Re: incorrectly rounded square root
Marco Atzeri <[email protected]>
| Newsgroups | gmane.comp.lib.newlib |
|---|---|
| Message-ID | <[email protected]> |
On 02.06.2021 20:43, Jeff Johnston wrote: > On Wed, Jun 2, 2021 at 9:08 AM Joel Sherrill <[email protected]> wrote: > >> >> >> On Wed, Jun 2, 2021 at 2:51 AM Paul Zimmermann <[email protected]> >> wrote: >> >> > I'll second Joel's comment. The code is extremely close to the glibc code > both in sqrtf and fesetround. The only > thing I can think of is that the glibc code does the x87 stuff first and > does the set back into FPU state before doing the > SSE stuff. The newlib code sets back the FPU state at the end after the > SSE stuff. Don't know if this is relevant or not. > > Any Cygwin users out there who can verify that the code is working/not > working for them? > > -- Jeff J. > current Cygwin produces for both i686 and X86_64 $ gcc -DNEWLIB -fno-builtin test_sqrt.c -lm $ ./a.exe RNDN: 0x1.ff83fp+63 RNDZ: 0x1.ff83fp+63 RNDU: 0x1.ff83fp+63 RNDD: 0x1.ff83fp+63