From c0c49d60cfeff3b2aa801d6598143a073989654a Mon Sep 17 00:00:00 2001 From: Joseph Myers Date: Thu, 31 Aug 2017 16:39:25 +0000 Subject: Simplify NAN definitions. Similar to my patches for HUGE_VAL and INFINITY. this patch eliminates the bits/nan.h headers. __builtin_nanf ("") is used to define NAN for GCC 3.3 and later; the fallback is (0.0f / 0.0f), which is a constant expression for a quiet NaN of type float, but raises a spurious "invalid" exception outside static initializers, which seems the best that can be done purely in standard C. Again, if anyone actually uses a compiler with its own incompatible extension for producing a constant quiet NaN, we can add compiler conditionals. Tested for x86_64. * math/math.h [__USE_ISOC99] (NAN): Define directly here. Do not include . * math/Makefile (headers): Remove bits/nan.h. * bits/nan.h: Remove. * sysdeps/ieee754/bits/nan.h: Likewise. * sysdeps/mips/bits/nan.h: Likewise. --- math/Makefile | 1 - math/math.h | 11 +++++++++-- 2 files changed, 9 insertions(+), 3 deletions(-) (limited to 'math') diff --git a/math/Makefile b/math/Makefile index b9a06f0..0601f3a 100644 --- a/math/Makefile +++ b/math/Makefile @@ -23,7 +23,6 @@ include ../Makeconfig # Installed header files. headers := math.h bits/mathcalls.h bits/mathinline.h \ - bits/nan.h \ fpu_control.h complex.h bits/cmathcalls.h fenv.h \ bits/fenv.h bits/fenvinline.h bits/mathdef.h tgmath.h \ bits/math-finite.h bits/math-vector.h \ diff --git a/math/math.h b/math/math.h index 5f5a498..bbc1ab9 100644 --- a/math/math.h +++ b/math/math.h @@ -65,8 +65,15 @@ __BEGIN_DECLS # define INFINITY HUGE_VALF # endif -/* Get machine-dependent NAN value (returned for some domain errors). */ -# include +/* IEEE Not A Number. */ +# if __GNUC_PREREQ (3, 3) +# define NAN (__builtin_nanf ("")) +# else +/* This will raise an "invalid" exception outside static initializers, + but is the best that can be done in ISO C while remaining a + constant expression. */ +# define NAN (0.0f / 0.0f) +# endif #endif /* __USE_ISOC99 */ #if __GLIBC_USE (IEC_60559_BFP_EXT) -- cgit v1.1