[llvm-profdata] Default to MemProf version 3

[kazutakahirata]

It's very confusing to have support for Verion 3 but not default to
it. This patch teaches llvm-profdata to use MemProf version 3 by
default.

[llvmbot]

@llvm/pr-subscribers-pgo

Author: Kazu Hirata (kazutakahirata)

Changes

It's very confusing to have support for Verion 3 but not default to
it. This patch teaches llvm-profdata to use MemProf version 3 by
default.

---

Full diff: https://github.com/llvm/llvm-project/pull/108863.diff

1 Files Affected:

• (modified) llvm/tools/llvm-profdata/llvm-profdata.cpp (+1-1)

diff --git a/llvm/tools/llvm-profdata/llvm-profdata.cpp b/llvm/tools/llvm-profdata/llvm-profdata.cpp
index 5efef97cc57878..1dbe39a3f3699c 100644
--- a/llvm/tools/llvm-profdata/llvm-profdata.cpp
+++ b/llvm/tools/llvm-profdata/llvm-profdata.cpp
@@ -332,7 +332,7 @@ cl::opt<bool> DoWritePrevVersion(
 cl::opt<memprof::IndexedVersion> MemProfVersionRequested(
     "memprof-version", cl::Hidden, cl::sub(MergeSubcommand),
     cl::desc("Specify the version of the memprof format to use"),
-    cl::init(memprof::Version0),
+    cl::init(memprof::Version3),
     cl::values(clEnumValN(memprof::Version0, "0", "version 0"),
                clEnumValN(memprof::Version1, "1", "version 1"),
                clEnumValN(memprof::Version2, "2", "version 2"),

[teresajohnson]

We should probably have a test that checks the default version is the one expected

[kazutakahirata]

We should probably have a test that checks the default version is the one expected

I just added a test to see if the default version is V3.

I could add a test to see if the default version is the latest by scanning the help message of llvm-profdata for example, but I am wondering if that would make it harder to develop a new version of the MemProf format. During development, we might want to add a new version without bumping the default version in llvm-profdata.