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pass/return structs of char and short as i8/i16 to avoid 

aweful through-memory coersion, just like we do for i32 now.

llvm-svn: 107078
This commit is contained in:
Chris Lattner 2010-06-28 21:59:07 +00:00
parent e233dda2e2
commit 93af332819
3 changed files with 11 additions and 7 deletions
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14
clang/lib/CodeGen/TargetInfo.cpp
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@ -1116,11 +1116,15 @@ ABIArgInfo X86_64ABIInfo::getCoerceResult(QualType Ty,
return (Ty->isPromotableIntegerType() ?
ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
// If this is a 32-bit structure that is passed as an int64, then it will be
// passed in the low 32-bits of a 64-bit GPR, which is the same as how an
// i32 is passed. Coerce to a i32 instead of a i64.
if (Context.getTypeSizeInChars(Ty).getQuantity() == 4)
CoerceTo = llvm::Type::getInt32Ty(CoerceTo->getContext());
// 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.
switch (Context.getTypeSizeInChars(Ty).getQuantity()) {
default: break;
case 1: CoerceTo = llvm::Type::getInt8Ty(CoerceTo->getContext()); break;
case 2: CoerceTo = llvm::Type::getInt16Ty(CoerceTo->getContext()); break;
case 4: CoerceTo = llvm::Type::getInt32Ty(CoerceTo->getContext()); break;
}
} else if (CoerceTo->isDoubleTy()) {
assert(Ty.isCanonical() && "should always have a canonical type here");

2
clang/test/CodeGenCXX/mangle-exprs.cpp
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@ -39,6 +39,6 @@ namespace Casts {
// CHECK: define weak_odr void @_ZN5Casts7static_ILj4EEEvPN9enable_ifIXleT_cvjLi4EEvE4typeE
template void static_<4>(void*);
// CHECK: define weak_odr i64 @_ZN5Casts1fILi6EEENS_1TIXT_EEEv
// CHECK: define weak_odr i8 @_ZN5Casts1fILi6EEENS_1TIXT_EEEv
template T<6> f<6>();
}

2
clang/test/CodeGenCXX/member-functions.cpp
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@ -58,6 +58,6 @@ struct T {
void test3() {
T t1, t2;
// RUN: grep "call i64 @_ZN1TplERKS_" %t
// RUN: grep "call i8 @_ZN1TplERKS_" %t
T result = t1 + t2;
}