Support for instrumenting only selected files or functions

This change implements support for applying profile instrumentation
only to selected files or functions. The implementation uses the
sanitizer special case list format to select which files and functions
to instrument, and relies on the new noprofile IR attribute to exclude
functions from instrumentation.

Differential Revision: https://reviews.llvm.org/D94820

include/llvm/Bitcode/LLVMBitCodes.h

@@ -656,6 +656,7 @@ enum AttributeKindCodes {
   ATTR_KIND_MUSTPROGRESS = 70,
   ATTR_KIND_NO_CALLBACK = 71,
   ATTR_KIND_HOT = 72,
+  ATTR_KIND_NO_PROFILE = 73,
 };
 
 enum ComdatSelectionKindCodes {

include/llvm/IR/Attributes.td

@@ -148,6 +148,9 @@ def NoSync : EnumAttr<"nosync">;
 /// Disable Indirect Branch Tracking.
 def NoCfCheck : EnumAttr<"nocf_check">;
 
+/// Function should be instrumented.
+def NoProfile : EnumAttr<"noprofile">;
+
 /// Function doesn't unwind stack.
 def NoUnwind : EnumAttr<"nounwind">;
 

lib/AsmParser/LLLexer.cpp

@@ -663,6 +663,7 @@ lltok::Kind LLLexer::LexIdentifier() {
   KEYWORD(nonlazybind);
   KEYWORD(nomerge);
   KEYWORD(nonnull);
+  KEYWORD(noprofile);
   KEYWORD(noredzone);
   KEYWORD(noreturn);
   KEYWORD(nosync);

lib/AsmParser/LLParser.cpp

@@ -1368,6 +1368,7 @@ bool LLParser::parseFnAttributeValuePairs(AttrBuilder &B,
     case lltok::kw_noreturn: B.addAttribute(Attribute::NoReturn); break;
     case lltok::kw_nosync: B.addAttribute(Attribute::NoSync); break;
     case lltok::kw_nocf_check: B.addAttribute(Attribute::NoCfCheck); break;
+    case lltok::kw_noprofile: B.addAttribute(Attribute::NoProfile); break;
     case lltok::kw_norecurse: B.addAttribute(Attribute::NoRecurse); break;
     case lltok::kw_nounwind: B.addAttribute(Attribute::NoUnwind); break;
     case lltok::kw_null_pointer_is_valid:
@@ -1778,6 +1779,7 @@ bool LLParser::parseOptionalParamAttrs(AttrBuilder &B) {
     case lltok::kw_noinline:
     case lltok::kw_nonlazybind:
     case lltok::kw_nomerge:
+    case lltok::kw_noprofile:
     case lltok::kw_noredzone:
     case lltok::kw_noreturn:
     case lltok::kw_nocf_check:
@@ -1886,6 +1888,7 @@ bool LLParser::parseOptionalReturnAttrs(AttrBuilder &B) {
     case lltok::kw_noinline:
     case lltok::kw_nonlazybind:
     case lltok::kw_nomerge:
+    case lltok::kw_noprofile:
     case lltok::kw_noredzone:
     case lltok::kw_noreturn:
     case lltok::kw_nocf_check:

lib/AsmParser/LLToken.h

@@ -210,6 +210,7 @@ enum Kind {
   kw_nonlazybind,
   kw_nomerge,
   kw_nonnull,
+  kw_noprofile,
   kw_noredzone,
   kw_noreturn,
   kw_nosync,

lib/Bitcode/Writer/BitcodeWriter.cpp

@@ -680,6 +680,8 @@ static uint64_t getAttrKindEncoding(Attribute::AttrKind Kind) {
     return bitc::ATTR_KIND_NOSYNC;
   case Attribute::NoCfCheck:
     return bitc::ATTR_KIND_NOCF_CHECK;
+  case Attribute::NoProfile:
+    return bitc::ATTR_KIND_NO_PROFILE;
   case Attribute::NoUnwind:
     return bitc::ATTR_KIND_NO_UNWIND;
   case Attribute::NullPointerIsValid:

lib/IR/Attributes.cpp

@@ -403,6 +403,8 @@ std::string Attribute::getAsString(bool InAttrGrp) const {
     return "nocf_check";
   if (hasAttribute(Attribute::NoRecurse))
     return "norecurse";
+  if (hasAttribute(Attribute::NoProfile))
+    return "noprofile";
   if (hasAttribute(Attribute::NoUnwind))
     return "nounwind";
   if (hasAttribute(Attribute::OptForFuzzing))

lib/IR/Verifier.cpp

@@ -1655,6 +1655,7 @@ static bool isFuncOnlyAttr(Attribute::AttrKind Kind) {
   case Attribute::StrictFP:
   case Attribute::NullPointerIsValid:
   case Attribute::MustProgress:
+  case Attribute::NoProfile:
     return true;
   default:
     break;

lib/Transforms/Instrumentation/PGOInstrumentation.cpp

@@ -1591,6 +1591,8 @@ static bool InstrumentAllFunctions(
   for (auto &F : M) {
     if (F.isDeclaration())
       continue;
+    if (F.hasFnAttribute(llvm::Attribute::NoProfile))
+      continue;
     auto &TLI = LookupTLI(F);
     auto *BPI = LookupBPI(F);
     auto *BFI = LookupBFI(F);

lib/Transforms/Utils/CodeExtractor.cpp

@@ -973,6 +973,7 @@ Function *CodeExtractor::constructFunction(const ValueSet &inputs,
       case Attribute::UWTable:
       case Attribute::NoCfCheck:
       case Attribute::MustProgress:
+      case Attribute::NoProfile:
         break;
       }
 

test/Transforms/PGOProfile/noprofile.ll

@@ -0,0 +1,25 @@
+; RUN: opt < %s -pgo-instr-gen -S | FileCheck %s
+; RUN: opt < %s -passes=pgo-instr-gen -S | FileCheck %s
+
+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"
+
+@i = dso_local global i32 0, align 4
+
+define i32 @test1() {
+entry:
+; CHECK: call void @llvm.instrprof.increment
+  %0 = load i32, i32* @i, align 4
+  %add = add i32 %0, 1
+  ret i32 %add
+}
+
+define i32 @test2() #0 {
+entry:
+; CHECK-NOT: call void @llvm.instrprof.increment
+  %0 = load i32, i32* @i, align 4
+  %sub = sub i32 %0, 1
+  ret i32 %sub
+}
+
+attributes #0 = { noprofile }