[InstrProf] Fix frontend generated function hash #165358

zsrkmyn · 2025-10-28T08:17:36Z

The most significant 4 bits in function hash are reserved bits, and are now used as context-sensitive flag, so they must be masked out. This tries to fix #160248.

The most significant 4 bits in function hash are reserved bits, and are now used as context-sensitive flag, so they must be masked out. This tries to fix llvm#160248.

llvmbot · 2025-10-28T08:18:11Z

@llvm/pr-subscribers-pgo

@llvm/pr-subscribers-clang

Author: Stephen Senran Zhang (zsrkmyn)

Changes

The most significant 4 bits in function hash are reserved bits, and are now used as context-sensitive flag, so they must be masked out. This tries to fix #160248.

Full diff: https://github.com/llvm/llvm-project/pull/165358.diff

16 Files Affected:

(modified) clang/lib/CodeGen/CodeGenPGO.cpp (+7-2)
(modified) clang/test/Profile/Inputs/c-counter-overflows.proftext (+1-1)
(added) clang/test/Profile/Inputs/c-general.profdata.v12 ()
(modified) clang/test/Profile/Inputs/c-general.proftext (+6-6)
(modified) clang/test/Profile/Inputs/c-unprofiled-blocks.proftext (+2-2)
(modified) clang/test/Profile/Inputs/cxx-rangefor.proftext (+1-1)
(modified) clang/test/Profile/Inputs/misexpect-switch-default.proftext (+1-1)
(modified) clang/test/Profile/Inputs/misexpect-switch-nonconst.proftext (+1-1)
(modified) clang/test/Profile/c-collision.c (+2-2)
(modified) clang/test/Profile/c-general.c (+1)
(modified) llvm/include/llvm/ProfileData/InstrProf.h (+5-2)
(modified) llvm/include/llvm/ProfileData/InstrProfData.inc (+1-1)
(modified) llvm/lib/ProfileData/InstrProf.cpp (+3-2)
(modified) llvm/lib/ProfileData/InstrProfWriter.cpp (+1-1)
(modified) llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp (+1-1)
(modified) llvm/test/tools/llvm-profdata/profile-version.test (+1-1)

diff --git a/clang/lib/CodeGen/CodeGenPGO.cpp b/clang/lib/CodeGen/CodeGenPGO.cpp
index 8f095649f87ce..06d7380b4e37c 100644
--- 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
index 4d0287c787051..8633060507014 100644
--- 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
new file mode 100644
index 0000000000000..57a72faaecc85
Binary files /dev/null and b/clang/test/Profile/Inputs/c-general.profdata.v12 differ
diff --git a/clang/test/Profile/Inputs/c-general.proftext b/clang/test/Profile/Inputs/c-general.proftext
index 08280ef39a89d..72e1be6e8846f 100644
--- 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
index d880663fed32d..7af509715f8f7 100644
--- 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
index d41205bbde147..cfc88da8f9726 100644
--- 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/misexpect-switch-default.proftext b/clang/test/Profile/Inputs/misexpect-switch-default.proftext
index 533da91765234..112426e0c7b57 100644
--- 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
index 0da9379357ae7..99d067c57f16f 100644
--- 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
index 6c779c6facaa2..f35ba1bfb7627 100644
--- 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
index ee36a43dac081..6c865e608a037 100644
--- 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/llvm/include/llvm/ProfileData/InstrProf.h b/llvm/include/llvm/ProfileData/InstrProf.h
index 85a9efe73855b..0532500e68db3 100644
--- a/llvm/include/llvm/ProfileData/InstrProf.h
+++ b/llvm/include/llvm/ProfileData/InstrProf.h
@@ -1059,7 +1059,8 @@ struct NamedInstrProfRecord : InstrProfRecord {
   uint64_t Hash;
 
   // We reserve this bit as the flag for context sensitive profile record.
-  static const int CS_FLAG_IN_FUNC_HASH = 60;
+  static constexpr unsigned CS_FLAG_IN_FUNC_HASH = 60;
+  static constexpr uint64_t FUNC_HASH_MASK = 0x0FFF'FFFF'FFFF'FFFF;
 
   NamedInstrProfRecord() = default;
   NamedInstrProfRecord(StringRef Name, uint64_t Hash,
@@ -1174,7 +1175,9 @@ 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
index 0496f240dc823..46d6bb5bd8896 100644
--- 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
index 02087355ab318..54987872f2d8b 100644
--- 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
index a3473514d4637..0f15ca8ff6df7 100644
--- 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
index 120c4f65a7292..9981ec8220ff7 100644
--- 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
index cb68a648d5e5a..e811699ac63ed 100644
--- 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

llvmbot · 2025-10-28T08:18:12Z

@llvm/pr-subscribers-clang-codegen

Author: Stephen Senran Zhang (zsrkmyn)

Changes

The most significant 4 bits in function hash are reserved bits, and are now used as context-sensitive flag, so they must be masked out. This tries to fix #160248.

