[Coverage] Support -fprofile-list for cold function coverage

clang/docs/UsersManual.rst

@@ -3394,9 +3394,9 @@ This can be done using the ``-fprofile-list`` option.
 
     $ clang++ -O2 -fprofile-instr-generate -fcoverage-mapping -fprofile-list=fun.list -fprofile-list=code.list code.cc -o code
 
-Supported sections are ``[clang]``, ``[llvm]``, and ``[csllvm]`` representing
-clang PGO, IRPGO, and CSIRPGO, respectively. Supported prefixes are ``function``
-and ``source``. Supported categories are ``allow``, ``skip``, and ``forbid``.
+Supported sections are ``[clang]``, ``[llvm]``, ``[csllvm]``, and ``[coldcov]`` representing
+clang PGO, IRPGO, CSIRPGO and cold function coverage, respectively. Supported prefixes are 
+``function`` and ``source``. Supported categories are ``allow``, ``skip``, and ``forbid``.
 ``skip`` adds the ``skipprofile`` attribute while ``forbid`` adds the
 ``noprofile`` attribute to the appropriate function. Use
 ``default:<allow|skip|forbid>`` to specify the default category.

clang/include/clang/Basic/CodeGenOptions.def

@@ -223,7 +223,7 @@ AFFECTING_VALUE_CODEGENOPT(OptimizeSize, 2, 0) ///< If -Os (==1) or -Oz (==2) is
 CODEGENOPT(AtomicProfileUpdate , 1, 0) ///< Set -fprofile-update=atomic
 CODEGENOPT(ContinuousProfileSync, 1, 0) ///< Enable continuous instrumentation profiling
 /// Choose profile instrumenation kind or no instrumentation.
-ENUM_CODEGENOPT(ProfileInstr, ProfileInstrKind, 2, ProfileNone)
+ENUM_CODEGENOPT(ProfileInstr, ProfileInstrKind, 4, ProfileNone)
 /// Choose profile kind for PGO use compilation.
 ENUM_CODEGENOPT(ProfileUse, ProfileInstrKind, 2, ProfileNone)
 /// Partition functions into N groups and select only functions in group i to be

clang/include/clang/Basic/CodeGenOptions.h

@@ -86,6 +86,8 @@ class CodeGenOptions : public CodeGenOptionsBase {
                        // to use with PGO.
     ProfileIRInstr,    // IR level PGO instrumentation in LLVM.
     ProfileCSIRInstr, // IR level PGO context sensitive instrumentation in LLVM.
+    ProfileIRColdCov, // IR level cold function coverage instrumentation in
+                      // LLVM.
   };
 
   enum EmbedBitcodeKind {

clang/include/clang/Driver/Options.td

@@ -7679,9 +7679,9 @@ def fpatchable_function_entry_section_EQ
       HelpText<"Use Section instead of __patchable_function_entries">,
       MarshallingInfoString<CodeGenOpts<"PatchableFunctionEntrySection">>;
 def fprofile_instrument_EQ : Joined<["-"], "fprofile-instrument=">,
-    HelpText<"Enable PGO instrumentation">, Values<"none,clang,llvm,csllvm">,
+    HelpText<"Enable PGO instrumentation">, Values<"none,clang,llvm,csllvm,coldcov">,
     NormalizedValuesScope<"CodeGenOptions">,
-    NormalizedValues<["ProfileNone", "ProfileClangInstr", "ProfileIRInstr", "ProfileCSIRInstr"]>,
+    NormalizedValues<["ProfileNone", "ProfileClangInstr", "ProfileIRInstr", "ProfileCSIRInstr", "ProfileIRColdCov"]>,
     MarshallingInfoEnum<CodeGenOpts<"ProfileInstr">, "ProfileNone">;
 def fprofile_instrument_path_EQ : Joined<["-"], "fprofile-instrument-path=">,
     HelpText<"Generate instrumented code to collect execution counts into "

clang/lib/Basic/ProfileList.cpp

@@ -81,6 +81,8 @@ static StringRef getSectionName(CodeGenOptions::ProfileInstrKind Kind) {
     return "llvm";
   case CodeGenOptions::ProfileCSIRInstr:
     return "csllvm";
+  case CodeGenOptions::ProfileIRColdCov:
+    return "coldcov";
   }
   llvm_unreachable("Unhandled CodeGenOptions::ProfileInstrKind enum");
 }

clang/lib/Driver/ToolChains/Clang.cpp

@@ -628,6 +628,7 @@ static void addPGOAndCoverageFlags(const ToolChain &TC, Compilation &C,
     CmdArgs.push_back("--pgo-instrument-cold-function-only");
     CmdArgs.push_back("-mllvm");
     CmdArgs.push_back("--pgo-function-entry-coverage");
+    CmdArgs.push_back("-fprofile-instrument=coldcov");
   }
 
   if (auto *A = Args.getLastArg(options::OPT_ftemporal_profile)) {

clang/test/CodeGen/profile-filter.c

@@ -9,6 +9,9 @@
 // RUN: echo -e "[clang]\nfun:test1\n[llvm]\nfun:test2" > %t-section.list
 // RUN: %clang_cc1 -fprofile-instrument=llvm -fprofile-list=%t-section.list -emit-llvm %s -o - | FileCheck %s --check-prefix=SECTION
 
+// RUN: echo -e "[coldcov]\nfun:test*\n!fun:test2" > %t-cold-func.list
+// RUN: %clang_cc1 -fprofile-instrument=coldcov -fprofile-list=%t-cold-func.list -emit-llvm %s -o - | FileCheck %s --check-prefix=COLDCOV
+
 // RUN: echo -e "fun:test*\n!fun:test1" > %t-exclude.list
 // RUN: %clang_cc1 -fprofile-instrument=clang -fcoverage-mapping -dump-coverage-mapping -fprofile-list=%t-exclude.list -emit-llvm %s -o - | FileCheck %s --check-prefix=EXCLUDE
 
@@ -36,6 +39,8 @@ unsigned i;
 // SECTION: @test1
 // EXCLUDE: noprofile
 // EXCLUDE: @test1
+// COLDCOV-NOT: noprofile
+// COLDCOV: @test1
 unsigned test1(void) {
   // CHECK: %pgocount = load i64, ptr @__profc_{{_?}}test1
   // FUNC: %pgocount = load i64, ptr @__profc_{{_?}}test1
@@ -55,6 +60,8 @@ unsigned test1(void) {
 // SECTION: @test2
 // EXCLUDE-NOT: noprofile
 // EXCLUDE: @test2
+// COLDCOV: noprofile
+// COLDCOV: @test2
 unsigned test2(void) {
   // CHECK: %pgocount = load i64, ptr @__profc_{{_?}}test2
   // FUNC-NOT: %pgocount = load i64, ptr @__profc_{{_?}}test2

clang/test/Driver/fprofile-generate-cold-function-coverage.c

@@ -2,7 +2,7 @@
 // CHECK: "--instrument-cold-function-only-path=default_%m.profraw" 
 // CHECK: "--pgo-instrument-cold-function-only"
 // CHECK: "--pgo-function-entry-coverage"
-// CHECK-NOT:  "-fprofile-instrument"
+// CHECK:  "-fprofile-instrument=coldcov"
 // CHECK-NOT:  "-fprofile-instrument-path=
 
 // RUN: %clang -### -c -fprofile-generate-cold-function-coverage=dir %s 2>&1 | FileCheck %s --check-prefix=CHECK-EQ