Add refract intrinsic

See: https://github.com/gpuweb/gpuweb/pull/1901

Bug: tint:950
Change-Id: I6f00ab753a2ddf2374352ddf636e1abfebe86ba7
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/56777
Kokoro: Kokoro <noreply+kokoro@google.com>
Commit-Queue: Ben Clayton <bclayton@google.com>
Reviewed-by: Antonio Maiorano <amaiorano@google.com>

src/intrinsics.def

@@ -354,6 +354,7 @@ fn pow(f32, f32) -> f32
 fn pow<N: num>(vec<N, f32>, vec<N, f32>) -> vec<N, f32>
 fn reflect(f32, f32) -> f32
 fn reflect<N: num>(vec<N, f32>, vec<N, f32>) -> vec<N, f32>
+fn refract<N: num>(vec<N, f32>, vec<N, f32>, f32) -> vec<N, f32>
 fn reverseBits<T: iu32>(T) -> T
 fn reverseBits<N: num, T: iu32>(vec<N, T>) -> vec<N, T>
 fn round(f32) -> f32

src/reader/spirv/function.cc

@@ -365,6 +365,8 @@ std::string GetGlslStd450FuncName(uint32_t ext_opcode) {
       return "sign";
     case GLSLstd450Reflect:
       return "reflect";
+    case GLSLstd450Refract:
+      return "refract";
     case GLSLstd450Round:
     case GLSLstd450RoundEven:
       return "round";
@@ -419,8 +421,6 @@ std::string GetGlslStd450FuncName(uint32_t ext_opcode) {
     case GLSLstd450PackDouble2x32:
     case GLSLstd450UnpackDouble2x32:
 
-    case GLSLstd450Refract:
-
     case GLSLstd450FindILsb:
     case GLSLstd450FindSMsb:
     case GLSLstd450FindUMsb:
@@ -1055,9 +1055,8 @@ void FunctionEmitter::IncrementLocation(ast::DecorationList* decos) {
   }
 }
 
-ast::Decoration* FunctionEmitter::SetLocation(
-    ast::DecorationList* decos,
-    ast::Decoration* replacement) {
+ast::Decoration* FunctionEmitter::SetLocation(ast::DecorationList* decos,
+                                              ast::Decoration* replacement) {
   if (!replacement) {
     return nullptr;
   }

src/sem/intrinsic_type.cc

@@ -193,6 +193,9 @@ IntrinsicType ParseIntrinsicType(const std::string& name) {
   if (name == "reflect") {
     return IntrinsicType::kReflect;
   }
+  if (name == "refract") {
+    return IntrinsicType::kRefract;
+  }
   if (name == "reverseBits") {
     return IntrinsicType::kReverseBits;
   }
@@ -436,6 +439,8 @@ const char* str(IntrinsicType i) {
       return "pow";
     case IntrinsicType::kReflect:
       return "reflect";
+    case IntrinsicType::kRefract:
+      return "refract";
     case IntrinsicType::kReverseBits:
       return "reverseBits";
     case IntrinsicType::kRound:

src/sem/intrinsic_type.h

@@ -88,6 +88,7 @@ enum class IntrinsicType {
   kPack4x8unorm,
   kPow,
   kReflect,
+  kRefract,
   kReverseBits,
   kRound,
   kSelect,

src/writer/hlsl/generator_impl.cc

@@ -1840,6 +1840,7 @@ std::string GeneratorImpl::generate_builtin_name(
     case sem::IntrinsicType::kNormalize:
     case sem::IntrinsicType::kPow:
     case sem::IntrinsicType::kReflect:
+    case sem::IntrinsicType::kRefract:
     case sem::IntrinsicType::kRound:
     case sem::IntrinsicType::kSign:
     case sem::IntrinsicType::kSin:

src/writer/msl/generator_impl.cc

@@ -832,6 +832,7 @@ std::string GeneratorImpl::generate_builtin_name(
     case sem::IntrinsicType::kNormalize:
     case sem::IntrinsicType::kPow:
     case sem::IntrinsicType::kReflect:
+    case sem::IntrinsicType::kRefract:
     case sem::IntrinsicType::kSelect:
     case sem::IntrinsicType::kSin:
     case sem::IntrinsicType::kSinh:

