[PATCH] D94433: Do not emit non-power-of-2 alignment assume bundles (PR48713).

[Roman Lebedev via Phabricator via llvm-commits]

lebedev.ri added a comment.

This looks like it's moving in the right direction.
Please split this up into clang change and a verifier change.



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Comment at: clang/lib/CodeGen/CGCall.cpp:4561-4565
+    // Non power-of-2 alignment is UB and rejected by the IR verifier.
+    if (!AlignmentCI->getValue().isPowerOf2()) {
+      AA = nullptr; // We're done. Disallow doing anything else.
       return Attrs;
+    }
----------------
No, we should emit it as a simple assumption.


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Comment at: llvm/lib/IR/Verifier.cpp:4611-4619
         Assert(Call.getOperand(Elem.Begin + 1)->getType()->isIntegerTy(),
                "second argument should be an integer");
+	ConstantInt *Alignment = dyn_cast<ConstantInt>(Call.getOperand(Elem.Begin + 1));
+	if (Alignment)
+	  Assert(Alignment->getValue().isPowerOf2(),
+           "alignment must be a power of 2", Call);
         if (ArgCount == 3)
----------------
@jdoerfert Should second/third arguments be a *constant* integers ?



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  https://reviews.llvm.org/D94433/new/

https://reviews.llvm.org/D94433