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Fix a bug where RecursivelyDeleteTriviallyDeadInstructions could

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delete the instruction pointed to by CGP's current instruction
iterator, leading to a crash on the testcase.  This fixes PR9578.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129200 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2011-04-09 07:05:44 +00:00
parent c3e4e59d10
commit 0403b473dd
2 changed files with 46 additions and 3 deletions
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21
lib/Transforms/Scalar/CodeGenPrepare.cpp
View File

@ -889,11 +889,26 @@ bool CodeGenPrepare::OptimizeMemoryInst(Instruction *MemoryInst, Value *Addr,
MemoryInst->replaceUsesOfWith(Repl, SunkAddr);
// If we have no uses, recursively delete the value and all dead instructions
// using it.
if (Repl->use_empty()) {
// This can cause recursive deletion, which can invalidate our iterator.
// Use a WeakVH to hold onto it in case this happens.
WeakVH IterHandle(CurInstIterator);
BasicBlock *BB = CurInstIterator->getParent();
RecursivelyDeleteTriviallyDeadInstructions(Repl);
// This address is now available for reassignment, so erase the table entry;
// we don't want to match some completely different instruction.
SunkAddrs[Addr] = 0;
if (IterHandle != CurInstIterator) {
// If the iterator instruction was recursively deleted, start over at the
// start of the block.
CurInstIterator = BB->begin();
SunkAddrs.clear();
} else {
// This address is now available for reassignment, so erase the table
// entry; we don't want to match some completely different instruction.
SunkAddrs[Addr] = 0;
}
}
++NumMemoryInsts;
return true;

28
test/CodeGen/Generic/crash.ll
View File

@ -38,3 +38,31 @@ unreachable
declare void @Parse_Vector(double*)
declare i32 @llvm.objectsize.i32(i8*, i1)
; PR9578
%struct.S0 = type { i32, i8, i32 }
define void @func_82() nounwind optsize {
entry:
br label %for.body.i
for.body.i: ; preds = %for.body.i, %entry
br i1 undef, label %func_74.exit.for.cond29.thread_crit_edge, label %for.body.i
func_74.exit.for.cond29.thread_crit_edge: ; preds = %for.body.i
%f13576.pre = getelementptr inbounds %struct.S0* undef, i64 0, i32 1
store i8 0, i8* %f13576.pre, align 4, !tbaa !0
br label %lbl_468
lbl_468: ; preds = %lbl_468, %func_74.exit.for.cond29.thread_crit_edge
%f13577.ph = phi i8* [ %f13576.pre, %func_74.exit.for.cond29.thread_crit_edge ], [ %f135.pre, %lbl_468 ]
store i8 1, i8* %f13577.ph, align 1
%f135.pre = getelementptr inbounds %struct.S0* undef, i64 0, i32 1
br i1 undef, label %lbl_468, label %for.end74
for.end74: ; preds = %lbl_468
ret void
}
!0 = metadata !{metadata !"omnipotent char", metadata !1}
!1 = metadata !{metadata !"Simple C/C++ TBAA", null}