src/writer/spirv/builder.cc

@@ -209,6 +209,8 @@ uint32_t intrinsic_to_glsl_method(const sem::Intrinsic* intrinsic) {
       return GLSLstd450Pow;
     case IntrinsicType::kReflect:
       return GLSLstd450Reflect;
+    case IntrinsicType::kRefract:
+      return GLSLstd450Refract;
     case IntrinsicType::kRound:
       return GLSLstd450RoundEven;
     case IntrinsicType::kSign:

test/intrinsics/gen/refract/7e02e6.wgsl

@@ -0,0 +1,45 @@
+// Copyright 2021 The Tint Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+////////////////////////////////////////////////////////////////////////////////
+// File generated by tools/intrinsic-gen
+// using the template:
+//   test/intrinsics/intrinsics.wgsl.tmpl
+// and the intrinsic defintion file:
+//   src/intrinsics.def
+//
+// Do not modify this file directly
+////////////////////////////////////////////////////////////////////////////////
+
+
+// fn refract(vec<4, f32>, vec<4, f32>, f32) -> vec<4, f32>
+fn refract_7e02e6() {
+  var res: vec4<f32> = refract(vec4<f32>(), vec4<f32>(), 1.0);
+}
+
+[[stage(vertex)]]
+fn vertex_main() -> [[builtin(position)]] vec4<f32> {
+  refract_7e02e6();
+  return vec4<f32>();
+}
+
+[[stage(fragment)]]
+fn fragment_main() {
+  refract_7e02e6();
+}
+
+[[stage(compute), workgroup_size(1)]]
+fn compute_main() {
+  refract_7e02e6();
+}

test/intrinsics/gen/refract/7e02e6.wgsl.expected.hlsl

@@ -0,0 +1,24 @@
+void refract_7e02e6() {
+  float4 res = refract(float4(0.0f, 0.0f, 0.0f, 0.0f), float4(0.0f, 0.0f, 0.0f, 0.0f), 1.0f);
+}
+
+struct tint_symbol {
+  float4 value : SV_Position;
+};
+
+tint_symbol vertex_main() {
+  refract_7e02e6();
+  const tint_symbol tint_symbol_1 = {float4(0.0f, 0.0f, 0.0f, 0.0f)};
+  return tint_symbol_1;
+}
+
+void fragment_main() {
+  refract_7e02e6();
+  return;
+}
+
+[numthreads(1, 1, 1)]
+void compute_main() {
+  refract_7e02e6();
+  return;
+}

test/intrinsics/gen/refract/7e02e6.wgsl.expected.msl

@@ -0,0 +1,27 @@
+#include <metal_stdlib>
+
+using namespace metal;
+struct tint_symbol {
+  float4 value [[position]];
+};
+
+void refract_7e02e6() {
+  float4 res = refract(float4(), float4(), 1.0f);
+}
+
+vertex tint_symbol vertex_main() {
+  refract_7e02e6();
+  tint_symbol const tint_symbol_1 = {.value=float4()};
+  return tint_symbol_1;
+}
+
+fragment void fragment_main() {
+  refract_7e02e6();
+  return;
+}
+
+kernel void compute_main() {
+  refract_7e02e6();
+  return;
+}
+

