Add -finstrument-function-entry-bare flag

This is an instrumentation flag that's similar to
-finstrument-functions, but it only inserts calls on function entry, the
calls are inserted post-inlining, and they don't take any arugments.

This is intended for users who want to instrument function entry with
minimal overhead.

(-pg would be another alternative, but forces frame pointer emission and
affects link flags, so is probably best left alone to be used for
generating gcov data.)

Differential revision: https://reviews.llvm.org/D40276

llvm-svn: 318785

1 files changed, 13 insertions, 0 deletions

diff --git a/clang/test/CodeGen/instrument-functions.c b/clang/test/CodeGen/instrument-functions.c
index b440e6a2635..c075c3972dd 100644
--- a/clang/test/CodeGen/instrument-functions.c
+++ b/clang/test/CodeGen/instrument-functions.c
@@ -1,8 +1,12 @@
 // RUN: %clang_cc1 -S -debug-info-kind=standalone -emit-llvm -o - %s -finstrument-functions -disable-llvm-passes | FileCheck %s
+// RUN: %clang_cc1 -S -debug-info-kind=standalone -emit-llvm -o - %s -finstrument-function-entry-bare -disable-llvm-passes | FileCheck -check-prefix=BARE %s
 
 int test1(int x) {
 // CHECK: @test1(i32 {{.*}}%x) #[[ATTR1:[0-9]+]]
 // CHECK: ret
+
+// BARE: @test1(i32 {{.*}}%x) #[[ATTR1:[0-9]+]]
+// BARE: ret
   return x;
 }
 
@@ -10,6 +14,9 @@ int test2(int) __attribute__((no_instrument_function));
 int test2(int x) {
 // CHECK: @test2(i32 {{.*}}%x) #[[ATTR2:[0-9]+]]
 // CHECK: ret
+
+// BARE: @test2(i32 {{.*}}%x) #[[ATTR2:[0-9]+]]
+// BARE: ret
   return x;
 }
 
@@ -17,5 +24,11 @@ int test2(int x) {
 // CHECK-SAME: "instrument-function-entry"="__cyg_profile_func_enter"
 // CHECK-SAME: "instrument-function-exit"="__cyg_profile_func_exit"
 
+// BARE: attributes #[[ATTR1]] =
+// BARE-SAME: "instrument-function-entry-inlined"="__cyg_profile_func_enter_bare"
+
 // CHECK: attributes #[[ATTR2]] =
 // CHECK-NOT: "instrument-function-entry"
+
+// BARE: attributes #[[ATTR2]] =
+// BARE-NOT: "instrument-function-entry"