[llvm] [GlobalISel] Check width of APInts in Reassoc PtrAdd combine (PR #84335)

[Mirko Brkušanin via llvm-commits]

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@@ -4653,7 +4653,8 @@ bool CombinerHelper::matchReassocFoldConstantsInSubTree(GPtrAdd &MI,
     return false;
 
   MatchInfo = [=, &MI](MachineIRBuilder &B) {
-    auto NewCst = B.buildConstant(MRI.getType(Src2Reg), *C1 + *C2);
+    auto NewCst = B.buildConstant(MRI.getType(Src2Reg),
+                                  C1->sextOrTrunc(C2->getBitWidth()) + *C2);
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mbrkusanin wrote:

Should we always pick larger one instead?

https://github.com/llvm/llvm-project/pull/84335