commit 94f5a3aa5c4a99f9c972e1c925a0c4fa2c5d9024
author James Price <jrprice@google.com> Thu Jul 20 14:50:56 2023 +0000
committer Dawn LUCI CQ <dawn-scoped@luci-project-accounts.iam.gserviceaccount.com> Thu Jul 20 14:50:56 2023 +0000
tree 7835d7e247ce5b5069e8beb8d0e896192e296525
parent 0768c6f3cd0ac099f40f9f7ccf552157d4979176

[ir][spirv-writer] Handle fwidth* builtins

These map directly to SPIR-V instruction, but we need to add the
DerivativeControl capability for the `fine` and `coarse` variants.

Also remove the capability from the regular dpdx and dpdy instructions
which don't need it.

Bug: tint:1906
Change-Id: Iad71dad2f2f824cb59bbd2cd2c5f47148344591d
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/142029
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>
Reviewed-by: Dan Sinclair <dsinclair@chromium.org>
Commit-Queue: James Price <jrprice@google.com>

src/tint/lang/spirv/writer/generator_impl_ir.cc

diff --git a/src/tint/lang/spirv/writer/generator_impl_ir.cc b/src/tint/lang/spirv/writer/generator_impl_ir.cc
index a1f7ace..2d7942b 100644
--- a/src/tint/lang/spirv/writer/generator_impl_ir.cc
+++ b/src/tint/lang/spirv/writer/generator_impl_ir.cc
@@ -1208,7 +1208,6 @@
             glsl_ext_inst(GLSLstd450Distance);
             break;
         case builtin::Function::kDpdx:
-            module_.PushCapability(SpvCapabilityDerivativeControl);
             op = spv::Op::OpDPdx;
             break;
         case builtin::Function::kDpdxCoarse:
@@ -1220,7 +1219,6 @@
             op = spv::Op::OpDPdxFine;
             break;
         case builtin::Function::kDpdy:
-            module_.PushCapability(SpvCapabilityDerivativeControl);
             op = spv::Op::OpDPdy;
             break;
         case builtin::Function::kDpdyCoarse:
@@ -1253,6 +1251,17 @@
         case builtin::Function::kFrexp:
             glsl_ext_inst(GLSLstd450FrexpStruct);
             break;
+        case builtin::Function::kFwidth:
+            op = spv::Op::OpFwidth;
+            break;
+        case builtin::Function::kFwidthCoarse:
+            module_.PushCapability(SpvCapabilityDerivativeControl);
+            op = spv::Op::OpFwidthCoarse;
+            break;
+        case builtin::Function::kFwidthFine:
+            module_.PushCapability(SpvCapabilityDerivativeControl);
+            op = spv::Op::OpFwidthFine;
+            break;
         case builtin::Function::kInsertBits:
             op = spv::Op::OpBitFieldInsert;
             break;

src/tint/lang/spirv/writer/generator_impl_ir_builtin_test.cc

diff --git a/src/tint/lang/spirv/writer/generator_impl_ir_builtin_test.cc b/src/tint/lang/spirv/writer/generator_impl_ir_builtin_test.cc
index 7880ee1..561dd2a 100644
--- a/src/tint/lang/spirv/writer/generator_impl_ir_builtin_test.cc
+++ b/src/tint/lang/spirv/writer/generator_impl_ir_builtin_test.cc
@@ -98,6 +98,9 @@
                     BuiltinTestCase{kF16, builtin::Function::kFloor, "Floor"},
                     BuiltinTestCase{kF32, builtin::Function::kFract, "Fract"},
                     BuiltinTestCase{kF16, builtin::Function::kFract, "Fract"},
+                    BuiltinTestCase{kF32, builtin::Function::kFwidth, "OpFwidth"},
+                    BuiltinTestCase{kF32, builtin::Function::kFwidthCoarse, "OpFwidthCoarse"},
+                    BuiltinTestCase{kF32, builtin::Function::kFwidthFine, "OpFwidthFine"},
                     BuiltinTestCase{kF32, builtin::Function::kInverseSqrt, "InverseSqrt"},
                     BuiltinTestCase{kF16, builtin::Function::kInverseSqrt, "InverseSqrt"},
                     BuiltinTestCase{kF32, builtin::Function::kLog, "Log"},