diff options
Diffstat (limited to 'lib/CodeGen/TargetInfo.cpp')
| -rw-r--r-- | lib/CodeGen/TargetInfo.cpp | 12 |
1 files changed, 5 insertions, 7 deletions
diff --git a/lib/CodeGen/TargetInfo.cpp b/lib/CodeGen/TargetInfo.cpp index 88f8579b9a..33291dd552 100644 --- a/lib/CodeGen/TargetInfo.cpp +++ b/lib/CodeGen/TargetInfo.cpp @@ -1983,19 +1983,17 @@ static llvm::Value *EmitVAArgFromMemory(llvm::Value *VAListAddr, // AMD64-ABI 3.5.7p5: Step 7. Align l->overflow_arg_area upwards to a 16 // byte boundary if alignment needed by type exceeds 8 byte boundary. + // It isn't stated explicitly in the standard, but in practice we use + // alignment greater than 16 where necessary. uint64_t Align = CGF.getContext().getTypeAlign(Ty) / 8; if (Align > 8) { - // Note that we follow the ABI & gcc here, even though the type - // could in theory have an alignment greater than 16. This case - // shouldn't ever matter in practice. - - // overflow_arg_area = (overflow_arg_area + 15) & ~15; + // overflow_arg_area = (overflow_arg_area + align - 1) & -align; llvm::Value *Offset = - llvm::ConstantInt::get(CGF.Int32Ty, 15); + llvm::ConstantInt::get(CGF.Int64Ty, Align - 1); overflow_arg_area = CGF.Builder.CreateGEP(overflow_arg_area, Offset); llvm::Value *AsInt = CGF.Builder.CreatePtrToInt(overflow_arg_area, CGF.Int64Ty); - llvm::Value *Mask = llvm::ConstantInt::get(CGF.Int64Ty, ~15LL); + llvm::Value *Mask = llvm::ConstantInt::get(CGF.Int64Ty, -(uint64_t)Align); overflow_arg_area = CGF.Builder.CreateIntToPtr(CGF.Builder.CreateAnd(AsInt, Mask), overflow_arg_area->getType(), |