  mat4x2 m_1 = mat4x2(vec2(0.0f, 1.0f), vec2(2.0f, 3.0f), vec2(4.0f, 5.0f), vec2(6.0f, 7.0f));
+  return mat4x2(vec2(0.0f, 1.0f), vec2(2.0f, 3.0f), vec2(4.0f, 5.0f), vec2(6.0f, 7.0f));
+}
+
diff --git a/test/tint/expressions/type_ctor/mat4x2/inferred/identity/f32.wgsl.expected.hlsl b/test/tint/expressions/type_ctor/mat4x2/inferred/identity/f32.wgsl.expected.hlsl
new file mode 100644
index 0000000..de0cb92
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat4x2/inferred/identity/f32.wgsl.expected.hlsl
@@ -0,0 +1,11 @@
+[numthreads(1, 1, 1)]
+void unused_entry_point() {
+  return;
+}
+
+static const float4x2 m = float4x2(float2(0.0f, 1.0f), float2(2.0f, 3.0f), float2(4.0f, 5.0f), float2(6.0f, 7.0f));
+
+float4x2 f() {
+  const float4x2 m_1 = float4x2(float2(0.0f, 1.0f), float2(2.0f, 3.0f), float2(4.0f, 5.0f), float2(6.0f, 7.0f));
+  return float4x2(float2(0.0f, 1.0f), float2(2.0f, 3.0f), float2(4.0f, 5.0f), float2(6.0f, 7.0f));
+}
diff --git a/test/tint/expressions/type_ctor/mat4x2/inferred/identity/f32.wgsl.expected.msl b/test/tint/expressions/type_ctor/mat4x2/inferred/identity/f32.wgsl.expected.msl
new file mode 100644
index 0000000..19ae099
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat4x2/inferred/identity/f32.wgsl.expected.msl
@@ -0,0 +1,10 @@
+#include <metal_stdlib>
+
+using namespace metal;
+constant float4x2 m = float4x2(float2(0.0f, 1.0f), float2(2.0f, 3.0f), float2(4.0f, 5.0f), float2(6.0f, 7.0f));
+
+float4x2 f() {
+  float4x2 const m_1 = float4x2(float2(0.0f, 1.0f), float2(2.0f, 3.0f), float2(4.0f, 5.0f), float2(6.0f, 7.0f));
+  return float4x2(float2(0.0f, 1.0f), float2(2.0f, 3.0f), float2(4.0f, 5.0f), float2(6.0f, 7.0f));
+}
+
diff --git a/test/tint/expressions/type_ctor/mat4x2/inferred/identity/f32.wgsl.expected.spvasm b/test/tint/expressions/type_ctor/mat4x2/inferred/identity/f32.wgsl.expected.spvasm
new file mode 100644
index 0000000..045b57c
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat4x2/inferred/identity/f32.wgsl.expected.spvasm
@@ -0,0 +1,39 @@
+; SPIR-V
+; Version: 1.3
+; Generator: Google Tint Compiler; 0
+; Bound: 24
+; Schema: 0
+               OpCapability Shader
+               OpMemoryModel Logical GLSL450
+               OpEntryPoint GLCompute %unused_entry_point "unused_entry_point"
+               OpExecutionMode %unused_entry_point LocalSize 1 1 1
+               OpName %m "m"
+               OpName %unused_entry_point "unused_entry_point"
+               OpName %f "f"
+      %float = OpTypeFloat 32
+    %v2float = OpTypeVector %float 2
+%mat4v2float = OpTypeMatrix %v2float 4
+    %float_0 = OpConstant %float 0
+    %float_1 = OpConstant %float 1
+          %6 = OpConstantComposite %v2float %float_0 %float_1
+    %float_2 = OpConstant %float 2
+    %float_3 = OpConstant %float 3
+          %9 = OpConstantComposite %v2float %float_2 %float_3
+    %float_4 = OpConstant %float 4
+    %float_5 = OpConstant %float 5
+         %12 = OpConstantComposite %v2float %float_4 %float_5
+    %float_6 = OpConstant %float 6
+    %float_7 = OpConstant %float 7
+         %15 = OpConstantComposite %v2float %float_6 %float_7
+          %m = OpConstantComposite %mat4v2float %6 %9 %12 %15
+       %void = OpTypeVoid
+         %17 = OpTypeFunction %void
+         %21 = OpTypeFunction %mat4v2float
+%unused_entry_point = OpFunction %void None %17
+         %20 = OpLabel
+               OpReturn
+               OpFunctionEnd
+          %f = OpFunction %mat4v2float None %21
+         %23 = OpLabel
+               OpReturnValue %m
+               OpFunctionEnd
diff --git a/test/tint/expressions/type_ctor/mat4x2/inferred/identity/f32.wgsl.expected.wgsl b/test/tint/expressions/type_ctor/mat4x2/inferred/identity/f32.wgsl.expected.wgsl
new file mode 100644
index 0000000..ace9fa2
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat4x2/inferred/identity/f32.wgsl.expected.wgsl
@@ -0,0 +1,6 @@
+let m = mat4x2(mat4x2(0.0f, 1.0f, 2.0f, 3.0f, 4.0f, 5.0f, 6.0f, 7.0f));
+
+fn f() -> mat4x2<f32> {
+  let m_1 = mat4x2(m);
+  return m_1;
+}
diff --git a/test/tint/expressions/type_ctor/mat4x2/identity/f32.wgsl b/test/tint/expressions/type_ctor/mat4x2/zero/f32.wgsl
