// Do branch inversion.
BasicBlock *CurrBlock = LastCondBlock;
bool EverChanged = false;
- while (1) {
+ for (;CurrBlock != FirstCondBlock;
+ CurrBlock = CurrBlock->getSinglePredecessor()) {
BranchInst *BI = dyn_cast<BranchInst>(CurrBlock->getTerminator());
CmpInst *CI = dyn_cast<CmpInst>(BI->getCondition());
+ if (!CI)
+ continue;
+
CmpInst::Predicate Predicate = CI->getPredicate();
// Canonicalize icmp_ne -> icmp_eq, fcmp_one -> fcmp_oeq
if ((Predicate == CmpInst::ICMP_NE) || (Predicate == CmpInst::FCMP_ONE)) {
BI->swapSuccessors();
EverChanged = true;
}
- if (CurrBlock == FirstCondBlock)
- break;
- CurrBlock = CurrBlock->getSinglePredecessor();
}
return EverChanged;
}
--- /dev/null
+; RUN: opt -flattencfg -S < %s | FileCheck %s
+
+
+; This test checks whether the pass completes without a crash.
+; The code is not transformed in any way
+;
+; CHECK-LABEL: @test_not_crash
+define void @test_not_crash(i32 %in_a) #0 {
+entry:
+ %cmp0 = icmp eq i32 %in_a, -1
+ %cmp1 = icmp ne i32 %in_a, 0
+ %cond0 = and i1 %cmp0, %cmp1
+ br i1 %cond0, label %b0, label %b1
+
+b0: ; preds = %entry
+ %cmp2 = icmp eq i32 %in_a, 0
+ %cmp3 = icmp ne i32 %in_a, 1
+ %cond1 = or i1 %cmp2, %cmp3
+ br i1 %cond1, label %exit, label %b1
+
+b1: ; preds = %entry, %b0
+ br label %exit
+
+exit: ; preds = %entry, %b0, %b1
+ ret void
+}