[llvm] Move ExpandMemCmp and MergeIcmp to the middle end (PR #77370)

[Nikita Popov via llvm-commits]

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@@ -731,13 +730,8 @@ void CodeGenPassBuilder<Derived, TargetMachineT>::addIRPasses(
   }
 
   if (getOptLevel() != CodeGenOptLevel::None) {
-    // The MergeICmpsPass tries to create memcmp calls by grouping sequences of
-    // loads and compares. ExpandMemCmpPass then tries to expand those calls
-    // into optimally-sized loads and compares. The transforms are enabled by a
-    // target lowering hook.
-    if (!Opt.DisableMergeICmps)
-      addFunctionPass(MergeICmpsPass(), PMW);
-    addFunctionPass(ExpandMemCmpPass(), PMW);
+    // MergeICmps and ExpandMemCmp now run in the middle-end optimization
+    // pipeline (see PassBuilderPipelines.cpp). They are no longer needed here.
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nikic wrote:

I don't think we need this comment.

https://github.com/llvm/llvm-project/pull/77370