[llvm] [PPCMergeStringPool] Avoid replacing constant with instruction (PR #88846)

[Chen Zheng via llvm-commits]

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@@ -117,9 +118,16 @@ class PPCMergeStringPool : public ModulePass {
 // sure that they can be replaced.
 static bool hasReplaceableUsers(GlobalVariable &GV) {
   for (User *CurrentUser : GV.users()) {
-    // Instruction users are always valid.
-    if (isa<Instruction>(CurrentUser))
+    if (isa<Instruction>(CurrentUser)) {
+      if (auto *II = dyn_cast<IntrinsicInst>(CurrentUser)) {
+        // Some intrinsics require a plain global.
+        if (II->getIntrinsicID() == Intrinsic::eh_typeid_for)
+          return false;
+      }
+
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chenzheng1030 wrote:

>From https://github.com/llvm/llvm-project/blob/853344d3ae8bb655b2d15175880bd3f65ab66434/llvm/lib/CodeGen/GlobalMerge.cpp#L601-L610, seems the `GlobalVariable` used in eh related instructions are not allowed to replace. Not sure why we don't have similar logic here. @stefanp-ibm do you know why? Thanks.

https://github.com/llvm/llvm-project/pull/88846