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

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-llvm-transforms

Author: Pavel Samolysov (samolisov)

<details>
<summary>Changes</summary>

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

---
Full diff: https://github.com/llvm/llvm-project/pull/93764.diff


3 Files Affected:

- (added) llvm/test/Transforms/PGOProfile/available_externally_functions.ll (+17) 
- (added) llvm/test/Transforms/PGOProfile/declarations_only.ll (+13) 
- (added) llvm/test/Transforms/PGOProfile/global_variables_only.ll (+9) 


``````````diff
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

``````````

</details>


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