[LV] Fix missing entry in willGenerateVectors

[artagnon]

willGenerateVectors switches on opcodes of a recipe, but Histogram is missing in the switch statement, which could cause a crash in some cases. The crash was initially observed when developing another patch.

[llvmbot]

@llvm/pr-subscribers-llvm-transforms

@llvm/pr-subscribers-vectorizers

Author: Ramkumar Ramachandra (artagnon)

Changes

willGenerateVectors switches on opcodes of a recipe, but Histogram is missing in the switch statement, which could cause a crash in some cases. The crash was initially observed when developing another patch: no test case is included with this patch, as the bug is evident.

---

Full diff: https://github.com/llvm/llvm-project/pull/136712.diff

1 Files Affected:

• (modified) llvm/lib/Transforms/Vectorize/LoopVectorize.cpp (+1)

diff --git a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
index 32c3435ccb38d..4f607f4732aba 100644
--- a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -4460,6 +4460,7 @@ static bool willGenerateVectors(VPlan &Plan, ElementCount VF,
       case VPDef::VPWidenSelectSC:
       case VPDef::VPBlendSC:
       case VPDef::VPFirstOrderRecurrencePHISC:
+      case VPDef::VPHistogramSC:
       case VPDef::VPWidenPHISC:
       case VPDef::VPWidenIntOrFpInductionSC:
       case VPDef::VPWidenPointerInductionSC:

[fhahn]

If possible, would still good to add a test case, to guard against regressions in the future.

[huntergr-arm]

LGTM, thanks for catching/fixing it.

[fhahn]

LGTM, thanks