From bd4ff65a601895ba816623cddb36ce466cceabe6 Mon Sep 17 00:00:00 2001
From: Tobias Hieta <tobias@hieta.se>
Date: Tue, 17 Sep 2024 09:39:01 +0200
Subject: [PATCH] Revert "[LoongArch] Eliminate the redundant sign extension of
 division (#107971)"

This reverts commit d752f29fb333d47724484e08b32d6499cc1e460e.
---
 llvm/lib/Target/LoongArch/LoongArchOptWInstrs.cpp | 15 ---------------
 1 file changed, 15 deletions(-)

diff --git a/llvm/lib/Target/LoongArch/LoongArchOptWInstrs.cpp b/llvm/lib/Target/LoongArch/LoongArchOptWInstrs.cpp
index ab90409fdf47d0..abac69054f3b91 100644
--- a/llvm/lib/Target/LoongArch/LoongArchOptWInstrs.cpp
+++ b/llvm/lib/Target/LoongArch/LoongArchOptWInstrs.cpp
@@ -637,19 +637,6 @@ static bool isSignExtendedW(Register SrcReg, const LoongArchSubtarget &ST,
         break;
       }
       return false;
-    // If all incoming values are sign-extended and all users only use
-    // the lower 32 bits, then convert them to W versions.
-    case LoongArch::DIV_D: {
-      if (!AddRegToWorkList(MI->getOperand(1).getReg()))
-        return false;
-      if (!AddRegToWorkList(MI->getOperand(2).getReg()))
-        return false;
-      if (hasAllWUsers(*MI, ST, MRI)) {
-        FixableDef.insert(MI);
-        break;
-      }
-      return false;
-    }
     }
   }
 
@@ -664,8 +651,6 @@ static unsigned getWOp(unsigned Opcode) {
     return LoongArch::ADDI_W;
   case LoongArch::ADD_D:
     return LoongArch::ADD_W;
-  case LoongArch::DIV_D:
-    return LoongArch::DIV_W;
   case LoongArch::LD_D:
   case LoongArch::LD_WU:
     return LoongArch::LD_W;