PR4286: Make RewriteLoadUserOfWholeAlloca and

RewriteStoreUserOfWholeAlloca deal with tail padding because 
isSafeUseOfBitCastedAllocation expects them to.  Otherwise, we crash 
trying to erase the bitcast.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72688 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Eli Friedman 2009-06-01 09:14:32 +00:00
parent 3728a02534
commit 41b33f437f
2 changed files with 30 additions and 8 deletions

View File

@ -903,11 +903,13 @@ void SROA::RewriteStoreUserOfWholeAlloca(StoreInst *SI,
// If this isn't a store of an integer to the whole alloca, it may be a store
// to the first element. Just ignore the store in this case and normal SROA
// will handle it. We don't handle types here that have tail padding, like
// an alloca of type {i1}.
// will handle it.
if (!isa<IntegerType>(SrcVal->getType()) ||
TD->getTypeSizeInBits(SrcVal->getType()) != AllocaSizeBits)
TD->getTypeAllocSizeInBits(SrcVal->getType()) != AllocaSizeBits)
return;
// Handle tail padding by extending the operand
if (TD->getTypeSizeInBits(SrcVal->getType()) != AllocaSizeBits)
SrcVal = new ZExtInst(SrcVal, IntegerType::get(AllocaSizeBits), "", SI);
DOUT << "PROMOTING STORE TO WHOLE ALLOCA: " << *AI << *SI;
@ -1016,10 +1018,9 @@ void SROA::RewriteLoadUserOfWholeAlloca(LoadInst *LI, AllocationInst *AI,
// If this isn't a load of the whole alloca to an integer, it may be a load
// of the first element. Just ignore the load in this case and normal SROA
// will handle it. We don't handle types here that have tail padding, like
// an alloca of type {i1}.
// will handle it.
if (!isa<IntegerType>(LI->getType()) ||
TD->getTypeSizeInBits(LI->getType()) != AllocaSizeBits)
TD->getTypeAllocSizeInBits(LI->getType()) != AllocaSizeBits)
return;
DOUT << "PROMOTING LOAD OF WHOLE ALLOCA: " << *AI << *LI;
@ -1035,7 +1036,7 @@ void SROA::RewriteLoadUserOfWholeAlloca(LoadInst *LI, AllocationInst *AI,
ArrayEltBitOffset = TD->getTypeAllocSizeInBits(ArrayEltTy);
}
Value *ResultVal = Constant::getNullValue(LI->getType());
Value *ResultVal = Constant::getNullValue(IntegerType::get(AllocaSizeBits));
for (unsigned i = 0, e = NewElts.size(); i != e; ++i) {
// Load the value from the alloca. If the NewElt is an aggregate, cast
@ -1082,7 +1083,11 @@ void SROA::RewriteLoadUserOfWholeAlloca(LoadInst *LI, AllocationInst *AI,
ResultVal = BinaryOperator::CreateOr(SrcField, ResultVal, "", LI);
}
// Handle tail padding by truncating the result
if (TD->getTypeSizeInBits(LI->getType()) != AllocaSizeBits)
ResultVal = new TruncInst(ResultVal, LI->getType(), "", LI);
LI->replaceAllUsesWith(ResultVal);
LI->eraseFromParent();
}

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@ -0,0 +1,17 @@
; RUN: llvm-as < %s | opt -scalarrepl
; PR4286
target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"
target triple = "x86_64-undermydesk-freebsd8.0"
%struct.singlebool = type <{ i8 }>
define zeroext i8 @doit() nounwind {
entry:
%a = alloca %struct.singlebool, align 1 ; <%struct.singlebool*> [#uses=2]
%storetmp.i = bitcast %struct.singlebool* %a to i1* ; <i1*> [#uses=1]
store i1 true, i1* %storetmp.i
%tmp = getelementptr %struct.singlebool* %a, i64 0, i32 0 ; <i8*> [#uses=1]
%tmp1 = load i8* %tmp ; <i8> [#uses=1]
ret i8 %tmp1
}