Add GCC-compatible flags -fprofile-generate and -fprofile-use.

This patch adds support for specifying where the profile is emitted in a
way similar to GCC. These flags are used to specify directories instead
of filenames. When -fprofile-generate=DIR is used, the compiler will
generate code to write to <DIR>/default.profraw.

The patch also adds a couple of extensions: LLVM_PROFILE_FILE can still be
used to override the directory and file name to use and -fprofile-use
accepts both directories and filenames.

To simplify the set of flags used in the backend, all the flags get
canonicalized to -fprofile-instr-{generate,use} when passed to the
backend. The decision to use a default name for the profile is done
in the driver.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@241825 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 48 insertions, 0 deletions

diff --git a/test/Profile/gcc-flag-compatibility.c b/test/Profile/gcc-flag-compatibility.c
new file mode 100644
index 0000000000..53a7651c14
--- /dev/null
+++ b/test/Profile/gcc-flag-compatibility.c
@@ -0,0 +1,48 @@
+// Tests for -fprofile-generate and -fprofile-use flag compatibility. These two
+// flags behave similarly to their GCC counterparts:
+//
+// -fprofile-generate         Generates the profile file ./default.profraw
+// -fprofile-generate=<dir>   Generates the profile file <dir>/default.profraw
+// -fprofile-use              Uses the profile file ./default.profdata
+// -fprofile-use=<dir>        Uses the profile file <dir>/default.profdata
+// -fprofile-use=<dir>/file   Uses the profile file <dir>/file
+
+// Check that -fprofile-generate uses the runtime default profile file.
+// RUN: %clang %s -c -S -o - -emit-llvm -fprofile-generate | FileCheck -check-prefix=PROFILE-GEN %s
+// PROFILE-GEN: @__llvm_profile_runtime = external global i32
+// PROFILE-GEN-NOT: call void @__llvm_profile_override_default_filename
+// PROFILE-GEN-NOT: declare void @__llvm_profile_override_default_filename(i8*)
+
+// Check that -fprofile-generate=/path/to generates /path/to/default.profraw
+// RUN: %clang %s -c -S -o - -emit-llvm -fprofile-generate=/path/to | FileCheck -check-prefix=PROFILE-GEN-EQ %s
+// PROFILE-GEN-EQ: private constant [25 x i8] c"/path/to/default.profraw\00"
+// PROFILE-GEN-EQ: call void @__llvm_profile_override_default_filename(i8* getelementptr inbounds ([25 x i8], [25 x i8]* @0, i32 0, i32 0))
+// PROFILE-GEN-EQ: declare void @__llvm_profile_override_default_filename(i8*)
+
+// Check that -fprofile-use reads default.profdata
+// RUN: llvm-profdata merge %S/Inputs/gcc-flag-compatibility.proftext -o default.profdata
+// RUN: %clang %s -o - -mllvm -disable-llvm-optzns -emit-llvm -S -fprofile-use | FileCheck -check-prefix=PROFILE-USE-1 %s
+// PROFILE-USE-1: = !{!"branch_weights", i32 101, i32 2}
+
+// Check that -fprofile-use=some/path reads some/path/default.profdata
+// RUN: rm -rf %t.dir
+// RUN: mkdir -p %t.dir/some/path
+// RUN: llvm-profdata merge %S/Inputs/gcc-flag-compatibility.proftext -o %t.dir/some/path/default.profdata
+// RUN: %clang %s -o - -mllvm -disable-llvm-optzns -emit-llvm -S -fprofile-use=%t.dir/some/path | FileCheck -check-prefix=PROFILE-USE-2 %s
+// PROFILE-USE-2: = !{!"branch_weights", i32 101, i32 2}
+
+// Check that -fprofile-use=some/path/file.prof reads some/path/file.prof
+// RUN: rm -rf %t.dir
+// RUN: mkdir -p %t.dir/some/path
+// RUN: llvm-profdata merge %S/Inputs/gcc-flag-compatibility.proftext -o %t.dir/some/path/file.prof
+// RUN: %clang %s -o - -mllvm -disable-llvm-optzns -emit-llvm -S -fprofile-use=%t.dir/some/path/file.prof | FileCheck -check-prefix=PROFILE-USE-3 %s
+// PROFILE-USE-3: = !{!"branch_weights", i32 101, i32 2}
+
+int X = 0;
+
+int main() {
+  int i;
+  for (i = 0; i < 100; i++)
+    X += i;
+  return 0;
+}