serge-sans-paille updated this revision to Diff 266133.
serge-sans-paille added a comment.
With v3 version + Make cast explicit
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D79961/new/
https://reviews.llvm.org/D79961
Files:
clang/docs/ReleaseNotes.rst
clang/lib/CodeGen/CodeGenPGO.cpp
clang/test/Profile/Inputs/c-counter-overflows.proftext
clang/test/Profile/Inputs/c-general.profdata.v2
clang/test/Profile/Inputs/c-general.profdata.v3
clang/test/Profile/Inputs/c-general.proftext
clang/test/Profile/Inputs/c-unprofiled-blocks.proftext
clang/test/Profile/Inputs/cxx-rangefor.proftext
clang/test/Profile/Inputs/cxx-throws.proftext
clang/test/Profile/Inputs/misexpect-switch-default.proftext
clang/test/Profile/Inputs/misexpect-switch-nonconst.proftext
clang/test/Profile/Inputs/misexpect-switch.proftext
clang/test/Profile/c-collision.c
clang/test/Profile/c-general.c
Index: clang/test/Profile/c-general.c
===================================================================
--- clang/test/Profile/c-general.c
+++ clang/test/Profile/c-general.c
@@ -5,6 +5,7 @@
// 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-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-path=%S/Inputs/c-general.profdata.v3 | 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-path=%S/Inputs/c-general.profdata.v2 | FileCheck -allow-deprecated-dag-overlap -check-prefix=PGOUSE %s
// Also check compatibility with older profiles.
// RUN: %clang_cc1 -triple x86_64-apple-macosx10.9 -main-file-name c-general.c %s -o - -emit-llvm -fprofile-instrument-use-path=%S/Inputs/c-general.profdata.v1 | FileCheck -allow-deprecated-dag-overlap -check-prefix=PGOUSE %s
Index: clang/test/Profile/c-collision.c
===================================================================
--- /dev/null
+++ clang/test/Profile/c-collision.c
@@ -0,0 +1,22 @@
+// Test that a slight change in the code leads to a different hash.
+// 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,
+
+extern int bar;
+void foo() {
+ if (bar) {
+ }
+ if (bar) {
+ }
+ if (bar) {
+ if (bar) {
+#ifdef EXTRA
+ if (bar) {
+ }
+#endif
+ }
+ }
+}
Index: clang/test/Profile/Inputs/misexpect-switch.proftext
===================================================================
--- clang/test/Profile/Inputs/misexpect-switch.proftext
+++ clang/test/Profile/Inputs/misexpect-switch.proftext
@@ -1,6 +1,6 @@
main
# Func Hash:
-1965403898329309329
+872687477373597607
# Num Counters:
9
# Counter Values:
Index: clang/test/Profile/Inputs/misexpect-switch-nonconst.proftext
===================================================================
--- clang/test/Profile/Inputs/misexpect-switch-nonconst.proftext
+++ clang/test/Profile/Inputs/misexpect-switch-nonconst.proftext
@@ -1,6 +1,6 @@
main
# Func Hash:
-1965403898329309329
+3721743393642630379
# Num Counters:
10
# Counter Values:
Index: clang/test/Profile/Inputs/misexpect-switch-default.proftext
===================================================================
--- clang/test/Profile/Inputs/misexpect-switch-default.proftext
+++ clang/test/Profile/Inputs/misexpect-switch-default.proftext
@@ -1,6 +1,6 @@
main
# Func Hash:
-8712453512413296413
+8734802134600123338
# Num Counters:
9
# Counter Values:
Index: clang/test/Profile/Inputs/cxx-throws.proftext
===================================================================
--- clang/test/Profile/Inputs/cxx-throws.proftext
+++ clang/test/Profile/Inputs/cxx-throws.proftext
@@ -1,5 +1,5 @@
_Z6throwsv
-340120998528097520
+18172607911962830854
9
1
100
Index: clang/test/Profile/Inputs/cxx-rangefor.proftext