test/intrinsics/gen/refract/7e02e6.wgsl.expected.spvasm

@@ -0,0 +1,67 @@
+; SPIR-V
+; Version: 1.3
+; Generator: Google Tint Compiler; 0
+; Bound: 32
+; Schema: 0
+               OpCapability Shader
+         %14 = OpExtInstImport "GLSL.std.450"
+               OpMemoryModel Logical GLSL450
+               OpEntryPoint Vertex %vertex_main "vertex_main" %tint_pointsize %tint_symbol_1
+               OpEntryPoint Fragment %fragment_main "fragment_main"
+               OpEntryPoint GLCompute %compute_main "compute_main"
+               OpExecutionMode %fragment_main OriginUpperLeft
+               OpExecutionMode %compute_main LocalSize 1 1 1
+               OpName %tint_pointsize "tint_pointsize"
+               OpName %tint_symbol_1 "tint_symbol_1"
+               OpName %refract_7e02e6 "refract_7e02e6"
+               OpName %res "res"
+               OpName %tint_symbol_2 "tint_symbol_2"
+               OpName %tint_symbol "tint_symbol"
+               OpName %vertex_main "vertex_main"
+               OpName %fragment_main "fragment_main"
+               OpName %compute_main "compute_main"
+               OpDecorate %tint_pointsize BuiltIn PointSize
+               OpDecorate %tint_symbol_1 BuiltIn Position
+      %float = OpTypeFloat 32
+%_ptr_Output_float = OpTypePointer Output %float
+          %4 = OpConstantNull %float
+%tint_pointsize = OpVariable %_ptr_Output_float Output %4
+    %v4float = OpTypeVector %float 4
+%_ptr_Output_v4float = OpTypePointer Output %v4float
+          %8 = OpConstantNull %v4float
+%tint_symbol_1 = OpVariable %_ptr_Output_v4float Output %8
+       %void = OpTypeVoid
+          %9 = OpTypeFunction %void
+    %float_1 = OpConstant %float 1
+%_ptr_Function_v4float = OpTypePointer Function %v4float
+         %18 = OpTypeFunction %void %v4float
+%refract_7e02e6 = OpFunction %void None %9
+         %12 = OpLabel
+        %res = OpVariable %_ptr_Function_v4float Function %8
+         %13 = OpExtInst %v4float %14 Refract %8 %8 %float_1
+               OpStore %res %13
+               OpReturn
+               OpFunctionEnd
+%tint_symbol_2 = OpFunction %void None %18
+%tint_symbol = OpFunctionParameter %v4float
+         %21 = OpLabel
+               OpStore %tint_symbol_1 %tint_symbol
+               OpReturn
+               OpFunctionEnd
+%vertex_main = OpFunction %void None %9
+         %23 = OpLabel
+               OpStore %tint_pointsize %float_1
+         %24 = OpFunctionCall %void %refract_7e02e6
+         %25 = OpFunctionCall %void %tint_symbol_2 %8
+               OpReturn
+               OpFunctionEnd
+%fragment_main = OpFunction %void None %9
+         %27 = OpLabel
+         %28 = OpFunctionCall %void %refract_7e02e6
+               OpReturn
+               OpFunctionEnd
+%compute_main = OpFunction %void None %9
+         %30 = OpLabel
+         %31 = OpFunctionCall %void %refract_7e02e6
+               OpReturn
+               OpFunctionEnd

test/intrinsics/gen/refract/7e02e6.wgsl.expected.wgsl

@@ -0,0 +1,19 @@
+fn refract_7e02e6() {
+  var res : vec4<f32> = refract(vec4<f32>(), vec4<f32>(), 1.0);
+}
+
+[[stage(vertex)]]
+fn vertex_main() -> [[builtin(position)]] vec4<f32> {
+  refract_7e02e6();
+  return vec4<f32>();
+}
+
+[[stage(fragment)]]
+fn fragment_main() {
+  refract_7e02e6();
+}
+
+[[stage(compute), workgroup_size(1)]]
+fn compute_main() {
+  refract_7e02e6();
+}

test/intrinsics/gen/refract/cbc1d2.wgsl

@@ -0,0 +1,45 @@
+// Copyright 2021 The Tint Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+////////////////////////////////////////////////////////////////////////////////
+// File generated by tools/intrinsic-gen
+// using the template:
+//   test/intrinsics/intrinsics.wgsl.tmpl
+// and the intrinsic defintion file:
+//   src/intrinsics.def
+//
+// Do not modify this file directly
+////////////////////////////////////////////////////////////////////////////////
+
+
+// fn refract(vec<3, f32>, vec<3, f32>, f32) -> vec<3, f32>
+fn refract_cbc1d2() {
+  var res: vec3<f32> = refract(vec3<f32>(), vec3<f32>(), 1.0);
+}
+
+[[stage(vertex)]]
+fn vertex_main() -> [[builtin(position)]] vec4<f32> {
+  refract_cbc1d2();
+  return vec4<f32>();
+}
+
+[[stage(fragment)]]
+fn fragment_main() {
+  refract_cbc1d2();
+}
+
+[[stage(compute), workgroup_size(1)]]
+fn compute_main() {
+  refract_cbc1d2();
+}

