[llvm] [InstCombine] Remove redundant alignment assumptions. (PR #123348)

[Yingwei Zheng via llvm-commits]

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@@ -3404,6 +3405,32 @@ Instruction *InstCombinerImpl::visitCallInst(CallInst &CI) {
         MaybeSimplifyHint(OBU.Inputs[0]);
         MaybeSimplifyHint(OBU.Inputs[1]);
       }
+
+      // Try to remove redundant alignment assumptions.
+      if (OBU.getTagName() == "align" && OBU.Inputs.size() == 2) {
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dtcxzyw wrote:

As we emit a bunch of alignment assumptions, can we turn the tag name `align` into a tag ID `OB_align`?

https://github.com/llvm/llvm-project/pull/123348