[llvm] [PGO] Add tests for modules with only globals and function declarations (PR #93764)

[Pavel Samolysov via llvm-commits]

https://github.com/samolisov created https://github.com/llvm/llvm-project/pull/93764

When a module contains globals and/or function declarations only, the '__llvm_profile_raw_version' variable should not be generated because the module was not instrumented at all.

NFC

>From 76ca96858d78d15ae4e1ae298db6f7328a54c769 Mon Sep 17 00:00:00 2001
From: Pavel Samolysov <samolisov at gmail.com>
Date: Thu, 30 May 2024 06:02:01 +0300
Subject: [PATCH] [PGO] Add tests for modules with only globals and function
 declarations

When a module contains globals and/or function declarations only, the
'__llvm_profile_raw_version' variable should not be generated because
the module was not instrumented at all.

NFC
---
 .../available_externally_functions.ll           | 17 +++++++++++++++++
 .../Transforms/PGOProfile/declarations_only.ll  | 13 +++++++++++++
 .../PGOProfile/global_variables_only.ll         |  9 +++++++++
 3 files changed, 39 insertions(+)
 create mode 100644 llvm/test/Transforms/PGOProfile/available_externally_functions.ll
 create mode 100644 llvm/test/Transforms/PGOProfile/declarations_only.ll
 create mode 100644 llvm/test/Transforms/PGOProfile/global_variables_only.ll

diff --git a/llvm/test/Transforms/PGOProfile/available_externally_functions.ll b/llvm/test/Transforms/PGOProfile/available_externally_functions.ll
new file mode 100644
index 0000000000000..f455ca066aa7a
--- /dev/null
+++ b/llvm/test/Transforms/PGOProfile/available_externally_functions.ll
@@ -0,0 +1,17 @@
+; RUN: opt < %s -passes=pgo-instr-gen -S | FileCheck %s --check-prefix=GEN --check-prefix=GEN-COMDAT
+
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+; GEN-COMDAT: $__llvm_profile_raw_version = comdat any
+; GEN-COMDAT: @__llvm_profile_raw_version = hidden constant i64 {{[0-9]+}}, comdat
+; GEN: @__profn_foo = linkonce_odr hidden constant [3 x i8] c"foo"
+; GEN: @__profn_bar = linkonce_odr hidden constant [3 x i8] c"bar"
+
+define available_externally hidden void @foo() {
+  ret void
+}
+
+define available_externally i32 @bar() {
+  ret i32 42
+}
diff --git a/llvm/test/Transforms/PGOProfile/declarations_only.ll b/llvm/test/Transforms/PGOProfile/declarations_only.ll
new file mode 100644
index 0000000000000..e7208fc264c7c
--- /dev/null
+++ b/llvm/test/Transforms/PGOProfile/declarations_only.ll
@@ -0,0 +1,13 @@
+; RUN: opt < %s -passes=pgo-instr-gen -S | FileCheck %s --check-prefix=GEN --check-prefix=GEN-COMDAT
+
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+; GEN-COMDAT: $__llvm_profile_raw_version = comdat any
+; GEN-COMDAT: @__llvm_profile_raw_version = hidden constant i64 {{[0-9]+}}, comdat
+; GEN-NOT: @__profn_test_1 = private constant [6 x i8] c"test_1"
+; GEN-NOT: @__profn_test_2 = private constant [6 x i8] c"test_2"
+
+declare i32 @test_1(i32 %i)
+
+declare i32 @test_2(i32 %i)
diff --git a/llvm/test/Transforms/PGOProfile/global_variables_only.ll b/llvm/test/Transforms/PGOProfile/global_variables_only.ll
new file mode 100644
index 0000000000000..3bfa29af5d34f
--- /dev/null
+++ b/llvm/test/Transforms/PGOProfile/global_variables_only.ll
@@ -0,0 +1,9 @@
+; RUN: opt < %s -passes=pgo-instr-gen -S | FileCheck %s --check-prefix=GEN-COMDAT
+
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+; GEN-COMDAT: $__llvm_profile_raw_version = comdat any
+; GEN-COMDAT: @__llvm_profile_raw_version = hidden constant i64 {{[0-9]+}}, comdat
+
+ at var = internal unnamed_addr global [35 x ptr] zeroinitializer, align 16