[llvm] [Metadata] Handle memprof, callsite merging when one is missing. (PR #132106)

[Teresa Johnson via llvm-commits]

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@@ -0,0 +1,50 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
+;; Test to ensure that memprof related metadata is not dropped when
+;; instructions are combined. Currently the metadata from the first instruction
+;; is kept, which prevents full loss of profile context information.
+
+; RUN: opt < %s -passes=simplifycfg -S | FileCheck %s
+
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+define dso_local noundef nonnull ptr @_Z10test_rightb(i1 noundef zeroext %b) local_unnamed_addr #0 {
+; CHECK-LABEL: define dso_local noundef nonnull ptr @_Z10test_rightb(
+; CHECK-SAME: i1 noundef zeroext [[B:%.*]]) local_unnamed_addr {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    [[CALL:%.*]] = call noalias noundef nonnull dereferenceable(4) ptr @_Znwm(i64 noundef 4), !memprof [[META0:![0-9]+]], !callsite [[META3:![0-9]+]]
+; CHECK-NEXT:    ret ptr [[CALL]]
+;
+entry:
+  br i1 %b, label %if.then, label %if.else
+
+if.then:                                          ; preds = %entry
+  %call = call noalias noundef nonnull dereferenceable(4) ptr @_Znwm(i64 noundef 4)
+  br label %if.end
+
+if.else:                                          ; preds = %entry
+  %call1 = call noalias noundef nonnull dereferenceable(4) ptr @_Znwm(i64 noundef 4), !memprof !4, !callsite !7
+  br label %if.end
+
+if.end:                                           ; preds = %if.else, %if.then
+  %x.0 = phi ptr [ %call, %if.then ], [ %call1, %if.else ]
+  ret ptr %x.0
+}
+
+declare ptr @_Znwm(i64) nounwind readonly
+
+!0 = !{!1}
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teresajohnson wrote:

!0 through !3 appear dead in this test and can be removed

https://github.com/llvm/llvm-project/pull/132106