test/intrinsics/gen/refract/cbc1d2.wgsl.expected.hlsl

@@ -0,0 +1,24 @@
+void refract_cbc1d2() {
+  float3 res = refract(float3(0.0f, 0.0f, 0.0f), float3(0.0f, 0.0f, 0.0f), 1.0f);
+}
+
+struct tint_symbol {
+  float4 value : SV_Position;
+};
+
+tint_symbol vertex_main() {
+  refract_cbc1d2();
+  const tint_symbol tint_symbol_1 = {float4(0.0f, 0.0f, 0.0f, 0.0f)};
+  return tint_symbol_1;
+}
+
+void fragment_main() {
+  refract_cbc1d2();
+  return;
+}
+
+[numthreads(1, 1, 1)]
+void compute_main() {
+  refract_cbc1d2();
+  return;
+}

test/intrinsics/gen/refract/cbc1d2.wgsl.expected.msl

@@ -0,0 +1,27 @@
+#include <metal_stdlib>
+
+using namespace metal;
+struct tint_symbol {
+  float4 value [[position]];
+};
+
+void refract_cbc1d2() {
+  float3 res = refract(float3(), float3(), 1.0f);
+}
+
+vertex tint_symbol vertex_main() {
+  refract_cbc1d2();
+  tint_symbol const tint_symbol_1 = {.value=float4()};
+  return tint_symbol_1;
+}
+
+fragment void fragment_main() {
+  refract_cbc1d2();
+  return;
+}
+
+kernel void compute_main() {
+  refract_cbc1d2();
+  return;
+}
+

test/intrinsics/gen/refract/cbc1d2.wgsl.expected.spvasm

@@ -0,0 +1,69 @@
+; SPIR-V
+; Version: 1.3
+; Generator: Google Tint Compiler; 0
+; Bound: 34
+; Schema: 0
+               OpCapability Shader
+         %15 = OpExtInstImport "GLSL.std.450"
+               OpMemoryModel Logical GLSL450
+               OpEntryPoint Vertex %vertex_main "vertex_main" %tint_pointsize %tint_symbol_1
+               OpEntryPoint Fragment %fragment_main "fragment_main"
+               OpEntryPoint GLCompute %compute_main "compute_main"
+               OpExecutionMode %fragment_main OriginUpperLeft
+               OpExecutionMode %compute_main LocalSize 1 1 1
+               OpName %tint_pointsize "tint_pointsize"
+               OpName %tint_symbol_1 "tint_symbol_1"
+               OpName %refract_cbc1d2 "refract_cbc1d2"
+               OpName %res "res"
+               OpName %tint_symbol_2 "tint_symbol_2"
+               OpName %tint_symbol "tint_symbol"
+               OpName %vertex_main "vertex_main"
+               OpName %fragment_main "fragment_main"
+               OpName %compute_main "compute_main"
+               OpDecorate %tint_pointsize BuiltIn PointSize
+               OpDecorate %tint_symbol_1 BuiltIn Position
+      %float = OpTypeFloat 32
+%_ptr_Output_float = OpTypePointer Output %float
+          %4 = OpConstantNull %float
+%tint_pointsize = OpVariable %_ptr_Output_float Output %4
+    %v4float = OpTypeVector %float 4
+%_ptr_Output_v4float = OpTypePointer Output %v4float
+          %8 = OpConstantNull %v4float
+%tint_symbol_1 = OpVariable %_ptr_Output_v4float Output %8
+       %void = OpTypeVoid
+          %9 = OpTypeFunction %void
+    %v3float = OpTypeVector %float 3
+         %16 = OpConstantNull %v3float
+    %float_1 = OpConstant %float 1
+%_ptr_Function_v3float = OpTypePointer Function %v3float
+         %20 = OpTypeFunction %void %v4float
+%refract_cbc1d2 = OpFunction %void None %9
+         %12 = OpLabel
+        %res = OpVariable %_ptr_Function_v3float Function %16
+         %13 = OpExtInst %v3float %15 Refract %16 %16 %float_1
+               OpStore %res %13
+               OpReturn
+               OpFunctionEnd
+%tint_symbol_2 = OpFunction %void None %20
+%tint_symbol = OpFunctionParameter %v4float
+         %23 = OpLabel
+               OpStore %tint_symbol_1 %tint_symbol
+               OpReturn
+               OpFunctionEnd
+%vertex_main = OpFunction %void None %9
+         %25 = OpLabel
+               OpStore %tint_pointsize %float_1
+         %26 = OpFunctionCall %void %refract_cbc1d2
+         %27 = OpFunctionCall %void %tint_symbol_2 %8
+               OpReturn
+               OpFunctionEnd
+%fragment_main = OpFunction %void None %9
+         %29 = OpLabel
+         %30 = OpFunctionCall %void %refract_cbc1d2
+               OpReturn
+               OpFunctionEnd
+%compute_main = OpFunction %void None %9
+         %32 = OpLabel
+         %33 = OpFunctionCall %void %refract_cbc1d2
+               OpReturn
+               OpFunctionEnd

