[llvm] [ExpandMemCmp] Recognize canonical form of (icmp sle/sge X, 0) in getMemCmpOneBlock. (PR #121540)

[Nikita Popov via llvm-commits]

================
@@ -680,9 +680,19 @@ Value *MemCmpExpansion::getMemCmpOneBlock() {
         Shift == (CI->getType()->getIntegerBitWidth() - 1)) {
       Pred = ICmpInst::ICMP_SLT;
       NeedsZExt = true;
+    } else if (match(UI, m_ICmp(Pred, m_Specific(CI), m_Zero()))) {
+      // Compare with 0. Pred is already set.
+    } else if (match(UI, m_ICmp(Pred, m_Specific(CI), m_AllOnes())) &&
+               Pred == ICmpInst::ICMP_SGT) {
----------------
nikic wrote:

Use m_SpecificICmp instead.

https://github.com/llvm/llvm-project/pull/121540