[InstrProf] Test that entry coverage counts accumulate (#81806)

Author: ellishg

compiler-rt/test/profile/instrprof-block-coverage.c

@@ -5,6 +5,9 @@
 // RUN: %clang_profuse=%t.profdata -mllvm -pgo-verify-bfi -o - -S -emit-llvm %s 2>%t.errs | FileCheck %s --implicit-check-not="!prof"
 // RUN: FileCheck %s < %t.errs --allow-empty --check-prefix=CHECK-ERROR
 
+// RUN: llvm-profdata merge -o %t2.profdata %t1.profraw %t1.profraw %t2.profraw %t2.profraw
+// RUN: llvm-profdata show %t2.profdata | FileCheck %s --check-prefix=COUNTS
+
 #include <stdlib.h>
 
 // CHECK: @foo({{.*}})
@@ -45,3 +48,5 @@ int main(int argc, char *argv[]) {
 // CHECK-DAG: ![[PROF2]] = !{!"branch_weights", i32 0, i32 1}
 
 // CHECK-ERROR-NOT: warning: {{.*}}: Found inconsistent block coverage
+
+// COUNTS: Maximum function count: 4

compiler-rt/test/profile/instrprof-entry-coverage.c

@@ -3,10 +3,19 @@
 // RUN: llvm-profdata merge -o %t.profdata %t.profraw
 // RUN: llvm-profdata show --covered %t.profdata | FileCheck %s --implicit-check-not goo
 
+// We deliberately merge the raw profile twice to test that internal counts can
+// grow larger than one. Technically, accumulating coverage values is different
+// than accumulating counts, but this helps discriminate cold functions from hot
+// functions when the number of raw profiles is large.
+// RUN: llvm-profdata merge -o %t2.profdata %t.profraw %t.profraw
+// RUN: llvm-profdata show %t2.profdata | FileCheck %s --check-prefix=COUNTS
+
 // RUN: %clang_cspgogen -O1 -mllvm -pgo-function-entry-coverage %s -o %t.cs.out
 // RUN: env LLVM_PROFILE_FILE=%t.csprofraw %run %t.cs.out
 // RUN: llvm-profdata merge -o %t.csprofdata %t.csprofraw
 // RUN: llvm-profdata show --covered %t.csprofdata --showcs | FileCheck %s --implicit-check-not goo
+// RUN: llvm-profdata merge -o %t2.csprofdata %t.csprofraw %t.csprofraw
+// RUN: llvm-profdata show --showcs %t2.csprofdata | FileCheck %s --check-prefix=COUNTS
 
 void markUsed(int a) {
   volatile int g;
@@ -26,3 +35,5 @@ int main(int argc, char *argv[]) {
 // CHECK-DAG: main
 // CHECK-DAG: foo
 // CHECK-DAG: bar
+
+// COUNTS: Maximum function count: 2