On Mon, Nov 5, 2012 at 2:42 PM, Manman Ren <[email protected]> wrote: > Author: mren > Date: Mon Nov 5 16:42:46 2012 > New Revision: 167416 > > URL: http://llvm.org/viewvc/llvm-project?rev=167416&view=rev > Log: > ARM byval: when type alignment is bigger than ABI alignment, we can't > guarantee > the type alignment of the byval argument. This patch will disable byval in > this case, > it also increases the size threshold for turning on byval. > > A backend fix will be attempted. > > rdar://12596507 > > Modified: > cfe/trunk/lib/CodeGen/TargetInfo.cpp > > Modified: cfe/trunk/lib/CodeGen/TargetInfo.cpp > URL: > http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/TargetInfo.cpp?rev=167416&r1=167415&r2=167416&view=diff > ============================================================================== > --- cfe/trunk/lib/CodeGen/TargetInfo.cpp (original) > +++ cfe/trunk/lib/CodeGen/TargetInfo.cpp Mon Nov 5 16:42:46 2012 > @@ -3220,8 +3220,16 @@ > } > > // Support byval for ARM. > - if (getContext().getTypeSizeInChars(Ty) > CharUnits::fromQuantity(64) || > - getContext().getTypeAlign(Ty) > 64) { > + // The ABI alignment for APCS is 4-byte and for AAPCS at least 4-byte and > at most 8-byte. > + // Byval can't handle the case where type alignment is bigger than ABI > alignment. > + // We also increase the threshold for byval due to its overhead. > + uint64_t ABIAlign = 4; > + uint64_t TyAlign = getContext().getTypeAlign(Ty) / 8; > + if (getABIKind() == ARMABIInfo::AAPCS_VFP || > + getABIKind() == ARMABIInfo::AAPCS) > + ABIAlign = std::min(std::max(TyAlign, (uint64_t)4), (uint64_t)8); > + if (getContext().getTypeSizeInChars(Ty) > CharUnits::fromQuantity(64*8) && > + TyAlign <= ABIAlign) { > return ABIArgInfo::getIndirect(0, /*ByVal=*/true); > }
ABIArgInfo::getIndirect takes an optional "Realign"; it's possible this code should be using it. -Eli _______________________________________________ cfe-commits mailing list [email protected] http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits
