[clang] [llvm] Adding splitdouble HLSL function (PR #109331)

[Tex Riddell via cfe-commits]

================
@@ -0,0 +1,98 @@
+// RUN: %clang_cc1 -finclude-default-header -x hlsl -triple dxil-pc-shadermodel6.3-library %s -fnative-half-type -emit-llvm -O1 -o - | FileCheck %s
+// RUN: %clang_cc1 -finclude-default-header -x hlsl -triple spirv-vulkan-library %s -fnative-half-type -emit-llvm -O0 -o - | FileCheck %s --check-prefix=SPIRV
+
+
+
+// CHECK: define {{.*}} i32 {{.*}}test_scalar{{.*}}(double {{.*}} [[VALD:%.*]])
+// CHECK: [[VALRET:%.*]] = {{.*}} call { i32, i32 } @llvm.dx.splitdouble.i32(double [[VALD]])
+// CHECK-NEXT: extractvalue { i32, i32 } [[VALRET]], 0
+// CHECK-NEXT: extractvalue { i32, i32 } [[VALRET]], 1
+// SPIRV: define spir_func {{.*}} i32 {{.*}}test_scalar{{.*}}(double {{.*}} [[VALD:%.*]])
+// SPIRV-NOT: @llvm.dx.splitdouble.i32
+// SPIRV: [[REG:%.*]] = load double, ptr [[VALD]].addr, align 8
+// SPIRV-NEXT: [[CAST:%.*]] = bitcast double [[REG]] to <2 x i32>
+// SPIRV-NEXT: extractelement <2 x i32> [[CAST]], i64 0
+// SPIRV-NEXT: extractelement <2 x i32> [[CAST]], i64 1
+uint test_scalar(double D) {
+  uint A, B;
+  asuint(D, A, B);
+  return A + B;
+}
+
+// CHECK: define {{.*}} i32 {{.*}}test_double1{{.*}}(<1 x double> {{.*}} [[VALD:%.*]])
+// CHECK: [[TRUNC:%.*]] = extractelement <1 x double> %D, i64 0
+// CHECK-NEXT: [[VALRET:%.*]] = {{.*}} call { i32, i32 } @llvm.dx.splitdouble.i32(double [[TRUNC]])
+// CHECK-NEXT: extractvalue { i32, i32 } [[VALRET]], 0
+// CHECK-NEXT: extractvalue { i32, i32 } [[VALRET]], 1
+// SPIRV: define spir_func {{.*}} i32 {{.*}}test_double1{{.*}}(<1 x double> {{.*}} [[VALD:%.*]])
+// SPIRV-NOT: @llvm.dx.splitdouble.i32
+// SPIRV: [[REG:%.*]] = load <1 x double>, ptr [[VALD]].addr, align 8
+// SPIRV-NEXT: [[TRUNC:%.*]] = extractelement <1 x double> %1, i64 0
+// SPIRV-NEXT: [[CAST:%.*]] = bitcast double [[TRUNC]] to <2 x i32>
+// SPIRV-NEXT: extractelement <2 x i32> [[CAST]], i64 0
+// SPIRV-NEXT: extractelement <2 x i32> [[CAST]], i64 1
+uint test_double1(double1 D) {
+  uint A, B;
+  asuint(D, A, B);
+  return A + B;
+}
+
+// CHECK: define {{.*}} <2 x i32> {{.*}}test_vector2{{.*}}(<2 x double> {{.*}} [[VALD:%.*]])
+// CHECK: [[VALRET:%.*]] = {{.*}} call { <2 x i32>, <2 x i32> } @llvm.dx.splitdouble.v2i32(<2 x double> [[VALD]])
+// CHECK-NEXT: extractvalue { <2 x i32>, <2 x i32> } [[VALRET]], 0
+// CHECK-NEXT: extractvalue { <2 x i32>, <2 x i32> } [[VALRET]], 1
+// SPIRV: define spir_func {{.*}} <2 x i32> {{.*}}test_vector2{{.*}}(<2 x double> {{.*}} [[VALD:%.*]])
+// SPIRV-NOT: @llvm.dx.splitdouble.i32
+// SPIRV: [[REG:%.*]] = load <2 x double>, ptr [[VALD]].addr, align 16
+// SPIRV-NEXT: [[CAST1:%.*]] = bitcast <2 x double> [[REG]] to <4 x i32>
+// SPIRV-NEXT: [[SHUF1:%.*]] = shufflevector <4 x i32> [[CAST1]], <4 x i32> poison, <2 x i32> <i32 0, i32 2>
+// SPIRV-NEXT: [[SHUF2:%.*]] = shufflevector <4 x i32> [[CAST1]], <4 x i32> poison, <2 x i32> <i32 1, i32 3>
+uint2 test_vector2(double2 D) {
+  uint2 A, B;
+  asuint(D, A, B);
+  return A + B;
+}
+
+// CHECK: define {{.*}} <3 x i32> {{.*}}test_vector3{{.*}}(<3 x double> {{.*}} [[VALD:%.*]])
+// CHECK: [[VALRET:%.*]] = {{.*}} call { <3 x i32>, <3 x i32> } @llvm.dx.splitdouble.v3i32(<3 x double> [[VALD]])
+// CHECK-NEXT: extractvalue { <3 x i32>, <3 x i32> } [[VALRET]], 0
+// CHECK-NEXT: extractvalue { <3 x i32>, <3 x i32> } [[VALRET]], 1
+// SPIRV: define spir_func {{.*}} <3 x i32> {{.*}}test_vector3{{.*}}(<3 x double> {{.*}} [[VALD:%.*]])
+// SPIRV-NOT: @llvm.dx.splitdouble.i32
+// SPIRV: [[REG:%.*]] = load <3 x double>, ptr [[VALD]].addr, align 32
+// SPIRV-NEXT: [[VALRET1:%.*]] = shufflevector <3 x double> [[REG]], <3 x double> poison, <2 x i32> <i32 0, i32 1>
+// SPIRV-NEXT: [[CAST1:%.*]] = bitcast <2 x double> [[VALRET1]] to <4 x i32>
+// SPIRV-NEXT: [[SHUF1:%.*]] = shufflevector <4 x i32> [[CAST1]], <4 x i32> poison, <2 x i32> <i32 0, i32 2>
+// SPIRV-NEXT: [[SHUF2:%.*]] = shufflevector <4 x i32> [[CAST1]], <4 x i32> poison, <2 x i32> <i32 1, i32 3>
+// SPIRV-NEXT: [[EXTRACT:%.*]] = extractelement <3 x double> [[REG]], i64 2
+// SPIRV-NEXT: [[CAST:%.*]] = bitcast double [[EXTRACT]] to <2 x i32>
+// SPIRV-NEXT: %[[#]] = shufflevector <2 x i32> [[SHUF1]], <2 x i32> [[CAST]], <3 x i32> <i32 0, i32 1, i32 2>
+// SPIRV-NEXT: %[[#]] = shufflevector <2 x i32> [[SHUF2]], <2 x i32> [[CAST]], <3 x i32> <i32 0, i32 1, i32 2>
----------------
tex3d wrote:

This shuffle does not look correct.  It should be selecting the second value from the second vector.  It's confusing because the first vector has already been shuffled into separate high/low vectors, but the second vector contains one high and one low component that needs indexing differently between these last two shuffles.
```suggestion
// SPIRV-NEXT: %[[#]] = shufflevector <2 x i32> [[SHUF2]], <2 x i32> [[CAST]], <3 x i32> <i32 0, i32 1, i32 3>
```

https://github.com/llvm/llvm-project/pull/109331