[Unroll] Don't crash when simplified branch condition is undef.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@243544 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Michael Zolotukhin 2015-07-29 18:10:29 +00:00
parent 952e40ff00
commit 815580fe7a
2 changed files with 39 additions and 4 deletions

View File

@ -599,8 +599,13 @@ analyzeLoopUnrollCost(const Loop *L, unsigned TripCount, ScalarEvolution &SE,
if (BI->isConditional()) {
if (Constant *SimpleCond =
SimplifiedValues.lookup(BI->getCondition())) {
BasicBlock *Succ = BI->getSuccessor(
cast<ConstantInt>(SimpleCond)->isZero() ? 1 : 0);
BasicBlock *Succ = nullptr;
// Just take the first successor if condition is undef
if (isa<UndefValue>(SimpleCond))
Succ = BI->getSuccessor(0);
else
Succ = BI->getSuccessor(
cast<ConstantInt>(SimpleCond)->isZero() ? 1 : 0);
if (L->contains(Succ))
BBWorklist.insert(Succ);
continue;
@ -609,8 +614,13 @@ analyzeLoopUnrollCost(const Loop *L, unsigned TripCount, ScalarEvolution &SE,
} else if (SwitchInst *SI = dyn_cast<SwitchInst>(TI)) {
if (Constant *SimpleCond =
SimplifiedValues.lookup(SI->getCondition())) {
BasicBlock *Succ =
SI->getSuccessor(cast<ConstantInt>(SimpleCond)->getSExtValue());
BasicBlock *Succ = nullptr;
// Just take the first successor if condition is undef
if (isa<UndefValue>(SimpleCond))
Succ = SI->getSuccessor(0);
else
Succ =
SI->getSuccessor(cast<ConstantInt>(SimpleCond)->getSExtValue());
if (L->contains(Succ))
BBWorklist.insert(Succ);
continue;

View File

@ -2,6 +2,8 @@
; RUN: opt < %s -S -loop-unroll -unroll-max-iteration-count-to-analyze=1000 -unroll-threshold=10 -unroll-percent-dynamic-cost-saved-threshold=20 -o /dev/null
target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
@known_constant = internal unnamed_addr constant [10 x i32] [i32 1, i32 1, i32 1, i32 1, i32 1, i32 1, i32 1, i32 1, i32 1, i32 1], align 16
define void @foo1() {
entry:
br label %for.body
@ -32,3 +34,26 @@ for.body:
for.exit:
ret void
}
define void @cmp_undef() {
entry:
br label %for.body
for.body: ; preds = %for.inc, %entry
%iv.0 = phi i64 [ 0, %entry ], [ %iv.1, %for.inc ]
%arrayidx1 = getelementptr inbounds [10 x i32], [10 x i32]* @known_constant, i64 0, i64 %iv.0
%x1 = load i32, i32* %arrayidx1, align 4
%cmp = icmp eq i32 %x1, undef
br i1 %cmp, label %if.then, label %for.inc
if.then: ; preds = %for.body
br label %for.inc
for.inc: ; preds = %for.body, %if.then
%iv.1 = add nuw nsw i64 %iv.0, 1
%exitcond = icmp eq i64 %iv.1, 10
br i1 %exitcond, label %for.end, label %for.body
for.end: ; preds = %for.inc
ret void
}