[MemProf] Add test for hot hints (#124394)

The change in PR124219 required removing one of the tests added for
-memprof-use-hot-hints, since we no longer label any contexts as hot in
metadata, so add a new test that checks the hot attribute instead.

Author: teresajohnson

llvm/test/Transforms/PGOProfile/memprof.ll

@@ -85,6 +85,14 @@
 ; RAND2: random hotness seed = 1730170724
 ; RUN: opt < %s -passes='memprof-use<profile-filename=%t.memprofdatarand2>' -pgo-warn-missing-function -S -stats 2>&1 | FileCheck %s --check-prefixes=MEMPROFRAND2,ALL,MEMPROFONLY,MEMPROFSTATS
 
+;; With the hot access density threshold set to 0, and hot hints enabled,
+;; the unconditionally notcold call to new should instead get a hot attribute.
+; RUN: opt < %s -passes='memprof-use<profile-filename=%t.memprofdata>' -pgo-warn-missing-function -S -memprof-print-match-info -stats -memprof-min-ave-lifetime-access-density-hot-threshold=0 -memprof-use-hot-hints 2>&1 | FileCheck %s --check-prefixes=MEMPROFHOT,ALL
+
+;; However, with the same threshold, but hot hints not enabled, it should be
+;; notcold again.
+; RUN: opt < %s -passes='memprof-use<profile-filename=%t.memprofdata>' -pgo-warn-missing-function -S -memprof-min-ave-lifetime-access-density-hot-threshold=0 2>&1 | FileCheck %s --check-prefixes=MEMPROF,ALL
+
 ; MEMPROFMATCHINFO: MemProf notcold context with id 1093248920606587996 has total profiled size 10 is matched
 ; MEMPROFMATCHINFO: MemProf notcold context with id 5725971306423925017 has total profiled size 10 is matched
 ; MEMPROFMATCHINFO: MemProf notcold context with id 6792096022461663180 has total profiled size 10 is matched
@@ -192,6 +200,7 @@ entry:
   store ptr %argv, ptr %argv.addr, align 8
   ; MEMPROF: call {{.*}} @_Znam{{.*}} #[[A1:[0-9]+]]
   ; MEMPROFNOCOLINFO: call {{.*}} @_Znam{{.*}} #[[A1:[0-9]+]]
+  ; MEMPROFHOT: call {{.*}} @_Znam{{.*}} #[[A1:[0-9]+]]
   %call = call noalias noundef nonnull ptr @_Znam(i64 noundef 10) #6, !dbg !35
   store ptr %call, ptr %a, align 8, !dbg !36
   ; MEMPROF: call {{.*}} @_Znam{{.*}} #[[A2:[0-9]+]]
@@ -404,6 +413,8 @@ for.end:                                          ; preds = %for.cond
 ; MEMPROFNOCOLINFO: ![[C10]] = !{i64 -4535090212904553409}
 ; MEMPROFNOCOLINFO: ![[C11]] = !{i64 3577763375057267810}
 
+; MEMPROFHOT: #[[A1]] = { builtin allocsize(0) "memprof"="hot" }
+
 ;; For the specific random seed, this is the expected order of hotness
 ; MEMPROFRAND2: !"cold"
 ; MEMPROFRAND2: !"cold"