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From: "jakub at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug middle-end/107370] long double sqrtl constant folding is wrong Date: Mon, 24 Oct 2022 19:27:26 +0000 [thread overview] Message-ID: <bug-107370-4-CuRut4uGXd@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-107370-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107370 Jakub Jelinek <jakub at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |jakub at gcc dot gnu.org --- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> --- On powerpc64le-linux with -O2 -nostdinc -mlong-double-128 -mabi=ieeelongdouble int main() { __builtin_printf("%.20Lg \n",__builtin_sqrtl(2.0L)); } we also emit on the trunk: .long 325511829 .long -922176773 .long -429395012 .long 1073703433 And similarly for: long double foo (long double x) { return __builtin_hypotl (x, x); } with -O2 -nostdinc -mlong-double-128 -mabi=ieeelongdouble -ffast-math where we optimize the hypotl to fabs(x) * M_PI2l (dconst_sqrt2) it is the same constant. const REAL_VALUE_TYPE * dconst_sqrt2_ptr (void) { static REAL_VALUE_TYPE value; /* Initialize mathematical constants for constant folding builtins. These constants need to be given to at least 160 bits precision. */ if (value.cl == rvc_zero) { mpfr_t m; mpfr_init2 (m, SIGNIFICAND_BITS); mpfr_sqrt_ui (m, 2, MPFR_RNDN); real_from_mpfr (&value, m, NULL_TREE, MPFR_RNDN); mpfr_clear (m); } return &value; }
next prev parent reply other threads:[~2022-10-24 19:27 UTC|newest] Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-10-24 6:11 [Bug c/107370] New: long double precision is wrong in ARM 64 jacob at jacob dot remcomp.fr 2022-10-24 6:22 ` [Bug c/107370] " jacob at jacob dot remcomp.fr 2022-10-24 15:19 ` [Bug target/107370] " pinskia at gcc dot gnu.org 2022-10-24 18:33 ` jacob at jacob dot remcomp.fr 2022-10-24 18:40 ` [Bug middle-end/107370] long double sqrtl constant folding is wrong pinskia at gcc dot gnu.org 2022-10-24 19:27 ` jakub at gcc dot gnu.org [this message] 2022-10-24 19:53 ` jacob at jacob dot remcomp.fr 2022-10-24 19:56 ` jacob at jacob dot remcomp.fr 2022-10-24 20:00 ` joseph at codesourcery dot com 2022-10-24 20:01 ` jacob at jacob dot remcomp.fr 2022-10-24 20:08 ` jacob at jacob dot remcomp.fr 2022-10-24 20:09 ` jacob at jacob dot remcomp.fr 2022-10-24 20:21 ` jakub at gcc dot gnu.org 2022-10-24 20:25 ` jakub at gcc dot gnu.org 2022-10-24 20:32 ` jakub at gcc dot gnu.org 2022-10-24 20:50 ` jacob at jacob dot remcomp.fr 2022-10-24 20:51 ` jacob at jacob dot remcomp.fr 2022-10-24 20:56 ` jacob at jacob dot remcomp.fr 2022-10-24 20:59 ` jacob at jacob dot remcomp.fr 2022-10-24 21:01 ` jacob at jacob dot remcomp.fr 2022-10-24 21:02 ` jakub at gcc dot gnu.org 2022-10-24 21:03 ` jacob at jacob dot remcomp.fr 2022-10-24 21:06 ` jacob at jacob dot remcomp.fr 2022-10-24 21:09 ` jakub at gcc dot gnu.org 2022-10-24 21:26 ` jacob at jacob dot remcomp.fr 2022-10-24 21:29 ` pinskia at gcc dot gnu.org 2022-10-24 21:31 ` pinskia at gcc dot gnu.org
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