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Fix simplifycfg crash in handing block merge. 

llvm-svn: 55971
This commit is contained in:
Devang Patel 2008-09-09 01:06:56 +00:00
parent 41cf9dedc6
commit 0f7a3507cf
2 changed files with 71 additions and 1 deletions
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12
llvm/lib/Transforms/Utils/BasicBlockUtils.cpp
View File

@ -54,7 +54,17 @@ bool llvm::MergeBlockIntoPredecessor(BasicBlock* BB, Pass* P) {
// Can't merge if there are multiple successors.
if (!OnlySucc) return false;
// Can't merge if there is PHI loop.
for (BasicBlock::iterator BI = BB->begin(), BE = BB->end(); BI != BE; ++BI) {
if (PHINode *PN = dyn_cast<PHINode>(BI)) {
for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i)
if (PN->getIncomingValue(i) == PN)
return false;
} else
break;
}
// Begin by getting rid of unneeded PHIs.
while (PHINode *PN = dyn_cast<PHINode>(&BB->front())) {
PN->replaceAllUsesWith(PN->getIncomingValue(0));

60
llvm/test/Transforms/SimplifyCFG/2008-09-08-MultiplePred.ll Normal file
View File

@ -0,0 +1,60 @@
; RUN: llvm-as < %s | opt -simplifycfg -disable-output
; PR 2777
@g_103 = common global i32 0 ; <i32*> [#uses=1]
define i32 @func_127(i32 %p_129) nounwind {
entry:
load i32* @g_103, align 4 ; <i32>:0 [#uses=1]
icmp eq i32 %0, 0 ; <i1>:1 [#uses=2]
br i1 %1, label %bb6.preheader, label %entry.return_crit_edge
entry.return_crit_edge: ; preds = %entry
br label %return
bb6.preheader: ; preds = %entry
br i1 %1, label %bb6.preheader.split.us, label %bb6.preheader.split
bb6.preheader.split.us: ; preds = %bb6.preheader
br label %return.loopexit.split
bb6.preheader.split: ; preds = %bb6.preheader
br label %bb6
bb6: ; preds = %bb17.bb6_crit_edge, %bb6.preheader.split
%indvar35 = phi i32 [ 0, %bb6.preheader.split ], [ %indvar.next36, %bb17.bb6_crit_edge ] ; <i32> [#uses=1]
%p_129_addr.3.reg2mem.0 = phi i32 [ %p_129_addr.2, %bb17.bb6_crit_edge ], [ %p_129, %bb6.preheader.split ] ; <i32> [#uses=3]
icmp eq i32 %p_129_addr.3.reg2mem.0, 0 ; <i1>:2 [#uses=1]
br i1 %2, label %bb6.bb17_crit_edge, label %bb8
bb6.bb17_crit_edge: ; preds = %bb6
br label %bb17
bb8: ; preds = %bb6
br label %bb13
bb13: ; preds = %bb8
br label %bb17
bb17: ; preds = %bb13, %bb6.bb17_crit_edge
%p_129_addr.2 = phi i32 [ %p_129_addr.3.reg2mem.0, %bb13 ], [ %p_129_addr.3.reg2mem.0, %bb6.bb17_crit_edge ] ; <i32> [#uses=1]
%indvar.next36 = add i32 %indvar35, 1 ; <i32> [#uses=2]
%exitcond37 = icmp eq i32 %indvar.next36, -1 ; <i1> [#uses=1]
br i1 %exitcond37, label %return.loopexit, label %bb17.bb6_crit_edge
bb17.bb6_crit_edge: ; preds = %bb17
br label %bb6
return.loopexit: ; preds = %bb17
br label %return.loopexit.split
return.loopexit.split: ; preds = %return.loopexit, %bb6.preheader.split.us
br label %return
return: ; preds = %return.loopexit.split, %entry.return_crit_edge
ret i32 1
}
define i32 @func_135(i8 zeroext %p_137, i32 %p_138, i32 %p_140) nounwind {
entry:
ret i32 undef
}