craig.topper updated this revision to Diff 214540.
craig.topper added a comment.
More test check lines. Test the compatibility flag.
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D64672/new/
https://reviews.llvm.org/D64672
Files:
clang/docs/ReleaseNotes.rst
clang/include/clang/Basic/LangOptions.h
clang/lib/CodeGen/TargetInfo.cpp
clang/lib/Frontend/CompilerInvocation.cpp
clang/test/CodeGen/pr42607.c
Index: clang/test/CodeGen/pr42607.c
===================================================================
--- /dev/null
+++ clang/test/CodeGen/pr42607.c
@@ -0,0 +1,22 @@
+// RUN: %clang_cc1 -triple x86_64-linux-gnu %s -target-feature +avx512f -S -emit-llvm -o - | FileCheck %s --check-prefix=NEWABI
+// RUN: %clang_cc1 -triple x86_64-apple-darwin %s -target-feature +avx512f -S -emit-llvm -o - | FileCheck %s --check-prefix=OLDABI
+// RUN: %clang_cc1 -triple x86_64-unknown-freebsd10.0 %s -target-feature +avx512f -S -emit-llvm -o - | FileCheck %s --check-prefix=OLDABI
+// RUN: %clang_cc1 -triple x86_64-linux-gnu %s -target-feature +avx512f -S -emit-llvm -o - -fclang-abi-compat=9 | FileCheck %s --check-prefix=OLDABI
+
+typedef unsigned long long v16u64 __attribute__((vector_size(16)));
+typedef unsigned __int128 v16u128 __attribute__((vector_size(16)));
+
+v16u64 bar(v16u64 a, v16u128 b) {
+// NEWABI: define <2 x i64> @bar(<2 x i64> %{{.*}}, <2 x i64> %{{.*}})
+// OLDABI: define <2 x i64> @bar(<2 x i64> %{{.*}}, <1 x i128> %{{.*}})
+ return a + (v16u64)b;
+}
+
+typedef unsigned long long v64u64 __attribute__((vector_size(64)));
+typedef unsigned __int128 v64u128 __attribute__((vector_size(64)));
+
+v64u64 foo(v64u64 a, v64u128 b) {
+// NEWABI: define <8 x i64> @foo(<8 x i64> %{{.*}}, <4 x i128>* byval(<4 x i128>) align 64 %{{.*}})
+// OLDABI: define <8 x i64> @foo(<8 x i64> %{{.*}}, <4 x i128> %{{.*}})
+ return a + (v64u64)b;
+}
Index: clang/lib/Frontend/CompilerInvocation.cpp
===================================================================
--- clang/lib/Frontend/CompilerInvocation.cpp
+++ clang/lib/Frontend/CompilerInvocation.cpp
@@ -3129,6 +3129,8 @@
Opts.setClangABICompat(LangOptions::ClangABI::Ver6);
else if (Major <= 7)
Opts.setClangABICompat(LangOptions::ClangABI::Ver7);
+ else if (Major <= 9)
+ Opts.setClangABICompat(LangOptions::ClangABI::Ver9);
} else if (Ver != "latest") {
Diags.Report(diag::err_drv_invalid_value)
<< A->getAsString(Args) << A->getValue();
Index: clang/lib/CodeGen/TargetInfo.cpp
===================================================================
--- clang/lib/CodeGen/TargetInfo.cpp
+++ clang/lib/CodeGen/TargetInfo.cpp
@@ -2177,6 +2177,17 @@
return true;
}
+ // GCC classifies vectors of __int128 as memory.
+ bool passInt128VectorsInMem() const {
+ // Clang <= 9.0 did not do this.
+ if (getContext().getLangOpts().getClangABICompat() <=
+ LangOptions::ClangABI::Ver9)
+ return false;
+
+ const llvm::Triple &T = getTarget().getTriple();
+ return T.isOSLinux() || T.isOSNetBSD();
+ }
+
X86AVXABILevel AVXLevel;
// Some ABIs (e.g. X32 ABI and Native Client OS) use 32 bit pointers on
// 64-bit hardware.
