[llvm] [LoongArch] Eliminate the redundant sign extension of division (PR #107971)

[Yingwei Zheng via llvm-commits]

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@@ -637,6 +637,19 @@ 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: {
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dtcxzyw wrote:

Does it also hold for `MOD_D`?


https://github.com/llvm/llvm-project/pull/107971