similarity index 100%
rename from test/tint/expressions/type_ctor/mat4x2/identity/f32.wgsl
rename to test/tint/expressions/type_ctor/mat4x2/zero/f32.wgsl
diff --git a/test/tint/expressions/type_ctor/mat4x2/identity/f32.wgsl.expected.glsl b/test/tint/expressions/type_ctor/mat4x2/zero/f32.wgsl.expected.glsl
similarity index 100%
rename from test/tint/expressions/type_ctor/mat4x2/identity/f32.wgsl.expected.glsl
rename to test/tint/expressions/type_ctor/mat4x2/zero/f32.wgsl.expected.glsl
diff --git a/test/tint/expressions/type_ctor/mat4x2/identity/f32.wgsl.expected.hlsl b/test/tint/expressions/type_ctor/mat4x2/zero/f32.wgsl.expected.hlsl
similarity index 100%
rename from test/tint/expressions/type_ctor/mat4x2/identity/f32.wgsl.expected.hlsl
rename to test/tint/expressions/type_ctor/mat4x2/zero/f32.wgsl.expected.hlsl
diff --git a/test/tint/expressions/type_ctor/mat4x2/identity/f32.wgsl.expected.msl b/test/tint/expressions/type_ctor/mat4x2/zero/f32.wgsl.expected.msl
similarity index 100%
rename from test/tint/expressions/type_ctor/mat4x2/identity/f32.wgsl.expected.msl
rename to test/tint/expressions/type_ctor/mat4x2/zero/f32.wgsl.expected.msl
diff --git a/test/tint/expressions/type_ctor/mat4x2/identity/f32.wgsl.expected.spvasm b/test/tint/expressions/type_ctor/mat4x2/zero/f32.wgsl.expected.spvasm
similarity index 100%
rename from test/tint/expressions/type_ctor/mat4x2/identity/f32.wgsl.expected.spvasm
rename to test/tint/expressions/type_ctor/mat4x2/zero/f32.wgsl.expected.spvasm
diff --git a/test/tint/expressions/type_ctor/mat4x2/identity/f32.wgsl.expected.wgsl b/test/tint/expressions/type_ctor/mat4x2/zero/f32.wgsl.expected.wgsl
similarity index 100%
rename from test/tint/expressions/type_ctor/mat4x2/identity/f32.wgsl.expected.wgsl
rename to test/tint/expressions/type_ctor/mat4x2/zero/f32.wgsl.expected.wgsl
diff --git a/test/tint/expressions/type_ctor/mat4x3/explicit/identity/f32.wgsl b/test/tint/expressions/type_ctor/mat4x3/explicit/identity/f32.wgsl
new file mode 100644
index 0000000..f940087
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat4x3/explicit/identity/f32.wgsl
@@ -0,0 +1,9 @@
+let m = mat4x3(mat4x3<f32>(0.0f, 1.0f, 2.0f,
+                           3.0f, 4.0f, 5.0f,
+                           6.0f, 7.0f, 8.0f,
+                           9.0f, 10.0f, 11.0f));
+
+fn f() -> mat4x3<f32> {
+    let m_1 = mat4x3(m);
+    return m_1;
+}
diff --git a/test/tint/expressions/type_ctor/mat4x3/explicit/identity/f32.wgsl.expected.glsl b/test/tint/expressions/type_ctor/mat4x3/explicit/identity/f32.wgsl.expected.glsl
new file mode 100644
index 0000000..87a80c9
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat4x3/explicit/identity/f32.wgsl.expected.glsl
@@ -0,0 +1,12 @@
+#version 310 es
+
+layout(local_size_x = 1, local_size_y = 1, local_size_z = 1) in;
+void unused_entry_point() {
+  return;
+}
+const mat4x3 m = mat4x3(vec3(0.0f, 1.0f, 2.0f), vec3(3.0f, 4.0f, 5.0f), vec3(6.0f, 7.0f, 8.0f), vec3(9.0f, 10.0f, 11.0f));
+mat4x3 f() {
+  mat4x3 m_1 = mat4x3(vec3(0.0f, 1.0f, 2.0f), vec3(3.0f, 4.0f, 5.0f), vec3(6.0f, 7.0f, 8.0f), vec3(9.0f, 10.0f, 11.0f));
+  return mat4x3(vec3(0.0f, 1.0f, 2.0f), vec3(3.0f, 4.0f, 5.0f), vec3(6.0f, 7.0f, 8.0f), vec3(9.0f, 10.0f, 11.0f));
+}
+
diff --git a/test/tint/expressions/type_ctor/mat4x3/explicit/identity/f32.wgsl.expected.hlsl b/test/tint/expressions/type_ctor/mat4x3/explicit/identity/f32.wgsl.expected.hlsl
new file mode 100644
index 0000000..30ebfbf
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat4x3/explicit/identity/f32.wgsl.expected.hlsl
@@ -0,0 +1,11 @@
+[numthreads(1, 1, 1)]
+void unused_entry_point() {
+  return;
+}
+
+static const float4x3 m = float4x3(float3(0.0f, 1.0f, 2.0f), float3(3.0f, 4.0f, 5.0f), float3(6.0f, 7.0f, 8.0f), float3(9.0f, 10.0f, 11.0f));
+
+float4x3 f() {
+  const float4x3 m_1 = float4x3(float3(0.0f, 1.0f, 2.0f), float3(3.0f, 4.0f, 5.0f), float3(6.0f, 7.0f, 8.0f), float3(9.0f, 10.0f, 11.0f));
+  return float4x3(float3(0.0f, 1.0f, 2.0f), float3(3.0f, 4.0f, 5.0f), float3(6.0f, 7.0f, 8.0f), float3(9.0f, 10.0f, 11.0f));
+}
diff --git a/test/tint/expressions/type_ctor/mat4x3/explicit/identity/f32.wgsl.expected.msl b/test/tint/expressions/type_ctor/mat4x3/explicit/identity/f32.wgsl.expected.msl
