[clang] [llvm] [WIP] [llvm] The sysV ABI (PR #194718)
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Sun May 10 12:09:45 PDT 2026
https://github.com/vortex73 updated https://github.com/llvm/llvm-project/pull/194718
>From d99f84ff12be25b08e5c0c6a70bb121c4c04c630 Mon Sep 17 00:00:00 2001
From: Narayan Sreekumar <nsreekumar6 at gmail.com>
Date: Wed, 29 Apr 2026 01:56:09 +0530
Subject: [PATCH] feat: Implement the SysV ABI for the LLVM ABI Library.
---
clang/lib/CodeGen/CodeGenModule.cpp | 41 +-
clang/test/CodeGen/X86/avx512fp16-abi.c | 2 +
clang/test/CodeGen/X86/bfloat-half-abi.c | 1 +
clang/test/CodeGen/X86/fp128-abi.c | 1 +
llvm/include/llvm/ABI/TargetInfo.h | 15 +
llvm/include/llvm/ABI/Types.h | 5 +
llvm/lib/ABI/CMakeLists.txt | 1 +
llvm/lib/ABI/Targets/X86.cpp | 1429 ++++++++++++++++++++++
llvm/lib/ABI/Types.cpp | 48 +
9 files changed, 1538 insertions(+), 5 deletions(-)
create mode 100644 llvm/lib/ABI/Targets/X86.cpp
diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index 2d91b7eaa52dc..685d496139acc 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -344,7 +344,8 @@ bool CodeGenModule::shouldUseLLVMABILowering() const {
return false;
// Only opt in for targets that have an LLVMABI implementation; others
// continue through the legacy ABIInfo path.
- return getTriple().isBPF();
+ const llvm::Triple &T = getTriple();
+ return T.isBPF() || (T.getArch() == llvm::Triple::x86_64 && T.isOSLinux());
}
const llvm::abi::TargetInfo &
@@ -352,10 +353,40 @@ CodeGenModule::getLLVMABITargetInfo(llvm::abi::TypeBuilder &TB) {
if (TheLLVMABITargetInfo)
return *TheLLVMABITargetInfo;
- assert(getTriple().isBPF() &&
- "LLVMABI lowering requested for an unsupported target");
- TheLLVMABITargetInfo = llvm::abi::createBPFTargetInfo(TB);
- return *TheLLVMABITargetInfo;
+ const llvm::Triple &T = getTriple();
+ if (T.isBPF()) {
+ TheLLVMABITargetInfo = llvm::abi::createBPFTargetInfo(TB);
+ return *TheLLVMABITargetInfo;
+ }
+
+ if (T.getArch() == llvm::Triple::x86_64) {
+ StringRef ABI = getTarget().getABI();
+ llvm::abi::X86AVXABILevel AVXLevel =
+ ABI == "avx512" ? llvm::abi::X86AVXABILevel::AVX512
+ : ABI == "avx" ? llvm::abi::X86AVXABILevel::AVX
+ : llvm::abi::X86AVXABILevel::None;
+
+ llvm::abi::ABICompatInfo CompatInfo;
+ LangOptions::ClangABI Compat = getLangOpts().getClangABICompat();
+ CompatInfo.ClassifyIntegerMMXAsSSE =
+ Compat > LangOptions::ClangABI::Ver3_8 && !T.isOSDarwin() &&
+ !T.isPS() && !T.isOSFreeBSD();
+ CompatInfo.HonorsRevision98 = !T.isOSDarwin();
+ CompatInfo.PassInt128VectorsInMem = Compat > LangOptions::ClangABI::Ver9 &&
+ (T.isOSLinux() || T.isOSNetBSD());
+ CompatInfo.ReturnCXXRecordGreaterThan128InMem =
+ Compat > LangOptions::ClangABI::Ver20;
+ CompatInfo.Clang11Compat =
+ Compat <= LangOptions::ClangABI::Ver11 || T.isPS();
+
+ bool Has64BitPointers = getTarget().getPointerWidth(LangAS::Default) == 64;
+
+ TheLLVMABITargetInfo = llvm::abi::createX8664TargetInfo(
+ TB, T, AVXLevel, Has64BitPointers, CompatInfo);
+ return *TheLLVMABITargetInfo;
+ }
+
+ llvm_unreachable("LLVMABI lowering requested for an unsupported target");
}
static void checkDataLayoutConsistency(const TargetInfo &Target,
diff --git a/clang/test/CodeGen/X86/avx512fp16-abi.c b/clang/test/CodeGen/X86/avx512fp16-abi.c
index 1856f1e22715c..5daecd3c6a76e 100644
--- a/clang/test/CodeGen/X86/avx512fp16-abi.c
+++ b/clang/test/CodeGen/X86/avx512fp16-abi.c
@@ -1,5 +1,7 @@
// RUN: %clang_cc1 -triple x86_64-linux -emit-llvm -target-feature +avx512fp16 < %s | FileCheck %s --check-prefixes=CHECK,CHECK-C
// RUN: %clang_cc1 -triple x86_64-linux -emit-llvm -target-feature +avx512fp16 -x c++ -std=c++11 < %s | FileCheck %s --check-prefixes=CHECK,CHECK-CPP
+// RUN: %clang_cc1 -triple x86_64-linux -emit-llvm -target-feature +avx512fp16 -fexperimental-abi-lowering < %s | FileCheck %s --check-prefixes=CHECK,CHECK-C
+// RUN: %clang_cc1 -triple x86_64-linux -emit-llvm -target-feature +avx512fp16 -x c++ -std=c++11 -fexperimental-abi-lowering < %s | FileCheck %s --check-prefixes=CHECK,CHECK-CPP
struct half1 {
_Float16 a;
diff --git a/clang/test/CodeGen/X86/bfloat-half-abi.c b/clang/test/CodeGen/X86/bfloat-half-abi.c
index 42250791848ac..59ce742f5181a 100644
--- a/clang/test/CodeGen/X86/bfloat-half-abi.c
+++ b/clang/test/CodeGen/X86/bfloat-half-abi.c
@@ -1,4 +1,5 @@
// RUN: %clang_cc1 -triple x86_64-linux -emit-llvm -target-feature +sse2 < %s | FileCheck %s --check-prefixes=CHECK
+// RUN: %clang_cc1 -triple x86_64-linux -emit-llvm -target-feature +sse2 -fexperimental-abi-lowering < %s | FileCheck %s --check-prefixes=CHECK
struct bfloat1 {
__bf16 a;
diff --git a/clang/test/CodeGen/X86/fp128-abi.c b/clang/test/CodeGen/X86/fp128-abi.c
index 2a0ae5009338a..564a0b5912f60 100644
--- a/clang/test/CodeGen/X86/fp128-abi.c
+++ b/clang/test/CodeGen/X86/fp128-abi.c
@@ -1,5 +1,6 @@
// RUN: %clang_cc1 -triple x86_64-linux -emit-llvm -target-feature +sse2 < %s | FileCheck %s --check-prefixes=CHECK
// RUN: %clang_cc1 -triple x86_64-linux -emit-llvm -target-feature -sse2 < %s | FileCheck %s --check-prefixes=CHECK
+// RUN: %clang_cc1 -triple x86_64-linux -emit-llvm -target-feature +sse2 -fexperimental-abi-lowering < %s | FileCheck %s --check-prefixes=CHECK
struct st1 {
__float128 a;
diff --git a/llvm/include/llvm/ABI/TargetInfo.h b/llvm/include/llvm/ABI/TargetInfo.h
index f4feb3b164fbb..c09f4a153aaf5 100644
--- a/llvm/include/llvm/ABI/TargetInfo.h
+++ b/llvm/include/llvm/ABI/TargetInfo.h
@@ -16,7 +16,9 @@
#include "llvm/ABI/FunctionInfo.h"
#include "llvm/ABI/Types.h"
+#include "llvm/TargetParser/Triple.h"
#include <cassert>
+#include <memory>
namespace llvm {
namespace abi {
@@ -83,6 +85,19 @@ class TargetInfo {
std::unique_ptr<TargetInfo> createBPFTargetInfo(TypeBuilder &TB);
+/// The AVX ABI level for X86 targets.
+enum class X86AVXABILevel {
+ None,
+ AVX,
+ AVX512,
+};
+
+std::unique_ptr<TargetInfo> createX8664TargetInfo(TypeBuilder &TB,
+ const Triple &TargetTriple,
+ X86AVXABILevel AVXLevel,
+ bool Has64BitPointers,
+ const ABICompatInfo &Compat);
+
} // namespace abi
} // namespace llvm
diff --git a/llvm/include/llvm/ABI/Types.h b/llvm/include/llvm/ABI/Types.h
index b66f28212fa4f..0a13af84891f4 100644
--- a/llvm/include/llvm/ABI/Types.h
+++ b/llvm/include/llvm/ABI/Types.h
@@ -310,6 +310,11 @@ class RecordType : public Type {
bool isEmpty() const;
+ /// Returns the field, base, or virtual base whose extent contains
+ /// \p OffsetInBits, or nullptr if no such element exists. Empty bases and
+ /// unnamed bitfields are skipped.
