On 2018-03-02 10:20:41 +1100, sisyphus1@xxxxxxxxxxxxxxx wrote: > -----Original Message----- From: Vincent Lefevre > Sent: Friday, February 23, 2018 1:08 AM > To: gcc-help@xxxxxxxxxxx > Subject: __float128 and _Float128 compatibility from ABI point of view > > > For the next MPFR major release (4.1.0), we plan to change __float128 to > > _Float128 (with a fallback to __float128 when necessary): > > With current svn (rev 12452), how do I determine which of the two > types was used ? You can either see the tests in config.log or check whether there is -D_Float128=__float128 in DEFS (or an equivalent #define in config.h if you have such a file). > Also, tfma.exe is failing on x64 builds of rev 12452 on Windows (gcc-7.2.0): > > ######################### > tfma.c:592: MPFR assertion failed: inex < 0 > > This application has requested the Runtime to terminate it in an unusual > way. > Please contact the application's support team for more information. > ######################### > > This can be addressed by replacing: > > mpfr_set_ui (x, (1UL << (GMP_NUMB_BITS / 2)) + 1, MPFR_RNDN); > mpfr_set_ui (y, (1UL << (GMP_NUMB_BITS / 2)) - 1, MPFR_RNDN); Thanks. This is obviously wrong. Unfortunately I didn't have the time to check all the numerous commits. > with, for example: > > mpfr_set_ui (x, 1, MPFR_RNDN); > mpfr_set_ui (y, 1, MPFR_RNDN); > mpfr_mul_2exp(x, x, GMP_NUMB_BITS / 2, MPFR_RNDN); > mpfr_mul_2exp(y, y, GMP_NUMB_BITS / 2, MPFR_RNDN); > mpfr_add_ui(x, x, 1, MPFR_RNDN); > mpfr_add_si(y, y, -1, MPFR_RNDN); I've changed it to: mpfr_set_ui_2exp (x, 1, GMP_NUMB_BITS / 2, MPFR_RNDN); mpfr_sub_ui (y, x, 1, MPFR_RNDN); mpfr_add_ui (x, x, 1, MPFR_RNDN); > The problem is that, with Windows x64 builds, unsigned long is only > 32 bits and GMP_NUMB_BITS is 64. This is a configuration not yet tested on my side (I currently use the 32-bit wine, but I suppose that I could use wine64 in a similar way). -- Vincent Lefèvre <vincent@xxxxxxxxxx> - Web: <https://www.vinc17.net/> 100% accessible validated (X)HTML - Blog: <https://www.vinc17.net/blog/> Work: CR INRIA - computer arithmetic / AriC project (LIP, ENS-Lyon)
