compiler-rt/test/profile/instrprof-thinlto-indirect-call-promotion.cpp

   1 // This is a regression test for ThinLTO indirect-call-promotion when candidate
   2 // callees need to be imported from another IR module.  In the C++ test case,
   3 // `main` calls `global_func` which is defined in another module. `global_func`
   4 // has two indirect callees, one has external linkage and one has local linkage.
   5 // All three functions should be imported into the IR module of main.
   6
   7 // What the test does:
   8 // - Generate raw profiles from executables and convert it to indexed profiles.
   9 //   During the conversion, a profiled callee address in raw profiles will be
  10 //   converted to function hash in indexed profiles.
  11 // - Run IRPGO profile use and ThinTLO prelink pipeline and get LLVM bitcodes
  12 //   for both cpp files in the C++ test case.
  13 // - Generate ThinLTO summary file with LLVM bitcodes, and run `function-import` pass.
  14 // - Run `pgo-icall-prom` pass for the IR module which needs to import callees.
  15
  16 // REQUIRES: windows || linux || darwin
  17
  18 // The test failed on ppc when building the instrumented binary.
  19 // ld.lld: error: /lib/../lib64/Scrt1.o: ABI version 1 is not supported
  20 // UNSUPPORTED: ppc
  21
  22 // This test and IR test llvm/test/Transforms/PGOProfile/thinlto_indirect_call_promotion.ll
  23 // are complementary to each other; a compiler-rt test has better test coverage
  24 // on different platforms, and the IR test is less restrictive in terms of
  25 // running environment and could be executed more widely.
  26
  27 // Use lld as linker for more robust test. We need to REQUIRE LLVMgold.so for
  28 // LTO if default linker is GNU ld or gold anyway.
  29 // REQUIRES: lld-available
  30
  31 // RUN: rm -rf %t && split-file %s %t && cd %t
  32
  33 // Do setup work for all below tests.
  34 // Generate raw profiles from real programs and convert it into indexed profiles.
  35 // Use clangxx_pgogen for IR level instrumentation for C++.
  36 // RUN: %clangxx_pgogen -fuse-ld=lld -O2 lib.cpp main.cpp -o main
  37 // RUN: env LLVM_PROFILE_FILE=main.profraw %run ./main
  38 // RUN: llvm-profdata merge main.profraw -o main.profdata
  39
  40 // Use profile on lib and get bitcode. Explicitly skip ICP pass to test ICP happens as
  41 // expected in the IR module that imports functions from lib.
  42 // RUN: %clang -mllvm -disable-icp -fprofile-use=main.profdata -flto=thin -O2 -c lib.cpp -o lib.bc
  43
  44 // Use profile on main and get bitcode.
  45 // RUN: %clang -fprofile-use=main.profdata -flto=thin -O2 -c main.cpp -o main.bc
  46
  47 // Run llvm-lto to get summary file.
  48 // RUN: llvm-lto -thinlto -o summary main.bc lib.bc
  49
  50 // Test the imports of functions. Default import thresholds would work but do
  51 // explicit override to be more futureproof. Note all functions have one basic
  52 // block with a function-entry-count of one, so they are actually hot functions
  53 // per default profile summary hotness cutoff.
  54 // 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
  55
  56 // Test that both candidates are ICP'ed and there is no `!VP` in the IR.
  57 // 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"
  58
  59 // IMPORTS-DAG: main.cpp: Import {{.*}}callee1{{.*}}
  60 // IMPORTS-DAG: main.cpp: Import {{.*}}callee0{{.*}}llvm.[[#]]
  61 // IMPORTS-DAG: main.cpp: Import {{.*}}global_func{{.*}}
  62
  63 // PGOName-DAG: define {{.*}}callee1{{.*}} !prof ![[#]] {
  64 // PGOName-DAG: define internal {{.*}}callee0{{.*}} !prof ![[#]] !PGOFuncName ![[#MD:]] {
  65 // PGOName-DAG: ![[#MD]] = !{!"{{.*}}lib.cpp;{{.*}}callee0{{.*}}"}
  66
  67 // ICP-REMARK: Promote indirect call to {{.*}}callee0{{.*}}llvm.[[#]] with count 1 out of 1
  68 // ICP-REMARK: Promote indirect call to {{.*}}callee1{{.*}} with count 1 out of 1
  69
  70 // ICP-IR: br i1 %[[#]], label %if.true.direct_targ, label %if.false.orig_indirect, !prof ![[#BRANCH_WEIGHT1:]]
  71 // ICP-IR: br i1 %[[#]], label %if.true.direct_targ1, label %if.false.orig_indirect2, !prof ![[#BRANCH_WEIGHT1]]
  72 // ICP-IR: ![[#BRANCH_WEIGHT1]] = !{!"branch_weights", i32 1, i32 0}
  73
  74 //--- lib.h
  75 void global_func();
  76
  77 //--- lib.cpp
  78 #include "lib.h"
  79 static void callee0() {}
  80 void callee1() {}
  81 typedef void (*FPT)();
  82 FPT calleeAddrs[] = {callee0, callee1};
  83 // `global_func`` might call one of two indirect callees. callee0 has internal
  84 // linkage and callee1 has external linkage.
  85 void global_func() {
  86   FPT fp = calleeAddrs[0];
  87   fp();
  88   fp = calleeAddrs[1];
  89   fp();
  90 }
  91
  92 //--- main.cpp
  93 #include "lib.h"
  94 int main() { global_func(); }