new file mode 100644
index 0000000..d7238cd
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat4x3/explicit/identity/f32.wgsl.expected.msl
@@ -0,0 +1,10 @@
+#include <metal_stdlib>
+
+using namespace metal;
+constant float4x3 m = float4x3(float3(0.0f, 1.0f, 2.0f), float3(3.0f, 4.0f, 5.0f), float3(6.0f, 7.0f, 8.0f), float3(9.0f, 10.0f, 11.0f));
+
+float4x3 f() {
+  float4x3 const m_1 = float4x3(float3(0.0f, 1.0f, 2.0f), float3(3.0f, 4.0f, 5.0f), float3(6.0f, 7.0f, 8.0f), float3(9.0f, 10.0f, 11.0f));
+  return float4x3(float3(0.0f, 1.0f, 2.0f), float3(3.0f, 4.0f, 5.0f), float3(6.0f, 7.0f, 8.0f), float3(9.0f, 10.0f, 11.0f));
+}
+
diff --git a/test/tint/expressions/type_ctor/mat4x3/explicit/identity/f32.wgsl.expected.spvasm b/test/tint/expressions/type_ctor/mat4x3/explicit/identity/f32.wgsl.expected.spvasm
new file mode 100644
index 0000000..16d9efb
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat4x3/explicit/identity/f32.wgsl.expected.spvasm
@@ -0,0 +1,43 @@
+; SPIR-V
+; Version: 1.3
+; Generator: Google Tint Compiler; 0
+; Bound: 28
+; Schema: 0
+               OpCapability Shader
+               OpMemoryModel Logical GLSL450
+               OpEntryPoint GLCompute %unused_entry_point "unused_entry_point"
+               OpExecutionMode %unused_entry_point LocalSize 1 1 1
+               OpName %m "m"
+               OpName %unused_entry_point "unused_entry_point"
+               OpName %f "f"
+      %float = OpTypeFloat 32
+    %v3float = OpTypeVector %float 3
+%mat4v3float = OpTypeMatrix %v3float 4
+    %float_0 = OpConstant %float 0
+    %float_1 = OpConstant %float 1
+    %float_2 = OpConstant %float 2
+          %7 = OpConstantComposite %v3float %float_0 %float_1 %float_2
+    %float_3 = OpConstant %float 3
+    %float_4 = OpConstant %float 4
+    %float_5 = OpConstant %float 5
+         %11 = OpConstantComposite %v3float %float_3 %float_4 %float_5
+    %float_6 = OpConstant %float 6
+    %float_7 = OpConstant %float 7
+    %float_8 = OpConstant %float 8
+         %15 = OpConstantComposite %v3float %float_6 %float_7 %float_8
+    %float_9 = OpConstant %float 9
+   %float_10 = OpConstant %float 10
+   %float_11 = OpConstant %float 11
+         %19 = OpConstantComposite %v3float %float_9 %float_10 %float_11
+          %m = OpConstantComposite %mat4v3float %7 %11 %15 %19
+       %void = OpTypeVoid
+         %21 = OpTypeFunction %void
+         %25 = OpTypeFunction %mat4v3float
+%unused_entry_point = OpFunction %void None %21
+         %24 = OpLabel
+               OpReturn
+               OpFunctionEnd
+          %f = OpFunction %mat4v3float None %25
+         %27 = OpLabel
+               OpReturnValue %m
+               OpFunctionEnd
diff --git a/test/tint/expressions/type_ctor/mat4x3/explicit/identity/f32.wgsl.expected.wgsl b/test/tint/expressions/type_ctor/mat4x3/explicit/identity/f32.wgsl.expected.wgsl
new file mode 100644
index 0000000..4daec06
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat4x3/explicit/identity/f32.wgsl.expected.wgsl
@@ -0,0 +1,6 @@
+let m = mat4x3(mat4x3<f32>(0.0f, 1.0f, 2.0f, 3.0f, 4.0f, 5.0f, 6.0f, 7.0f, 8.0f, 9.0f, 10.0f, 11.0f));
+
+fn f() -> mat4x3<f32> {
+  let m_1 = mat4x3(m);
+  return m_1;
+}
diff --git a/test/tint/expressions/type_ctor/mat4x3/inferred/identity/f32.wgsl b/test/tint/expressions/type_ctor/mat4x3/inferred/identity/f32.wgsl
new file mode 100644
index 0000000..aba260d
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat4x3/inferred/identity/f32.wgsl
@@ -0,0 +1,9 @@
+let m = mat4x3(mat4x3(0.0f, 1.0f, 2.0f,
+                      3.0f, 4.0f, 5.0f,
+                      6.0f, 7.0f, 8.0f,
+                      9.0f, 10.0f, 11.0f));
+
+fn f() -> mat4x3<f32> {
+    let m_1 = mat4x3(m);
+    return m_1;
+}
diff --git a/test/tint/expressions/type_ctor/mat4x3/inferred/identity/f32.wgsl.expected.glsl b/test/tint/expressions/type_ctor/mat4x3/inferred/identity/f32.wgsl.expected.glsl
new file mode 100644
index 0000000..87a80c9
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat4x3/inferred/identity/f32.wgsl.expected.glsl
@@ -0,0 +1,12 @@
