diff options
| -rw-r--r-- | llvm/lib/Analysis/ScalarEvolutionExpander.cpp | 1 | ||||
| -rw-r--r-- | llvm/test/Transforms/IndVarSimplify/pr26974.ll | 60 |
2 files changed, 61 insertions, 0 deletions
diff --git a/llvm/lib/Analysis/ScalarEvolutionExpander.cpp b/llvm/lib/Analysis/ScalarEvolutionExpander.cpp index d083037a90f..4db3c7fb7f9 100644 --- a/llvm/lib/Analysis/ScalarEvolutionExpander.cpp +++ b/llvm/lib/Analysis/ScalarEvolutionExpander.cpp @@ -1820,6 +1820,7 @@ unsigned SCEVExpander::replaceCongruentIVs(Loop *L, const DominatorTree *DT, IsomorphicInc->getType()); if (OrigInc != IsomorphicInc && TruncExpr == SE.getSCEV(IsomorphicInc) + && SE.LI.replacementPreservesLCSSAForm(IsomorphicInc, OrigInc) && ((isa<PHINode>(OrigInc) && isa<PHINode>(IsomorphicInc)) || hoistIVInc(OrigInc, IsomorphicInc))) { DEBUG_WITH_TYPE(DebugType, dbgs() diff --git a/llvm/test/Transforms/IndVarSimplify/pr26974.ll b/llvm/test/Transforms/IndVarSimplify/pr26974.ll new file mode 100644 index 00000000000..28a736441cd --- /dev/null +++ b/llvm/test/Transforms/IndVarSimplify/pr26974.ll @@ -0,0 +1,60 @@ +; RUN: opt -indvars -S < %s | FileCheck %s + +target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128" + +; indvars will try to replace %b.0.lcssa with %t.1. If it does this, +; it will break LCSSA. + +@c = external global i32, align 4 + +; CHECK-LABEL: @fn1 +define void @fn1() { +entry: + br label %for.body + +for.cond1.preheader: ; preds = %for.body + %0 = load i32, i32* @c, align 4 + br i1 undef, label %for.cond1.us.preheader, label %for.cond1 + +for.cond1.us.preheader: ; preds = %for.cond1.preheader + br label %for.cond1.us + +for.cond1.us: ; preds = %for.cond1.us, %for.cond1.us.preheader + br label %for.cond1.us + +for.body: ; preds = %for.body, %entry + br i1 undef, label %for.body, label %for.cond1.preheader + +for.cond1: ; preds = %for.cond1.preheader + br i1 true, label %for.body9.lr.ph, label %for.cond13.preheader + +for.body9.lr.ph: ; preds = %for.cond1 + br i1 undef, label %for.body9.us.preheader, label %for.body9 + +for.body9.us.preheader: ; preds = %for.body9.lr.ph + br label %for.body9.us + +for.body9.us: ; preds = %for.body9.us, %for.body9.us.preheader + br label %for.body9.us + +for.cond13.preheader: ; preds = %for.body9, %for.cond1 + %b.0.lcssa = phi i32 [ %0, %for.body9 ], [ 0, %for.cond1 ] + br label %for.cond13 + +for.body9: ; preds = %for.body9.lr.ph + br label %for.cond13.preheader + +for.cond13: ; preds = %for.cond13, %for.cond13.preheader + %d.1 = phi i32 [ %t.1, %for.cond13 ], [ %0, %for.cond13.preheader ] + %t.1 = phi i32 [ %b.0.lcssa, %for.cond13 ], [ %0, %for.cond13.preheader ] + br i1 undef, label %for.cond18.preheader, label %for.cond13 + +for.cond18.preheader: ; preds = %for.cond13 + br label %for.cond18 + +for.cond18: ; preds = %for.cond18, %for.cond18.preheader + %b.1 = phi i32 [ %xor, %for.cond18 ], [ %b.0.lcssa, %for.cond18.preheader ] + %add = add nsw i32 %b.1, %d.1 + %xor = xor i32 %add, %b.1 + br label %for.cond18 +} |
