Enable SeparateConstOffsetFromGEPPass() at -O3

[gsocshubham]

Summary

Resolves - https://github.com/llvm/llvm-project/issues/50528

Please review and suggest changes.

[gsocshubham]

Is it correct place to add SeparateConstOffsetFromGEPPass after AggressiveInstCombinePass since I want splitted GEP so that early cse can optimize it?

llvm/lib/Passes/PassBuilderPipelines.cpp

 #include "llvm/Transforms/Scalar/Reassociate.h"
 #include "llvm/Transforms/Scalar/SCCP.h"
 #include "llvm/Transforms/Scalar/SROA.h"
+#include "llvm/Transforms/Scalar/SeparateConstOffsetFromGEP.h"
 #include "llvm/Transforms/Scalar/SimpleLoopUnswitch.h"
 #include "llvm/Transforms/Scalar/SimplifyCFG.h"
 #include "llvm/Transforms/Scalar/SpeculativeExecution.h"

   FPM.addPass(
       SimplifyCFGPass(SimplifyCFGOptions().convertSwitchRangeToICmp(true)));
   FPM.addPass(InstCombinePass());
-  if (Level == OptimizationLevel::O3)
+  if (Level == OptimizationLevel::O3) {
     FPM.addPass(AggressiveInstCombinePass());
+    FPM.addPass(SeparateConstOffsetFromGEPPass(true));
+  }
 
   if (!Level.isOptimizingForSize())
     FPM.addPass(LibCallsShrinkWrapPass());