+ const FieldInfo *getElementContainingOffset(unsigned OffsetInBits) const;
+
static bool classof(const Type *T) {
return T->getKind() == TypeKind::Record;
}
diff --git a/llvm/lib/ABI/CMakeLists.txt b/llvm/lib/ABI/CMakeLists.txt
index a5c102b57d074..47ce5926e6039 100644
--- a/llvm/lib/ABI/CMakeLists.txt
+++ b/llvm/lib/ABI/CMakeLists.txt
@@ -4,6 +4,7 @@ add_llvm_component_library(LLVMABI
TargetInfo.cpp
IRTypeMapper.cpp
Targets/BPF.cpp
+ Targets/X86.cpp
ADDITIONAL_HEADER_DIRS
${LLVM_MAIN_INCLUDE_DIR}/llvm/ABI
diff --git a/llvm/lib/ABI/Targets/X86.cpp b/llvm/lib/ABI/Targets/X86.cpp
new file mode 100644
index 0000000000000..62d4489f93d19
--- /dev/null
+++ b/llvm/lib/ABI/Targets/X86.cpp
@@ -0,0 +1,1429 @@
+//===- X86.cpp ------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ABI/FunctionInfo.h"
+#include "llvm/ABI/TargetInfo.h"
+#include "llvm/ABI/Types.h"
+#include "llvm/Support/Alignment.h"
+#include "llvm/Support/Casting.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/MathExtras.h"
+#include "llvm/Support/TypeSize.h"
+#include "llvm/TargetParser/Triple.h"
+#include <algorithm>
+#include <cassert>
+#include <cstdint>
+
+namespace llvm {
+namespace abi {
+
+static unsigned getNativeVectorSizeForAVXABI(X86AVXABILevel AVXLevel) {
+ switch (AVXLevel) {
+ case X86AVXABILevel::AVX512:
+ return 512;
+ case X86AVXABILevel::AVX:
+ return 256;
+ case X86AVXABILevel::None:
+ return 128;
+ }
+ llvm_unreachable("Unknown AVXLevel");
+}
+
+class X86_64TargetInfo : public TargetInfo {
+public:
+ enum Class {
+ Integer = 0,
+ SSE,
+ SSEUp,
+ X87,
+ X87UP,
+ Complex_X87,
+ NoClass,
+ Memory
+ };
+
+private:
+ TypeBuilder &TB;
+ X86AVXABILevel AVXLevel;
+ bool Has64BitPointers;
+ const llvm::Triple &TargetTriple;
+
+ static Class merge(Class Accum, Class Field);
+
+ void postMerge(unsigned AggregateSize, Class &Lo, Class &Hi) const;
+
+ void classify(const Type *T, uint64_t OffsetBase, Class &Lo, Class &Hi,
+ bool IsNamedArg, bool IsRegCall = false) const;
+
+ const Type *getIntegerTypeAtOffset(const Type *IRType, unsigned IROffset,
+ const Type *SourceTy,
+ unsigned SourceOffset,
+ bool InMemory = false) const;
+
+ const Type *getSSETypeAtOffset(const Type *ABIType, unsigned ABIOffset,
+ const Type *SourceTy,
+ unsigned SourceOffset) const;
+ bool isIllegalVectorType(const Type *Ty) const;
+ bool containsMatrixField(const RecordType *RT) const;
+
+ void computeInfo(FunctionInfo &FI) const override;
+ ArgInfo getIndirectReturnResult(const Type *Ty) const;
+ const Type *getFPTypeAtOffset(const Type *Ty, unsigned Offset) const;
+
+ const Type *isSingleElementStruct(const Type *Ty) const;
+ const Type *getByteVectorType(const Type *Ty) const;
+
+ const Type *createPairType(const Type *Lo, const Type *Hi) const;
+ ArgInfo getIndirectResult(const Type *Ty, unsigned FreeIntRegs) const;
+
+ ArgInfo classifyReturnType(const Type *RetTy) const;
+
+ ArgInfo classifyArgumentType(const Type *Ty, unsigned FreeIntRegs,
+ unsigned &NeededInt, unsigned &NeededSse,
+ bool IsNamedArg, bool IsRegCall = false) const;
+ const Type *useFirstFieldIfTransparentUnion(const Type *Ty) const;
+
+public:
+ X86_64TargetInfo(TypeBuilder &TypeBuilder, const Triple &Triple,
+ X86AVXABILevel AVXABILevel, bool Has64BitPtrs,
+ const ABICompatInfo &Compat)
+ : TargetInfo(Compat), TB(TypeBuilder), AVXLevel(AVXABILevel),
+ Has64BitPointers(Has64BitPtrs), TargetTriple(Triple) {}
+
+ bool has64BitPointers() const { return Has64BitPointers; }
+};
+
+// Gets the "best" type to represent the union.
+static const Type *reduceUnionForX8664(const RecordType *UnionType,
+ TypeBuilder &TB) {
+ assert(UnionType->isUnion() && "Expected union type");
+
+ ArrayRef<FieldInfo> Fields = UnionType->getFields();
+ if (Fields.empty()) {
+ return nullptr;
+ }
+
+ const Type *StorageType = nullptr;
+
+ for (const auto &Field : Fields) {
+ if (Field.IsBitField && Field.IsUnnamedBitfield &&
+ Field.BitFieldWidth == 0) {
+ continue;
+ }
+
+ const Type *FieldType = Field.FieldType;
+
+ if (UnionType->isTransparentUnion() && !StorageType) {
+ StorageType = FieldType;
+ break;
+ }
+
+ if (!StorageType ||
+ FieldType->getAlignment() > StorageType->getAlignment() ||
+ (FieldType->getAlignment() == StorageType->getAlignment() &&
+ TypeSize::isKnownGT(FieldType->getSizeInBits(),
+ StorageType->getSizeInBits()))) {
+ StorageType = FieldType;
+ }
+ }
+ return StorageType;
+}
+
+void X86_64TargetInfo::postMerge(unsigned AggregateSize, Class &Lo,
+ Class &Hi) const {
+ // AMD64-ABI 3.2.3p2: Rule 5. Then a post merger cleanup is done:
+ //
+ // (a) If one of the classes is Memory, the whole argument is passed in
+ // memory.
+ //
+ // (b) If X87UP is not preceded by X87, the whole argument is passed in
+ // memory.
+ //
+ // (c) If the size of the aggregate exceeds two eightbytes and the first
+ // eightbyte isn't SSE or any other eightbyte isn't SSEUP, the whole
+ // argument is passed in memory. NOTE: This is necessary to keep the
+ // ABI working for processors that don't support the __m256 type.
+ //
+ // (d) If SSEUP is not preceded by SSE or SSEUP, it is converted to SSE.
+ //
+ // Some of these are enforced by the merging logic. Others can arise
+ // only with unions; for example:
+ // union { _Complex double; unsigned; }
+ //
+ // Note that clauses (b) and (c) were added in 0.98.
+
+ if (Hi == Memory)
+ Lo = Memory;
+ if (Hi == X87UP && Lo != X87 && getABICompatInfo().HonorsRevision98)
+ Lo = Memory;
+ if (AggregateSize > 128 && (Lo != SSE || Hi != SSEUp))
+ Lo = Memory;
+ if (Hi == SSEUp && Lo != SSE)
+ Hi = SSE;
+}
+X86_64TargetInfo::Class X86_64TargetInfo::merge(Class Accum, Class Field) {
+ // AMD64-ABI 3.2.3p2: Rule 4. Each field of an object is
+ // classified recursively so that always two fields are
+ // considered. The resulting class is calculated according to
+ // the classes of the fields in the eightbyte:
+ //
+ // (a) If both classes are equal, this is the resulting class.
+ //
+ // (b) If one of the classes is NO_CLASS, the resulting class is
+ // the other class.
+ //
+ // (c) If one of the classes is MEMORY, the result is the MEMORY
+ // class.
+ //
+ // (d) If one of the classes is INTEGER, the result is the
+ // INTEGER.
+ //
+ // (e) If one of the classes is X87, X87UP, COMPLEX_X87 class,
+ // MEMORY is used as class.
+ //
+ // (f) Otherwise class SSE is used.
+
+ // Accum should never be memory (we should have returned) or
+ // ComplexX87 (because this cannot be passed in a structure).
