[SPIRV] Use OpCopyLogical to reconstruct values (microsoft#7530)

When DXC needs to change the layout of a value, it currently has to
extract each individual scalar, and then reconstruct using the type with
the different layout.

If you have a large array or struct with many member, this generates a
lot of extra code.

Starting in SPIR-V 1.4, the OpCopyLogical instruction is available to do
the reconstruction.

This should help generate less code, which will lead to improved compile
time and maybe smaller binary sizes.

Fixes microsoft#7493

Author: s-perron

tools/clang/include/clang/SPIRV/AstTypeProbe.h

@@ -337,6 +337,10 @@ bool isOrContainsNonFpColMajorMatrix(const ASTContext &,
                                      const SpirvCodeGenOptions &, QualType type,
                                      const Decl *decl);
 
+/// brief Returns true if the type is a boolean type or an aggragate type that
+/// contains a boolean type.
+bool isOrContainsBoolType(QualType type);
+
 /// \brief Returns true if the given type is `vk::ext_result_id<T>`.
 bool isExtResultIdType(QualType type);
 

tools/clang/lib/SPIRV/AstTypeProbe.cpp

@@ -1353,6 +1353,27 @@ bool isOrContainsNonFpColMajorMatrix(const ASTContext &astContext,
   return false;
 }
 
+bool isOrContainsBoolType(QualType type) {
+  if (isBoolOrVecMatOfBoolType(type)) {
+    return true;
+  }
+
+  if (const auto *arrayType = type->getAsArrayTypeUnsafe()) {
+    return isOrContainsBoolType(arrayType->getElementType());
+  }
+
+  if (const auto *recordType = type->getAs<RecordType>()) {
+    for (auto field : recordType->getDecl()->fields()) {
+      if (isOrContainsBoolType(field->getType())) {
+        return true;
+      }
+    }
+    return false;
+  }
+
+  return false;
+}
+
 bool isTypeInVkNamespace(const RecordType *type) {
   if (const auto *nameSpaceDecl =
           dyn_cast<NamespaceDecl>(type->getDecl()->getDeclContext())) {

tools/clang/lib/SPIRV/SpirvEmitter.cpp

@@ -7108,6 +7108,38 @@ void SpirvEmitter::storeValue(SpirvInstruction *lhsPtr,
   }
 }
 
+bool SpirvEmitter::canUseOpCopyLogical(QualType type) const {
+  if (featureManager.getSpirvVersion(featureManager.getTargetEnv()) <
+      VersionTuple(1, 4)) {
+    return false;
+  }
+
+  if (!type->isArrayType() && !type->isRecordType()) {
+    return false;
+  }
+
+  if (const auto *recordType = type->getAs<RecordType>()) {
+    if (isTypeInVkNamespace(recordType) &&
+        (recordType->getDecl()->getName().equals("BufferPointer") ||
+         recordType->getDecl()->getName().equals("SpirvType") ||
+         recordType->getDecl()->getName().equals("SpirvOpaqueType"))) {
+      // vk::BufferPointer<T> lowers to a pointer type. No need to reconstruct
+      // the value. The vk::Spirv*Type should be treated an opaque type. All we
+      // can do is leave it the same.
+      return false;
+    }
+  }
+
+  if (hlsl::IsHLSLVecMatType(type) || hlsl::IsHLSLResourceType(type)) {
+    return false;
+  }
+
+  // If the type contains a bool it is possible that one type represents it with
+  // a bool and the other with an int. If that happens, OpCopyLogical is not
+  // valid.
+  return !isOrContainsBoolType(type);
+}
+
 SpirvInstruction *SpirvEmitter::reconstructValue(SpirvInstruction *srcVal,
                                                  const QualType valType,
                                                  SpirvLayoutRule dstLR,
@@ -7171,6 +7203,13 @@ SpirvInstruction *SpirvEmitter::reconstructValue(SpirvInstruction *srcVal,
     return result;
   };
 