+#version 310 es
+
+layout(local_size_x = 1, local_size_y = 1, local_size_z = 1) in;
+void unused_entry_point() {
+  return;
+}
+const mat4x3 m = mat4x3(vec3(0.0f, 1.0f, 2.0f), vec3(3.0f, 4.0f, 5.0f), vec3(6.0f, 7.0f, 8.0f), vec3(9.0f, 10.0f, 11.0f));
+mat4x3 f() {
+  mat4x3 m_1 = mat4x3(vec3(0.0f, 1.0f, 2.0f), vec3(3.0f, 4.0f, 5.0f), vec3(6.0f, 7.0f, 8.0f), vec3(9.0f, 10.0f, 11.0f));
+  return mat4x3(vec3(0.0f, 1.0f, 2.0f), vec3(3.0f, 4.0f, 5.0f), vec3(6.0f, 7.0f, 8.0f), vec3(9.0f, 10.0f, 11.0f));
+}
+
diff --git a/test/tint/expressions/type_ctor/mat4x3/inferred/identity/f32.wgsl.expected.hlsl b/test/tint/expressions/type_ctor/mat4x3/inferred/identity/f32.wgsl.expected.hlsl
new file mode 100644
index 0000000..30ebfbf
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat4x3/inferred/identity/f32.wgsl.expected.hlsl
@@ -0,0 +1,11 @@
+[numthreads(1, 1, 1)]
+void unused_entry_point() {
+  return;
+}
+
+static const float4x3 m = float4x3(float3(0.0f, 1.0f, 2.0f), float3(3.0f, 4.0f, 5.0f), float3(6.0f, 7.0f, 8.0f), float3(9.0f, 10.0f, 11.0f));
+
+float4x3 f() {
+  const float4x3 m_1 = float4x3(float3(0.0f, 1.0f, 2.0f), float3(3.0f, 4.0f, 5.0f), float3(6.0f, 7.0f, 8.0f), float3(9.0f, 10.0f, 11.0f));
+  return float4x3(float3(0.0f, 1.0f, 2.0f), float3(3.0f, 4.0f, 5.0f), float3(6.0f, 7.0f, 8.0f), float3(9.0f, 10.0f, 11.0f));
+}
diff --git a/test/tint/expressions/type_ctor/mat4x3/inferred/identity/f32.wgsl.expected.msl b/test/tint/expressions/type_ctor/mat4x3/inferred/identity/f32.wgsl.expected.msl
new file mode 100644
index 0000000..d7238cd
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat4x3/inferred/identity/f32.wgsl.expected.msl
@@ -0,0 +1,10 @@
+#include <metal_stdlib>
+
+using namespace metal;
+constant float4x3 m = float4x3(float3(0.0f, 1.0f, 2.0f), float3(3.0f, 4.0f, 5.0f), float3(6.0f, 7.0f, 8.0f), float3(9.0f, 10.0f, 11.0f));
+
+float4x3 f() {
+  float4x3 const m_1 = float4x3(float3(0.0f, 1.0f, 2.0f), float3(3.0f, 4.0f, 5.0f), float3(6.0f, 7.0f, 8.0f), float3(9.0f, 10.0f, 11.0f));
+  return float4x3(float3(0.0f, 1.0f, 2.0f), float3(3.0f, 4.0f, 5.0f), float3(6.0f, 7.0f, 8.0f), float3(9.0f, 10.0f, 11.0f));
+}
+
diff --git a/test/tint/expressions/type_ctor/mat4x3/inferred/identity/f32.wgsl.expected.spvasm b/test/tint/expressions/type_ctor/mat4x3/inferred/identity/f32.wgsl.expected.spvasm
new file mode 100644
index 0000000..16d9efb
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat4x3/inferred/identity/f32.wgsl.expected.spvasm
@@ -0,0 +1,43 @@
+; SPIR-V
+; Version: 1.3
+; Generator: Google Tint Compiler; 0
+; Bound: 28
+; Schema: 0
+               OpCapability Shader
+               OpMemoryModel Logical GLSL450
+               OpEntryPoint GLCompute %unused_entry_point "unused_entry_point"
+               OpExecutionMode %unused_entry_point LocalSize 1 1 1
+               OpName %m "m"
+               OpName %unused_entry_point "unused_entry_point"
+               OpName %f "f"
+      %float = OpTypeFloat 32
+    %v3float = OpTypeVector %float 3
+%mat4v3float = OpTypeMatrix %v3float 4
+    %float_0 = OpConstant %float 0
+    %float_1 = OpConstant %float 1
+    %float_2 = OpConstant %float 2
+          %7 = OpConstantComposite %v3float %float_0 %float_1 %float_2
+    %float_3 = OpConstant %float 3
+    %float_4 = OpConstant %float 4
+    %float_5 = OpConstant %float 5
+         %11 = OpConstantComposite %v3float %float_3 %float_4 %float_5
+    %float_6 = OpConstant %float 6
+    %float_7 = OpConstant %float 7
+    %float_8 = OpConstant %float 8
+         %15 = OpConstantComposite %v3float %float_6 %float_7 %float_8
+    %float_9 = OpConstant %float 9
+   %float_10 = OpConstant %float 10
+   %float_11 = OpConstant %float 11
+         %19 = OpConstantComposite %v3float %float_9 %float_10 %float_11
+          %m = OpConstantComposite %mat4v3float %7 %11 %15 %19
+       %void = OpTypeVoid
+         %21 = OpTypeFunction %void
+         %25 = OpTypeFunction %mat4v3float
+%unused_entry_point = OpFunction %void None %21
+         %24 = OpLabel
+               OpReturn
+               OpFunctionEnd
+          %f = OpFunction %mat4v3float None %25
+         %27 = OpLabel
