[llvm] [DAGCombiner] Remove unneeded m_BitReverse from visitBITREVERSE. NFC (PR #168918)

[Craig Topper via llvm-commits]

https://github.com/topperc created https://github.com/llvm/llvm-project/pull/168918

We already know we're looking at BITREVERSE, we can match on the source operand.

>From 334bd13450a39075be70ac77e0da7897bb2fd63a Mon Sep 17 00:00:00 2001
From: Craig Topper <craig.topper at sifive.com>
Date: Thu, 20 Nov 2025 09:48:18 -0800
Subject: [PATCH] [DAGCombiner] Remove unneeded m_BitReverse from
 visitBITREVERSE. NFC

We already know we're looking at BITREVERSE, we can match on the
source operand.
---
 llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 94afdc5db6613..6c9a0ba4be07f 100644
--- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -11763,12 +11763,12 @@ SDValue DAGCombiner::visitBITREVERSE(SDNode *N) {
 
   // fold (bitreverse (lshr (bitreverse x), y)) -> (shl x, y)
   if ((!LegalOperations || TLI.isOperationLegal(ISD::SHL, VT)) &&
-      sd_match(N, m_BitReverse(m_Srl(m_BitReverse(m_Value(X)), m_Value(Y)))))
+      sd_match(N0, m_Srl(m_BitReverse(m_Value(X)), m_Value(Y))))
     return DAG.getNode(ISD::SHL, DL, VT, X, Y);
 
   // fold (bitreverse (shl (bitreverse x), y)) -> (lshr x, y)
   if ((!LegalOperations || TLI.isOperationLegal(ISD::SRL, VT)) &&
-      sd_match(N, m_BitReverse(m_Shl(m_BitReverse(m_Value(X)), m_Value(Y)))))
+      sd_match(N0, m_Shl(m_BitReverse(m_Value(X)), m_Value(Y))))
     return DAG.getNode(ISD::SRL, DL, VT, X, Y);
 
   return SDValue();