[llvm] <Fix> incorrect IndexReg parameter (PR #82881)

[via llvm-commits]

https://github.com/RicoAfoat updated https://github.com/llvm/llvm-project/pull/82881

>From 1310e960dd95f56c97002ec3ec18da5547c8c132 Mon Sep 17 00:00:00 2001
From: RicoAfoat <3094209316 at qq.com>
Date: Sat, 24 Feb 2024 18:09:53 +0800
Subject: [PATCH 1/2] <Fix> incorrect IndexReg parameter

---
 llvm/lib/Target/X86/X86ISelDAGToDAG.cpp | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp b/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp
index c8f80ced354538..50be61c56e951c 100644
--- a/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp
+++ b/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp
@@ -2732,13 +2732,14 @@ bool X86DAGToDAGISel::matchAddressRecursively(SDValue N, X86ISelAddressMode &AM,
       insertDAGNode(*CurDAG, N, Zext);
       SDValue NewShl = CurDAG->getNode(ISD::SHL, DL, VT, Zext, ShlAmt);
       insertDAGNode(*CurDAG, N, NewShl);
+      CurDAG->ReplaceAllUsesWith(N, NewShl);
+      CurDAG->RemoveDeadNode(N.getNode());
 
       // Convert the shift to scale factor.
       AM.Scale = 1 << ShAmtV;
-      AM.IndexReg = Zext;
-
-      CurDAG->ReplaceAllUsesWith(N, NewShl);
-      CurDAG->RemoveDeadNode(N.getNode());
+      // If matchIndexRecursively is not called here, 
+      // Zext may be replaced by other nodes but later used to call a builder method
+      AM.IndexReg = matchIndexRecursively(Zext, AM, Depth + 1);
       return false;
     }
 

>From 8048ca07fbb1fd2d4071e04da25929ae63ddbdd7 Mon Sep 17 00:00:00 2001
From: RicoAfoat <3094209316 at qq.com>
Date: Sat, 24 Feb 2024 21:52:34 +0800
Subject: [PATCH 2/2] <Fix> A replaced SDValue is used to call getNode function

---
 llvm/lib/Target/X86/X86ISelDAGToDAG.cpp | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp b/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp
index c8f80ced354538..5cbd9ab4dc2d6c 100644
--- a/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp
+++ b/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp
@@ -2732,13 +2732,15 @@ bool X86DAGToDAGISel::matchAddressRecursively(SDValue N, X86ISelAddressMode &AM,
       insertDAGNode(*CurDAG, N, Zext);
       SDValue NewShl = CurDAG->getNode(ISD::SHL, DL, VT, Zext, ShlAmt);
       insertDAGNode(*CurDAG, N, NewShl);
+      CurDAG->ReplaceAllUsesWith(N, NewShl);
+      CurDAG->RemoveDeadNode(N.getNode());
 
       // Convert the shift to scale factor.
       AM.Scale = 1 << ShAmtV;
-      AM.IndexReg = Zext;
-
-      CurDAG->ReplaceAllUsesWith(N, NewShl);
-      CurDAG->RemoveDeadNode(N.getNode());
+      // If matchIndexRecursively is not called here,
+      // Zext may be replaced by other nodes but later used to call a builder
+      // method
+      AM.IndexReg = matchIndexRecursively(Zext, AM, Depth + 1);
       return false;
     }