+               OpReturnValue %m
+               OpFunctionEnd
diff --git a/test/tint/expressions/type_ctor/mat4x3/inferred/identity/f32.wgsl.expected.wgsl b/test/tint/expressions/type_ctor/mat4x3/inferred/identity/f32.wgsl.expected.wgsl
new file mode 100644
index 0000000..d7e3f24
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat4x3/inferred/identity/f32.wgsl.expected.wgsl
@@ -0,0 +1,6 @@
+let m = mat4x3(mat4x3(0.0f, 1.0f, 2.0f, 3.0f, 4.0f, 5.0f, 6.0f, 7.0f, 8.0f, 9.0f, 10.0f, 11.0f));
+
+fn f() -> mat4x3<f32> {
+  let m_1 = mat4x3(m);
+  return m_1;
+}
diff --git a/test/tint/expressions/type_ctor/mat4x3/identity/f32.wgsl b/test/tint/expressions/type_ctor/mat4x3/zero/f32.wgsl
similarity index 100%
rename from test/tint/expressions/type_ctor/mat4x3/identity/f32.wgsl
rename to test/tint/expressions/type_ctor/mat4x3/zero/f32.wgsl
diff --git a/test/tint/expressions/type_ctor/mat4x3/identity/f32.wgsl.expected.glsl b/test/tint/expressions/type_ctor/mat4x3/zero/f32.wgsl.expected.glsl
similarity index 100%
rename from test/tint/expressions/type_ctor/mat4x3/identity/f32.wgsl.expected.glsl
rename to test/tint/expressions/type_ctor/mat4x3/zero/f32.wgsl.expected.glsl
diff --git a/test/tint/expressions/type_ctor/mat4x3/identity/f32.wgsl.expected.hlsl b/test/tint/expressions/type_ctor/mat4x3/zero/f32.wgsl.expected.hlsl
similarity index 100%
rename from test/tint/expressions/type_ctor/mat4x3/identity/f32.wgsl.expected.hlsl
rename to test/tint/expressions/type_ctor/mat4x3/zero/f32.wgsl.expected.hlsl
diff --git a/test/tint/expressions/type_ctor/mat4x3/identity/f32.wgsl.expected.msl b/test/tint/expressions/type_ctor/mat4x3/zero/f32.wgsl.expected.msl
similarity index 100%
rename from test/tint/expressions/type_ctor/mat4x3/identity/f32.wgsl.expected.msl
rename to test/tint/expressions/type_ctor/mat4x3/zero/f32.wgsl.expected.msl
diff --git a/test/tint/expressions/type_ctor/mat4x3/identity/f32.wgsl.expected.spvasm b/test/tint/expressions/type_ctor/mat4x3/zero/f32.wgsl.expected.spvasm
similarity index 100%
rename from test/tint/expressions/type_ctor/mat4x3/identity/f32.wgsl.expected.spvasm
rename to test/tint/expressions/type_ctor/mat4x3/zero/f32.wgsl.expected.spvasm
diff --git a/test/tint/expressions/type_ctor/mat4x3/identity/f32.wgsl.expected.wgsl b/test/tint/expressions/type_ctor/mat4x3/zero/f32.wgsl.expected.wgsl
similarity index 100%
rename from test/tint/expressions/type_ctor/mat4x3/identity/f32.wgsl.expected.wgsl
rename to test/tint/expressions/type_ctor/mat4x3/zero/f32.wgsl.expected.wgsl
diff --git a/test/tint/expressions/type_ctor/mat4x4/explicit/identity/f32.wgsl b/test/tint/expressions/type_ctor/mat4x4/explicit/identity/f32.wgsl
new file mode 100644
index 0000000..bc5556d
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat4x4/explicit/identity/f32.wgsl
@@ -0,0 +1,9 @@
+let m = mat4x4(mat4x4<f32>(0.0f, 1.0f, 2.0f, 3.0f,
+                           4.0f, 5.0f, 6.0f, 7.0f,
+                           8.0f, 9.0f, 10.0f, 11.0f,
+                           12.0f, 13.0f, 14.0f, 15.0f));
+
+fn f() -> mat4x4<f32> {
+    let m_1 = mat4x4(m);
+    return m_1;
+}
diff --git a/test/tint/expressions/type_ctor/mat4x4/explicit/identity/f32.wgsl.expected.glsl b/test/tint/expressions/type_ctor/mat4x4/explicit/identity/f32.wgsl.expected.glsl
new file mode 100644
index 0000000..3c5cf24
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat4x4/explicit/identity/f32.wgsl.expected.glsl
@@ -0,0 +1,12 @@
+#version 310 es
+
+layout(local_size_x = 1, local_size_y = 1, local_size_z = 1) in;
+void unused_entry_point() {
+  return;
+}
+const mat4 m = mat4(vec4(0.0f, 1.0f, 2.0f, 3.0f), vec4(4.0f, 5.0f, 6.0f, 7.0f), vec4(8.0f, 9.0f, 10.0f, 11.0f), vec4(12.0f, 13.0f, 14.0f, 15.0f));
+mat4 f() {
+  mat4 m_1 = mat4(vec4(0.0f, 1.0f, 2.0f, 3.0f), vec4(4.0f, 5.0f, 6.0f, 7.0f), vec4(8.0f, 9.0f, 10.0f, 11.0f), vec4(12.0f, 13.0f, 14.0f, 15.0f));
+  return mat4(vec4(0.0f, 1.0f, 2.0f, 3.0f), vec4(4.0f, 5.0f, 6.0f, 7.0f), vec4(8.0f, 9.0f, 10.0f, 11.0f), vec4(12.0f, 13.0f, 14.0f, 15.0f));
+}
+
diff --git a/test/tint/expressions/type_ctor/mat4x4/explicit/identity/f32.wgsl.expected.hlsl b/test/tint/expressions/type_ctor/mat4x4/explicit/identity/f32.wgsl.expected.hlsl
