[InstrProf] Fix frontend generated function hash (#165358)

zsrkmyn · web-flow · commit 5af27f8c208b · 2025-11-06T09:22:06.000-08:00
diff --git a/clang/lib/CodeGen/CodeGenPGO.cpp b/clang/lib/CodeGen/CodeGenPGO.cpp
@@ -58,9 +58,10 @@ enum PGOHashVersion : unsigned {
   PGO_HASH_V1,
   PGO_HASH_V2,
   PGO_HASH_V3,
+  PGO_HASH_V4,
 
   // Keep this set to the latest hash version.
-  PGO_HASH_LATEST = PGO_HASH_V3
+  PGO_HASH_LATEST = PGO_HASH_V4
 };
 
 namespace {
@@ -152,7 +153,9 @@ static PGOHashVersion getPGOHashVersion(llvm::IndexedInstrProfReader *PGOReader,
     return PGO_HASH_V1;
   if (PGOReader->getVersion() <= 5)
     return PGO_HASH_V2;
-  return PGO_HASH_V3;
+  if (PGOReader->getVersion() <= 12)
+    return PGO_HASH_V3;
+  return PGO_HASH_V4;
 }
 
 /// A RecursiveASTVisitor that fills a map of statements to PGO counters.
@@ -1099,6 +1102,8 @@ void CodeGenPGO::mapRegionCounters(const Decl *D) {
   assert(Walker.NextCounter > 0 && "no entry counter mapped for decl");
   NumRegionCounters = Walker.NextCounter;
   FunctionHash = Walker.Hash.finalize();
+  if (HashVersion >= PGO_HASH_V4)
+    FunctionHash &= llvm::NamedInstrProfRecord::FUNC_HASH_MASK;
 }
 
 bool CodeGenPGO::skipRegionMappingForDecl(const Decl *D) {
diff --git a/clang/test/Profile/Inputs/c-counter-overflows.proftext b/clang/test/Profile/Inputs/c-counter-overflows.proftext
@@ -1,5 +1,5 @@
 main
-7779561829442898616
+862032801801816760
 8
 1
 68719476720
diff --git a/clang/test/Profile/Inputs/c-general.profdata.v12 b/clang/test/Profile/Inputs/c-general.profdata.v12
diff --git a/clang/test/Profile/Inputs/c-general.proftext b/clang/test/Profile/Inputs/c-general.proftext
@@ -7,7 +7,7 @@ simple_loops
 75
 
 conditionals
-4904767535850050386
+293081517422662482
 13
 1
 100
@@ -24,7 +24,7 @@ conditionals
 1
 
 early_exits
-2880354649761471549
+574511640547777597
 9
 1
 0
@@ -37,7 +37,7 @@ early_exits
 0
 
 jumps
-15051420506203462683
+63440946314451995
 22
 1
 1
@@ -86,7 +86,7 @@ switches
 0
 
 big_switch
-13144136522122330070
+461999971447013334
 17
 1
 32
@@ -125,7 +125,7 @@ boolean_operators
 33
 
 boolop_loops
-12402604614320574815
+873389568252105055
 13
 1
 50
@@ -149,7 +149,7 @@ conditional_operator
 1
 
 do_fallthrough
-8714614136504380050
+644163604256451218
 4
 1
 10
diff --git a/clang/test/Profile/Inputs/c-unprofiled-blocks.proftext b/clang/test/Profile/Inputs/c-unprofiled-blocks.proftext
@@ -1,5 +1,5 @@
 never_called
-6820425066224770721
+1055817543190535841
 9
 0
 0
@@ -17,7 +17,7 @@ main
 1
 
