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instcombine: disable optimization of 'invoke null/undef'. I'll move this functionality to SimplifyCFG (since we cannot make changes to the CFG here). 

Fixes the crashes with the attached test case

llvm-svn: 158951
This commit is contained in:
Nuno Lopes 2012-06-21 23:52:14 +00:00
parent f6d5e935bb
commit 771e7bd4ba
2 changed files with 58 additions and 11 deletions
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22
llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
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@ -917,24 +917,24 @@ Instruction *InstCombiner::visitCallSite(CallSite CS) {
}
if (isa<ConstantPointerNull>(Callee) || isa<UndefValue>(Callee)) {
// This instruction is not reachable, just remove it. We insert a store to
// undef so that we know that this code is not reachable, despite the fact
// that we can't modify the CFG here.
new StoreInst(ConstantInt::getTrue(Callee->getContext()),
UndefValue::get(Type::getInt1PtrTy(Callee->getContext())),
CS.getInstruction());
// If CS does not return void then replaceAllUsesWith undef.
// This allows ValueHandlers and custom metadata to adjust itself.
if (!CS.getInstruction()->getType()->isVoidTy())
ReplaceInstUsesWith(*CS.getInstruction(),
UndefValue::get(CS.getInstruction()->getType()));
if (InvokeInst *II = dyn_cast<InvokeInst>(CS.getInstruction())) {
// Don't break the CFG, insert a dummy cond branch.
BranchInst::Create(II->getNormalDest(), II->getUnwindDest(),
ConstantInt::getTrue(Callee->getContext()), II);
if (isa<InvokeInst>(CS.getInstruction())) {
// Can't remove an invoke because we cannot change the CFG.
return 0;
}
// This instruction is not reachable, just remove it. We insert a store to
// undef so that we know that this code is not reachable, despite the fact
// that we can't modify the CFG here.
new StoreInst(ConstantInt::getTrue(Callee->getContext()),
UndefValue::get(Type::getInt1PtrTy(Callee->getContext())),
CS.getInstruction());
return EraseInstFromFunction(*CS.getInstruction());
}

47
llvm/test/Transforms/InstCombine/invoke.ll Normal file
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@ -0,0 +1,47 @@
; RUN: opt < %s -instcombine -S | FileCheck %s
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-s0:64:64-f80:128:128-n8:16:32:64-S128"
declare i32 @__gxx_personality_v0(...)
declare void @__cxa_call_unexpected(i8*)
declare i64 @llvm.objectsize.i64(i8*, i1) nounwind readonly
; CHECK: @f1
define i64 @f1() nounwind uwtable ssp {
entry:
; CHECK: nvoke noalias i8* undef()
%call = invoke noalias i8* undef()
to label %invoke.cont unwind label %lpad
invoke.cont:
; CHECK: ret i64 0
%0 = tail call i64 @llvm.objectsize.i64(i8* %call, i1 false)
ret i64 %0
lpad:
%1 = landingpad { i8*, i32 } personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*)
filter [0 x i8*] zeroinitializer
%2 = extractvalue { i8*, i32 } %1, 0
tail call void @__cxa_call_unexpected(i8* %2) noreturn nounwind
unreachable
}
; CHECK: @f2
define i64 @f2() nounwind uwtable ssp {
entry:
; CHECK: nvoke noalias i8* null()
%call = invoke noalias i8* null()
to label %invoke.cont unwind label %lpad
invoke.cont:
; CHECK: ret i64 0
%0 = tail call i64 @llvm.objectsize.i64(i8* %call, i1 false)
ret i64 %0
lpad:
%1 = landingpad { i8*, i32 } personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*)
filter [0 x i8*] zeroinitializer
%2 = extractvalue { i8*, i32 } %1, 0
tail call void @__cxa_call_unexpected(i8* %2) noreturn nounwind
unreachable
}