[FunctionSpecialization][nfc] Add a test for zero function entry count (#160156)

This test is a follow up to
7d748a9
which fixes an assertion crash that occurs if the profile count is 0.

Additionally, modify `profile-counts.ll` to use `update_test_checks.py`.

Author: alanzhao1

llvm/test/Transforms/FunctionSpecialization/profile-counts.ll

@@ -1,20 +1,40 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --check-globals all --version 6
 ; RUN: opt -passes="ipsccp<func-spec>" -force-specialization -S < %s | FileCheck %s
 target datalayout = "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128"
 
 @A = external dso_local constant i32, align 4
 @B = external dso_local constant i32, align 4
 
-; CHECK: define dso_local i32 @bar(i32 %x, i32 %y, ptr %z) !prof ![[BAR_PROF:[0-9]]] {
+;.
+; CHECK: @A = external dso_local constant i32, align 4
+; CHECK: @B = external dso_local constant i32, align 4
+;.
 define dso_local i32 @bar(i32 %x, i32 %y, ptr %z) !prof !0 {
+; CHECK-LABEL: define dso_local i32 @bar(
+; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]], ptr [[Z:%.*]]) !prof [[PROF0:![0-9]+]] {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    [[TOBOOL:%.*]] = icmp ne i32 [[X]], 0
+; CHECK-NEXT:    br i1 [[TOBOOL]], label %[[IF_THEN:.*]], label %[[IF_ELSE:.*]], !prof [[PROF1:![0-9]+]]
+; CHECK:       [[IF_THEN]]:
+; CHECK-NEXT:    [[CALL:%.*]] = call i32 @foo.specialized.1(i32 [[X]], ptr @A)
+; CHECK-NEXT:    [[CALL1:%.*]] = call i32 @foo.specialized.2(i32 [[Y]], ptr @B)
+; CHECK-NEXT:    [[CALL2:%.*]] = call i32 @foo.specialized.2(i32 [[Y]], ptr @B)
+; CHECK-NEXT:    [[ADD:%.*]] = add i32 [[CALL]], [[CALL1]]
+; CHECK-NEXT:    [[ADD1:%.*]] = add i32 [[ADD]], [[CALL2]]
+; CHECK-NEXT:    br label %[[RETURN:.*]]
+; CHECK:       [[IF_ELSE]]:
+; CHECK-NEXT:    [[CALL3:%.*]] = call i32 @foo.specialized.2(i32 [[Y]], ptr @B)
+; CHECK-NEXT:    br label %[[RETURN]]
+; CHECK:       [[RETURN]]:
+; CHECK-NEXT:    [[RETVAL_0:%.*]] = phi i32 [ [[ADD1]], %[[IF_THEN]] ], [ [[CALL3]], %[[IF_ELSE]] ]
+; CHECK-NEXT:    [[CALL4:%.*]] = call i32 @foo(i32 [[X]], ptr [[Z]])
+; CHECK-NEXT:    [[ADD2:%.*]] = add i32 [[RETVAL_0]], [[CALL4]]
+; CHECK-NEXT:    ret i32 [[ADD2]]
+;
 entry:
   %tobool = icmp ne i32 %x, 0
-; CHECK: br i1 %tobool, label %if.then, label %if.else, !prof ![[BRANCH_PROF:[0-9]]]
   br i1 %tobool, label %if.then, label %if.else, !prof !1
 
-; CHECK: if.then:
-; CHECK: call i32 @foo.specialized.1(i32 %x, ptr @A)
-; CHECK: call i32 @foo.specialized.2(i32 %y, ptr @B)
-; CHECK: call i32 @foo.specialized.2(i32 %y, ptr @B)
 if.then:
   %call = call i32 @foo(i32 %x, ptr @A)
   %call1 = call i32 @foo(i32 %y, ptr @B)
@@ -23,36 +43,73 @@ if.then:
   %add1 = add i32 %add, %call2
   br label %return
 
-; CHECK: if.else:
-; CHECK: call i32 @foo.specialized.2(i32 %y, ptr @B)
 if.else:
   %call3 = call i32 @foo(i32 %y, ptr @B)
   br label %return
 
-; CHECK: return:
-; CHECK: call i32 @foo(i32 %x, ptr %z)
 return:
   %retval.0 = phi i32 [ %add1, %if.then ], [ %call3, %if.else ]
   %call4 = call i32 @foo(i32 %x, ptr %z);
   %add2 = add i32 %retval.0, %call4
   ret i32 %add2
 }
 
