writer/hlsl: Special case negative zero
Fixed: tint:960
Change-Id: I04de8713fe299607f32fd93288a22b75a9dff381
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/58760
Reviewed-by: Ben Clayton <bclayton@chromium.org>
Reviewed-by: James Price <jrprice@google.com>
Commit-Queue: Ben Clayton <bclayton@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>
diff --git a/src/writer/hlsl/generator_impl.cc b/src/writer/hlsl/generator_impl.cc
index fc9e505..de9ea80 100644
--- a/src/writer/hlsl/generator_impl.cc
+++ b/src/writer/hlsl/generator_impl.cc
@@ -2502,13 +2502,20 @@
if (auto* l = lit->As<ast::BoolLiteral>()) {
out << (l->IsTrue() ? "true" : "false");
} else if (auto* fl = lit->As<ast::FloatLiteral>()) {
- if (std::isinf(fl->value())) {
- out << (fl->value() >= 0 ? "asfloat(0x7f800000u)"
- : "asfloat(0xff800000u)");
- } else if (std::isnan(fl->value())) {
- out << "asfloat(0x7fc00000u)";
- } else {
- out << FloatToString(fl->value()) << "f";
+ bool positive = !std::signbit(fl->value());
+ switch (std::fpclassify(fl->value())) {
+ case FP_INFINITE:
+ out << (positive ? "asfloat(0x7f800000u)" : "asfloat(0xff800000u)");
+ break;
+ case FP_NAN:
+ out << "asfloat(0x7fc00000u)";
+ break;
+ case FP_ZERO:
+ out << (positive ? "0.0f" : "asfloat(0x80000000u)");
+ break;
+ default:
+ out << FloatToString(fl->value()) << "f";
+ break;
}
} else if (auto* sl = lit->As<ast::SintLiteral>()) {
out << sl->value();
diff --git a/test/expressions/literals/-inf.spvasm b/test/expressions/literals/neg_inf.spvasm
similarity index 100%
rename from test/expressions/literals/-inf.spvasm
rename to test/expressions/literals/neg_inf.spvasm
diff --git a/test/expressions/literals/-inf.spvasm.expected.hlsl b/test/expressions/literals/neg_inf.spvasm.expected.hlsl
similarity index 100%
rename from test/expressions/literals/-inf.spvasm.expected.hlsl
rename to test/expressions/literals/neg_inf.spvasm.expected.hlsl
diff --git a/test/expressions/literals/-inf.spvasm.expected.msl b/test/expressions/literals/neg_inf.spvasm.expected.msl
similarity index 100%
rename from test/expressions/literals/-inf.spvasm.expected.msl
rename to test/expressions/literals/neg_inf.spvasm.expected.msl
diff --git a/test/expressions/literals/-inf.spvasm.expected.spvasm b/test/expressions/literals/neg_inf.spvasm.expected.spvasm
similarity index 100%
rename from test/expressions/literals/-inf.spvasm.expected.spvasm
rename to test/expressions/literals/neg_inf.spvasm.expected.spvasm
diff --git a/test/expressions/literals/-inf.spvasm.expected.wgsl b/test/expressions/literals/neg_inf.spvasm.expected.wgsl
similarity index 100%
rename from test/expressions/literals/-inf.spvasm.expected.wgsl
rename to test/expressions/literals/neg_inf.spvasm.expected.wgsl
diff --git a/test/expressions/literals/neg_zero.spvasm b/test/expressions/literals/neg_zero.spvasm
new file mode 100644
index 0000000..610537b
--- /dev/null
+++ b/test/expressions/literals/neg_zero.spvasm
@@ -0,0 +1,21 @@
+ OpCapability Shader
+ OpMemoryModel Logical GLSL450
+ OpEntryPoint Fragment %main "main" %out_var_SV_TARGET
+ OpExecutionMode %main OriginUpperLeft
+ OpSource HLSL 600
+ OpName %out_var_SV_TARGET "out.var.SV_TARGET"
+ OpName %main "main"
+ OpDecorate %out_var_SV_TARGET Location 0
+ %float = OpTypeFloat 32
+ %float_0x1p_128 = OpConstant %float -0
+ %v4float = OpTypeVector %float 4
+%_ptr_Output_v4float = OpTypePointer Output %v4float
+ %void = OpTypeVoid
+ %9 = OpTypeFunction %void
+ %out_var_SV_TARGET = OpVariable %_ptr_Output_v4float Output
+ %main = OpFunction %void None %9
+ %10 = OpLabel
+ %12 = OpCompositeConstruct %v4float %float_0x1p_128 %float_0x1p_128 %float_0x1p_128 %float_0x1p_128
+ OpStore %out_var_SV_TARGET %12
+ OpReturn
+ OpFunctionEnd
diff --git a/test/expressions/literals/neg_zero.spvasm.expected.hlsl b/test/expressions/literals/neg_zero.spvasm.expected.hlsl
new file mode 100644
index 0000000..f1ac2f2
--- /dev/null
+++ b/test/expressions/literals/neg_zero.spvasm.expected.hlsl
@@ -0,0 +1,20 @@