 dead_code
-5254464978620792806
+642778960193404902
 10
 1
 0
diff --git a/clang/test/Profile/Inputs/cxx-rangefor.proftext b/clang/test/Profile/Inputs/cxx-rangefor.proftext
@@ -1,5 +1,5 @@
 _Z9range_forv
-8789831523895825398
+719380991647896566
 5
 1
 4
diff --git a/clang/test/Profile/Inputs/cxx-throws.proftext b/clang/test/Profile/Inputs/cxx-throws.proftext
@@ -1,5 +1,5 @@
 _Z6throwsv
-18172607911962830854
+878785342860126214
 9
 1
 100
diff --git a/clang/test/Profile/Inputs/misexpect-switch-default.proftext b/clang/test/Profile/Inputs/misexpect-switch-default.proftext
@@ -1,6 +1,6 @@
 main
 # Func Hash:
-8734802134600123338
+664351602352194506
 # Num Counters:
 9
 # Counter Values:
diff --git a/clang/test/Profile/Inputs/misexpect-switch-nonconst.proftext b/clang/test/Profile/Inputs/misexpect-switch-nonconst.proftext
@@ -1,6 +1,6 @@
 main
 # Func Hash:
-3721743393642630379
+262978879822089451
 # Num Counters:
 10
 # Counter Values:
diff --git a/clang/test/Profile/c-collision.c b/clang/test/Profile/c-collision.c
@@ -2,8 +2,8 @@
 // RUN: %clang_cc1 -UEXTRA -triple x86_64-unknown-linux-gnu -main-file-name c-collision.c %s -o - -emit-llvm -fprofile-instrument=clang | FileCheck %s --check-prefix=CHECK-NOEXTRA
 // RUN: %clang_cc1 -DEXTRA -triple x86_64-unknown-linux-gnu -main-file-name c-collision.c %s -o - -emit-llvm -fprofile-instrument=clang | FileCheck %s --check-prefix=CHECK-EXTRA
 
-// CHECK-NOEXTRA: @__profd_foo = private global { {{.*}} } { i64 6699318081062747564, i64 7156072912471487002,
-// CHECK-EXTRA:   @__profd_foo = private global { {{.*}} } { i64 6699318081062747564, i64 -4383447408116050035,
+// CHECK-NOEXTRA: @__profd_foo = private global { {{.*}} } { i64 6699318081062747564, i64 238543884830405146,
+// CHECK-EXTRA:   @__profd_foo = private global { {{.*}} } { i64 6699318081062747564, i64 228238610311337869,
 
 extern int bar;
 void foo(void) {
diff --git a/clang/test/Profile/c-general.c b/clang/test/Profile/c-general.c
@@ -4,6 +4,7 @@
 
 // RUN: llvm-profdata merge %S/Inputs/c-general.proftext -o %t.profdata
 // RUN: %clang_cc1 -triple x86_64-apple-macosx10.9 -main-file-name c-general.c %s -o - -emit-llvm -fprofile-instrument-use=clang -fprofile-instrument-use-path=%t.profdata | FileCheck -allow-deprecated-dag-overlap  -check-prefix=PGOUSE %s
+// RUN: %clang_cc1 -triple x86_64-apple-macosx10.9 -main-file-name c-general.c %s -o - -emit-llvm -fprofile-instrument-use=clang -fprofile-instrument-use-path=%S/Inputs/c-general.profdata.v12 | FileCheck -allow-deprecated-dag-overlap  -check-prefix=PGOUSE %s
 // RUN: %clang_cc1 -triple x86_64-apple-macosx10.9 -main-file-name c-general.c %s -o - -emit-llvm -fprofile-instrument-use=clang -fprofile-instrument-use-path=%S/Inputs/c-general.profdata.v5 | FileCheck -allow-deprecated-dag-overlap  -check-prefix=PGOUSE %s
 // RUN: %clang_cc1 -triple x86_64-apple-macosx10.9 -main-file-name c-general.c %s -o - -emit-llvm -fprofile-instrument-use=clang -fprofile-instrument-use-path=%S/Inputs/c-general.profdata.v3 | FileCheck -allow-deprecated-dag-overlap  -check-prefix=PGOUSE %s
 // Also check compatibility with older profiles.
diff --git a/compiler-rt/include/profile/InstrProfData.inc b/compiler-rt/include/profile/InstrProfData.inc
@@ -722,7 +722,7 @@ serializeValueProfDataFrom(ValueProfRecordClosure *Closure,
 /* Raw profile format version (start from 1). */
 #define INSTR_PROF_RAW_VERSION 10
 /* Indexed profile format version (start from 1). */
-#define INSTR_PROF_INDEX_VERSION 12
+#define INSTR_PROF_INDEX_VERSION 13
 /* Coverage mapping format version (start from 0). */
 #define INSTR_PROF_COVMAP_VERSION 6
 
diff --git a/llvm/include/llvm/ProfileData/InstrProf.h b/llvm/include/llvm/ProfileData/InstrProf.h
@@ -1058,8 +1058,10 @@ struct NamedInstrProfRecord : InstrProfRecord {
   StringRef Name;
   uint64_t Hash;
 
