diff options
| -rw-r--r-- | llvm/lib/Transforms/Utils/LoopUtils.cpp | 2 | ||||
| -rw-r--r-- | llvm/test/Transforms/LoopVectorize/AArch64/first-order-recurrence.ll | 41 |
2 files changed, 42 insertions, 1 deletions
diff --git a/llvm/lib/Transforms/Utils/LoopUtils.cpp b/llvm/lib/Transforms/Utils/LoopUtils.cpp index c18887f697e..a2964c38a87 100644 --- a/llvm/lib/Transforms/Utils/LoopUtils.cpp +++ b/llvm/lib/Transforms/Utils/LoopUtils.cpp @@ -541,7 +541,7 @@ bool RecurrenceDescriptor::isFirstOrderRecurrence(PHINode *Phi, Loop *TheLoop, // Get the previous value. The previous value comes from the latch edge while // the initial value comes form the preheader edge. auto *Previous = dyn_cast<Instruction>(Phi->getIncomingValueForBlock(Latch)); - if (!Previous || !TheLoop->contains(Previous)) + if (!Previous || !TheLoop->contains(Previous) || isa<PHINode>(Previous)) return false; // Ensure every user of the phi node is dominated by the previous value. The diff --git a/llvm/test/Transforms/LoopVectorize/AArch64/first-order-recurrence.ll b/llvm/test/Transforms/LoopVectorize/AArch64/first-order-recurrence.ll index de950a84a1a..5129568075f 100644 --- a/llvm/test/Transforms/LoopVectorize/AArch64/first-order-recurrence.ll +++ b/llvm/test/Transforms/LoopVectorize/AArch64/first-order-recurrence.ll @@ -256,3 +256,44 @@ for.cond.for.end_crit_edge: for.end: ret void } + +; CHECK-LABEL: @PR27246 +; +; int PR27246() { +; unsigned int e, n; +; for (int i = 1; i < 49; ++i) { +; for (int k = i; k > 1; --k) +; e = k; +; n = e; +; } +; return n; +; } +; +; CHECK-NOT: vector.ph: +; +define i32 @PR27246() { +entry: + br label %for.cond1.preheader + +for.cond1.preheader: + %i.016 = phi i32 [ 1, %entry ], [ %inc, %for.cond.cleanup3 ] + %e.015 = phi i32 [ undef, %entry ], [ %e.1.lcssa, %for.cond.cleanup3 ] + br label %for.cond1 + +for.cond.cleanup: + %e.1.lcssa.lcssa = phi i32 [ %e.1.lcssa, %for.cond.cleanup3 ] + ret i32 %e.1.lcssa.lcssa + +for.cond1: + %e.1 = phi i32 [ %k.0, %for.cond1 ], [ %e.015, %for.cond1.preheader ] + %k.0 = phi i32 [ %dec, %for.cond1 ], [ %i.016, %for.cond1.preheader ] + %cmp2 = icmp sgt i32 %k.0, 1 + %dec = add nsw i32 %k.0, -1 + br i1 %cmp2, label %for.cond1, label %for.cond.cleanup3 + +for.cond.cleanup3: + %e.1.lcssa = phi i32 [ %e.1, %for.cond1 ] + %inc = add nuw nsw i32 %i.016, 1 + %exitcond = icmp eq i32 %inc, 49 + br i1 %exitcond, label %for.cond.cleanup, label %for.cond1.preheader +} |
