[Bug middle-end/116651] New: Memory allocation elision for std::vector like cases

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116651 Bug ID: 116651 Summary: Memory allocation elision for std::vector like cases Product: gcc Version: 15.0 Status: UNCONFIRMED Keywords: missed-optimization Severity: norma

[Bug middle-end/115309] New: Simple coroutine based generator is not optimized well

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115309 Bug ID: 115309 Summary: Simple coroutine based generator is not optimized well Product: gcc Version: 15.0 Status: UNCONFIRMED Keywords: missed-optimization Severity: nor

[Bug middle-end/114661] New: Bit operations not optimized to multiplication

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114661 Bug ID: 114661 Summary: Bit operations not optimized to multiplication Product: gcc Version: 14.0 Status: UNCONFIRMED Keywords: missed-optimization Severity: normal

[Bug middle-end/114660] Exponentiating by squaring not performed for x * y * y * y * y

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114660 --- Comment #1 from Antony Polukhin --- The above godbolt link for an old version of GCC, here's for 14.0 https://godbolt.org/z/dTPYY1T9W

[Bug middle-end/114660] New: Exponentiating by squaring not performed for x * y * y * y * y

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114660 Bug ID: 114660 Summary: Exponentiating by squaring not performed for x * y * y * y * y Product: gcc Version: 14.0 Status: UNCONFIRMED Keywords: missed-optimiza

[Bug middle-end/114559] New: After function inlining some optimizations missing

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114559 Bug ID: 114559 Summary: After function inlining some optimizations missing Product: gcc Version: 14.0 Status: UNCONFIRMED Keywords: missed-optimization Severity: normal

[Bug middle-end/114391] catch() and immediate throw; could be optimized to noop

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114391 --- Comment #2 from Antony Polukhin --- > Is there something to optimize when foo() cannot be tail-called? Yes. Just `catch (...) { throw; }`, no more restrictions. I do not even think, that it should be the outer most EH region: void foo();

[Bug middle-end/114391] New: catch() and immediate throw; could be optimized to noop

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114391 Bug ID: 114391 Summary: catch() and immediate throw; could be optimized to noop Product: gcc Version: 14.0 Status: UNCONFIRMED Keywords: missed-optimization

[Bug middle-end/114270] New: Integer multiplication on floating point constant with conversion back to integer is not optimized

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114270 Bug ID: 114270 Summary: Integer multiplication on floating point constant with conversion back to integer is not optimized Product: gcc Version: 14.0 Status: UNCONFIRMED

[Bug middle-end/113959] New: Optimize `__builtin_isnan(x) || __builtin_isinf(x)` to `__builtin_isfinite(x)`

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113959 Bug ID: 113959 Summary: Optimize `__builtin_isnan(x) || __builtin_isinf(x)` to `__builtin_isfinite(x)` Product: gcc Version: 14.0 Status: UNCONFIRMED Keywords:

[Bug tree-optimization/112683] New: Optimizing memcpy range by extending to word bounds

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112683 Bug ID: 112683 Summary: Optimizing memcpy range by extending to word bounds Product: gcc Version: 14.0 Status: UNCONFIRMED Keywords: missed-optimization Severity: normal

[Bug libstdc++/112682] New: More efficient std::basic_string move construction

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112682 Bug ID: 112682 Summary: More efficient std::basic_string move construction Product: gcc Version: 14.0 Status: UNCONFIRMED Severity: normal Priority: P3 Componen

[Bug tree-optimization/112584] New: Suboptimal stack usage on third memcpy

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112584 Bug ID: 112584 Summary: Suboptimal stack usage on third memcpy Product: gcc Version: 13.2.1 Status: UNCONFIRMED Keywords: missed-optimization Severity: normal

[Bug libstdc++/112440] New: Compiler does not grok basic_string::resize and basic_string::reserve if _CharT is char

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112440 Bug ID: 112440 Summary: Compiler does not grok basic_string::resize and basic_string::reserve if _CharT is char Product: gcc Version: 13.2.1 Status: UNCONFIRMED

[Bug c++/111690] New: Redefinition of operator == not detected with friend <=>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111690 Bug ID: 111690 Summary: Redefinition of operator == not detected with friend <=> Product: gcc Version: 14.0 Status: UNCONFIRMED Keywords: accepts-invalid

[Bug target/110170] Sub-optimal conditional jumps in conditional-swap with floating point