+ assert((Accum != Memory && Accum != Complex_X87) &&
+ "Invalid accumulated classification during merge.");
+
+ if (Accum == Field || Field == NoClass)
+ return Accum;
+ if (Field == Memory)
+ return Memory;
+ if (Accum == NoClass)
+ return Field;
+ if (Accum == Integer || Field == Integer)
+ return Integer;
+ if (Field == X87 || Field == X87UP || Field == Complex_X87 || Accum == X87 ||
+ Accum == X87UP)
+ return Memory;
+
+ return SSE;
+}
+
+bool X86_64TargetInfo::containsMatrixField(const RecordType *RT) const {
+ for (const auto &Field : RT->getFields()) {
+ const Type *FieldType = Field.FieldType;
+
+ if (const auto *AT = dyn_cast<ArrayType>(FieldType)) {
+ if (AT->isMatrixType())
+ return true;
+ continue;
+ }
+
+ if (const auto *NestedRT = dyn_cast<RecordType>(FieldType))
+ if (containsMatrixField(NestedRT))
+ return true;
+ }
+ return false;
+}
+
+void X86_64TargetInfo::classify(const Type *T, uint64_t OffsetBase, Class &Lo,
+ Class &Hi, bool IsNamedArg,
+ bool IsRegCall) const {
+ Lo = Hi = NoClass;
+ Class &Current = OffsetBase < 64 ? Lo : Hi;
+ Current = Memory;
+
+ if (T->isVoid()) {
+ Current = NoClass;
+ return;
+ }
+
+ if (const auto *IT = dyn_cast<IntegerType>(T)) {
+ auto BitWidth = IT->getSizeInBits().getFixedValue();
+
+ if (BitWidth == 128 ||
+ (IT->isBitInt() && BitWidth > 64 && BitWidth <= 128)) {
+ Lo = Integer;
+ Hi = Integer;
+ } else if (BitWidth <= 64)
+ Current = Integer;
+
+ return;
+ }
+
+ if (const auto *FT = dyn_cast<FloatType>(T)) {
+ const auto *FltSem = FT->getSemantics();
+
+ if (FltSem == &llvm::APFloat::IEEEsingle() ||
+ FltSem == &llvm::APFloat::IEEEdouble() ||
+ FltSem == &llvm::APFloat::IEEEhalf() ||
+ FltSem == &llvm::APFloat::BFloat()) {
+ Current = SSE;
+ } else if (FltSem == &llvm::APFloat::IEEEquad()) {
+ Lo = SSE;
+ Hi = SSEUp;
+ } else if (FltSem == &llvm::APFloat::x87DoubleExtended()) {
+ Lo = X87;
+ Hi = X87UP;
+ } else
+ Current = SSE;
+ return;
+ }
+ if (T->isPointer()) {
+ Current = Integer;
+ return;
+ }
+
+ if (const auto *MPT = dyn_cast<MemberPointerType>(T)) {
+ if (MPT->isFunctionPointer()) {
+ if (Has64BitPointers) {
+ Lo = Hi = Integer;
+ } else {
+ uint64_t EbFuncPtr = OffsetBase / 64;
+ uint64_t EbThisAdj = (OffsetBase + 64 - 1) / 64;
+ if (EbFuncPtr != EbThisAdj) {
+ Lo = Hi = Integer;
+ } else
+ Current = Integer;
+ }
+ } else
+ Current = Integer;
+ return;
+ }
+
+ if (const auto *VT = dyn_cast<VectorType>(T)) {
+ auto Size = VT->getSizeInBits().getFixedValue();
+ const Type *ElementType = VT->getElementType();
+
+ if (Size == 1 || Size == 8 || Size == 16 || Size == 32) {
+ // gcc passes the following as integer:
+ // 4 bytes - <4 x char>, <2 x short>, <1 x int>, <1 x float>
+ // 2 bytes - <2 x char>, <1 x short>
+ // 1 byte - <1 x char>
+ Current = Integer;
+ // If this type crosses an eightbyte boundary, it should be
+ // split.
+ uint64_t EbLo = (OffsetBase) / 64;
+ uint64_t EbHi = (OffsetBase + Size - 1) / 64;
+ if (EbLo != EbHi)
+ Hi = Lo;
+ } else if (Size == 64) {
+ if (const auto *FT = dyn_cast<FloatType>(ElementType)) {
+ // gcc passes <1 x double> in memory. :(
+ if (FT->getSemantics() == &llvm::APFloat::IEEEdouble())
+ return;
+ }
+
+ // gcc passes <1 x long long> as SSE but clang used to unconditionally
+ // pass them as integer. For platforms where clang is the de facto
+ // platform compiler, we must continue to use integer.
+ if (const auto *IT = dyn_cast<IntegerType>(ElementType)) {
+ uint64_t ElemBits = IT->getSizeInBits().getFixedValue();
+ if (!getABICompatInfo().ClassifyIntegerMMXAsSSE &&
+ (ElemBits == 64 || ElemBits == 32)) {
+ Current = Integer;
+ } else
+ Current = SSE;
+ } else
+ Current = SSE;
+ // If this type crosses an eightbyte boundary, it should be
+ // split.
+ if (OffsetBase && OffsetBase != 64)
+ Hi = Lo;
+ } else if (Size == 128 ||
+ (IsNamedArg && Size <= getNativeVectorSizeForAVXABI(AVXLevel))) {
+ if (const auto *IT = dyn_cast<IntegerType>(ElementType)) {
+ uint64_t ElemBits = IT->getSizeInBits().getFixedValue();
+ // gcc passes 256 and 512 bit <X x __int128> vectors in memory. :(
+ if (getABICompatInfo().PassInt128VectorsInMem && Size != 128 &&
+ ElemBits == 128)
+ 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
+ // greater than 128-bits, so a 64-bit split in Hi and Lo makes sense.
+ // This design isn't correct for 256-bits, but since there're no cases
+ // where the upper parts would need to be inspected, avoid adding
+ // complexity and just consider Hi to match the 64-256 part.
+ //
+ // Note that per 3.5.7 of AMD64-ABI, 256-bit args are only passed in
+ // registers if they are "named", i.e. not part of the "..." of a
+ // variadic function.
+ //
+ // Similarly, per 3.2.3. of the AVX512 draft, 512-bits ("named") args are
+ // split into eight eightbyte chunks, one SSE and seven SSEUP.
+ Lo = SSE;
+ Hi = SSEUp;
+ }
+ return;
+ }
+
+ if (const auto *CT = dyn_cast<ComplexType>(T)) {
+ const Type *ElementType = CT->getElementType();
+ uint64_t Size = T->getSizeInBits().getFixedValue();
+
+ if (isa<IntegerType>(ElementType)) {
+ if (Size <= 64)
+ Current = Integer;
+ else if (Size <= 128)
+ Lo = Hi = Integer;
+ } else if (const auto *EFT = dyn_cast<FloatType>(ElementType)) {
+ const auto *FltSem = EFT->getSemantics();
+ if (FltSem == &llvm::APFloat::IEEEhalf() ||
+ FltSem == &llvm::APFloat::IEEEsingle() ||
+ FltSem == &llvm::APFloat::BFloat())
+ Current = SSE;
+ else if (FltSem == &llvm::APFloat::IEEEquad())
+ Current = Memory;
+ else if (FltSem == &llvm::APFloat::x87DoubleExtended())
+ Current = Complex_X87;
+ else if (FltSem == &llvm::APFloat::IEEEdouble())
+ Lo = Hi = SSE;
+ else
+ llvm_unreachable("Unexpected long double representation!");
+ }
+
+ uint64_t ElementSize = ElementType->getSizeInBits().getFixedValue();
+ // If this complex type crosses an eightbyte boundary then it
+ // should be split.
+ uint64_t EbReal = OffsetBase / 64;
+ uint64_t EbImag = (OffsetBase + ElementSize) / 64;
+ if (Hi == NoClass && EbReal != EbImag)
+ Hi = Lo;
+
+ return;
+ }
+
+ if (const auto *AT = dyn_cast<ArrayType>(T)) {
+ uint64_t Size = AT->getSizeInBits().getFixedValue();
+
+ if (!IsRegCall && Size > 512)
+ return;
+
+ const Type *ElementType = AT->getElementType();
+ uint64_t ElemAlign = ElementType->getAlignment().value() * 8;
+ if (OffsetBase % ElemAlign)
+ return;
+
+ Current = NoClass;
+ uint64_t EltSize = ElementType->getSizeInBits().getFixedValue();
+ uint64_t ArraySize = AT->getNumElements();
+
+ if (Size > 128 &&
+ (Size != EltSize || Size > getNativeVectorSizeForAVXABI(AVXLevel)))
+ return;
+
+ for (uint64_t I = 0, Offset = OffsetBase; I < ArraySize;
+ ++I, Offset += EltSize) {
+ Class FieldLo, FieldHi;
+ classify(ElementType, Offset, FieldLo, FieldHi, IsNamedArg);
+ Lo = merge(Lo, FieldLo);
+ Hi = merge(Hi, FieldHi);
+ if (Lo == Memory || Hi == Memory)
+ break;
+ }
+ postMerge(Size, Lo, Hi);
+ assert((Hi != SSEUp || Lo == SSE) && "Invalid SSEUp array classification.");
+ return;
+ }
+ if (const auto *RT = dyn_cast<RecordType>(T)) {
+ uint64_t Size = RT->getSizeInBits().getFixedValue();
+
+ if (containsMatrixField(RT)) {
+ Lo = Memory;
+ return;
+ }
+
+ // AMD64-ABI 3.2.3p2: Rule 1. If the size of an object is larger
+ // than eight eightbytes, ..., it has class MEMORY.