===================================================================
--- clang/test/Profile/Inputs/cxx-rangefor.proftext
+++ clang/test/Profile/Inputs/cxx-rangefor.proftext
@@ -1,5 +1,5 @@
_Z9range_forv
-6169071350249721981
+8789831523895825398
5
1
4
Index: clang/test/Profile/Inputs/c-unprofiled-blocks.proftext
===================================================================
--- clang/test/Profile/Inputs/c-unprofiled-blocks.proftext
+++ clang/test/Profile/Inputs/c-unprofiled-blocks.proftext
@@ -1,5 +1,5 @@
never_called
-5644096560937528444
+6820425066224770721
9
0
0
@@ -17,7 +17,7 @@
1
dead_code
-9636018207904213947
+5254464978620792806
10
1
0
Index: clang/test/Profile/Inputs/c-general.proftext
===================================================================
--- clang/test/Profile/Inputs/c-general.proftext
+++ clang/test/Profile/Inputs/c-general.proftext
@@ -7,7 +7,7 @@
75
conditionals
-4190663230902537370
+4904767535850050386
11
1
100
@@ -22,7 +22,7 @@
100
early_exits
-8265526549255474475
+2880354649761471549
9
1
0
@@ -35,7 +35,7 @@
0
jumps
-15872630527555456493
+15051420506203462683
22
1
1
@@ -61,7 +61,7 @@
9
switches
-11892326508727782373
+43242458792028222
19
1
1
@@ -84,7 +84,7 @@
0
big_switch
-16933280399284440835
+13144136522122330070
17
1
32
@@ -117,7 +117,7 @@
50
boolop_loops
-11270260636676715317
+12402604614320574815
9
1
50
@@ -137,7 +137,7 @@
1
do_fallthrough
-6898770640283947069
+8714614136504380050
4
1
10
Index: clang/test/Profile/Inputs/c-counter-overflows.proftext
===================================================================
--- clang/test/Profile/Inputs/c-counter-overflows.proftext
+++ clang/test/Profile/Inputs/c-counter-overflows.proftext
@@ -1,5 +1,5 @@
main
-10111551811706059223
+7779561829442898616
8
1
68719476720
Index: clang/lib/CodeGen/CodeGenPGO.cpp
===================================================================
--- clang/lib/CodeGen/CodeGenPGO.cpp
+++ clang/lib/CodeGen/CodeGenPGO.cpp
@@ -52,9 +52,10 @@
enum PGOHashVersion : unsigned {
PGO_HASH_V1,
PGO_HASH_V2,
+ PGO_HASH_V3,
// Keep this set to the latest hash version.
- PGO_HASH_LATEST = PGO_HASH_V2
+ PGO_HASH_LATEST = PGO_HASH_V3
};
namespace {
@@ -747,13 +748,21 @@
return Working;
// Check for remaining work in Working.
- if (Working)
- MD5.update(Working);
+ if (Working) {
+ // Keep the buggy behavior from v1 and v2 for backward-compatibility. This
+ // is buggy because it converts a uint64_t into an array of uint8_t.
+ if (HashVersion == PGO_HASH_V1 or HashVersion == PGO_HASH_V2) {
+ MD5.update({(uint8_t)Working});
+ } else {
+ using namespace llvm::support;
+ uint64_t Swapped = endian::byte_swap<uint64_t, little>(Working);
+ MD5.update(llvm::makeArrayRef((uint8_t *)&Swapped, sizeof(Swapped)));
+ }
+ }
// Finalize the MD5 and return the hash.
llvm::MD5::MD5Result Result;
MD5.final(Result);
- using namespace llvm::support;
return Result.low();
}
Index: clang/docs/ReleaseNotes.rst
===================================================================
--- clang/docs/ReleaseNotes.rst
+++ clang/docs/ReleaseNotes.rst
@@ -82,6 +82,10 @@
linker. If the user links the program with the ``clang`` or ``clang-cl``
drivers, the driver will pass this flag for them.
+- Clang's profile files generated through ``-fprofile-instr-generate`` are using
+ a fixed hashing algorithm that prevents some collision when loading
+ out-of-date profile informations. Clang can still read old profile files.
+
New Compiler Flags
------------------
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