[llvm] [ExpandMemCmp] Use m_SpecificInt to simplify code. NFC (PR #121532)

Craig Topper via llvm-commits llvm-commits at lists.llvm.org
Thu Jan 2 16:42:26 PST 2025


https://github.com/topperc created https://github.com/llvm/llvm-project/pull/121532

None

>From de080772d10d2c22f4d801a39713aa6825dafbd0 Mon Sep 17 00:00:00 2001
From: Craig Topper <craig.topper at sifive.com>
Date: Thu, 2 Jan 2025 16:41:14 -0800
Subject: [PATCH] [ExpandMemCmp] Use m_SpecificInt to simplify code. NFC

---
 llvm/lib/CodeGen/ExpandMemCmp.cpp | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/llvm/lib/CodeGen/ExpandMemCmp.cpp b/llvm/lib/CodeGen/ExpandMemCmp.cpp
index f8ca7e370f6ef9..e18b2d3c31691c 100644
--- a/llvm/lib/CodeGen/ExpandMemCmp.cpp
+++ b/llvm/lib/CodeGen/ExpandMemCmp.cpp
@@ -669,15 +669,15 @@ Value *MemCmpExpansion::getMemCmpOneBlock() {
   if (CI->hasOneUser()) {
     auto *UI = cast<Instruction>(*CI->user_begin());
     CmpPredicate Pred = ICmpInst::Predicate::BAD_ICMP_PREDICATE;
-    uint64_t Shift;
     bool NeedsZExt = false;
     // This is a special case because instead of checking if the result is less
     // than zero:
     //    bool result = memcmp(a, b, NBYTES) < 0;
     // Compiler is clever enough to generate the following code:
     //    bool result = memcmp(a, b, NBYTES) >> 31;
-    if (match(UI, m_LShr(m_Value(), m_ConstantInt(Shift))) &&
-        Shift == (CI->getType()->getIntegerBitWidth() - 1)) {
+    if (match(UI,
+              m_LShr(m_Value(),
+                     m_SpecificInt(CI->getType()->getIntegerBitWidth() - 1)))) {
       Pred = ICmpInst::ICMP_SLT;
       NeedsZExt = true;
     } else {



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