test/intrinsics/gen/refract/cbc1d2.wgsl.expected.wgsl

@@ -0,0 +1,19 @@
+fn refract_cbc1d2() {
+  var res : vec3<f32> = refract(vec3<f32>(), vec3<f32>(), 1.0);
+}
+
+[[stage(vertex)]]
+fn vertex_main() -> [[builtin(position)]] vec4<f32> {
+  refract_cbc1d2();
+  return vec4<f32>();
+}
+
+[[stage(fragment)]]
+fn fragment_main() {
+  refract_cbc1d2();
+}
+
+[[stage(compute), workgroup_size(1)]]
+fn compute_main() {
+  refract_cbc1d2();
+}

test/intrinsics/gen/refract/cd905f.wgsl

@@ -0,0 +1,45 @@
+// Copyright 2021 The Tint Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+////////////////////////////////////////////////////////////////////////////////
+// File generated by tools/intrinsic-gen
+// using the template:
+//   test/intrinsics/intrinsics.wgsl.tmpl
+// and the intrinsic defintion file:
+//   src/intrinsics.def
+//
+// Do not modify this file directly
+////////////////////////////////////////////////////////////////////////////////
+
+
+// fn refract(vec<2, f32>, vec<2, f32>, f32) -> vec<2, f32>
+fn refract_cd905f() {
+  var res: vec2<f32> = refract(vec2<f32>(), vec2<f32>(), 1.0);
+}
+
+[[stage(vertex)]]
+fn vertex_main() -> [[builtin(position)]] vec4<f32> {
+  refract_cd905f();
+  return vec4<f32>();
+}
+
+[[stage(fragment)]]
+fn fragment_main() {
+  refract_cd905f();
+}
+
+[[stage(compute), workgroup_size(1)]]
+fn compute_main() {
+  refract_cd905f();
+}

test/intrinsics/gen/refract/cd905f.wgsl.expected.hlsl

@@ -0,0 +1,24 @@
+void refract_cd905f() {
+  float2 res = refract(float2(0.0f, 0.0f), float2(0.0f, 0.0f), 1.0f);
+}
+
+struct tint_symbol {
+  float4 value : SV_Position;
+};
+
+tint_symbol vertex_main() {
+  refract_cd905f();
+  const tint_symbol tint_symbol_1 = {float4(0.0f, 0.0f, 0.0f, 0.0f)};
+  return tint_symbol_1;
+}
+
+void fragment_main() {
+  refract_cd905f();
+  return;
+}
+
+[numthreads(1, 1, 1)]
+void compute_main() {
+  refract_cd905f();
+  return;
+}

test/intrinsics/gen/refract/cd905f.wgsl.expected.msl

@@ -0,0 +1,27 @@
+#include <metal_stdlib>
+
+using namespace metal;
+struct tint_symbol {
+  float4 value [[position]];
+};
+
+void refract_cd905f() {
+  float2 res = refract(float2(), float2(), 1.0f);
+}
+
+vertex tint_symbol vertex_main() {
+  refract_cd905f();
+  tint_symbol const tint_symbol_1 = {.value=float4()};
+  return tint_symbol_1;
+}
+
+fragment void fragment_main() {
+  refract_cd905f();
+  return;
+}
+
+kernel void compute_main() {
+  refract_cd905f();
+  return;
+}
+