+ if (Size > 512)
+ return;
+
+ // AMD64-ABI 3.2.3p2: Rule 2. If a C++ object has either a non-trivial
+ // copy constructor or a non-trivial destructor, it is passed by invisible
+ // reference.
+ if (getRecordArgABI(RT))
+ return;
+
+ // Assume variable sized types are passed in memory.
+ if (RT->hasFlexibleArrayMember())
+ return;
+
+ // Reset Lo class, this will be recomputed.
+ Current = NoClass;
+
+ // If this is a C++ record, classify the bases first.
+ if (RT->isCXXRecord()) {
+ for (const auto &Base : RT->getBaseClasses()) {
+
+ // Classify this field.
+ //
+ // AMD64-ABI 3.2.3p2: Rule 3. If the size of the aggregate exceeds a
+ // single eightbyte, each is classified separately. Each eightbyte gets
+ // initialized to class NO_CLASS.
+ Class FieldLo, FieldHi;
+ uint64_t Offset = OffsetBase + Base.OffsetInBits;
+ classify(Base.FieldType, Offset, FieldLo, FieldHi, IsNamedArg);
+ Lo = merge(Lo, FieldLo);
+ Hi = merge(Hi, FieldHi);
+
+ if (getABICompatInfo().ReturnCXXRecordGreaterThan128InMem &&
+ (Size > 128 &&
+ (Size != Base.FieldType->getSizeInBits().getFixedValue() ||
+ Size > getNativeVectorSizeForAVXABI(AVXLevel))))
+ Lo = Memory;
+
+ if (Lo == Memory || Hi == Memory) {
+ postMerge(Size, Lo, Hi);
+ return;
+ }
+ }
+ }
+
+ // Classify the fields one at a time, merging the results.
+
+ bool IsUnion = RT->isUnion() && !getABICompatInfo().Clang11Compat;
+ for (const auto &Field : RT->getFields()) {
+ uint64_t Offset = OffsetBase + Field.OffsetInBits;
+ bool BitField = Field.IsBitField;
+
+ if (BitField && Field.IsUnnamedBitfield)
+ continue;
+
+ if (Size > 128 &&
+ ((!IsUnion &&
+ Size != Field.FieldType->getSizeInBits().getFixedValue()) ||
+ Size > getNativeVectorSizeForAVXABI(AVXLevel))) {
+ Lo = Memory;
+ postMerge(Size, Lo, Hi);
+ return;
+ }
+
+ bool IsInMemory = Offset % (Field.FieldType->getAlignment().value() * 8);
+ if (!BitField && IsInMemory) {
+ Lo = Memory;
+ postMerge(Size, Lo, Hi);
+ return;
+ }
+
+ Class FieldLo, FieldHi;
+
+ if (BitField) {
+ uint64_t BitFieldSize = Field.BitFieldWidth;
+ uint64_t EbLo = Offset / 64;
+ uint64_t EbHi = (Offset + BitFieldSize - 1) / 64;
+
+ if (EbLo) {
+ assert(EbHi == EbLo && "Invalid classification, type > 16 bytes.");
+ FieldLo = NoClass;
+ FieldHi = Integer;
+ } else {
+ FieldLo = Integer;
+ FieldHi = EbHi ? Integer : NoClass;
+ }
+ } else
+ classify(Field.FieldType, Offset, FieldLo, FieldHi, IsNamedArg);
+
+ Lo = merge(Lo, FieldLo);
+ Hi = merge(Hi, FieldHi);
+ if (Lo == Memory || Hi == Memory)
+ break;
+ }
+ postMerge(Size, Lo, Hi);
+ return;
+ }
+
+ Lo = Memory;
+ Hi = NoClass;
+}
+
+const Type *
+X86_64TargetInfo::useFirstFieldIfTransparentUnion(const Type *Ty) const {
+ if (const auto *RT = dyn_cast<RecordType>(Ty)) {
+ if (RT->isUnion() && RT->isTransparentUnion()) {
+ auto Fields = RT->getFields();
+ assert(!Fields.empty() && "sema created an empty transparent union");
+ return Fields.front().FieldType;
+ }
+ }
+ return Ty;
+}
+
+ArgInfo
+X86_64TargetInfo::classifyArgumentType(const Type *Ty, unsigned FreeIntRegs,
+ unsigned &NeededInt, unsigned &NeededSSE,
+ bool IsNamedArg, bool IsRegCall) const {
+
+ Ty = useFirstFieldIfTransparentUnion(Ty);
+
+ X86_64TargetInfo::Class Lo, Hi;
+ classify(Ty, 0, Lo, Hi, IsNamedArg, IsRegCall);
+
+ // Check some invariants
+ assert((Hi != Memory || Lo == Memory) && "Invalid memory classification.");
+ assert((Hi != SSEUp || Lo == SSE) && "Invalid SSEUp classification.");
+
+ NeededInt = 0;
+ NeededSSE = 0;
+ const Type *ResType = nullptr;
+
+ switch (Lo) {
+ case NoClass:
+ if (Hi == NoClass)
+ return ArgInfo::getIgnore();
+ // If the low part is just padding, it takes no register, leave ResType
+ // null.
+ assert((Hi == SSE || Hi == Integer || Hi == X87UP) &&
+ "Unknown missing lo part");
+ break;
+
+ // AMD64-ABI 3.2.3p3: Rule 1. If the class is MEMORY, pass the argument
+ // on the stack.
+ case Memory:
+ // AMD64-ABI 3.2.3p3: Rule 5. If the class is X87, X87UP or
+ // COMPLEX_X87, it is passed in memory.
+ case X87:
+ case Complex_X87:
+ if (getRecordArgABI(Ty) == RAA_Indirect)
+ ++NeededInt;
+ return getIndirectResult(Ty, FreeIntRegs);
+
+ case SSEUp:
+ case X87UP:
+ llvm_unreachable("Invalid classification for lo word.");
+
+ // AMD64-ABI 3.2.3p3: Rule 2. If the class is INTEGER, the next
+ // available register of the sequence %rdi, %rsi, %rdx, %rcx, %r8
+ // and %r9 is used.
+ case Integer:
+ ++NeededInt;
+
+ // Pick an 8-byte type based on the preferred type.
+ ResType = getIntegerTypeAtOffset(Ty, 0, Ty, 0);
+
+ // If we have a sign or zero extended integer, make sure to return Extend
+ // so that the parameter gets the right LLVM IR attributes.
+ if (Hi == NoClass && ResType->isInteger()) {
+ if (Ty->isInteger() && isPromotableInteger(cast<IntegerType>(Ty)))
+ return ArgInfo::getExtend(Ty);
+ }
+
+ if (ResType->isInteger() && ResType->getSizeInBits() == 128) {
+ assert(Hi == Integer);
+ ++NeededInt;
+ return ArgInfo::getDirect(ResType);
+ }
+ break;
+
+ // AMD64-ABI 3.2.3p3: Rule 3. If the class is SSE, the next
+ // available SSE register is used, the registers are taken in the
+ // order from %xmm0 to %xmm7.
+ case SSE:
+ ResType = getSSETypeAtOffset(Ty, 0, Ty, 0);
+ ++NeededSSE;
+ break;
+ }
+
+ const Type *HighPart = nullptr;
+ switch (Hi) {
+ // Memory was handled previously, Complex_X87 and X87 should
+ // never occur as hi classes, and X87UP must be preceded by X87,
+ // which is passed in memory.
+ case Memory:
+ case X87:
+ case Complex_X87:
+ llvm_unreachable("Invalid classification for hi word.");
+
+ case NoClass:
+ break;
+
+ case Integer:
+ ++NeededInt;
+ // Pick an 8-byte type based on the preferred type.
+ HighPart = getIntegerTypeAtOffset(Ty, 8, Ty, 8);
+
+ if (Lo == NoClass) // Pass HighPart at offset 8 in memory.
+ return ArgInfo::getDirect(HighPart, 8);
+ break;
+
+ // X87UP generally doesn't occur here (long double is passed in
+ // memory), except in situations involving unions.
+ case X87UP:
+ case SSE:
+ ++NeededSSE;
+ HighPart = getSSETypeAtOffset(Ty, 8, Ty, 8);
+
+ if (Lo == NoClass) // Pass HighPart at offset 8 in memory.
+ return ArgInfo::getDirect(HighPart, 8);
+ break;
+
+ // AMD64-ABI 3.2.3p3: Rule 4. If the class is SSEUP, the
+ // eightbyte is passed in the upper half of the last used SSE
+ // register. This only happens when 128-bit vectors are passed.
