[compiler-rt] [llvm] [msan] Add 32-bit platforms support (PR #109284)

[via llvm-commits]

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@@ -5709,11 +5716,26 @@ struct VarArgPowerPCHelper : public VarArgHelperBase {
     for (CallInst *OrigInst : VAStartInstrumentationList) {
       NextNodeIRBuilder IRB(OrigInst);
       Value *VAListTag = OrigInst->getArgOperand(0);
-      Value *RegSaveAreaPtrPtr = IRB.CreateIntToPtr(
-          IRB.CreatePtrToInt(VAListTag, MS.IntptrTy), MS.PtrTy);
+      Value *RegSaveAreaPtrPtr;
+
+      Triple TargetTriple(F.getParent()->getTargetTriple());
+
+      // In PPC32 va_list_tag is a struct, whereas in PPC64 it's a pointer
+      if (TargetTriple.isPPC64()) {
+        RegSaveAreaPtrPtr = IRB.CreateIntToPtr(
+            IRB.CreatePtrToInt(VAListTag, MS.IntptrTy), MS.PtrTy);
+      } else {
+        RegSaveAreaPtrPtr = IRB.CreateIntToPtr(
+            IRB.CreateAdd(IRB.CreatePtrToInt(VAListTag, MS.IntptrTy),
+                          ConstantInt::get(MS.IntptrTy, 8)),
+            MS.PtrTy);
+      }
+
       Value *RegSaveAreaPtr = IRB.CreateLoad(MS.PtrTy, RegSaveAreaPtrPtr);
       Value *RegSaveAreaShadowPtr, *RegSaveAreaOriginPtr;
-      const Align Alignment = Align(8);
+      const DataLayout &DL = F.getDataLayout();
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k-kashapov wrote:

DL is declared in `visitCallBase`, this funciton is `finalizeInstrumentation`.

https://github.com/llvm/llvm-project/pull/109284