test/intrinsics/gen/refract/cd905f.wgsl.expected.spvasm

@@ -0,0 +1,69 @@
+; SPIR-V
+; Version: 1.3
+; Generator: Google Tint Compiler; 0
+; Bound: 34
+; Schema: 0
+               OpCapability Shader
+         %15 = OpExtInstImport "GLSL.std.450"
+               OpMemoryModel Logical GLSL450
+               OpEntryPoint Vertex %vertex_main "vertex_main" %tint_pointsize %tint_symbol_1
+               OpEntryPoint Fragment %fragment_main "fragment_main"
+               OpEntryPoint GLCompute %compute_main "compute_main"
+               OpExecutionMode %fragment_main OriginUpperLeft
+               OpExecutionMode %compute_main LocalSize 1 1 1
+               OpName %tint_pointsize "tint_pointsize"
+               OpName %tint_symbol_1 "tint_symbol_1"
+               OpName %refract_cd905f "refract_cd905f"
+               OpName %res "res"
+               OpName %tint_symbol_2 "tint_symbol_2"
+               OpName %tint_symbol "tint_symbol"
+               OpName %vertex_main "vertex_main"
+               OpName %fragment_main "fragment_main"
+               OpName %compute_main "compute_main"
+               OpDecorate %tint_pointsize BuiltIn PointSize
+               OpDecorate %tint_symbol_1 BuiltIn Position
+      %float = OpTypeFloat 32
+%_ptr_Output_float = OpTypePointer Output %float
+          %4 = OpConstantNull %float
+%tint_pointsize = OpVariable %_ptr_Output_float Output %4
+    %v4float = OpTypeVector %float 4
+%_ptr_Output_v4float = OpTypePointer Output %v4float
+          %8 = OpConstantNull %v4float
+%tint_symbol_1 = OpVariable %_ptr_Output_v4float Output %8
+       %void = OpTypeVoid
+          %9 = OpTypeFunction %void
+    %v2float = OpTypeVector %float 2
+         %16 = OpConstantNull %v2float
+    %float_1 = OpConstant %float 1
+%_ptr_Function_v2float = OpTypePointer Function %v2float
+         %20 = OpTypeFunction %void %v4float
+%refract_cd905f = OpFunction %void None %9
+         %12 = OpLabel
+        %res = OpVariable %_ptr_Function_v2float Function %16
+         %13 = OpExtInst %v2float %15 Refract %16 %16 %float_1
+               OpStore %res %13
+               OpReturn
+               OpFunctionEnd
+%tint_symbol_2 = OpFunction %void None %20
+%tint_symbol = OpFunctionParameter %v4float
+         %23 = OpLabel
+               OpStore %tint_symbol_1 %tint_symbol
+               OpReturn
+               OpFunctionEnd
+%vertex_main = OpFunction %void None %9
+         %25 = OpLabel
+               OpStore %tint_pointsize %float_1
+         %26 = OpFunctionCall %void %refract_cd905f
+         %27 = OpFunctionCall %void %tint_symbol_2 %8
+               OpReturn
+               OpFunctionEnd
+%fragment_main = OpFunction %void None %9
+         %29 = OpLabel
+         %30 = OpFunctionCall %void %refract_cd905f
+               OpReturn
+               OpFunctionEnd
+%compute_main = OpFunction %void None %9
+         %32 = OpLabel
+         %33 = OpFunctionCall %void %refract_cd905f
+               OpReturn
+               OpFunctionEnd

test/intrinsics/gen/refract/cd905f.wgsl.expected.wgsl

@@ -0,0 +1,19 @@
+fn refract_cd905f() {
+  var res : vec2<f32> = refract(vec2<f32>(), vec2<f32>(), 1.0);
+}
+
+[[stage(vertex)]]
+fn vertex_main() -> [[builtin(position)]] vec4<f32> {
+  refract_cd905f();
+  return vec4<f32>();
+}
+
+[[stage(fragment)]]
+fn fragment_main() {
+  refract_cd905f();
+}
+
+[[stage(compute), workgroup_size(1)]]
+fn compute_main() {
+  refract_cd905f();
+}