+ case SSEUp:
+ assert(Lo == SSE && "Unexpected SSEUp classification");
+ ResType = getByteVectorType(Ty);
+ break;
+ }
+
+ // If a high part was specified, merge it together with the low part. It is
+ // known to pass in the high eightbyte of the result. We do this by forming a
+ // first class struct aggregate with the high and low part: {low, high}
+ if (HighPart)
+ ResType = createPairType(ResType, HighPart);
+
+ return ArgInfo::getDirect(ResType);
+}
+
+ArgInfo X86_64TargetInfo::classifyReturnType(const Type *RetTy) const {
+ // AMD64-ABI 3.2.3p4: Rule 1. Classify the return type with the
+ // classification algorithm.
+
+ X86_64TargetInfo::Class Lo, Hi;
+ classify(RetTy, 0, Lo, Hi, /*isNamedArg*/ true);
+
+ // Check some invariants
+ assert((Hi != Memory || Lo == Memory) && "Invalid memory classification.");
+ assert((Hi != SSEUp || Lo == SSE) && "Invalid SSEUp classification.");
+
+ const Type *ResType = nullptr;
+ switch (Lo) {
+ case NoClass:
+ if (Hi == NoClass)
+ return ArgInfo::getIgnore();
+ // If the low part is just padding, it takes no register, leave ResType
+ // null.
+ assert((Hi == SSE || Hi == Integer || Hi == X87UP) &&
+ "Unknown missing lo part");
+ break;
+ case SSEUp:
+ case X87UP:
+ llvm_unreachable("Invalid classification for lo word.");
+
+ // AMD64-ABI 3.2.3p4: Rule 2. Types of class memory are returned via
+ // hidden argument.
+ case Memory:
+ return getIndirectReturnResult(RetTy);
+
+ // AMD64-ABI 3.2.3p4: Rule 3. If the class is INTEGER, the next
+ // available register of the sequence %rax, %rdx is used.
+ case Integer:
+ ResType = getIntegerTypeAtOffset(RetTy, 0, RetTy, 0);
+ // If we have a sign or zero extended integer, make sure to return Extend
+ // so that the parameter gets the right LLVM IR attributes.
+ if (Hi == NoClass && ResType->isInteger()) {
+ if (const IntegerType *IntTy = dyn_cast<IntegerType>(RetTy)) {
+ if (isPromotableInteger(IntTy))
+ return ArgInfo::getExtend(RetTy);
+ }
+ }
+ if (ResType->isInteger() && ResType->getSizeInBits() == 128) {
+ assert(Hi == Integer);
+ return ArgInfo::getDirect(ResType);
+ }
+ break;
+
+ // AMD64-ABI 3.2.3p4: Rule 4. If the class is SSE, the next
+ // available SSE register of the sequence %xmm0, %xmm1 is used.
+ case SSE:
+ ResType = getSSETypeAtOffset(RetTy, 0, RetTy, 0);
+ break;
+
+ // AMD64-ABI 3.2.3p4: Rule 6. If the class is X87, the value is
+ // returned on the X87 stack in %st0 as 80-bit x87 number.
+ case X87:
+ ResType = TB.getFloatType(APFloat::x87DoubleExtended(), Align(16));
+ break;
+
+ // AMD64-ABI 3.2.3p4: Rule 8. If the class is COMPLEX_X87, the real
+ // part of the value is returned in %st0 and the imaginary part in
+ // %st1.
+ case Complex_X87:
+ assert(Hi == Complex_X87 && "Unexpected ComplexX87 classification.");
+ {
+ const Type *X87Type =
+ TB.getFloatType(APFloat::x87DoubleExtended(), Align(16));
+ FieldInfo Fields[] = {FieldInfo(X87Type, 0), FieldInfo(X87Type, 128)};
+ ResType = TB.getRecordType(Fields, TypeSize::getFixed(256), Align(16));
+ }
+ break;
+ }
+
+ const Type *HighPart = nullptr;
+ switch (Hi) {
+ // Memory was handled previously and X87 should
+ // never occur as a hi class.
+ case Memory:
+ case X87:
+ llvm_unreachable("Invalid classification for hi word.");
+
+ case Complex_X87:
+ case NoClass:
+ break;
+
+ case Integer:
+ HighPart = getIntegerTypeAtOffset(RetTy, 8, RetTy, 8);
+ if (Lo == NoClass)
+ return ArgInfo::getDirect(HighPart, 8);
+ break;
+
+ case SSE:
+ HighPart = getSSETypeAtOffset(RetTy, 8, RetTy, 8);
+ if (Lo == NoClass)
+ return ArgInfo::getDirect(HighPart, 8);
+ break;
+
+ // AMD64-ABI 3.2.3p4: Rule 5. If the class is SSEUP, the eightbyte
+ // is passed in the next available eightbyte chunk if the last used
+ // vector register.
+ //
+ // SSEUP should always be preceded by SSE, just widen.
+ case SSEUp:
+ assert(Lo == SSE && "Unexpected SSEUp classification.");
+ ResType = getByteVectorType(RetTy);
+ break;
+
+ // AMD64-ABI 3.2.3p4: Rule 7. If the class is X87UP, the value is
+ // returned together with the previous X87 value in %st0.
+ case X87UP:
+ // If X87Up is preceded by X87, we don't need to do
+ // anything. However, in some cases with unions it may not be
+ // preceded by X87. In such situations we follow gcc and pass the
+ // extra bits in an SSE reg.
+ if (Lo != X87) {
+ HighPart = getSSETypeAtOffset(RetTy, 8, RetTy, 8);
+ if (Lo == NoClass) // Return HighPart at offset 8 in memory.
+ return ArgInfo::getDirect(HighPart, 8);
+ }
+ break;
+ }
+
+ // If a high part was specified, merge it together with the low part. It is
+ // known to pass in the high eightbyte of the result. We do this by forming a
+ // first class struct aggregate with the high and low part: {low, high}
+ if (HighPart)
+ ResType = createPairType(ResType, HighPart);
+
+ return ArgInfo::getDirect(ResType);
+}
+
+/// Given a high and low type that can ideally
+/// be used as elements of a two register pair to pass or return, return a
+/// first class aggregate to represent them. For example, if the low part of
+/// a by-value argument should be passed as i32* and the high part as float,
+/// return {i32*, float}.
+const Type *X86_64TargetInfo::createPairType(const Type *Lo,
+ const Type *Hi) const {
+ // In order to correctly satisfy the ABI, we need to the high part to start
+ // at offset 8. If the high and low parts we inferred are both 4-byte types
+ // (e.g. i32 and i32) then the resultant struct type ({i32,i32}) won't have
+ // the second element at offset 8. Check for this:
+ unsigned LoSize = (unsigned)Lo->getTypeAllocSize();
+ llvm::Align HiAlign = Hi->getAlignment();
+ unsigned HiStart = alignTo(LoSize, HiAlign);
+
+ assert(HiStart != 0 && HiStart <= 8 && "Invalid x86-64 argument pair!");
+
+ // To handle this, we have to increase the size of the low part so that the
+ // second element will start at an 8 byte offset. We can't increase the size
+ // of the second element because it might make us access off the end of the
+ // struct.
+ const Type *AdjustedLo = Lo;
+ if (HiStart != 8) {
+ // There are usually two sorts of types the ABI generation code can produce
+ // for the low part of a pair that aren't 8 bytes in size: half, float or
+ // i8/i16/i32. This can also include pointers when they are 32-bit (X32 and
+ // NaCl).
+ // Promote these to a larger type.
