[clang-tools-extra] [compiler-rt] [llvm] [clang] [PGO][GlobalValue][LTO]In GlobalValues::getGlobalIdentifier, use semicolon as delimiter for local-linkage varibles. (PR #74008)

[Fangrui Song via cfe-commits]

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@@ -0,0 +1,97 @@
+// This is a regression test for ThinLTO indirect-call-promotion when candidate
+// callees need to be imported from another IR module.  In the C++ test case,
+// `main` calls `global_func` which is defined in another module. `global_func`
+// has two indirect callees, one has external linkage and one has local linkage.
+// All three functions should be imported into the IR module of main.
+
+// What the test does:
+// - Generate raw profiles from executables and convert it to indexed profiles.
+//   During the conversion, a profiled callee address in raw profiles will be
+//   converted to function hash in indexed profiles.
+// - Run IRPGO profile use and ThinTLO prelink pipeline and get LLVM bitcodes
+//   for both cpp files in the C++ test case.
+// - Generate ThinLTO summary file with LLVM bitcodes, and run `function-import` pass.
+// - Run `pgo-icall-prom` pass for the IR module which needs to import callees.
+
+// RUN: rm -rf %t && split-file %s %t && cd %t
+
+// Use clang*_{pgogen,pgouse} for IR level instrumentation, and use clangxx* for
+// C++.
+//
+// Do setup work for all below tests.
+// Generate raw profiles from real programs and convert it into indexed profiles.
+// RUN: %clangxx_pgogen -fuse-ld=lld -O2 lib.cpp main.cpp -o main
+// RUN: env LLVM_PROFILE_FILE=main.profraw %run ./main
+// RUN: llvm-profdata merge main.profraw -o main.profdata
+
+// Use profile on lib and get bitcode, test that local function callee0 has
+// expected !PGOFuncName metadata and external function callee1 doesn't have
+// !PGOFuncName metadata. Explicitly skip ICP pass to test ICP happens as
+// expected in the IR module that imports functions from lib.
+// RUN: %clang -target x86_64-unknown-linux-gnu -mllvm -disable-icp -fprofile-use=main.profdata -flto=thin -O2 -c lib.cpp -o lib.bc
+// RUN: llvm-dis lib.bc -o - | FileCheck %s --check-prefix=PGOName
+
+// Use profile on main and get bitcode.
+// RUN: %clang -target x86_64-unknown-linux-gnu -fprofile-use=main.profdata -flto=thin -O2 -c main.cpp -o main.bc
+
+// Run llvm-lto to get summary file.
+// RUN: llvm-lto -thinlto -o summary main.bc lib.bc
+
+// Test the imports of functions. Default import thresholds would work but do
+// explicit override to be more futureproof. Note all functions have one basic
+// block with a function-entry-count of one, so they are actually hot functions
+// per default profile summary hotness cutoff.
+// RUN: opt -passes=function-import -import-instr-limit=100 -import-cold-multiplier=1 -summary-file summary.thinlto.bc main.bc -o main.import.bc -print-imports 2>&1 | FileCheck %s --check-prefix=IMPORTS
+// Test that '_Z11global_funcv' has indirect calls annotated with value profiles.
+// RUN: llvm-dis main.import.bc -o - | FileCheck %s --check-prefix=IR
+
+// Test that both candidates are ICP'ed and there is no `!VP` in the IR.
+// RUN: opt main.import.bc -icp-lto -passes=pgo-icall-prom -S -pass-remarks=pgo-icall-prom 2>&1 | FileCheck %s --check-prefixes=ICP-IR,ICP-REMARK --implicit-check-not="!VP"
+
+// IMPORTS: main.cpp: Import _Z7callee1v
+// IMPORTS: main.cpp: Import _ZL7callee0v.llvm.{{[0-9]+}}
+// IMPORTS: main.cpp: Import _Z11global_funcv
+
+// PGOName: define dso_local void @_Z7callee1v() {{.*}} !prof !{{[0-9]+}} {
+// PGOName: define internal void @_ZL7callee0v() {{.*}} !prof !{{[0-9]+}} !PGOFuncName ![[MD:[0-9]+]] {
+// PGOName: ![[MD]] = !{!"{{.*}}lib.cpp;_ZL7callee0v"}
+
+// IR-LABEL: define available_externally {{.*}} void @_Z11global_funcv() {{.*}} !prof !35 {
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MaskRay wrote:

`!35` in `!prof !35`  may make the test too sensitive.

https://github.com/llvm/llvm-project/pull/74008