[llvm] [bolt][aarch64] simplify rodata/literal load for X86 & AArch64 (PR #165723)

[YongKang Zhu via llvm-commits]

================
@@ -1226,28 +1227,53 @@ bool SimplifyRODataLoads::simplifyRODataLoads(BinaryFunction &BF) {
       }
 
       // Get the contents of the section containing the target address of the
-      // memory operand. We are only interested in read-only sections.
+      // memory operand. We are only interested in read-only sections for X86,
+      // for aarch64 the sections can be read-only or executable.
       ErrorOr<BinarySection &> DataSection =
           BC.getSectionForAddress(TargetAddress);
-      if (!DataSection || DataSection->isWritable())
+      if (!DataSection)
         continue;
 
+      if (BC.isX86() && DataSection->isWritable())
+        continue;
+
+      if (DataSection->isText()) {
+        // If data is not part of a function, check if it is part of a global CI
+        // Do not proceed if there aren't data markers for CIs
+        BinaryFunction *BFTgt =
+            BC.getBinaryFunctionContainingAddress(TargetAddress,
+                                                  /*CheckPastEnd*/ false,
+                                                  /*UseMaxSize*/ true);
+        const bool IsInsideFunc =
+            BFTgt && BFTgt->isInConstantIsland(TargetAddress);
+
+        auto CIEndIter = BC.AddressToConstantIslandMap.end();
+        auto CIIter = BC.AddressToConstantIslandMap.find(TargetAddress);
+        if (!IsInsideFunc && CIIter == CIEndIter)
+          continue;
+      }
+
       if (BC.getRelocationAt(TargetAddress) ||
           BC.getDynamicRelocationAt(TargetAddress))
         continue;
 
-      uint32_t Offset = TargetAddress - DataSection->getAddress();
-      StringRef ConstantData = DataSection->getContents();
-
       ++NumLocalLoadsFound;
       if (BB->hasProfile())
         NumDynamicLocalLoadsFound += BB->getExecutionCount();
 
-      if (MIB->replaceMemOperandWithImm(Inst, ConstantData, Offset)) {
-        ++NumLocalLoadsSimplified;
-        if (BB->hasProfile())
-          NumDynamicLocalLoadsSimplified += BB->getExecutionCount();
-      }
+      uint32_t Offset = TargetAddress - DataSection->getAddress();
+      StringRef ConstantData = DataSection->getContents();
+      const InstructionListType Instrs =
+          MIB->materializeConstant(Inst, ConstantData, Offset);
+      if (Instrs.empty())
+        continue;
+
+      auto IIter = BB->findInstruction(&Inst);
+      It = std::next(BB->replaceInstruction(IIter, Instrs), Instrs.size());
----------------
yozhu wrote:

It should be `Instrs.size() - 1`, since the loop will do `++It` for the next iteration.

https://github.com/llvm/llvm-project/pull/165723