+ if (Lo->isFloat()) {
+ const FloatType *FT = cast<FloatType>(Lo);
+ if (FT->getSemantics() == &APFloat::IEEEhalf() ||
+ FT->getSemantics() == &APFloat::IEEEsingle() ||
+ FT->getSemantics() == &APFloat::BFloat())
+ AdjustedLo = TB.getFloatType(APFloat::IEEEdouble(), Align(8));
+ }
+ // Promote integers and pointers to i64
+ else if (Lo->isInteger() || Lo->isPointer())
+ AdjustedLo = TB.getIntegerType(64, Align(8), /*Signed=*/false);
+ else
+ assert((Lo->isInteger() || Lo->isPointer()) &&
+ "Invalid/unknown low type in pair");
+ unsigned AdjustedLoSize = AdjustedLo->getSizeInBits().getFixedValue() / 8;
+ HiStart = alignTo(AdjustedLoSize, HiAlign);
+ }
+
+ // Create the pair struct
+ FieldInfo Fields[] = {FieldInfo(AdjustedLo, 0), FieldInfo(Hi, HiStart * 8)};
+
+ // Verify the high part is at offset 8
+ assert((8 * 8) == Fields[1].OffsetInBits &&
+ "High part must be at offset 8 bytes");
+
+ return TB.getRecordType(Fields, TypeSize::getFixed(128), Align(8),
+ StructPacking::Default);
+}
+
+static bool bitsContainNoUserData(const Type *Ty, unsigned StartBit,
+ unsigned EndBit) {
+ // If range is completely beyond type size, it's definitely padding
+ unsigned TySize = Ty->getSizeInBits().getFixedValue();
+ if (TySize <= StartBit)
+ return true;
+
+ // Handle arrays - check each element
+ if (const ArrayType *AT = dyn_cast<ArrayType>(Ty)) {
+ const Type *EltTy = AT->getElementType();
+ unsigned EltSize = EltTy->getSizeInBits().getFixedValue();
+
+ for (unsigned I = 0; I < AT->getNumElements(); ++I) {
+ unsigned EltOffset = I * EltSize;
+ if (EltOffset >= EndBit)
+ break;
+
+ unsigned EltStart = (EltOffset < StartBit) ? StartBit - EltOffset : 0;
+ if (!bitsContainNoUserData(EltTy, EltStart, EndBit - EltOffset))
+ return false;
+ }
+ return true;
+ }
+
+ // Handle structs - check all fields and base classes
+ if (const RecordType *RT = dyn_cast<RecordType>(Ty)) {
+ if (RT->isUnion()) {
+ for (const auto &Field : RT->getFields()) {
+ if (Field.IsUnnamedBitfield)
+ continue;
+
+ unsigned FieldStart =
+ (Field.OffsetInBits < StartBit) ? StartBit - Field.OffsetInBits : 0;
+ unsigned FieldEnd =
+ FieldStart + Field.FieldType->getSizeInBits().getFixedValue();
+
+ // Check if field overlaps with the queried range
+ if (FieldStart < EndBit && FieldEnd > StartBit) {
+ // There's an overlap, so there is user data
+ unsigned RelativeStart =
+ (StartBit > FieldStart) ? StartBit - FieldStart : 0;
+ unsigned RelativeEnd =
+ (EndBit < FieldEnd)
+ ? EndBit - FieldStart
+ : Field.FieldType->getSizeInBits().getFixedValue();
+
+ if (!bitsContainNoUserData(Field.FieldType, RelativeStart,
+ RelativeEnd)) {
+ return false;
+ }
+ }
+ }
+ return true;
+ }
+ // Check base classes first (for C++ records)
+ if (RT->isCXXRecord()) {
+ for (unsigned I = 0; I < RT->getNumBaseClasses(); ++I) {
+ const FieldInfo &Base = RT->getBaseClasses()[I];
+ if (Base.OffsetInBits >= EndBit)
+ continue;
+
+ unsigned BaseStart =
+ (Base.OffsetInBits < StartBit) ? StartBit - Base.OffsetInBits : 0;
+ if (!bitsContainNoUserData(Base.FieldType, BaseStart,
+ EndBit - Base.OffsetInBits))
+ return false;
+ }
+ }
+
+ for (unsigned I = 0; I < RT->getNumFields(); ++I) {
+ const FieldInfo &Field = RT->getFields()[I];
+ if (Field.OffsetInBits >= EndBit)
+ break;
+
+ unsigned FieldStart =
+ (Field.OffsetInBits < StartBit) ? StartBit - Field.OffsetInBits : 0;
+ if (!bitsContainNoUserData(Field.FieldType, FieldStart,
+ EndBit - Field.OffsetInBits))
+ return false;
+ }
+ return true;
+ }
+
+ // For unions, vectors, and primitives - assume all bits are user data
+ return false;
+}
+
+const Type *X86_64TargetInfo::getIntegerTypeAtOffset(const Type *ABIType,
+ unsigned ABIOffset,
+ const Type *SourceTy,
+ unsigned SourceOffset,
+ bool InMemory) const {
+
+ const Type *WorkingType = ABIType;
+ if (InMemory && ABIType->isInteger()) {
+ const auto *IT = cast<IntegerType>(ABIType);
+ unsigned OriginalBitWidth = IT->getSizeInBits().getFixedValue();
+
+ unsigned WidenedBitWidth = OriginalBitWidth;
+ if (OriginalBitWidth <= 8) {
+ WidenedBitWidth = 8;
+ } else {
+ WidenedBitWidth = llvm::bit_ceil(OriginalBitWidth);
+ }
+
+ if (WidenedBitWidth != OriginalBitWidth) {
+ WorkingType = TB.getIntegerType(WidenedBitWidth, ABIType->getAlignment(),
+ IT->isSigned());
+ }
+ }
+ // If we're dealing with an un-offset ABI type, then it means that we're
+ // returning an 8-byte unit starting with it. See if we can safely use it.
+ if (ABIOffset == 0) {
+ // Pointers and int64's always fill the 8-byte unit.
+ if ((WorkingType->isPointer() && Has64BitPointers) ||
+ (WorkingType->isInteger() &&
+ cast<IntegerType>(WorkingType)->getSizeInBits() == 64))
+ return ABIType;
+
+ // If we have a 1/2/4-byte integer, we can use it only if the rest of the
+ // goodness in the source type is just tail padding. This is allowed to
+ // kick in for struct {double,int} on the int, but not on
+ // struct{double,int,int} because we wouldn't return the second int. We
+ // have to do this analysis on the source type because we can't depend on
+ // unions being lowered a specific way etc.
+ if ((WorkingType->isInteger() &&
+ (cast<IntegerType>(WorkingType)->getSizeInBits() == 1 ||
+ cast<IntegerType>(WorkingType)->getSizeInBits() == 8 ||
+ cast<IntegerType>(WorkingType)->getSizeInBits() == 16 ||
+ cast<IntegerType>(WorkingType)->getSizeInBits() == 32)) ||
+ (WorkingType->isPointer() && !Has64BitPointers)) {
+
+ unsigned BitWidth = WorkingType->isPointer()
+ ? 32
+ : cast<IntegerType>(WorkingType)->getSizeInBits();
+
+ if (bitsContainNoUserData(SourceTy, SourceOffset * 8 + BitWidth,
+ SourceOffset * 8 + 64))
+ return WorkingType;
+ }
+ }
+
+ if (const auto *RTy = dyn_cast<RecordType>(ABIType)) {
+ if (RTy->isUnion()) {
+ const Type *ReducedType = reduceUnionForX8664(RTy, TB);
+ if (ReducedType)
+ return getIntegerTypeAtOffset(ReducedType, ABIOffset, SourceTy,
+ SourceOffset, true);
+ }
+ if (const FieldInfo *Element =
+ RTy->getElementContainingOffset(ABIOffset * 8)) {
+
+ unsigned ElementOffsetBytes = Element->OffsetInBits / 8;
+ return getIntegerTypeAtOffset(Element->FieldType,
+ ABIOffset - ElementOffsetBytes, SourceTy,
+ SourceOffset, true);
+ }
+ }
+
+ if (const auto *ATy = dyn_cast<ArrayType>(ABIType)) {
+ const Type *EltTy = ATy->getElementType();
+ unsigned EltSize = EltTy->getSizeInBits() / 8;
+ if (EltSize > 0) {
+ unsigned EltOffset = (ABIOffset / EltSize) * EltSize;
+ return getIntegerTypeAtOffset(EltTy, ABIOffset - EltOffset, SourceTy,
+ SourceOffset, true);
+ }
+ }
+
+ // If we have a 128-bit integer, we can pass it safely using an i128
+ // so we return that
+ if (ABIType->isInteger() && ABIType->getSizeInBits() == 128) {
+ assert(ABIOffset == 0);
+ return ABIType;
+ }
+
+ unsigned TySizeInBytes =
+ llvm::divideCeil(SourceTy->getSizeInBits().getFixedValue(), 8);
+ if (auto *IT = dyn_cast<IntegerType>(SourceTy)) {
+ if (IT->isBitInt())
+ TySizeInBytes =
+ alignTo(SourceTy->getSizeInBits().getFixedValue(), 64) / 8;
+ }
+ assert(TySizeInBytes != SourceOffset && "Empty field?");
+ unsigned AvailableSize = TySizeInBytes - SourceOffset;
+ return TB.getIntegerType(std::min(AvailableSize, 8U) * 8, Align(1), false);
+}
+/// Returns the floating point type at the specified offset within a type, or
+/// nullptr if no floating point type is found at that offset.
