From 38c2e9b76729937b0b73b106b2b6a7daa1d2034a Mon Sep 17 00:00:00 2001 From: LLVM Packaging Team Date: Mon, 20 Jan 2020 09:26:04 +0000 Subject: [PATCH] D51639-optim-issue =================================================================== Gbp-Pq: Name D51639-optim-issue.diff --- lib/Transforms/Vectorize/LoopVectorize.cpp | 5 +++++ .../LoopVectorize/X86/uniform-phi.ll | 22 +++++++++++++++++++ 2 files changed, 27 insertions(+) diff --git a/lib/Transforms/Vectorize/LoopVectorize.cpp b/lib/Transforms/Vectorize/LoopVectorize.cpp index 5bcf0c0a..e84b3c35 100644 --- a/lib/Transforms/Vectorize/LoopVectorize.cpp +++ b/lib/Transforms/Vectorize/LoopVectorize.cpp @@ -5770,6 +5770,11 @@ void LoopVectorizationCostModel::collectLoopUniforms(unsigned VF) { for (auto OV : I->operand_values()) { if (isOutOfScope(OV)) continue; + // First order recurrence Phi's should typically be considered + // non-uniform. + auto *OP = dyn_cast(OV); + if (OP && Legal->isFirstOrderRecurrence(OP)) + continue; auto *OI = cast(OV); if (llvm::all_of(OI->users(), [&](User *U) -> bool { auto *J = cast(U); diff --git a/test/Transforms/LoopVectorize/X86/uniform-phi.ll b/test/Transforms/LoopVectorize/X86/uniform-phi.ll index 881f29a9..2be565e7 100644 --- a/test/Transforms/LoopVectorize/X86/uniform-phi.ll +++ b/test/Transforms/LoopVectorize/X86/uniform-phi.ll @@ -75,3 +75,25 @@ for.end: ; preds = %for.body ret i64 %retval } +; CHECK-LABEL: PR38786 +; Check that first order recurrence phis (%phi32 and %phi64) are not uniform. +; CHECK-NOT: LV: Found uniform instruction: %phi +define void @PR38786(double* %y, double* %x, i64 %n) { +entry: + br label %for.body + +for.body: + %phi32 = phi i32 [ 0, %entry ], [ %i32next, %for.body ] + %phi64 = phi i64 [ 0, %entry ], [ %i64next, %for.body ] + %i32next = add i32 %phi32, 1 + %i64next = zext i32 %i32next to i64 + %xip = getelementptr inbounds double, double* %x, i64 %i64next + %yip = getelementptr inbounds double, double* %y, i64 %phi64 + %xi = load double, double* %xip, align 8 + store double %xi, double* %yip, align 8 + %cmp = icmp slt i64 %i64next, %n + br i1 %cmp, label %for.body, label %for.end + +for.end: + ret void +} -- 2.30.2