[llvm] [profcheck] Add indirect call metadata (PR #154657)

[Mingming Liu via llvm-commits]

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@@ -92,12 +97,16 @@ bool ProfileInjector::inject() {
     return false;
   bool Changed = false;
   for (auto &BB : F) {
-    if (AnnotateSelect) {
-      for (auto &I : BB) {
-        if (isa<SelectInst>(I) && !I.getMetadata(LLVMContext::MD_prof))
-          setBranchWeights(I, {SelectTrueWeight, SelectFalseWeight},
-                           /*IsExpected=*/false);
-      }
+    for (auto &I : BB) {
+      if (AnnotateSelect && isa<SelectInst>(I) &&
+          !I.getMetadata(LLVMContext::MD_prof))
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mingmingl-llvm wrote:

nit: for reader's context, add a comment to explain how/when `I.getMetadata(LLVMContext::MD_prof)` is true (i.e., profile metadata already exists) and this set-metadata code path runs again on the same instruction, and why avoid setting it again (e.g. is setting `!prof` metadata idempotent, or if it's not necessarily idempotent, explain a little bit about why we prefer the first one)

https://github.com/llvm/llvm-project/pull/154657