+const Type *X86_64TargetInfo::getFPTypeAtOffset(const Type *Ty,
+ unsigned Offset) const {
+ // Check for direct match at offset 0
+ if (Offset == 0 && Ty->isFloat())
+ return Ty;
+
+ if (const ComplexType *CT = dyn_cast<ComplexType>(Ty)) {
+ const Type *ElementType = CT->getElementType();
+ unsigned ElementSize = ElementType->getSizeInBits().getFixedValue() / 8;
+
+ if (Offset == 0 || Offset == ElementSize)
+ return ElementType;
+ return nullptr;
+ }
+
+ // Handle struct types by checking each field
+ if (const RecordType *RT = dyn_cast<RecordType>(Ty)) {
+ if (const FieldInfo *Element = RT->getElementContainingOffset(Offset * 8)) {
+ unsigned ElementOffsetBytes = Element->OffsetInBits / 8;
+ return getFPTypeAtOffset(Element->FieldType, Offset - ElementOffsetBytes);
+ }
+ }
+
+ // Handle array types
+ if (const ArrayType *AT = dyn_cast<ArrayType>(Ty)) {
+ const Type *EltTy = AT->getElementType();
+ unsigned EltSize = EltTy->getSizeInBits() / 8;
+ unsigned EltIndex = Offset / EltSize;
+
+ return getFPTypeAtOffset(EltTy, Offset - (EltIndex * EltSize));
+ }
+
+ // No floating point type found at this offset
+ return nullptr;
+}
+
+/// Helper to check if a floating point type matches specific semantics
+static bool isFloatTypeWithSemantics(const Type *Ty,
+ const fltSemantics &Semantics) {
+ if (!Ty->isFloat())
+ return false;
+ const FloatType *FT = cast<FloatType>(Ty);
+ return FT->getSemantics() == &Semantics;
+}
+
+/// GetSSETypeAtOffset - Return a type that will be passed by the backend in the
+/// low 8 bytes of an XMM register, corresponding to the SSE class.
+const Type *X86_64TargetInfo::getSSETypeAtOffset(const Type *ABIType,
+ unsigned ABIOffset,
+ const Type *SourceTy,
+ unsigned SourceOffset) const {
+
+ if (const auto *RTy = dyn_cast<RecordType>(ABIType)) {
+ if (RTy->isUnion()) {
+ const Type *ReducedType = reduceUnionForX8664(RTy, TB);
+ if (ReducedType) {
+ return getSSETypeAtOffset(ReducedType, ABIOffset, SourceTy,
+ SourceOffset);
+ }
+ }
+ }
+
+ auto Is16bitFpTy = [](const Type *T) {
+ return isFloatTypeWithSemantics(T, APFloat::IEEEhalf()) ||
+ isFloatTypeWithSemantics(T, APFloat::BFloat());
+ };
+
+ // Get the floating point type at the requested offset
+ const Type *T0 = getFPTypeAtOffset(ABIType, ABIOffset);
+ if (!T0 || isFloatTypeWithSemantics(T0, APFloat::IEEEdouble()))
+ return TB.getFloatType(APFloat::IEEEdouble(), Align(8));
+
+ // Calculate remaining source size in bytes
+ unsigned SourceSize =
+ (SourceTy->getSizeInBits().getFixedValue() / 8) - SourceOffset;
+
+ // Try to get adjacent FP type
+ const Type *T1 = nullptr;
+ unsigned T0Size =
+ alignTo(T0->getSizeInBits().getFixedValue(), T0->getAlignment().value()) /
+ 8;
+ if (SourceSize > T0Size)
+ T1 = getFPTypeAtOffset(ABIType, ABIOffset + T0Size);
+
+ if (T1 == nullptr) {
+ if (Is16bitFpTy(T0) && SourceSize > 4)
+ T1 = getFPTypeAtOffset(ABIType, ABIOffset + 4);
+
+ if (T1 == nullptr)
+ return T0;
+ }
+ // Handle vector cases
+ if (isFloatTypeWithSemantics(T0, APFloat::IEEEsingle()) &&
+ isFloatTypeWithSemantics(T1, APFloat::IEEEsingle()))
+ return TB.getVectorType(T0, ElementCount::getFixed(2), Align(8));
+
+ if (Is16bitFpTy(T0) && Is16bitFpTy(T1)) {
+ const Type *T2 = nullptr;
+ if (SourceSize > 4)
+ T2 = getFPTypeAtOffset(ABIType, ABIOffset + 4);
+ if (!T2)
+ return TB.getVectorType(T0, ElementCount::getFixed(2), Align(8));
+ return TB.getVectorType(T0, ElementCount::getFixed(4), Align(8));
+ }
+
+ // Mixed half-float cases
+ if (Is16bitFpTy(T0) || Is16bitFpTy(T1))
+ return TB.getVectorType(TB.getFloatType(APFloat::IEEEhalf(), Align(2)),
+ ElementCount::getFixed(4), Align(8));
+
+ // Default to double
+ return TB.getFloatType(APFloat::IEEEdouble(), Align(8));
+}
+
+/// The ABI specifies that a value should be passed in a full vector XMM/YMM
+/// register. Pick an LLVM IR type that will be passed as a vector register.
+const Type *X86_64TargetInfo::getByteVectorType(const Type *Ty) const {
+ // Wrapper structs/arrays that only contain vectors are passed just like
+ // vectors; strip them off if present.
+ if (const Type *InnerTy = isSingleElementStruct(Ty))
+ Ty = InnerTy;
+
+ // Handle vector types
+ if (const VectorType *VT = dyn_cast<VectorType>(Ty)) {
+ // Don't pass vXi128 vectors in their native type, the backend can't
+ // legalize them.
+ if (getABICompatInfo().PassInt128VectorsInMem &&
+ VT->getElementType()->isInteger() &&
+ cast<IntegerType>(VT->getElementType())->getSizeInBits() == 128) {
+ unsigned Size = VT->getSizeInBits().getFixedValue();
+ return TB.getVectorType(TB.getIntegerType(64, Align(8), /*Signed=*/false),
+ ElementCount::getFixed(Size / 64),
+ Align(Size / 8));
+ }
+ return VT;
+ }
+
+ // Handle fp128
+ if (isFloatTypeWithSemantics(Ty, APFloat::IEEEquad()))
+ return Ty;
+
+ // We couldn't find the preferred IR vector type for 'Ty'.
+ unsigned Size = Ty->getSizeInBits().getFixedValue();
+ assert((Size == 128 || Size == 256 || Size == 512) && "Invalid vector size");
+
+ return TB.getVectorType(TB.getFloatType(APFloat::IEEEdouble(), Align(8)),
+ ElementCount::getFixed(Size / 64), Align(Size / 8));
+}
+
+// Returns the single element if this is a single-element struct wrapper
+const Type *X86_64TargetInfo::isSingleElementStruct(const Type *Ty) const {
+ const auto *RT = dyn_cast<RecordType>(Ty);
+ if (!RT)
+ return nullptr;
+
+ if (RT->hasFlexibleArrayMember())
+ return nullptr;
+
+ const Type *Found = nullptr;
+
+ for (const auto &Base : RT->getBaseClasses()) {
+ const Type *BaseTy = Base.FieldType;
+ auto *BaseRT = dyn_cast<RecordType>(BaseTy);
+
+ if (!BaseRT || BaseRT->isEmpty())
+ continue;
+
+ const Type *Elem = isSingleElementStruct(BaseTy);
+ if (!Elem || Found)
+ return nullptr;
+ Found = Elem;
+ }
+
+ for (const auto &FI : RT->getFields()) {
+ if (FI.isEmpty())
+ continue;
+
+ const Type *FTy = FI.FieldType;
+
+ while (auto *AT = dyn_cast<ArrayType>(FTy)) {
+ if (AT->getNumElements() != 1)
+ break;
+ FTy = AT->getElementType();
+ }
+
+ const Type *Elem;
+ if (auto *InnerRT = dyn_cast<RecordType>(FTy))
+ Elem = isSingleElementStruct(InnerRT);
+ else
+ Elem = FTy;
+ if (!Elem || Found)
+ return nullptr;
+ Found = Elem;
+ }
+
+ if (!Found)
+ return nullptr;
+ if (Found->getSizeInBits() != Ty->getSizeInBits())
+ return nullptr;
+
+ return Found;
+}
+
+bool X86_64TargetInfo::isIllegalVectorType(const Type *Ty) const {
+ if (const auto *VecTy = dyn_cast<VectorType>(Ty)) {
+ uint64_t Size = VecTy->getSizeInBits().getFixedValue();
+ unsigned LargestVector = getNativeVectorSizeForAVXABI(AVXLevel);
+
+ // Vectors <= 64 bits or > largest supported vector size are illegal
+ if (Size <= 64 || Size > LargestVector)
+ return true;
+
+ // Check for 128-bit integer element vectors that should be passed in memory
+ const Type *EltTy = VecTy->getElementType();
+ if (getABICompatInfo().PassInt128VectorsInMem && EltTy->isInteger()) {
+ const auto *IntTy = cast<IntegerType>(EltTy);
+ if (IntTy->getSizeInBits().getFixedValue() == 128)
+ return true;
+ }
+ }
+ return false;
+}
+
+ArgInfo X86_64TargetInfo::getIndirectResult(const Type *Ty,
+ unsigned FreeIntRegs) const {
+ // If this is a scalar LLVM value then assume LLVM will pass it in the right
+ // place naturally.