-  // We reserve this bit as the flag for context sensitive profile record.
-  static const int CS_FLAG_IN_FUNC_HASH = 60;
+  // We reserve the highest 4 bits as flags.
+  static constexpr uint64_t FUNC_HASH_MASK = 0x0FFF'FFFF'FFFF'FFFF;
+  // The 60th bit is for context sensitive profile record.
+  static constexpr unsigned CS_FLAG_IN_FUNC_HASH = 60;
 
   NamedInstrProfRecord() = default;
   NamedInstrProfRecord(StringRef Name, uint64_t Hash,
@@ -1174,7 +1176,9 @@ enum ProfVersion {
   Version11 = 11,
   // VTable profiling, decision record and bitmap are modified for mcdc.
   Version12 = 12,
-  // The current version is 12.
+  // In this version, the frontend PGO stable hash algorithm defaults to V4.
+  Version13 = 13,
+  // The current version is 13.
   CurrentVersion = INSTR_PROF_INDEX_VERSION
 };
 const uint64_t Version = ProfVersion::CurrentVersion;
diff --git a/llvm/include/llvm/ProfileData/InstrProfData.inc b/llvm/include/llvm/ProfileData/InstrProfData.inc
@@ -722,7 +722,7 @@ serializeValueProfDataFrom(ValueProfRecordClosure *Closure,
 /* Raw profile format version (start from 1). */
 #define INSTR_PROF_RAW_VERSION 10
 /* Indexed profile format version (start from 1). */
-#define INSTR_PROF_INDEX_VERSION 12
+#define INSTR_PROF_INDEX_VERSION 13
 /* Coverage mapping format version (start from 0). */
 #define INSTR_PROF_COVMAP_VERSION 6
 
diff --git a/llvm/lib/ProfileData/InstrProf.cpp b/llvm/lib/ProfileData/InstrProf.cpp
@@ -1690,7 +1690,7 @@ Expected<Header> Header::readFromBuffer(const unsigned char *Buffer) {
       IndexedInstrProf::ProfVersion::CurrentVersion)
     return make_error<InstrProfError>(instrprof_error::unsupported_version);
 
-  static_assert(IndexedInstrProf::ProfVersion::CurrentVersion == Version12,
+  static_assert(IndexedInstrProf::ProfVersion::CurrentVersion == Version13,
                 "Please update the reader as needed when a new field is added "
                 "or when indexed profile version gets bumped.");
 
@@ -1723,10 +1723,11 @@ size_t Header::size() const {
     // of the header, and byte offset of existing fields shouldn't change when
     // indexed profile version gets incremented.
     static_assert(
-        IndexedInstrProf::ProfVersion::CurrentVersion == Version12,
+        IndexedInstrProf::ProfVersion::CurrentVersion == Version13,
         "Please update the size computation below if a new field has "
         "been added to the header; for a version bump without new "
         "fields, add a case statement to fall through to the latest version.");
+  case 13ull:
   case 12ull:
     return 72;
   case 11ull:
diff --git a/llvm/lib/ProfileData/InstrProfWriter.cpp b/llvm/lib/ProfileData/InstrProfWriter.cpp
@@ -542,7 +542,7 @@ Error InstrProfWriter::writeImpl(ProfOStream &OS) {
   // The WritePrevVersion handling will either need to be removed or updated
   // if the version is advanced beyond 12.
   static_assert(IndexedInstrProf::ProfVersion::CurrentVersion ==
-                IndexedInstrProf::ProfVersion::Version12);
+                IndexedInstrProf::ProfVersion::Version13);
   if (static_cast<bool>(ProfileKind & InstrProfKind::IRInstrumentation))
     Header.Version |= VARIANT_MASK_IR_PROF;
   if (static_cast<bool>(ProfileKind & InstrProfKind::ContextSensitive))
diff --git a/llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp b/llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp
@@ -734,7 +734,7 @@ void FuncPGOInstrumentation<Edge, BBInfo>::computeCFGHash() {
   FunctionHash = (((uint64_t)JCH.getCRC()) << 28) + JC.getCRC();
 
   // Reserve bit 60-63 for other information purpose.
-  FunctionHash &= 0x0FFFFFFFFFFFFFFF;
+  FunctionHash &= NamedInstrProfRecord::FUNC_HASH_MASK;
   if (IsCS)
     NamedInstrProfRecord::setCSFlagInHash(FunctionHash);
   LLVM_DEBUG(dbgs() << "Function Hash Computation for " << F.getName() << ":\n"
diff --git a/llvm/test/tools/llvm-profdata/profile-version.test b/llvm/test/tools/llvm-profdata/profile-version.test
@@ -2,7 +2,7 @@ Test the profile version.
 
