6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-06-17 04:24:00 +00:00
Code Issues Projects Releases Wiki Activity

The alignment of an sret parameter is known: it must be at least the

Browse Source 
alignment of the return type.  Teach the optimizers this.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165226 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Duncan Sands
2012-10-04 13:36:31 +00:00
parent e660fc15fe
commit ffcf6dffee
3 changed files with 33 additions and 8 deletions
Download Patch File Download Diff File Expand all files Collapse all files

19
lib/Analysis/ValueTracking.cpp
View File

@ -308,11 +308,20 @@ void llvm::ComputeMaskedBits(Value *V, APInt &KnownZero, APInt &KnownOne,
}
if (Argument *A = dyn_cast<Argument>(V)) {
// Get alignment information off byval arguments if specified in the IR.
if (A->hasByValAttr())
if (unsigned Align = A->getParamAlignment())
KnownZero = APInt::getLowBitsSet(BitWidth,
CountTrailingZeros_32(Align));
unsigned Align = 0;
if (A->hasByValAttr()) {
// Get alignment information off byval arguments if specified in the IR.
Align = A->getParamAlignment();
} else if (TD && A->hasStructRetAttr()) {
// An sret parameter has at least the ABI alignment of the return type.
Type *EltTy = cast<PointerType>(A->getType())->getElementType();
if (EltTy->isSized())
Align = TD->getABITypeAlignment(EltTy);
}
if (Align)
KnownZero = APInt::getLowBitsSet(BitWidth, CountTrailingZeros_32(Align));
return;
}