+ //
+ // This assumption is optimistic, as there could be free registers available
+ // when we need to pass this argument in memory, and LLVM could try to pass
+ // the argument in the free register. This does not seem to happen currently,
+ // but this code would be much safer if we could mark the argument with
+ // 'onstack'. See PR12193.
+ if (!isAggregateTypeForABI(Ty) && !isIllegalVectorType(Ty) &&
+ !(Ty->isInteger() && cast<IntegerType>(Ty)->isBitInt())) {
+ return (Ty->isInteger() && isPromotableInteger(cast<IntegerType>(Ty))
+ ? ArgInfo::getExtend(Ty)
+ : ArgInfo::getDirect());
+ }
+
+ // Check if this is a record type that needs special handling
+ if (auto RecordRAA = getRecordArgABI(Ty))
+ return getNaturalAlignIndirect(Ty, RecordRAA ==
+ RecordArgABI::RAA_DirectInMemory);
+
+ // Compute the byval alignment. We specify the alignment of the byval in all
+ // cases so that the mid-level optimizer knows the alignment of the byval.
+ uint64_t AlignVal = std::max<uint64_t>(Ty->getAlignment().value(), 8u);
+
+ // Attempt to avoid passing indirect results using byval when possible. This
+ // is important for good codegen.
+ //
+ // We do this by coercing the value into a scalar type which the backend can
+ // handle naturally (i.e., without using byval).
+ //
+ // For simplicity, we currently only do this when we have exhausted all of the
+ // free integer registers. Doing this when there are free integer registers
+ // would require more care, as we would have to ensure that the coerced value
+ // did not claim the unused register. That would require either reording the
+ // arguments to the function (so that any subsequent inreg values came first),
+ // or only doing this optimization when there were no following arguments that
+ // might be inreg.
+ //
+ // We currently expect it to be rare (particularly in well written code) for
+ // arguments to be passed on the stack when there are still free integer
+ // registers available (this would typically imply large structs being passed
+ // by value), so this seems like a fair tradeoff for now.
+ //
+ // We can revisit this if the backend grows support for 'onstack' parameter
+ // attributes. See PR12193.
+ if (FreeIntRegs == 0) {
+ uint64_t Size = Ty->getSizeInBits().getFixedValue();
+
+ // If this type fits in an eightbyte, coerce it into the matching integral
+ // type, which will end up on the stack (with alignment 8).
+ if (AlignVal == 8 && Size <= 64) {
+ const Type *IntTy =
+ TB.getIntegerType(Size, llvm::Align(8), /*Signed=*/false);
+ return ArgInfo::getDirect(IntTy);
+ }
+ }
+
+ return ArgInfo::getIndirect(llvm::Align(AlignVal), /*ByVal=*/true);
+}
+
+ArgInfo X86_64TargetInfo::getIndirectReturnResult(const Type *Ty) const {
+ // If this is a scalar value, handle it specially.
+ if (!isAggregateTypeForABI(Ty)) {
+ // Bit-precise integers are returned indirectly regardless of size.
+ if (const auto *IntTy = dyn_cast<IntegerType>(Ty)) {
+ if (IntTy->isBitInt())
+ return getNaturalAlignIndirect(IntTy, /*ByVal=*/false);
+ if (isPromotableInteger(IntTy))
+ return ArgInfo::getExtend(Ty);
+ }
+ return ArgInfo::getDirect();
+ }
+
+ return getNaturalAlignIndirect(Ty, /*ByVal=*/false);
+}
+
+static bool classifyCXXReturnType(FunctionInfo &FI) {
+ const abi::Type *Ty = FI.getReturnType();
+
+ if (const auto *RT = llvm::dyn_cast<abi::RecordType>(Ty)) {
+ if (!RT->canPassInRegisters()) {
+ FI.getReturnInfo() =
+ ArgInfo::getIndirect(RT->getAlignment(), /*ByVal=*/false);
+ return true;
+ }
+ }
+
+ return false;
+}
+
+void X86_64TargetInfo::computeInfo(FunctionInfo &FI) const {
+ CallingConv::ID CallingConv = FI.getCallingConvention();
+
+ if (CallingConv == CallingConv::Win64 ||
+ CallingConv == CallingConv::X86_RegCall)
+ return;
+
+ bool IsRegCall = false;
+
+ unsigned FreeIntRegs = 6;
+ unsigned FreeSSERegs = 8;
+ unsigned NeededInt = 0, NeededSSE = 0;
+
+ if (!classifyCXXReturnType(FI)) {
+ const Type *RetTy = FI.getReturnType();
+ FI.getReturnInfo() = classifyReturnType(RetTy);
+ }
+
+ if (FI.getReturnInfo().isIndirect())
+ --FreeIntRegs;
+
+ unsigned NumRequiredArgs = FI.getNumRequiredArgs();
+
+ unsigned ArgNo = 0;
+ for (auto IT = FI.arg_begin(), IE = FI.arg_end(); IT != IE; ++IT, ++ArgNo) {
+ bool IsNamedArg = ArgNo < NumRequiredArgs;
+ const Type *ArgTy = IT->ABIType;
+ NeededInt = 0;
+ NeededSSE = 0;
+
+ ArgInfo AI = classifyArgumentType(ArgTy, FreeIntRegs, NeededInt, NeededSSE,
+ IsNamedArg, IsRegCall);
+
+ // AMD64-ABI 3.2.3p3: If there are no registers available for any
+ // eightbyte of an argument, the whole argument is passed on the
+ // stack. If registers have already been assigned for some
+ // eightbytes of such an argument, the assignments get reverted.
+ if (FreeIntRegs >= NeededInt && FreeSSERegs >= NeededSSE) {
+ FreeIntRegs -= NeededInt;
+ FreeSSERegs -= NeededSSE;
+ IT->Info = AI;
+ } else {
+ // Not enough registers, pass on stack
+ IT->Info = getIndirectResult(ArgTy, FreeIntRegs);
+ }
+ }
+}
+
+std::unique_ptr<TargetInfo> createX8664TargetInfo(TypeBuilder &TB,
+ const Triple &TargetTriple,
+ X86AVXABILevel AVXLevel,
+ bool Has64BitPointers,
+ const ABICompatInfo &Compat) {
+ return std::make_unique<X86_64TargetInfo>(TB, TargetTriple, AVXLevel,
+ Has64BitPointers, Compat);
+}
+
+} // namespace abi
+} // namespace llvm
diff --git a/llvm/lib/ABI/Types.cpp b/llvm/lib/ABI/Types.cpp
index 0a6080de3923b..6f2eb7225364a 100644
--- a/llvm/lib/ABI/Types.cpp
+++ b/llvm/lib/ABI/Types.cpp
@@ -7,6 +7,8 @@
//===----------------------------------------------------------------------===//
#include "llvm/ABI/Types.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/SmallVector.h"
#include "llvm/Support/Casting.h"
using namespace llvm;
@@ -30,6 +32,52 @@ bool RecordType::isEmpty() const {
return true;
}
+const FieldInfo *
+RecordType::getElementContainingOffset(unsigned OffsetInBits) const {
+ SmallVector<std::pair<unsigned, const FieldInfo *>, 16> AllElements;
+
+ for (const FieldInfo &Base : getBaseClasses()) {
+ const auto *BaseRT = dyn_cast<RecordType>(Base.FieldType);
+ if (!BaseRT || !BaseRT->isEmpty())
+ AllElements.emplace_back(Base.OffsetInBits, &Base);
+ }
+
+ for (const FieldInfo &VBase : getVirtualBaseClasses()) {
+ const auto *VBaseRT = dyn_cast<RecordType>(VBase.FieldType);
+ if (!VBaseRT || !VBaseRT->isEmpty())
+ AllElements.emplace_back(VBase.OffsetInBits, &VBase);
+ }
+
+ for (const FieldInfo &Field : getFields()) {
+ if (Field.IsUnnamedBitfield)
+ continue;
+ AllElements.emplace_back(Field.OffsetInBits, &Field);
+ }
+
+ llvm::stable_sort(AllElements, [](const auto &A, const auto &B) {
+ return A.first < B.first;
+ });
+
+ auto *It = llvm::upper_bound(AllElements, OffsetInBits,
+ [](unsigned Offset, const auto &Element) {
+ return Offset < Element.first;
+ });
+
+ if (It == AllElements.begin())
+ return nullptr;
+
+ --It;
+
+ const FieldInfo *Candidate = It->second;
+ unsigned ElementStart = It->first;
+ unsigned ElementSize = Candidate->FieldType->getSizeInBits().getFixedValue();
+
+ if (OffsetInBits >= ElementStart && OffsetInBits < ElementStart + ElementSize)
+ return Candidate;
+
+ return nullptr;
+}
+
bool FieldInfo::isEmpty() const {
if (IsUnnamedBitfield)
return true;
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