On Mon, Jan 12, 2015 at 7:52 AM, Kyrill Tkachov <kyrylo.tkac...@arm.com> wrote: > Hi all, > > As raised in https://gcc.gnu.org/ml/gcc-patches/2014-12/msg01237.html and > discussed in that thread, using __builtin_sqrt for vsqrt_f64 may end up in a > call to the library sqrt at -O0. To avoid that this patch uses a target > builtin for sqrt on DF mode and uses that to implement the intrinsic. > > With this patch I don't see sqrt calls being created at -O0 on a large > arm_neon.h testcase where they were generated before. > aarch64-none-elf testing and the intrinsics testsuite in particular are > clean. > Ok for trunk?
Maybe have a target fold which folds this into sqrt if -fno-math-errno is supplied. This might be useful the -ffast-math case. Maybe also fold it when a constant is supplied too. Thanks, Andrew > > Thanks, > Kyrill > > 2015-01-12 Kyrylo Tkachov <kyrylo.tkac...@arm.com> > > * config/aarch64/aarch64-simd-builtins.def (sqrt): Use BUILTIN_VDQF_DF. > * config/aarch64/arm_neon.h (vsqrt_f64): Use __builtin_aarch64_sqrtdf > instead of __builtin_sqrt.
