diff options
| -rw-r--r-- | llvm/lib/Transforms/Vectorize/LoopVectorize.cpp | 6 | ||||
| -rw-r--r-- | llvm/test/Transforms/LoopVectorize/if-conversion.ll | 27 |
2 files changed, 30 insertions, 3 deletions
diff --git a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp index 5267a2a3f19..487a7fb72f0 100644 --- a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp +++ b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp @@ -4526,10 +4526,10 @@ void InnerLoopVectorizer::widenPHIInstruction(Instruction *PN, unsigned UF, for (unsigned Part = 0; Part < UF; ++Part) { Value *In0 = getOrCreateVectorValue(P->getIncomingValue(In), Part); - // We might have single edge PHIs (blocks) - use an identity - // 'select' for the first PHI operand. + assert((Cond[Part] || NumIncoming == 1) && + "Multiple predecessors with one predecessor having a full mask"); if (In == 0) - Entry[Part] = Builder.CreateSelect(Cond[Part], In0, In0); + Entry[Part] = In0; // Initialize with the first incoming value. else // Select between the current value and the previous incoming edge // based on the incoming mask. diff --git a/llvm/test/Transforms/LoopVectorize/if-conversion.ll b/llvm/test/Transforms/LoopVectorize/if-conversion.ll index ad50e0b00fc..dfc062eaada 100644 --- a/llvm/test/Transforms/LoopVectorize/if-conversion.ll +++ b/llvm/test/Transforms/LoopVectorize/if-conversion.ll @@ -168,3 +168,30 @@ cond.end: for.end: ret i32 %or } + +; Handle PHI with single incoming value having a full mask. +; PR34523 + +; CHECK-LABEL: PR34523 +; CHECK: vector.body + +define void @PR34523() { +bb1: + br label %bb2 + +bb2: ; preds = %bb4, %bb1 + %i = phi i16 [ undef, %bb1 ], [ %_tmp2, %bb4 ] + br label %bb3 + +bb3: ; preds = %bb2 + %_tmp1 = phi [1 x [1 x i32]]* [ undef, %bb2 ] + br label %bb4 + +bb4: ; preds = %bb3 + %_tmp2 = add i16 %i, 1 + %_tmp3 = icmp slt i16 %_tmp2, 2 + br i1 %_tmp3, label %bb2, label %bb5 + +bb5: ; preds = %bb4 + unreachable +} |