new file mode 100644
index 0000000..1f3e190
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat4x4/explicit/identity/f32.wgsl.expected.hlsl
@@ -0,0 +1,11 @@
+[numthreads(1, 1, 1)]
+void unused_entry_point() {
+  return;
+}
+
+static const float4x4 m = float4x4(float4(0.0f, 1.0f, 2.0f, 3.0f), float4(4.0f, 5.0f, 6.0f, 7.0f), float4(8.0f, 9.0f, 10.0f, 11.0f), float4(12.0f, 13.0f, 14.0f, 15.0f));
+
+float4x4 f() {
+  const float4x4 m_1 = float4x4(float4(0.0f, 1.0f, 2.0f, 3.0f), float4(4.0f, 5.0f, 6.0f, 7.0f), float4(8.0f, 9.0f, 10.0f, 11.0f), float4(12.0f, 13.0f, 14.0f, 15.0f));
+  return float4x4(float4(0.0f, 1.0f, 2.0f, 3.0f), float4(4.0f, 5.0f, 6.0f, 7.0f), float4(8.0f, 9.0f, 10.0f, 11.0f), float4(12.0f, 13.0f, 14.0f, 15.0f));
+}
diff --git a/test/tint/expressions/type_ctor/mat4x4/explicit/identity/f32.wgsl.expected.msl b/test/tint/expressions/type_ctor/mat4x4/explicit/identity/f32.wgsl.expected.msl
new file mode 100644
index 0000000..ffac88e
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat4x4/explicit/identity/f32.wgsl.expected.msl
@@ -0,0 +1,10 @@
+#include <metal_stdlib>
+
+using namespace metal;
+constant float4x4 m = float4x4(float4(0.0f, 1.0f, 2.0f, 3.0f), float4(4.0f, 5.0f, 6.0f, 7.0f), float4(8.0f, 9.0f, 10.0f, 11.0f), float4(12.0f, 13.0f, 14.0f, 15.0f));
+
+float4x4 f() {
+  float4x4 const m_1 = float4x4(float4(0.0f, 1.0f, 2.0f, 3.0f), float4(4.0f, 5.0f, 6.0f, 7.0f), float4(8.0f, 9.0f, 10.0f, 11.0f), float4(12.0f, 13.0f, 14.0f, 15.0f));
+  return float4x4(float4(0.0f, 1.0f, 2.0f, 3.0f), float4(4.0f, 5.0f, 6.0f, 7.0f), float4(8.0f, 9.0f, 10.0f, 11.0f), float4(12.0f, 13.0f, 14.0f, 15.0f));
+}
+
diff --git a/test/tint/expressions/type_ctor/mat4x4/explicit/identity/f32.wgsl.expected.spvasm b/test/tint/expressions/type_ctor/mat4x4/explicit/identity/f32.wgsl.expected.spvasm
new file mode 100644
index 0000000..a4fc367
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat4x4/explicit/identity/f32.wgsl.expected.spvasm
@@ -0,0 +1,47 @@
+; SPIR-V
+; Version: 1.3
+; Generator: Google Tint Compiler; 0
+; Bound: 32
+; Schema: 0
+               OpCapability Shader
+               OpMemoryModel Logical GLSL450
+               OpEntryPoint GLCompute %unused_entry_point "unused_entry_point"
+               OpExecutionMode %unused_entry_point LocalSize 1 1 1
+               OpName %m "m"
+               OpName %unused_entry_point "unused_entry_point"
+               OpName %f "f"
+      %float = OpTypeFloat 32
+    %v4float = OpTypeVector %float 4
+%mat4v4float = OpTypeMatrix %v4float 4
+    %float_0 = OpConstant %float 0
+    %float_1 = OpConstant %float 1
+    %float_2 = OpConstant %float 2
+    %float_3 = OpConstant %float 3
+          %8 = OpConstantComposite %v4float %float_0 %float_1 %float_2 %float_3
+    %float_4 = OpConstant %float 4
+    %float_5 = OpConstant %float 5
+    %float_6 = OpConstant %float 6
+    %float_7 = OpConstant %float 7
+         %13 = OpConstantComposite %v4float %float_4 %float_5 %float_6 %float_7
+    %float_8 = OpConstant %float 8
+    %float_9 = OpConstant %float 9
+   %float_10 = OpConstant %float 10
+   %float_11 = OpConstant %float 11
+         %18 = OpConstantComposite %v4float %float_8 %float_9 %float_10 %float_11
+   %float_12 = OpConstant %float 12
+   %float_13 = OpConstant %float 13
+   %float_14 = OpConstant %float 14
+   %float_15 = OpConstant %float 15
+         %23 = OpConstantComposite %v4float %float_12 %float_13 %float_14 %float_15
+          %m = OpConstantComposite %mat4v4float %8 %13 %18 %23
+       %void = OpTypeVoid
+         %25 = OpTypeFunction %void
+         %29 = OpTypeFunction %mat4v4float
+%unused_entry_point = OpFunction %void None %25
+         %28 = OpLabel
+               OpReturn
+               OpFunctionEnd
+          %f = OpFunction %mat4v4float None %29
+         %31 = OpLabel
+               OpReturnValue %m
+               OpFunctionEnd
diff --git a/test/tint/expressions/type_ctor/mat4x4/explicit/identity/f32.wgsl.expected.wgsl b/test/tint/expressions/type_ctor/mat4x4/explicit/identity/f32.wgsl.expected.wgsl
new file mode 100644
index 0000000..908d9b9