-; CHECK: define internal i32 @foo(i32 %x, ptr %b) !prof ![[FOO_UNSPEC_PROF:[0-9]]]
-; CHECK: define internal i32 @foo.specialized.1(i32 %x, ptr %b) !prof ![[FOO_SPEC_1_PROF:[0-9]]]
-; CHECK: define internal i32 @foo.specialized.2(i32 %x, ptr %b) !prof ![[FOO_SPEC_2_PROF:[0-9]]]
-define internal i32 @foo(i32 %x, ptr %b) !prof !2 {
+define dso_local i32 @baz(i32 %x, i32 %y) !prof !2 {
+; CHECK-LABEL: define dso_local i32 @baz(
+; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) !prof [[PROF2:![0-9]+]] {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    [[TOBOOL:%.*]] = icmp ne i32 [[X]], 0
+; CHECK-NEXT:    br i1 [[TOBOOL]], label %[[IF_THEN:.*]], label %[[IF_ELSE:.*]]
+; CHECK:       [[IF_THEN]]:
+; CHECK-NEXT:    [[CALL:%.*]] = call i32 @foo.specialized.1(i32 [[X]], ptr @A)
+; CHECK-NEXT:    br label %[[RETURN:.*]]
+; CHECK:       [[IF_ELSE]]:
+; CHECK-NEXT:    [[CALL1:%.*]] = call i32 @foo.specialized.2(i32 [[Y]], ptr @B)
+; CHECK-NEXT:    br label %[[RETURN]]
+; CHECK:       [[RETURN]]:
+; CHECK-NEXT:    [[RETVAL_0:%.*]] = phi i32 [ [[CALL]], %[[IF_THEN]] ], [ [[CALL1]], %[[IF_ELSE]] ]
+; CHECK-NEXT:    ret i32 [[RETVAL_0]]
+;
+entry:
+  %tobool = icmp ne i32 %x, 0
+  br i1 %tobool, label %if.then, label %if.else
+
+if.then:
+  %call = call i32 @foo(i32 %x, ptr @A)
+  br label %return
+
+if.else:
+  %call1 = call i32 @foo(i32 %y, ptr @B)
+  br label %return
+
+return:
+  %retval.0 = phi i32 [ %call, %if.then ], [ %call1, %if.else ]
+  ret i32 %retval.0
+}
+
+define internal i32 @foo(i32 %x, ptr %b) !prof !3 {
+; CHECK-LABEL: define internal i32 @foo(
+; CHECK-SAME: i32 [[X:%.*]], ptr [[B:%.*]]) !prof [[PROF3:![0-9]+]] {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    [[TMP0:%.*]] = load i32, ptr [[B]], align 4
+; CHECK-NEXT:    [[ADD:%.*]] = add nsw i32 [[X]], [[TMP0]]
+; CHECK-NEXT:    ret i32 [[ADD]]
+;
 entry:
   %0 = load i32, ptr %b, align 4
   %add = add nsw i32 %x, %0
   ret i32 %add
 }
 
-; CHECK: ![[BAR_PROF]] = !{!"function_entry_count", i64 1000}
-; CHECK: ![[BRANCH_PROF]] = !{!"branch_weights", i32 1, i32 3}
-; CHECK: ![[FOO_UNSPEC_PROF]] =  !{!"function_entry_count", i64 500}
-; CHECK: ![[FOO_SPEC_1_PROF]] = !{!"function_entry_count", i64 250}
-; CHECK: ![[FOO_SPEC_2_PROF]] = !{!"function_entry_count", i64 1250}
 !0 = !{!"function_entry_count", i64 1000}
 !1 = !{!"branch_weights", i32 1, i32 3}
-!2 = !{!"function_entry_count", i64 2000}
+!2 = !{!"function_entry_count", i64 0}
+!3 = !{!"function_entry_count", i64 2000}
+;.
+; CHECK: [[PROF0]] = !{!"function_entry_count", i64 1000}
+; CHECK: [[PROF1]] = !{!"branch_weights", i32 1, i32 3}
+; CHECK: [[PROF2]] = !{!"function_entry_count", i64 0}
+; CHECK: [[PROF3]] = !{!"function_entry_count", i64 500}
+; CHECK: [[META4:![0-9]+]] = !{!"function_entry_count", i64 250}
+; CHECK: [[META5:![0-9]+]] = !{!"function_entry_count", i64 1250}
+;.