 RUN: llvm-profdata merge -o %t.profdata %p/Inputs/basic.proftext
 RUN: llvm-profdata show --profile-version %t.profdata | FileCheck %s
-CHECK: Profile version: 12
+CHECK: Profile version: 13
 
 RUN: llvm-profdata merge -o %t.prev.profdata %p/Inputs/basic.proftext --write-prev-version
 RUN: llvm-profdata show --profile-version %t.prev.profdata | FileCheck %s --check-prefix=PREV

Original file line number	Diff line number	Diff line change
`@@ -1,5 +1,5 @@`
`1`	`1`	`main`
`2`		`-7779561829442898616`
	`2`	`+862032801801816760`
`3`	`3`	`8`
`4`	`4`	`1`
`5`	`5`	`68719476720`
Original file line number	Diff line number	Diff line change
`@@ -7,7 +7,7 @@ simple_loops`
`7`	`7`	`75`
`8`	`8`
`9`	`9`	`conditionals`
`10`		`-4904767535850050386`
	`10`	`+293081517422662482`
`11`	`11`	`13`
`12`	`12`	`1`
`13`	`13`	`100`
`@@ -24,7 +24,7 @@ conditionals`
`24`	`24`	`1`
`25`	`25`
`26`	`26`	`early_exits`
`27`		`-2880354649761471549`
	`27`	`+574511640547777597`
`28`	`28`	`9`
`29`	`29`	`1`
`30`	`30`	`0`
`@@ -37,7 +37,7 @@ early_exits`
`37`	`37`	`0`
`38`	`38`
`39`	`39`	`jumps`
`40`		`-15051420506203462683`
	`40`	`+63440946314451995`
`41`	`41`	`22`
`42`	`42`	`1`
`43`	`43`	`1`
`@@ -86,7 +86,7 @@ switches`
`86`	`86`	`0`
`87`	`87`
`88`	`88`	`big_switch`
`89`		`-13144136522122330070`
	`89`	`+461999971447013334`
`90`	`90`	`17`
`91`	`91`	`1`
`92`	`92`	`32`
`@@ -125,7 +125,7 @@ boolean_operators`
`125`	`125`	`33`
`126`	`126`
`127`	`127`	`boolop_loops`
`128`		`-12402604614320574815`
	`128`	`+873389568252105055`
`129`	`129`	`13`
`130`	`130`	`1`
`131`	`131`	`50`
`@@ -149,7 +149,7 @@ conditional_operator`
`149`	`149`	`1`
`150`	`150`
`151`	`151`	`do_fallthrough`
`152`		`-8714614136504380050`
	`152`	`+644163604256451218`
`153`	`153`	`4`
`154`	`154`	`1`
`155`	`155`	`10`
Original file line number	Diff line number	Diff line change
`@@ -1,5 +1,5 @@`
`1`	`1`	`never_called`
`2`		`-6820425066224770721`
	`2`	`+1055817543190535841`
`3`	`3`	`9`
`4`	`4`	`0`
`5`	`5`	`0`
`@@ -17,7 +17,7 @@ main`
`17`	`17`	`1`
`18`	`18`
`19`	`19`	`dead_code`
`20`		`-5254464978620792806`
	`20`	`+642778960193404902`
`21`	`21`	`10`
`22`	`22`	`1`
`23`	`23`	`0`
Original file line number	Diff line number	Diff line change
`@@ -1,5 +1,5 @@`
`1`	`1`	`_Z9range_forv`
`2`		`-8789831523895825398`
	`2`	`+719380991647896566`
`3`	`3`	`5`
`4`	`4`	`1`
`5`	`5`	`4`
Original file line number	Diff line number	Diff line change
`@@ -1,5 +1,5 @@`
`1`	`1`	`_Z6throwsv`
`2`		`-18172607911962830854`
	`2`	`+878785342860126214`
`3`	`3`	`9`
`4`	`4`	`1`
`5`	`5`	`100`
Original file line number	Diff line number	Diff line change
`@@ -1,6 +1,6 @@`
`1`	`1`	`main`
`2`	`2`	`# Func Hash:`
`3`		`-8734802134600123338`
	`3`	`+664351602352194506`
`4`	`4`	`# Num Counters:`
`5`	`5`	`9`
`6`	`6`	`# Counter Values:`