If we're dealing with a zero-length array, don't lower to any

particular size, we just don't know what the length is yet.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95266 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Eric Christopher 2010-02-03 23:56:07 +00:00
parent 9e90619a0e
commit ec5ef6d8b0
2 changed files with 20 additions and 4 deletions

View File

@ -648,14 +648,19 @@ Instruction *InstCombiner::visitCallInst(CallInst &CI) {
if (const ArrayType *AT = dyn_cast<ArrayType>(ObjTy->getElementType())) {
// Deal with multi-dimensional arrays
// Deal with multi-dimensional arrays
const ArrayType *SAT = AT;
while ((AT = dyn_cast<ArrayType>(AT->getElementType())))
SAT = AT;
size_t numElems = SAT->getNumElements();
// We return the remaining bytes, so grab the size of an element
// in bytes.
// If numElems is 0, we don't know how large the array is so we can't
// make any determinations yet.
if (numElems == 0) break;
// We return the remaining bytes, so grab the size of an element
// in bytes.
size_t sizeofElem = SAT->getElementType()->getPrimitiveSizeInBits() / 8;
ConstantInt *Const =
@ -665,7 +670,7 @@ Instruction *InstCombiner::visitCallInst(CallInst &CI) {
ConstantInt::get(ReturnTy,
((numElems - indx) * sizeofElem)));
}
}
}
// TODO: Add more types here.
}
}

View File

@ -27,4 +27,15 @@ cond.false:
ret i8* %2;
}
@window = external global [0 x i8]
define i1 @baz() nounwind {
; CHECK: @baz
; CHECK-NEXT: llvm.objectsize.i32
%1 = tail call i32 @llvm.objectsize.i32(i8* getelementptr inbounds ([0 x i8]* @window, i32 0, i32 0), i1 false)
%2 = icmp eq i32 %1, -1
ret i1 %2
}
declare i32 @llvm.objectsize.i32(i8*, i1) nounwind readonly