From fec5f4e04195323a076ac92c9adc68e97dec738a Mon Sep 17 00:00:00 2001 From: Joseph Myers Date: Wed, 4 Jan 2017 17:06:33 +0000 Subject: [PATCH] Make MIPS soft-fp preserve NaN payloads for NAN2008. The MIPS sfp-machine.h has 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 (at the level of libgcc, it's not meaningful which argument is the first and which is the second). Tested for mips64-linux-gnu (soft float, NAN2008) with the glibc math/ tests. * config/mips/sfp-machine.h (_FP_CHOOSENAN): Always preserve NaN payload if [__mips_nan2008]. From-SVN: r244059 --- libgcc/ChangeLog | 5 +++++ libgcc/config/mips/sfp-machine.h | 14 +++++++++++++- 2 files changed, 18 insertions(+), 1 deletion(-) diff --git a/libgcc/ChangeLog b/libgcc/ChangeLog index 45e5c4ed023..f0eb567c591 100644 --- a/libgcc/ChangeLog +++ b/libgcc/ChangeLog @@ -1,3 +1,8 @@ +2017-01-04 Joseph Myers + + * config/mips/sfp-machine.h (_FP_CHOOSENAN): Always preserve NaN + payload if [__mips_nan2008]. + 2017-01-04 Alan Modra * Makefile.in (configure_deps): Update. diff --git a/libgcc/config/mips/sfp-machine.h b/libgcc/config/mips/sfp-machine.h index 7aa6d28a2cd..07d11580ee6 100644 --- a/libgcc/config/mips/sfp-machine.h +++ b/libgcc/config/mips/sfp-machine.h @@ -96,10 +96,21 @@ typedef int __gcc_CMPtype __attribute__ ((mode (__libgcc_cmp_return__))); # 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 /* Comment from glibc: */ /* 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) \ @@ -114,6 +125,7 @@ typedef int __gcc_CMPtype __attribute__ ((mode (__libgcc_cmp_return__))); } \ R##_c = FP_CLS_NAN; \ } while (0) +#endif #ifdef __mips_hard_float #define FP_EX_INVALID 0x40 -- 2.30.2