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c8235dda72
Various i386 libm functions return values with excess range and precision; Wilco Dijkstra's patches to make isfinite etc. expand inline cause this pre-existing issue to result in test failures (when e.g. a result that overflows float but not long double gets counted as overflowing for some purposes but not others). This patch addresses those cases arising from functions defined in C, adding a math_narrow_eval macro that forces values to memory to eliminate excess precision if FLT_EVAL_METHOD indicates this is needed, and is a no-op otherwise. I'll convert existing uses of volatile and asm for this purpose to use the new macro later, once i386 has clean test results again (which requires fixes for .S files as well). Tested for x86_64 and x86. Committed. [BZ #18980] * sysdeps/generic/math_private.h: Include <float.h>. (math_narrow_eval): New macro. [FLT_EVAL_METHOD != 0] (excess_precision): Likewise. * sysdeps/ieee754/dbl-64/e_cosh.c (__ieee754_cosh): Use math_narrow_eval on overflowing return value. * sysdeps/ieee754/dbl-64/e_lgamma_r.c (__ieee754_lgamma_r): Likewise. * sysdeps/ieee754/dbl-64/e_sinh.c (__ieee754_sinh): Likewise. * sysdeps/ieee754/flt-32/e_coshf.c (__ieee754_coshf): Likewise. * sysdeps/ieee754/flt-32/e_lgammaf_r.c (__ieee754_lgammaf_r): Likewise. * sysdeps/ieee754/flt-32/e_sinhf.c (__ieee754_sinhf): Likewise.
64 lines
1.6 KiB
C
64 lines
1.6 KiB
C
/* e_coshf.c -- float version of e_cosh.c.
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* Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
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* Optimizations by Ulrich Drepper <drepper@gmail.com>, 2011
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*/
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/*
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* ====================================================
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* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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*
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* Developed at SunPro, a Sun Microsystems, Inc. business.
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* Permission to use, copy, modify, and distribute this
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* software is freely granted, provided that this notice
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* is preserved.
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* ====================================================
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*/
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#include <math.h>
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#include <math_private.h>
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static const float huge = 1.0e30;
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static const float one = 1.0, half=0.5;
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float
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__ieee754_coshf (float x)
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{
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float t,w;
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int32_t ix;
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GET_FLOAT_WORD(ix,x);
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ix &= 0x7fffffff;
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/* |x| in [0,22] */
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if (ix < 0x41b00000) {
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/* |x| in [0,0.5*ln2], return 1+expm1(|x|)^2/(2*exp(|x|)) */
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if(ix<0x3eb17218) {
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if (ix<0x24000000) return one; /* cosh(tiny) = 1 */
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t = __expm1f(fabsf(x));
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w = one+t;
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return one+(t*t)/(w+w);
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}
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/* |x| in [0.5*ln2,22], return (exp(|x|)+1/exp(|x|)/2; */
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t = __ieee754_expf(fabsf(x));
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return half*t+half/t;
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}
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/* |x| in [22, log(maxdouble)] return half*exp(|x|) */
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if (ix < 0x42b17180) return half*__ieee754_expf(fabsf(x));
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/* |x| in [log(maxdouble), overflowthresold] */
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if (ix<=0x42b2d4fc) {
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w = __ieee754_expf(half*fabsf(x));
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t = half*w;
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return t*w;
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}
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/* x is INF or NaN */
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if(ix>=0x7f800000) return x*x;
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/* |x| > overflowthresold, cosh(x) overflow */
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return math_narrow_eval (huge*huge);
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}
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strong_alias (__ieee754_coshf, __coshf_finite)
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