[PATCH] D65281: [IR] Fix getPointerAlignment for CallBase

[Hideto Ueno via Phabricator via llvm-commits]

uenoku created this revision.
Herald added subscribers: llvm-commits, hiraditya.
Herald added a project: LLVM.

In current getPointerAlignemnt implementation, CallBase.getPointerAlignement(..) checks only parameter attriutes in the callsite.  For example,

  declare align 8 i8* @foo()
  
  define void @bar() {
      %a = tail call align 8 i8* @foo() ; getPointerAlignment returns 8
      %b = tail call i8* @foo() ; getPointerAlignemnt returns 0
      ret void
  }

This patch will fix the problem.


https://reviews.llvm.org/D65281

Files:
  llvm/lib/IR/Value.cpp


Index: llvm/lib/IR/Value.cpp
===================================================================
--- llvm/lib/IR/Value.cpp
+++ llvm/lib/IR/Value.cpp
@@ -726,9 +726,11 @@
       if (AllocatedType->isSized())
         Align = DL.getPrefTypeAlignment(AllocatedType);
     }
-  } else if (const auto *Call = dyn_cast<CallBase>(this))
-    Align = Call->getAttributes().getRetAlignment();
-  else if (const LoadInst *LI = dyn_cast<LoadInst>(this))
+  } else if (const auto *Call = dyn_cast<CallBase>(this)) {
+    Align = Call->getRetAlignment();
+    if (Align == 0 && Call->getCalledFunction())
+      Align = Call->getCalledFunction()->getAttributes().getRetAlignment();
+  } else if (const LoadInst *LI = dyn_cast<LoadInst>(this))
     if (MDNode *MD = LI->getMetadata(LLVMContext::MD_align)) {
       ConstantInt *CI = mdconst::extract<ConstantInt>(MD->getOperand(0));
       Align = CI->getLimitedValue();


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