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* [Bug rtl-optimization/40987] Wrong optimization with if-conversion [not found] <bug-40987-4@http.gcc.gnu.org/bugzilla/> @ 2012-01-21 21:33 ` pinskia at gcc dot gnu.org 2021-07-19 23:50 ` [Bug rtl-optimization/40987] ifcvt sometimes goes wrong for integer modes > 64bit pinskia at gcc dot gnu.org ` (2 subsequent siblings) 3 siblings, 0 replies; 4+ messages in thread From: pinskia at gcc dot gnu.org @ 2012-01-21 21:33 UTC (permalink / raw) To: gcc-bugs http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40987 Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Target|i686 | Host|i686 |HWI == 32 Build|i686 | --- Comment #11 from Andrew Pinski <pinskia at gcc dot gnu.org> 2012-01-21 21:27:18 UTC --- This bug is now hard to hit on the trunk as i?86 requires host wide word as 64bit. ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug rtl-optimization/40987] ifcvt sometimes goes wrong for integer modes > 64bit [not found] <bug-40987-4@http.gcc.gnu.org/bugzilla/> 2012-01-21 21:33 ` [Bug rtl-optimization/40987] Wrong optimization with if-conversion pinskia at gcc dot gnu.org @ 2021-07-19 23:50 ` pinskia at gcc dot gnu.org 2023-06-02 0:56 ` pinskia at gcc dot gnu.org 2023-06-02 1:02 ` pinskia at gcc dot gnu.org 3 siblings, 0 replies; 4+ messages in thread From: pinskia at gcc dot gnu.org @ 2021-07-19 23:50 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=40987 --- Comment #12 from Andrew Pinski <pinskia at gcc dot gnu.org> --- (In reply to Andrew Pinski from comment #11) > This bug is now hard to hit on the trunk as i?86 requires host wide word as > 64bit. HWINT is now required to be 64bit for all targets even. So this might happen if there is some TImode but then the patch might be best thing really. ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug rtl-optimization/40987] ifcvt sometimes goes wrong for integer modes > 64bit [not found] <bug-40987-4@http.gcc.gnu.org/bugzilla/> 2012-01-21 21:33 ` [Bug rtl-optimization/40987] Wrong optimization with if-conversion pinskia at gcc dot gnu.org 2021-07-19 23:50 ` [Bug rtl-optimization/40987] ifcvt sometimes goes wrong for integer modes > 64bit pinskia at gcc dot gnu.org @ 2023-06-02 0:56 ` pinskia at gcc dot gnu.org 2023-06-02 1:02 ` pinskia at gcc dot gnu.org 3 siblings, 0 replies; 4+ messages in thread From: pinskia at gcc dot gnu.org @ 2023-06-02 0:56 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=40987 --- Comment #13 from Andrew Pinski <pinskia at gcc dot gnu.org> --- Here is a x86_64-linux-gnu testcase: ``` #include <stdio.h> typedef __int128_t mytype; #define value (((__int128_t)(((unsigned long long)__LONG_LONG_MAX__)+1)) | (((__int128_t)0xffffffffffffffffull)<<64)) mytype func(long arg) __attribute__((noinline,noclone)); mytype func(long arg) { mytype val = 0; if (arg < 0) { // __int128_t t = 0x8000000000000000ull | (((__int128_t)0xffffffffffffffff)<<64); val = value; } return val; } int main() { mytype result = func(-1); if (result != value) { printf("failed.\n"); return 1; } printf("passed.\n"); return 0; } ``` It failed until GCC 4.9.0 ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug rtl-optimization/40987] ifcvt sometimes goes wrong for integer modes > 64bit [not found] <bug-40987-4@http.gcc.gnu.org/bugzilla/> ` (2 preceding siblings ...) 2023-06-02 0:56 ` pinskia at gcc dot gnu.org @ 2023-06-02 1:02 ` pinskia at gcc dot gnu.org 3 siblings, 0 replies; 4+ messages in thread From: pinskia at gcc dot gnu.org @ 2023-06-02 1:02 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=40987 Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Resolution|--- |FIXED Status|NEW |RESOLVED Target Milestone|--- |4.9.0 --- Comment #14 from Andrew Pinski <pinskia at gcc dot gnu.org> --- Looks like this was fixed with r0-127324-ge15eb172b0dd (aka PR 59545). Basically a signed integer overflow inside the compiler was causing the wrong code happening. ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2023-06-02 1:02 UTC | newest] Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- [not found] <bug-40987-4@http.gcc.gnu.org/bugzilla/> 2012-01-21 21:33 ` [Bug rtl-optimization/40987] Wrong optimization with if-conversion pinskia at gcc dot gnu.org 2021-07-19 23:50 ` [Bug rtl-optimization/40987] ifcvt sometimes goes wrong for integer modes > 64bit pinskia at gcc dot gnu.org 2023-06-02 0:56 ` pinskia at gcc dot gnu.org 2023-06-02 1:02 ` pinskia at gcc dot gnu.org
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