+static float4 out_var_SV_TARGET = float4(0.0f, 0.0f, 0.0f, 0.0f);
+
+void main_1() {
+ out_var_SV_TARGET = float4(asfloat(0x80000000u), asfloat(0x80000000u), asfloat(0x80000000u), asfloat(0x80000000u));
+ return;
+}
+
+struct main_out {
+ float4 out_var_SV_TARGET_1;
+};
+struct tint_symbol {
+ float4 out_var_SV_TARGET_1 : SV_Target0;
+};
+
+tint_symbol main() {
+ main_1();
+ const main_out tint_symbol_1 = {out_var_SV_TARGET};
+ const tint_symbol tint_symbol_2 = {tint_symbol_1.out_var_SV_TARGET_1};
+ return tint_symbol_2;
+}
diff --git a/test/expressions/literals/neg_zero.spvasm.expected.msl b/test/expressions/literals/neg_zero.spvasm.expected.msl
new file mode 100644
index 0000000..a5862ed
--- /dev/null
+++ b/test/expressions/literals/neg_zero.spvasm.expected.msl
@@ -0,0 +1,23 @@
+#include <metal_stdlib>
+
+using namespace metal;
+struct main_out {
+ float4 out_var_SV_TARGET_1;
+};
+struct tint_symbol_1 {
+ float4 out_var_SV_TARGET_1 [[color(0)]];
+};
+
+void main_1(thread float4* const tint_symbol_4) {
+ *(tint_symbol_4) = float4(-0.0f, -0.0f, -0.0f, -0.0f);
+ return;
+}
+
+fragment tint_symbol_1 tint_symbol() {
+ thread float4 tint_symbol_5 = 0.0f;
+ main_1(&(tint_symbol_5));
+ main_out const tint_symbol_2 = {.out_var_SV_TARGET_1=tint_symbol_5};
+ tint_symbol_1 const tint_symbol_3 = {.out_var_SV_TARGET_1=tint_symbol_2.out_var_SV_TARGET_1};
+ return tint_symbol_3;
+}
+
diff --git a/test/expressions/literals/neg_zero.spvasm.expected.spvasm b/test/expressions/literals/neg_zero.spvasm.expected.spvasm
new file mode 100644
index 0000000..ea3e75c
--- /dev/null
+++ b/test/expressions/literals/neg_zero.spvasm.expected.spvasm
@@ -0,0 +1,52 @@
+; SPIR-V
+; Version: 1.3
+; Generator: Google Tint Compiler; 0
+; Bound: 26
+; Schema: 0
+ OpCapability Shader
+ OpMemoryModel Logical GLSL450
+ OpEntryPoint Fragment %main "main" %tint_symbol_1
+ OpExecutionMode %main OriginUpperLeft
+ OpName %out_var_SV_TARGET "out_var_SV_TARGET"
+ OpName %tint_symbol_1 "tint_symbol_1"
+ OpName %main_1 "main_1"
+ OpName %main_out "main_out"
+ OpMemberName %main_out 0 "out_var_SV_TARGET_1"
+ OpName %tint_symbol_2 "tint_symbol_2"
+ OpName %tint_symbol "tint_symbol"
+ OpName %main "main"
+ OpDecorate %tint_symbol_1 Location 0
+ OpMemberDecorate %main_out 0 Offset 0
+ %float = OpTypeFloat 32
+ %v4float = OpTypeVector %float 4
+%_ptr_Private_v4float = OpTypePointer Private %v4float
+ %5 = OpConstantNull %v4float
+%out_var_SV_TARGET = OpVariable %_ptr_Private_v4float Private %5
+%_ptr_Output_v4float = OpTypePointer Output %v4float
+%tint_symbol_1 = OpVariable %_ptr_Output_v4float Output %5
+ %void = OpTypeVoid
+ %8 = OpTypeFunction %void
+ %float_n0 = OpConstant %float -0
+ %13 = OpConstantComposite %v4float %float_n0 %float_n0 %float_n0 %float_n0
+ %main_out = OpTypeStruct %v4float
+ %14 = OpTypeFunction %void %main_out
+ %main_1 = OpFunction %void None %8
+ %11 = OpLabel
+ OpStore %out_var_SV_TARGET %13
+ OpReturn
+ OpFunctionEnd
+%tint_symbol_2 = OpFunction %void None %14
+%tint_symbol = OpFunctionParameter %main_out
+ %18 = OpLabel
+ %19 = OpCompositeExtract %v4float %tint_symbol 0
+ OpStore %tint_symbol_1 %19
+ OpReturn
+ OpFunctionEnd
+ %main = OpFunction %void None %8
+ %21 = OpLabel
+ %22 = OpFunctionCall %void %main_1
+ %24 = OpLoad %v4float %out_var_SV_TARGET
+ %25 = OpCompositeConstruct %main_out %24
+ %23 = OpFunctionCall %void %tint_symbol_2 %25
+ OpReturn
+ OpFunctionEnd
diff --git a/test/expressions/literals/neg_zero.spvasm.expected.wgsl b/test/expressions/literals/neg_zero.spvasm.expected.wgsl
new file mode 100644
index 0000000..d9a2025
--- /dev/null
+++ b/test/expressions/literals/neg_zero.spvasm.expected.wgsl
@@ -0,0 +1,17 @@
+var<private> out_var_SV_TARGET : vec4<f32>;
+
+fn main_1() {
+ out_var_SV_TARGET = vec4<f32>(-0.0, -0.0, -0.0, -0.0);
+ return;
+}
+
+struct main_out {
+ [[location(0)]]
+ out_var_SV_TARGET_1 : vec4<f32>;
+};
+
+[[stage(fragment)]]
+fn main() -> main_out {
+ main_1();
+ return main_out(out_var_SV_TARGET);
+}