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat4x4/explicit/identity/f32.wgsl.expected.wgsl
@@ -0,0 +1,6 @@
+let m = mat4x4(mat4x4<f32>(0.0f, 1.0f, 2.0f, 3.0f, 4.0f, 5.0f, 6.0f, 7.0f, 8.0f, 9.0f, 10.0f, 11.0f, 12.0f, 13.0f, 14.0f, 15.0f));
+
+fn f() -> mat4x4<f32> {
+  let m_1 = mat4x4(m);
+  return m_1;
+}
diff --git a/test/tint/expressions/type_ctor/mat4x4/inferred/identity/f32.wgsl b/test/tint/expressions/type_ctor/mat4x4/inferred/identity/f32.wgsl
new file mode 100644
index 0000000..2b9f7e9
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat4x4/inferred/identity/f32.wgsl
@@ -0,0 +1,9 @@
+let m = mat4x4(mat4x4(0.0f, 1.0f, 2.0f, 3.0f,
+                      4.0f, 5.0f, 6.0f, 7.0f,
+                      8.0f, 9.0f, 10.0f, 11.0f,
+                      12.0f, 13.0f, 14.0f, 15.0f));
+
+fn f() -> mat4x4<f32> {
+    let m_1 = mat4x4(m);
+    return m_1;
+}
diff --git a/test/tint/expressions/type_ctor/mat4x4/inferred/identity/f32.wgsl.expected.glsl b/test/tint/expressions/type_ctor/mat4x4/inferred/identity/f32.wgsl.expected.glsl
new file mode 100644
index 0000000..3c5cf24
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat4x4/inferred/identity/f32.wgsl.expected.glsl
@@ -0,0 +1,12 @@
+#version 310 es
+
+layout(local_size_x = 1, local_size_y = 1, local_size_z = 1) in;
+void unused_entry_point() {
+  return;
+}
+const mat4 m = mat4(vec4(0.0f, 1.0f, 2.0f, 3.0f), vec4(4.0f, 5.0f, 6.0f, 7.0f), vec4(8.0f, 9.0f, 10.0f, 11.0f), vec4(12.0f, 13.0f, 14.0f, 15.0f));
+mat4 f() {
+  mat4 m_1 = mat4(vec4(0.0f, 1.0f, 2.0f, 3.0f), vec4(4.0f, 5.0f, 6.0f, 7.0f), vec4(8.0f, 9.0f, 10.0f, 11.0f), vec4(12.0f, 13.0f, 14.0f, 15.0f));
+  return mat4(vec4(0.0f, 1.0f, 2.0f, 3.0f), vec4(4.0f, 5.0f, 6.0f, 7.0f), vec4(8.0f, 9.0f, 10.0f, 11.0f), vec4(12.0f, 13.0f, 14.0f, 15.0f));
+}
+
diff --git a/test/tint/expressions/type_ctor/mat4x4/inferred/identity/f32.wgsl.expected.hlsl b/test/tint/expressions/type_ctor/mat4x4/inferred/identity/f32.wgsl.expected.hlsl
new file mode 100644
index 0000000..1f3e190
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat4x4/inferred/identity/f32.wgsl.expected.hlsl
@@ -0,0 +1,11 @@
+[numthreads(1, 1, 1)]
+void unused_entry_point() {
+  return;
+}
+
+static const float4x4 m = float4x4(float4(0.0f, 1.0f, 2.0f, 3.0f), float4(4.0f, 5.0f, 6.0f, 7.0f), float4(8.0f, 9.0f, 10.0f, 11.0f), float4(12.0f, 13.0f, 14.0f, 15.0f));
+
+float4x4 f() {
+  const float4x4 m_1 = float4x4(float4(0.0f, 1.0f, 2.0f, 3.0f), float4(4.0f, 5.0f, 6.0f, 7.0f), float4(8.0f, 9.0f, 10.0f, 11.0f), float4(12.0f, 13.0f, 14.0f, 15.0f));
+  return float4x4(float4(0.0f, 1.0f, 2.0f, 3.0f), float4(4.0f, 5.0f, 6.0f, 7.0f), float4(8.0f, 9.0f, 10.0f, 11.0f), float4(12.0f, 13.0f, 14.0f, 15.0f));
+}
diff --git a/test/tint/expressions/type_ctor/mat4x4/inferred/identity/f32.wgsl.expected.msl b/test/tint/expressions/type_ctor/mat4x4/inferred/identity/f32.wgsl.expected.msl
new file mode 100644
index 0000000..ffac88e
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat4x4/inferred/identity/f32.wgsl.expected.msl
@@ -0,0 +1,10 @@
+#include <metal_stdlib>
+
+using namespace metal;
+constant float4x4 m = float4x4(float4(0.0f, 1.0f, 2.0f, 3.0f), float4(4.0f, 5.0f, 6.0f, 7.0f), float4(8.0f, 9.0f, 10.0f, 11.0f), float4(12.0f, 13.0f, 14.0f, 15.0f));
+
+float4x4 f() {
+  float4x4 const m_1 = float4x4(float4(0.0f, 1.0f, 2.0f, 3.0f), float4(4.0f, 5.0f, 6.0f, 7.0f), float4(8.0f, 9.0f, 10.0f, 11.0f), float4(12.0f, 13.0f, 14.0f, 15.0f));
+  return float4x4(float4(0.0f, 1.0f, 2.0f, 3.0f), float4(4.0f, 5.0f, 6.0f, 7.0f), float4(8.0f, 9.0f, 10.0f, 11.0f), float4(12.0f, 13.0f, 14.0f, 15.0f));
+}
+
diff --git a/test/tint/expressions/type_ctor/mat4x4/inferred/identity/f32.wgsl.expected.spvasm b/test/tint/expressions/type_ctor/mat4x4/inferred/identity/f32.wgsl.expected.spvasm
new file mode 100644
index 0000000..a4fc367
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat4x4/inferred/identity/f32.wgsl.expected.spvasm
@@ -0,0 +1,47 @@
+; SPIR-V
+; Version: 1.3
+; Generator: Google Tint Compiler; 0
+; Bound: 32
+; Schema: 0
+               OpCapability Shader
+               OpMemoryModel Logical GLSL450
+               OpEntryPoint GLCompute %unused_entry_point "unused_entry_point"
