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| author | Joseph Myers <joseph@codesourcery.com> | 2017-01-04 17:15:39 +0000 |
|---|---|---|
| committer | Joseph Myers <joseph@codesourcery.com> | 2017-01-04 17:15:39 +0000 |
| commit | f5ee5362bf8c50e5a85bf758f3f5d91f262a446f (patch) | |
| tree | 8b5b7b42f97e28d660d34eef7254510c197569f3 /sysdeps/mips/mips32 | |
| parent | 2b18fe78fe7217430ed42d3284636c732793e352 (diff) | |
| download | glibc-f5ee5362bf8c50e5a85bf758f3f5d91f262a446f.tar.gz glibc-f5ee5362bf8c50e5a85bf758f3f5d91f262a446f.tar.xz glibc-f5ee5362bf8c50e5a85bf758f3f5d91f262a446f.zip | |
Make MIPS soft-fp preserve NaN payloads for NAN2008.
This corresponds to a patch applied to libgcc. In glibc it doesn't actually affect much (only fma, I think). The MIPS sfp-machine.h files have an _FP_CHOOSENAN implementation which emulates hardware semantics of not preserving signaling NaN payloads for an operation with two NaN arguments (although that doesn't suffice to avoid sNaN payload preservation in any case with just one NaN argument). However, those are only hardware semantics in the legacy NaN case; in the NAN2008 case, the architecture documentation says hardware preserves payloads in such cases. Furthermore, this implementation assumes legacy NaN semantics, so in the NAN2008 case the implementation actually has the effect of preserving sNaN payloads but not preserving qNaN payloads, when both should be preserved. This patch fixes the code just to copy from the first argument. Tested for mips64 soft-float. * sysdeps/mips/mips32/sfp-machine.h (_FP_CHOOSENAN): Always preserve NaN payload if [__mips_nan2008]. * sysdeps/mips/mips64/sfp-machine.h (_FP_CHOOSENAN): Likewise.
Diffstat (limited to 'sysdeps/mips/mips32')
| -rw-r--r-- | sysdeps/mips/mips32/sfp-machine.h | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/sysdeps/mips/mips32/sfp-machine.h b/sysdeps/mips/mips32/sfp-machine.h index 4e23aa8b26..5215655029 100644 --- a/sysdeps/mips/mips32/sfp-machine.h +++ b/sysdeps/mips/mips32/sfp-machine.h @@ -41,9 +41,20 @@ # define _FP_QNANNEGATEDP 1 #endif +#ifdef __mips_nan2008 +/* NaN payloads should be preserved for NAN2008. */ +# define _FP_CHOOSENAN(fs, wc, R, X, Y, OP) \ + do \ + { \ + R##_s = X##_s; \ + _FP_FRAC_COPY_##wc (R, X); \ + R##_c = FP_CLS_NAN; \ + } \ + while (0) +#else /* From my experiments it seems X is chosen unless one of the NaNs is sNaN, in which case the result is NANSIGN/NANFRAC. */ -#define _FP_CHOOSENAN(fs, wc, R, X, Y, OP) \ +# define _FP_CHOOSENAN(fs, wc, R, X, Y, OP) \ do { \ if ((_FP_FRAC_HIGH_RAW_##fs(X) | \ _FP_FRAC_HIGH_RAW_##fs(Y)) & _FP_QNANBIT_##fs) \ @@ -58,6 +69,7 @@ } \ R##_c = FP_CLS_NAN; \ } while (0) +#endif #define FP_EX_INVALID (1 << 4) #define FP_EX_DIVZERO (1 << 3) |