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fix PR7714 by not referencing off the end of a struct when passed by value in 

x86-64 abi.  This also improves codegen as well.  Some refactoring is needed of
this code.

llvm-svn: 109681
This commit is contained in:
Chris Lattner 2010-07-28 22:15:08 +00:00
parent a5fd522992
commit 4c1e484f39
2 changed files with 53 additions and 7 deletions
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46
clang/lib/CodeGen/TargetInfo.cpp
View File

@ -1112,7 +1112,12 @@ void X86_64ABIInfo::classify(QualType Ty, uint64_t OffsetBase,
ABIArgInfo X86_64ABIInfo::getCoerceResult(QualType Ty,
const llvm::Type *CoerceTo) const {
if (CoerceTo->isIntegerTy(64) || isa<llvm::PointerType>(CoerceTo)) {
// If this is a pointer passed as a pointer, just pass it directly.
if ((isa<llvm::PointerType>(CoerceTo) || CoerceTo->isIntegerTy(64)) &&
Ty->hasPointerRepresentation())
return ABIArgInfo::getExtend();
if (isa<llvm::IntegerType>(CoerceTo)) {
// Integer and pointer types will end up in a general purpose
// register.
@ -1120,10 +1125,12 @@ ABIArgInfo X86_64ABIInfo::getCoerceResult(QualType Ty,
if (const EnumType *EnumTy = Ty->getAs<EnumType>())
Ty = EnumTy->getDecl()->getIntegerType();
if (Ty->isIntegralOrEnumerationType() || Ty->hasPointerRepresentation())
if (Ty->isIntegralOrEnumerationType())
return (Ty->isPromotableIntegerType() ?
ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
// FIXME: Zap this.
// If this is a 8/16/32-bit structure that is passed as an int64, then it
// will be passed in the low 8/16/32-bits of a 64-bit GPR, which is the same
// as how an i8/i16/i32 is passed. Coerce to a i8/i16/i32 instead of a i64.
@ -1320,6 +1327,8 @@ ABIArgInfo X86_64ABIInfo::classifyArgumentType(QualType Ty,
X86_64ABIInfo::Class Lo, Hi;
classify(Ty, 0, Lo, Hi);
uint64_t TySizeInBytes = Context.getTypeSizeInChars(Ty).getQuantity();
// Check some invariants.
// FIXME: Enforce these by construction.
assert((Hi != Memory || Lo == Memory) && "Invalid memory classification.");
@ -1351,8 +1360,6 @@ ABIArgInfo X86_64ABIInfo::classifyArgumentType(QualType Ty,
// available register of the sequence %rdi, %rsi, %rdx, %rcx, %r8
// and %r9 is used.
case Integer:
// It is always safe to classify this as an i64 argument.
ResType = llvm::Type::getInt64Ty(VMContext);
++neededInt;
// If we can choose a better 8-byte type based on the preferred type, and if
@ -1361,6 +1368,19 @@ ABIArgInfo X86_64ABIInfo::classifyArgumentType(QualType Ty,
if (isa<llvm::IntegerType>(PrefTypeLo) ||
isa<llvm::PointerType>(PrefTypeLo))
ResType = PrefTypeLo;
if (ResType == 0) {
// It is always safe to classify this as an integer type up to i64 that
// isn't larger than the structure.
if (TySizeInBytes == 1)
ResType = llvm::Type::getInt8Ty(VMContext);
else if (TySizeInBytes == 2)
ResType = llvm::Type::getInt16Ty(VMContext);
else if (TySizeInBytes <= 4)
ResType = llvm::Type::getInt32Ty(VMContext);
else
ResType = llvm::Type::getInt64Ty(VMContext);
}
break;
// AMD64-ABI 3.2.3p3: Rule 3. If the class is SSE, the next
@ -1385,8 +1405,7 @@ ABIArgInfo X86_64ABIInfo::classifyArgumentType(QualType Ty,
case NoClass: break;
case Integer: {
// It is always safe to classify this as an i64 argument.
const llvm::Type *HiType = llvm::Type::getInt64Ty(VMContext);
const llvm::Type *HiType = 0;
++neededInt;
// If we can choose a better 8-byte type based on the preferred type, and if
@ -1395,7 +1414,20 @@ ABIArgInfo X86_64ABIInfo::classifyArgumentType(QualType Ty,
if (isa<llvm::IntegerType>(PrefTypeHi) ||
isa<llvm::PointerType>(PrefTypeHi))
HiType = PrefTypeHi;
if (HiType == 0) {
// It is always safe to classify this as an integer type up to i64 that
// isn't larger than the structure.
if (TySizeInBytes == 9)
HiType = llvm::Type::getInt8Ty(VMContext);
else if (TySizeInBytes == 10)
HiType = llvm::Type::getInt16Ty(VMContext);
else if (TySizeInBytes <= 12)
HiType = llvm::Type::getInt32Ty(VMContext);
else
HiType = llvm::Type::getInt64Ty(VMContext);
}
ResType = llvm::StructType::get(VMContext, ResType, HiType, NULL);
break;
}

14
clang/test/CodeGen/x86_64-arguments.c
View File

@ -131,3 +131,17 @@ void f22(L x, L y) { }
// CHECK: %y = alloca{{.*}}, align 16
// PR7714
struct f23S {
short f0;
unsigned f1;
int f2;
};
void f23(int A, struct f23S B) {
// CHECK: define void @f23(i32 %A, i64 %B.coerce0, i32 %B.coerce1)
}