@@ -2657,6 +2668,14 @@
Hi = Lo;
} else if (Size == 128 ||
(isNamedArg && Size <= getNativeVectorSizeForAVXABI(AVXLevel))) {
+ QualType ElementType = VT->getElementType();
+
+ // gcc passes 256 and 512 bit <X x __int128> vectors in memory. :(
+ if (passInt128VectorsInMem() && Size != 128 &&
+ (ElementType->isSpecificBuiltinType(BuiltinType::Int128) ||
+ ElementType->isSpecificBuiltinType(BuiltinType::UInt128)))
+ return;
+
// Arguments of 256-bits are split into four eightbyte chunks. The
// least significant one belongs to class SSE and all the others to class
// SSEUP. The original Lo and Hi design considers that types can't be
@@ -2899,6 +2918,11 @@
unsigned LargestVector = getNativeVectorSizeForAVXABI(AVXLevel);
if (Size <= 64 || Size > LargestVector)
return true;
+ QualType EltTy = VecTy->getElementType();
+ if (passInt128VectorsInMem() &&
+ (EltTy->isSpecificBuiltinType(BuiltinType::Int128) ||
+ EltTy->isSpecificBuiltinType(BuiltinType::UInt128)))
+ return true;
}
return false;
@@ -2973,14 +2997,28 @@
Ty = QualType(InnerTy, 0);
llvm::Type *IRType = CGT.ConvertType(Ty);
- if (isa<llvm::VectorType>(IRType) ||
- IRType->getTypeID() == llvm::Type::FP128TyID)
+ if (isa<llvm::VectorType>(IRType)) {
+ // Don't pass vXi128 vectors in their native type, the backend can't
+ // legalize them.
+ if (passInt128VectorsInMem() &&
+ IRType->getVectorElementType()->isIntegerTy(128)) {
+ // Use a vXi64 vector.
+ uint64_t Size = getContext().getTypeSize(Ty);
+ return llvm::VectorType::get(llvm::Type::getInt64Ty(getVMContext()),
+ Size / 64);
+ }
+
+ return IRType;
+ }
+
+ if (IRType->getTypeID() == llvm::Type::FP128TyID)
return IRType;
// We couldn't find the preferred IR vector type for 'Ty'.
uint64_t Size = getContext().getTypeSize(Ty);
assert((Size == 128 || Size == 256 || Size == 512) && "Invalid type found!");
+
// Return a LLVM IR vector type based on the size of 'Ty'.
return llvm::VectorType::get(llvm::Type::getDoubleTy(getVMContext()),
Size / 64);
Index: clang/include/clang/Basic/LangOptions.h
===================================================================
--- clang/include/clang/Basic/LangOptions.h
+++ clang/include/clang/Basic/LangOptions.h
@@ -138,6 +138,11 @@
/// rather than returning the required alignment.
Ver7,
+ /// Attempt to be ABI-compatible with code generated by Clang 9.0.x
+ /// (SVN r351319). This causes vectors of __int128 to be passed in memory
+ /// instead of passing in multiple scalar registers.
+ Ver9,
+
/// Conform to the underlying platform's C and C++ ABIs as closely
/// as we can.
Latest
Index: clang/docs/ReleaseNotes.rst
===================================================================
--- clang/docs/ReleaseNotes.rst
+++ clang/docs/ReleaseNotes.rst
@@ -125,7 +125,10 @@
ABI Changes in Clang
--------------------
-- ...
+- gcc passes vectors of __int128 in memory on X86-64. Clang historically
+ broke the vectors into multiple scalars using two 64-bit values for each
+ element. Clang now matches the gcc behavior on Linux and NetBSD. You can
+ switch back to old API behavior with flag: -fclang-abi-compat=9.0.
OpenMP Support in Clang
-----------------------
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