Full diff: https://github.com/llvm/llvm-project/pull/165358.diff

16 Files Affected:

(modified) clang/lib/CodeGen/CodeGenPGO.cpp (+7-2)
(modified) clang/test/Profile/Inputs/c-counter-overflows.proftext (+1-1)
(added) clang/test/Profile/Inputs/c-general.profdata.v12 ()
(modified) clang/test/Profile/Inputs/c-general.proftext (+6-6)
(modified) clang/test/Profile/Inputs/c-unprofiled-blocks.proftext (+2-2)
(modified) clang/test/Profile/Inputs/cxx-rangefor.proftext (+1-1)
(modified) clang/test/Profile/Inputs/misexpect-switch-default.proftext (+1-1)
(modified) clang/test/Profile/Inputs/misexpect-switch-nonconst.proftext (+1-1)
(modified) clang/test/Profile/c-collision.c (+2-2)
(modified) clang/test/Profile/c-general.c (+1)
(modified) llvm/include/llvm/ProfileData/InstrProf.h (+5-2)
(modified) llvm/include/llvm/ProfileData/InstrProfData.inc (+1-1)
(modified) llvm/lib/ProfileData/InstrProf.cpp (+3-2)
(modified) llvm/lib/ProfileData/InstrProfWriter.cpp (+1-1)
(modified) llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp (+1-1)
(modified) llvm/test/tools/llvm-profdata/profile-version.test (+1-1)

diff --git a/clang/lib/CodeGen/CodeGenPGO.cpp b/clang/lib/CodeGen/CodeGenPGO.cpp
index 8f095649f87ce..06d7380b4e37c 100644
--- 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
index 4d0287c787051..8633060507014 100644
--- 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
new file mode 100644
index 0000000000000..57a72faaecc85
Binary files /dev/null and b/clang/test/Profile/Inputs/c-general.profdata.v12 differ
diff --git a/clang/test/Profile/Inputs/c-general.proftext b/clang/test/Profile/Inputs/c-general.proftext
index 08280ef39a89d..72e1be6e8846f 100644
--- 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
index d880663fed32d..7af509715f8f7 100644
--- 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
index d41205bbde147..cfc88da8f9726 100644
--- 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/misexpect-switch-default.proftext b/clang/test/Profile/Inputs/misexpect-switch-default.proftext
index 533da91765234..112426e0c7b57 100644
--- 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
index 0da9379357ae7..99d067c57f16f 100644
--- 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
index 6c779c6facaa2..f35ba1bfb7627 100644
--- 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
index ee36a43dac081..6c865e608a037 100644
--- 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/llvm/include/llvm/ProfileData/InstrProf.h b/llvm/include/llvm/ProfileData/InstrProf.h
index 85a9efe73855b..0532500e68db3 100644
--- a/llvm/include/llvm/ProfileData/InstrProf.h
+++ b/llvm/include/llvm/ProfileData/InstrProf.h
@@ -1059,7 +1059,8 @@ struct NamedInstrProfRecord : InstrProfRecord {
   uint64_t Hash;
 
   // We reserve this bit as the flag for context sensitive profile record.
-  static const int CS_FLAG_IN_FUNC_HASH = 60;
+  static constexpr unsigned CS_FLAG_IN_FUNC_HASH = 60;
+  static constexpr uint64_t FUNC_HASH_MASK = 0x0FFF'FFFF'FFFF'FFFF;
 
   NamedInstrProfRecord() = default;
   NamedInstrProfRecord(StringRef Name, uint64_t Hash,
@@ -1174,7 +1175,9 @@ 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
index 0496f240dc823..46d6bb5bd8896 100644
--- 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
index 02087355ab318..54987872f2d8b 100644
--- 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
index a3473514d4637..0f15ca8ff6df7 100644
--- 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
index 120c4f65a7292..9981ec8220ff7 100644
--- 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
index cb68a648d5e5a..e811699ac63ed 100644
--- 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

llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp

ellishg · 2025-10-29T14:43:22Z

clang/test/Profile/Inputs/c-general.profdata.v12

It would be nice to avoid checking in a binary file. I'm guessing that we can't have this be a .proftext file because there is no way to set the version?

Correct. There are also c-general.profdata.v{1,3,5} already existing in the folder :-)

[InstrProf] Fix frontend generated function hash

0fc8d8d

The most significant 4 bits in function hash are reserved bits, and are now used as context-sensitive flag, so they must be masked out. This tries to fix llvm#160248.

llvmbot added clang Clang issues not falling into any other category clang:codegen IR generation bugs: mangling, exceptions, etc. PGO Profile Guided Optimizations llvm:transforms labels Oct 28, 2025

zsrkmyn requested review from bogner, chapuni, kazutakahirata and xur-llvm October 28, 2025 08:18

Update clang test

395f1cc

zsrkmyn requested a review from evodius96 October 29, 2025 02:12

ellishg reviewed Oct 29, 2025

View reviewed changes

zsrkmyn added 2 commits October 30, 2025 09:56

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[InstrProf] Fix frontend generated function hash #165358

[InstrProf] Fix frontend generated function hash #165358

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llvmbot commented Oct 28, 2025 •

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