[llvm] [AArch64][Build Attributes] Improve Parsing and Formatting (PR #126530)

[Oliver Stannard via llvm-commits]

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@@ -214,22 +215,20 @@ void AArch64TargetStreamer::emitAttribute(StringRef VendorName, unsigned Tag,
         return;
       }
       for (MCELFStreamer::AttributeItem &Item : SubSection.Content) {
+        // Tag already exists
         if (Item.Tag == Tag) {
-          if (!Override) {
-            if ((unsigned(-1) != Value && Item.IntValue != Value) ||
-                ("" != String && Item.StringValue != String)) {
-              assert(0 &&
-                     "Can not add AArch64 build attribute: An attribute with "
-                     "the same tag and a different value already exists");
-              return;
-            } else {
-              // Case Item.IntValue == Value, no need to emit twice
-              assert(0 &&
-                     "AArch64 build attribute: An attribute with the same tag "
-                     "and a same value already exists");
-              return;
-            }
+          // New value for existing tag: update tag
+          if ((unsigned(-1) != Value && Item.IntValue != Value) ||
----------------
ostannard wrote:

As you point out, this is very cold code, so I don't think we should be worrying about performance here.

I disagree that this increases readability - it's just adding extra code which doesn't do anything, and nobody reading this is going to be surprised y an assignment appearing to have no effect if the two values are the same.

https://github.com/llvm/llvm-project/pull/126530