[llvm] [SLP] The order of store chains needs to consider the size of the values. (PR #101810)

[via llvm-commits]

https://github.com/tcwzxx updated https://github.com/llvm/llvm-project/pull/101810

>From abdc067a10ece89a12902f4320eb4b9d7f98f7ac Mon Sep 17 00:00:00 2001
From: tcwzxx <tcwzxx at gmail.com>
Date: Sat, 3 Aug 2024 21:11:32 +0800
Subject: [PATCH] The order of store chains needs to consider the size of the
 values

---
 llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
index 8d2ce6bad6af7..97fb6798adcfc 100644
--- a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
+++ b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
@@ -19125,6 +19125,14 @@ bool SLPVectorizerPass::vectorizeStoreChains(BoUpSLP &R) {
     if (V->getPointerOperandType()->getTypeID() >
         V2->getPointerOperandType()->getTypeID())
       return false;
+    if (V->getValueOperand()->getType()->getScalarSizeInBits() <
+        V2->getValueOperand()->getType()->getScalarSizeInBits()) {
+      return true;
+    }
+    if (V->getValueOperand()->getType()->getScalarSizeInBits() >
+        V2->getValueOperand()->getType()->getScalarSizeInBits()) {
+      return false;
+    }
     // UndefValues are compatible with all other values.
     if (isa<UndefValue>(V->getValueOperand()) ||
         isa<UndefValue>(V2->getValueOperand()))