+               OpExecutionMode %unused_entry_point LocalSize 1 1 1
+               OpName %m "m"
+               OpName %unused_entry_point "unused_entry_point"
+               OpName %f "f"
+      %float = OpTypeFloat 32
+    %v4float = OpTypeVector %float 4
+%mat4v4float = OpTypeMatrix %v4float 4
+    %float_0 = OpConstant %float 0
+    %float_1 = OpConstant %float 1
+    %float_2 = OpConstant %float 2
+    %float_3 = OpConstant %float 3
+          %8 = OpConstantComposite %v4float %float_0 %float_1 %float_2 %float_3
+    %float_4 = OpConstant %float 4
+    %float_5 = OpConstant %float 5
+    %float_6 = OpConstant %float 6
+    %float_7 = OpConstant %float 7
+         %13 = OpConstantComposite %v4float %float_4 %float_5 %float_6 %float_7
+    %float_8 = OpConstant %float 8
+    %float_9 = OpConstant %float 9
+   %float_10 = OpConstant %float 10
+   %float_11 = OpConstant %float 11
+         %18 = OpConstantComposite %v4float %float_8 %float_9 %float_10 %float_11
+   %float_12 = OpConstant %float 12
+   %float_13 = OpConstant %float 13
+   %float_14 = OpConstant %float 14
+   %float_15 = OpConstant %float 15
+         %23 = OpConstantComposite %v4float %float_12 %float_13 %float_14 %float_15
+          %m = OpConstantComposite %mat4v4float %8 %13 %18 %23
+       %void = OpTypeVoid
+         %25 = OpTypeFunction %void
+         %29 = OpTypeFunction %mat4v4float
+%unused_entry_point = OpFunction %void None %25
+         %28 = OpLabel
+               OpReturn
+               OpFunctionEnd
+          %f = OpFunction %mat4v4float None %29
+         %31 = OpLabel
+               OpReturnValue %m
+               OpFunctionEnd
diff --git a/test/tint/expressions/type_ctor/mat4x4/inferred/identity/f32.wgsl.expected.wgsl b/test/tint/expressions/type_ctor/mat4x4/inferred/identity/f32.wgsl.expected.wgsl
new file mode 100644
index 0000000..b9e9f8f
--- /dev/null
+++ b/test/tint/expressions/type_ctor/mat4x4/inferred/identity/f32.wgsl.expected.wgsl
@@ -0,0 +1,6 @@
+let m = mat4x4(mat4x4(0.0f, 1.0f, 2.0f, 3.0f, 4.0f, 5.0f, 6.0f, 7.0f, 8.0f, 9.0f, 10.0f, 11.0f, 12.0f, 13.0f, 14.0f, 15.0f));
+
+fn f() -> mat4x4<f32> {
+  let m_1 = mat4x4(m);
+  return m_1;
+}
diff --git a/test/tint/expressions/type_ctor/mat4x4/identity/f32.wgsl b/test/tint/expressions/type_ctor/mat4x4/zero/f32.wgsl
similarity index 100%
rename from test/tint/expressions/type_ctor/mat4x4/identity/f32.wgsl
rename to test/tint/expressions/type_ctor/mat4x4/zero/f32.wgsl
diff --git a/test/tint/expressions/type_ctor/mat4x4/identity/f32.wgsl.expected.glsl b/test/tint/expressions/type_ctor/mat4x4/zero/f32.wgsl.expected.glsl
similarity index 100%
rename from test/tint/expressions/type_ctor/mat4x4/identity/f32.wgsl.expected.glsl
rename to test/tint/expressions/type_ctor/mat4x4/zero/f32.wgsl.expected.glsl
diff --git a/test/tint/expressions/type_ctor/mat4x4/identity/f32.wgsl.expected.hlsl b/test/tint/expressions/type_ctor/mat4x4/zero/f32.wgsl.expected.hlsl
similarity index 100%
rename from test/tint/expressions/type_ctor/mat4x4/identity/f32.wgsl.expected.hlsl
rename to test/tint/expressions/type_ctor/mat4x4/zero/f32.wgsl.expected.hlsl
diff --git a/test/tint/expressions/type_ctor/mat4x4/identity/f32.wgsl.expected.msl b/test/tint/expressions/type_ctor/mat4x4/zero/f32.wgsl.expected.msl
similarity index 100%
rename from test/tint/expressions/type_ctor/mat4x4/identity/f32.wgsl.expected.msl
rename to test/tint/expressions/type_ctor/mat4x4/zero/f32.wgsl.expected.msl
diff --git a/test/tint/expressions/type_ctor/mat4x4/identity/f32.wgsl.expected.spvasm b/test/tint/expressions/type_ctor/mat4x4/zero/f32.wgsl.expected.spvasm
similarity index 100%
rename from test/tint/expressions/type_ctor/mat4x4/identity/f32.wgsl.expected.spvasm
rename to test/tint/expressions/type_ctor/mat4x4/zero/f32.wgsl.expected.spvasm
diff --git a/test/tint/expressions/type_ctor/mat4x4/identity/f32.wgsl.expected.wgsl b/test/tint/expressions/type_ctor/mat4x4/zero/f32.wgsl.expected.wgsl
similarity index 100%
rename from test/tint/expressions/type_ctor/mat4x4/identity/f32.wgsl.expected.wgsl
rename to test/tint/expressions/type_ctor/mat4x4/zero/f32.wgsl.expected.wgsl