[llvm] [VPlan] Mark Scalar instruction as not predicated (PR #95191)

[via llvm-commits]

https://github.com/eastB233 updated https://github.com/llvm/llvm-project/pull/95191

>From 6db180353c40ab1b716cece50dd577ce8cf1bc93 Mon Sep 17 00:00:00 2001
From: Zhiheng Xie <eastb233 at qq.com>
Date: Thu, 13 Jun 2024 09:50:28 +0800
Subject: [PATCH] [VPlan] Treat Div/Rem as not Predicated if divisor is
 invariant

Fixes https://github.com/llvm/llvm-project/issues/94328
---
 llvm/lib/Transforms/Vectorize/LoopVectorize.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
index c7c19ef456c7c..2d8891b8a1794 100644
--- a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -3863,7 +3863,8 @@ bool LoopVectorizationCostModel::isPredicatedInst(Instruction *I) const {
   case Instruction::URem:
     // TODO: We can use the loop-preheader as context point here and get
     // context sensitive reasoning
-    return !isSafeToSpeculativelyExecute(I);
+    return !isSafeToSpeculativelyExecute(I) &&
+           !Legal->isInvariant(I->getOperand(1));
   case Instruction::Call:
     return Legal->isMaskRequired(I);
   }