diff options
| -rw-r--r-- | llvm/lib/Transforms/Vectorize/LoopVectorize.cpp | 6 | ||||
| -rw-r--r-- | llvm/test/Transforms/LoopVectorize/no_outside_user.ll | 30 |
2 files changed, 36 insertions, 0 deletions
diff --git a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp index 9e7335af5f7..1d82c7b8f54 100644 --- a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp +++ b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp @@ -2866,6 +2866,12 @@ bool LoopVectorizationLegality::canVectorizeInstrs() { DEBUG(dbgs() << "LV: Found an induction variable.\n"); Inductions[Phi] = InductionInfo(StartValue, IK); + + // Until we explicitly handle the case of an induction variable with + // an outside loop user we have to give up vectorizing this loop. + if (hasOutsideLoopUser(TheLoop, it, AllowedExit)) + return false; + continue; } diff --git a/llvm/test/Transforms/LoopVectorize/no_outside_user.ll b/llvm/test/Transforms/LoopVectorize/no_outside_user.ll index 6f0357c5e54..c83d7aac7b6 100644 --- a/llvm/test/Transforms/LoopVectorize/no_outside_user.ll +++ b/llvm/test/Transforms/LoopVectorize/no_outside_user.ll @@ -12,6 +12,7 @@ target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f3 ; We used to vectorize this loop. But it has a value that is used outside of the ; and is not a recognized reduction variable "tmp17". +; CHECK-LABEL: main ; CHECK-NOT: <2 x i32> define i32 @main() { @@ -38,4 +39,33 @@ f1.exit.loopexit: ret i32 %.lcssa } +; Don't vectorize this loop. Its phi node (induction variable) has an outside +; loop user. We currently don't handle this case. +; PR17179 +; CHECK-LABEL: test2 +; CHECK-NOT: <2 x + +@x1 = common global i32 0, align 4 +@x2 = common global i32 0, align 4 +@x0 = common global i32 0, align 4 + +define i32 @test2() { +entry: + store i32 0, i32* @x1, align 4 + %0 = load i32* @x0, align 4 + br label %for.cond1.preheader + +for.cond1.preheader: + %inc7 = phi i32 [ 0, %entry ], [ %inc, %for.cond1.preheader ] + %inc = add nsw i32 %inc7, 1 + %cmp = icmp eq i32 %inc, 52 + br i1 %cmp, label %for.end5, label %for.cond1.preheader + +for.end5: + %inc7.lcssa = phi i32 [ %inc7, %for.cond1.preheader ] + %xor = xor i32 %inc7.lcssa, %0 + store i32 52, i32* @x1, align 4 + store i32 1, i32* @x2, align 4 + ret i32 %xor +} |
