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[HLSL] Cleanup TargetInfo handling #90694

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Merged
merged 2 commits into from
May 2, 2024
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[HLSL] Cleanup TargetInfo handling #90694

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2464bcb
[NFC][HLSL] Cleanup TargetInfo handling
llvm-beanz May 1, 2024
3301513
Add test for sizeof(half)
llvm-beanz May 1, 2024
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10 changes: 1 addition & 9 deletions clang/lib/AST/ASTContext.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1612,15 +1612,7 @@ const llvm::fltSemantics &ASTContext::getFloatTypeSemantics(QualType T) const {
case BuiltinType::Float16:
return Target->getHalfFormat();
case BuiltinType::Half:
// For HLSL, when the native half type is disabled, half will be treat as
// float.
if (getLangOpts().HLSL)
if (getLangOpts().NativeHalfType)
return Target->getHalfFormat();
else
return Target->getFloatFormat();
else
return Target->getHalfFormat();
return Target->getHalfFormat();
case BuiltinType::Float: return Target->getFloatFormat();
case BuiltinType::Double: return Target->getDoubleFormat();
case BuiltinType::Ibm128:
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10 changes: 10 additions & 0 deletions clang/lib/Basic/TargetInfo.cpp
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Expand Up @@ -406,6 +406,16 @@ void TargetInfo::adjust(DiagnosticsEngine &Diags, LangOptions &Opts) {
LongDoubleAlign = 64;
}

// HLSL explicitly defines the sizes and formats of some data types, and we
// need to conform to those regardless of what architecture you are targeting.
if (Opts.HLSL) {
LongWidth = LongAlign = 64;
if (!Opts.NativeHalfType) {
HalfFormat = &llvm::APFloat::IEEEsingle();
HalfWidth = HalfAlign = 32;
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Just as a note, we don't actually use this value anywhere in the HLSL code generation paths (yet), which is why it wasn't causing problems that we overrode the format returned by the AST context, but didn't override these values.

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Is there a test case we can add for this?

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Yes, and I totally glossed over that this fixes a bug. Without this line sizeof(half) returns the wrong value.

}
}

if (Opts.OpenCL) {
// OpenCL C requires specific widths for types, irrespective of
// what these normally are for the target.
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1 change: 0 additions & 1 deletion clang/lib/Basic/Targets/DirectX.h
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Expand Up @@ -53,7 +53,6 @@ class LLVM_LIBRARY_VISIBILITY DirectXTargetInfo : public TargetInfo {
: TargetInfo(Triple) {
TLSSupported = false;
VLASupported = false;
LongWidth = LongAlign = 64;
AddrSpaceMap = &DirectXAddrSpaceMap;
UseAddrSpaceMapMangling = true;
HasLegalHalfType = true;
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11 changes: 11 additions & 0 deletions clang/test/SemaHLSL/Types/Arithmetic/half_size.hlsl
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@@ -0,0 +1,11 @@
// RUN: %clang_cc1 -triple dxil-pc-shadermodel6.4-library -verify %s
// RUN: %clang_cc1 -triple dxil-pc-shadermodel6.4-library -verify -fnative-half-type %s
// RUN: %clang_cc1 -triple spirv-linux-vulkan-library -verify %s
// RUN: %clang_cc1 -triple spirv-linux-vulkan-library -verify -fnative-half-type %s

// expected-no-diagnostics
#ifdef __HLSL_ENABLE_16_BIT
_Static_assert(sizeof(half) == 2, "half is 2 bytes");
#else
_Static_assert(sizeof(half) == 4, "half is 4 bytes");
#endif
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