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110170 --- Comment #13 from Antony Polukhin --- There's a typo at https://gcc.gnu.org/git/?p=gcc.git;a=blob;f=gcc/testsuite/g%2B%2B.target/i386/pr110170.C;h=e638b12a5ee2264ecef77acca86432a9f24b103b;hb=d41a57c46df6f8f7dae0c0a8b349e734806a837b#l87 It sh

[Bug target/110457] Unnecessary movsx eax, dil

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110457 --- Comment #4 from Antony Polukhin --- Oh, if there's an disagreement I'm fine with closing this issue as invalid/later/won't_fix

[Bug tree-optimization/110459] New: Trivial on stack variable was not optimized away

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110459 Bug ID: 110459 Summary: Trivial on stack variable was not optimized away Product: gcc Version: 14.0 Status: UNCONFIRMED Keywords: missed-optimization Severity: normal

[Bug target/110457] Unnecessary movsx eax, dil

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110457 --- Comment #1 from Antony Polukhin --- > However, it could be shortened to just: sample1(char): imul eax,edi,0x10111 ret; missed in previous message

[Bug target/110457] New: Unnecessary movsx eax, dil

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110457 Bug ID: 110457 Summary: Unnecessary movsx eax, dil Product: gcc Version: 14.0 Status: UNCONFIRMED Keywords: missed-optimization Severity: normal Priority: P3

[Bug c++/110363] New: New use-after-move warning

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110363 Bug ID: 110363 Summary: New use-after-move warning Product: gcc Version: 14.0 Status: UNCONFIRMED Keywords: diagnostic Severity: normal Priority: P3 C

[Bug tree-optimization/110362] New: Range information on lower bytes of __uint128_t

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110362 Bug ID: 110362 Summary: Range information on lower bytes of __uint128_t Product: gcc Version: 14.0 Status: UNCONFIRMED Keywords: missed-optimization Severity: normal

[Bug target/110170] Sub-optimal conditional jumps in conditional-swap with floating point

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110170 --- Comment #2 from Antony Polukhin --- -fno-trapping-math had no effect Some tests with nans seem to produce the same results for both code snippets: https://godbolt.org/z/GaKM3EhMq

[Bug tree-optimization/110170] New: Sub-optimal conditional jumps in conditional-swap with floating point

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110170 Bug ID: 110170 Summary: Sub-optimal conditional jumps in conditional-swap with floating point Product: gcc Version: 14.0 Status: UNCONFIRMED Keywords: missed-o

[Bug tree-optimization/109931] Knowledge on literal not used in optimization

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109931 --- Comment #3 from Antony Polukhin --- > But that's because nothing in the function asserts this? Without fully > specializing and unrolling on the constant "hello" argument at least. Yes, I was hoping for that unrolling to happen Probably a

[Bug tree-optimization/109931] New: Knowledge on literal not used in optimization

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109931 Bug ID: 109931 Summary: Knowledge on literal not used in optimization Product: gcc Version: 14.0 Status: UNCONFIRMED Keywords: missed-optimization Severity: normal

[Bug tree-optimization/109829] New: Optimizing __builtin_signbit(x) ? -x : x or abs for FP

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109829 Bug ID: 109829 Summary: Optimizing __builtin_signbit(x) ? -x : x or abs for FP Product: gcc Version: 13.0 Status: UNCONFIRMED Keywords: missed-optimization Severity: nor

[Bug middle-end/108465] New: Optimize (a < b) == (b < a) to a == b

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108465 Bug ID: 108465 Summary: Optimize (a < b) == (b < a) to a == b Product: gcc Version: 13.0 Status: UNCONFIRMED Keywords: missed-optimization Severity: normal Pri

[Bug libstdc++/71579] type_traits miss checks for type completeness in some traits

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71579 --- Comment #22 from Antony Polukhin --- > Maybe we should consider dropping all the static assertions from traits that > are implemented using a compiler built-in. Sounds like the right thing to do. > Our type trait and the __has_virtual_dest

[Bug libstdc++/104361] New: Biased Reference Counting for the standard library

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104361 Bug ID: 104361 Summary: Biased Reference Counting for the standard library Product: gcc Version: 12.0 Status: UNCONFIRMED Severity: normal Priority: P3 Componen

[Bug c++/103745] New: Warn on throwing an exception not derived from std::exception

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103745 Bug ID: 103745 Summary: Warn on throwing an exception not derived from std::exception Product: gcc Version: 12.0 Status: UNCONFIRMED Keywords: diagnostic

[Bug tree-optimization/19661] unnecessary atexit calls emitted for static objects with empty destructors