+  if (canUseOpCopyLogical(valType)) {
+    SpirvInstruction *copy = spvBuilder.createUnaryOp(
+        spv::Op::OpCopyLogical, valType, srcVal, srcVal->getSourceLocation());
+    copy->setLayoutRule(dstLR);
+    return copy;
+  }
+
   // Constant arrays
   if (const auto *arrayType = astContext.getAsConstantArrayType(valType)) {
     const auto elemType = arrayType->getElementType();

tools/clang/lib/SPIRV/SpirvEmitter.h

@@ -228,6 +228,8 @@ class SpirvEmitter : public ASTConsumer {
                   QualType lhsValType, SourceLocation loc,
                   SourceRange range = {});
 
+  bool canUseOpCopyLogical(QualType type) const;
+
   /// Decomposes and reconstructs the given srcVal of the given valType to meet
   /// the requirements of the dstLR layout rule.
   SpirvInstruction *reconstructValue(SpirvInstruction *srcVal, QualType valType,

tools/clang/test/CodeGenSPIRV/logical_copy.hlsl

@@ -0,0 +1,67 @@
+// RUN: %dxc %s -fcgl -spirv -T ps_6_8 -fspv-target-env=vulkan1.1spirv1.4 | FileCheck %s
+
+
+
+struct WithBool {
+  bool b;
+};
+
+struct StructWithBool {
+  WithBool wb;
+};
+
+struct StructWithoutBool {
+  int a;
+};
+
+struct OuterStruct {
+  StructWithBool a[2];
+  WithBool b;
+  StructWithoutBool c;
+  StructWithoutBool d[2];
+} S;
+
+
+// CHECK: %GetStruct = OpFunction %OuterStruct_0 None %34
+// CHECK: %bb_entry_0 = OpLabel
+// CHECK: [[ld:%[0-9]+]] = OpLoad %OuterStruct %39
+
+// The array `a` must be split up because it contains a bool that needs a
+// conversion from int to bool.
+// CHECK: [[arr_with_bool:%[0-9]+]] = OpCompositeExtract %_arr_StructWithBool_uint_2 [[ld]] 0
+// CHECK: [[struct_with_bool:%[0-9]+]] = OpCompositeExtract %StructWithBool [[arr_with_bool]] 0
+// CHECK: [[with_bool:%[0-9]+]] = OpCompositeExtract %WithBool [[struct_with_bool]] 0
+// CHECK: [[int:%[0-9]+]] = OpCompositeExtract %uint [[with_bool]] 0
+// CHECK: [[bool:%[0-9]+]] = OpINotEqual %bool [[int]] %uint_0
+// CHECK: [[with_bool:%[0-9]+]] = OpCompositeConstruct %WithBool_0 [[bool]]
+// CHECK: [[struct_with_bool:%[0-9]+]] = OpCompositeConstruct %StructWithBool_0 [[with_bool]]
+
+// Skip second element of the array. It is more of the same.
+// CHECK: [[a:%[0-9]+]] = OpCompositeConstruct %_arr_StructWithBool_0_uint_2 [[struct_with_bool]] {{%.*}}
+
+// The struct `b` must be split up for the same reason.
+// CHECK: [[with_bool:%[0-9]+]] = OpCompositeExtract %WithBool [[ld]] 1
+// CHECK: [[int:%[0-9]+]] = OpCompositeExtract %uint [[with_bool]] 0
+// CHECK: [[bool:%[0-9]+]] = OpINotEqual %bool [[int]] %uint_0
+// CHECK: [[b:%[0-9]+]] = OpCompositeConstruct %WithBool_0 [[bool]]
+
+// The struct `c` can use OpCopyLogical.
+// CHECK: %59 = OpCompositeExtract %StructWithoutBool [[ld]] 2
+// CHECK: [[c:%[0-9]+]] = OpCopyLogical %StructWithoutBool_0 %59
+
+// The array `d` can use OpCopyLogical.
+// CHECK: %61 = OpCompositeExtract %_arr_StructWithoutBool_uint_2 [[ld]] 3
+// CHECK: [[d:%[0-9]+]] = OpCopyLogical %_arr_StructWithoutBool_0_uint_2 %61
+
+// CHECK: [[r:%[0-9]+]] = OpCompositeConstruct %OuterStruct_0 [[a]] [[b]] [[c]] [[d]]
+// CHECK: OpStore {{%.*}} [[r]]
+// CHECK: OpFunctionEnd
+
+OuterStruct GetStruct() { return S; }
+
+uint main() : SV_TARGET
+{
+  GetStruct();
+  return 0;
+}
+