[llvm] [CodeGenPrepare] Resolve TODO: Treat disjoint-or as an add (PR #88667)

[via llvm-commits]

https://github.com/AtariDreams created https://github.com/llvm/llvm-project/pull/88667

Because we can treat Or-disjoint as an add, this allows for better codegen preparation.

>From 3106364fe49a7f917bee26748a32daca2a6cf0b7 Mon Sep 17 00:00:00 2001
From: Rose <gfunni234 at gmail.com>
Date: Sun, 14 Apr 2024 12:31:10 -0400
Subject: [PATCH] [CodeGenPrepare] Resolve TODO: Treat disjoint-or as an add

Because we can treat Or-disjoint as an add, this allows for better codegen preparation.
---
 llvm/lib/CodeGen/CodeGenPrepare.cpp | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/llvm/lib/CodeGen/CodeGenPrepare.cpp b/llvm/lib/CodeGen/CodeGenPrepare.cpp
index 22dbb3198a9f17..f0f82b1b03f8dd 100644
--- a/llvm/lib/CodeGen/CodeGenPrepare.cpp
+++ b/llvm/lib/CodeGen/CodeGenPrepare.cpp
@@ -4851,6 +4851,10 @@ bool AddressingModeMatcher::matchOperationAddr(User *AddrInst, unsigned Opcode,
       return matchAddr(AddrInst->getOperand(0), Depth);
     return false;
   }
+  case Instruction::Or:
+      if (!cast<PossiblyDisjointInst>(AddrInst)->isDisjoint())
+        break;
+  [[fallthrough]];
   case Instruction::Add: {
     // Check to see if we can merge in one operand, then the other.  If so, we
     // win.
@@ -4891,9 +4895,6 @@ bool AddressingModeMatcher::matchOperationAddr(User *AddrInst, unsigned Opcode,
     TPT.rollback(LastKnownGood);
     break;
   }
-  // case Instruction::Or:
-  //  TODO: We can handle "Or Val, Imm" iff this OR is equivalent to an ADD.
-  // break;
   case Instruction::Mul:
   case Instruction::Shl: {
     // Can only handle X*C and X << C.