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=19661 --- Comment #10 from Antony Polukhin --- Any progress? Multiple compilers already eliminate the atexit call. Moreover, some of the compilers even eliminate the guard variable after that https://godbolt.org/z/dbdfMrroa Note that the atexit elim

[Bug middle-end/101253] New: Optimize i % C1 == C0 || i % C1*C2 == C0 to i % C1 == C0

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101253 Bug ID: 101253 Summary: Optimize i % C1 == C0 || i % C1*C2 == C0 to i % C1 == C0 Product: gcc Version: 12.0 Status: UNCONFIRMED Keywords: missed-optimization

[Bug middle-end/101252] New: Optimize (b ? i % C0 : i % C1) into i & (b ? C0-1 : C1-1) for power of 2 C0 and C1

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101252 Bug ID: 101252 Summary: Optimize (b ? i % C0 : i % C1) into i & (b ? C0-1 : C1-1) for power of 2 C0 and C1 Product: gcc Version: 12.0 Status: UNCONFIRMED Keywo

[Bug middle-end/101251] New: Optimize i % (b ? C0 : C1) into i & (b ? C0-1 : C1-1) for power of 2 C0 and C1

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101251 Bug ID: 101251 Summary: Optimize i % (b ? C0 : C1) into i & (b ? C0-1 : C1-1) for power of 2 C0 and C1 Product: gcc Version: 12.0 Status: UNCONFIRMED Keywords:

[Bug c++/58487] Missed return value optimization

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58487 Antony Polukhin changed: What|Removed |Added CC||antoshkka at gmail dot com --- Comment

[Bug c++/58050] No return value optimization when calling static function through unnamed temporary

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58050 Antony Polukhin changed: What|Removed |Added CC||antoshkka at gmail dot com --- Comment

[Bug c++/100746] New: NRVO should not introduce aliasing

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100746 Bug ID: 100746 Summary: NRVO should not introduce aliasing Product: gcc Version: 11.0 Status: UNCONFIRMED Keywords: missed-optimization Severity: normal Priori

[Bug libstdc++/89120] std::minmax_element 2.5 times slower than hand written loop

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89120 --- Comment #2 from Antony Polukhin --- Long story short: I've found no way to improve the standard library code to always work faster. I'm in favor of closing this ticket as invalid/wont fix. Long story: I've tried to add a specialization of m

[Bug c++/80542] Warn about accidental copying of data in range based for

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80542 --- Comment #2 from Antony Polukhin --- This issue could be closed. GCC 11 has the required -Wrange-loop-construct warning: https://godbolt.org/z/343M6WMjb

[Bug libstdc++/99612] New: Remove "#pragma GCC system_header" from atomic file to warn on incorrect memory order

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99612 Bug ID: 99612 Summary: Remove "#pragma GCC system_header" from atomic file to warn on incorrect memory order Product: gcc Version: 11.0 Status: UNCONFIRMED Keyw

[Bug middle-end/98817] Optimize if (a != b) a = b;

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98817 --- Comment #5 from Antony Polukhin --- Please, close as invalid

[Bug middle-end/98817] Optimize if (a != b) a = b;

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98817 --- Comment #2 from Antony Polukhin --- (In reply to Jakub Jelinek from comment #1) > I'm not sure about this. Turning it into an unconditional store would mean > that the memory the reference points to must be writable, that might not be > alwa

[Bug middle-end/98817] New: Optimize if (a != b) a = b;

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98817 Bug ID: 98817 Summary: Optimize if (a != b) a = b; Product: gcc Version: 11.0 Status: UNCONFIRMED Keywords: missed-optimization Severity: normal Priority: P3

[Bug c++/98814] New: Add fix-it hints for missing asterisk

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98814 Bug ID: 98814 Summary: Add fix-it hints for missing asterisk Product: gcc Version: 11.0 Status: UNCONFIRMED Keywords: diagnostic Severity: normal Priority: P3

[Bug c++/98768] New: Improve diagnostics for incorrect result type checking "-> Type" in concepts

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98768 Bug ID: 98768 Summary: Improve diagnostics for incorrect result type checking "-> Type" in concepts Product: gcc Version: 11.0 Status: UNCONFIRMED Keywords: dia

[Bug c++/98767] New: Function signature lost in concept diagnostic message

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98767 Bug ID: 98767 Summary: Function signature lost in concept diagnostic message Product: gcc Version: 11.0 Status: UNCONFIRMED Keywords: diagnostic Severity: normal

[Bug tree-optimization/78427] missed optimization of loop condition

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78427 Antony Polukhin changed: What|Removed |Added CC||antoshkka at gmail dot com --- Comment