lib/libm: Add frexp and modf functions; use in stmhal; add tests.

Addresses issue #1081.
This commit is contained in:
Damien George 2015-01-22 13:48:29 +00:00
parent bd9c1ad601
commit 6d1f5070ce
5 changed files with 164 additions and 3 deletions

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@ -122,8 +122,6 @@ float tgammaf(float x) { return 0.0; }
float lgammaf(float x) { return 0.0; }
float erff(float x) { return 0.0; }
float erfcf(float x) { return 0.0; }
float modff(float x, float *y) { return 0.0; }
float frexpf(float x, int *exp) { return 0.0; }
float ldexpf(float x, int exp) { return 0.0; }
/*****************************************************************************/

70
lib/libm/sf_frexp.c Normal file
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@ -0,0 +1,70 @@
/*
* This file is part of the Micro Python project, http://micropython.org/
*
* These math functions are taken from newlib-nano-2, the newlib/libm/math
* directory, available from https://github.com/32bitmicro/newlib-nano-2.
*
* Appropriate copyright headers are reproduced below.
*/
/* sf_frexp.c -- float version of s_frexp.c.
* Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
*/
/*
* ====================================================
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
*
* Developed at SunPro, a Sun Microsystems, Inc. business.
* Permission to use, copy, modify, and distribute this
* software is freely granted, provided that this notice
* is preserved.
* ====================================================
*/
#include "fdlibm.h"
#ifdef __STDC__
static const float
#else
static float
#endif
two25 = 3.3554432000e+07; /* 0x4c000000 */
#ifdef __STDC__
float frexpf(float x, int *eptr)
#else
float frexpf(x, eptr)
float x; int *eptr;
#endif
{
__int32_t hx, ix;
GET_FLOAT_WORD(hx,x);
ix = 0x7fffffff&hx;
*eptr = 0;
if(!FLT_UWORD_IS_FINITE(ix)||FLT_UWORD_IS_ZERO(ix)) return x; /* 0,inf,nan */
if (FLT_UWORD_IS_SUBNORMAL(ix)) { /* subnormal */
x *= two25;
GET_FLOAT_WORD(hx,x);
ix = hx&0x7fffffff;
*eptr = -25;
}
*eptr += (ix>>23)-126;
hx = (hx&0x807fffff)|0x3f000000;
SET_FLOAT_WORD(x,hx);
return x;
}
#ifdef _DOUBLE_IS_32BITS
#ifdef __STDC__
double frexp(double x, int *eptr)
#else
double frexp(x, eptr)
double x; int *eptr;
#endif
{
return (double) frexpf((float) x, eptr);
}
#endif /* defined(_DOUBLE_IS_32BITS) */

82
lib/libm/sf_modf.c Normal file
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@ -0,0 +1,82 @@
/*
* This file is part of the Micro Python project, http://micropython.org/
*
* These math functions are taken from newlib-nano-2, the newlib/libm/common
* directory, available from https://github.com/32bitmicro/newlib-nano-2.
*
* Appropriate copyright headers are reproduced below.
*/
/* sf_modf.c -- float version of s_modf.c.
* Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
*/
/*
* ====================================================
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
*
* Developed at SunPro, a Sun Microsystems, Inc. business.
* Permission to use, copy, modify, and distribute this
* software is freely granted, provided that this notice
* is preserved.
* ====================================================
*/
#include "fdlibm.h"
#ifdef __STDC__
static const float one = 1.0;
#else
static float one = 1.0;
#endif
#ifdef __STDC__
float modff(float x, float *iptr)
#else
float modff(x, iptr)
float x,*iptr;
#endif
{
__int32_t i0,j0;
__uint32_t i;
GET_FLOAT_WORD(i0,x);
j0 = ((i0>>23)&0xff)-0x7f; /* exponent of x */
if(j0<23) { /* integer part in x */
if(j0<0) { /* |x|<1 */
SET_FLOAT_WORD(*iptr,i0&0x80000000); /* *iptr = +-0 */
return x;
} else {
i = (0x007fffff)>>j0;
if((i0&i)==0) { /* x is integral */
__uint32_t ix;
*iptr = x;
GET_FLOAT_WORD(ix,x);
SET_FLOAT_WORD(x,ix&0x80000000); /* return +-0 */
return x;
} else {
SET_FLOAT_WORD(*iptr,i0&(~i));
return x - *iptr;
}
}
} else { /* no fraction part */
__uint32_t ix;
*iptr = x*one;
GET_FLOAT_WORD(ix,x);
SET_FLOAT_WORD(x,ix&0x80000000); /* return +-0 */
return x;
}
}
#ifdef _DOUBLE_IS_32BITS
#ifdef __STDC__
double modf(double x, double *iptr)
#else
double modf(x, iptr)
double x,*iptr;
#endif
{
return (double) modff((float) x, (float *) iptr);
}
#endif /* defined(_DOUBLE_IS_32BITS) */

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@ -81,6 +81,8 @@ SRC_LIB = $(addprefix lib/,\
libm/sf_sin.c \
libm/sf_cos.c \
libm/sf_tan.c \
libm/sf_frexp.c \
libm/sf_modf.c \
fatfs/ff.c \
fatfs/option/ccsbcs.c \
mp-readline/readline.c \

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@ -33,7 +33,6 @@ functions = [('sqrt', sqrt, p_test_values),
('ceil', ceil, test_values),
('fabs', fabs, test_values),
('floor', floor, test_values),
#('frexp', frexp, test_values),
('trunc', trunc, test_values)
]
@ -42,6 +41,16 @@ for function_name, function, test_vals in functions:
for value in test_vals:
print("{:.5g}".format(function(value)))
tuple_functions = [('frexp', frexp, test_values),
('modf', modf, test_values),
]
for function_name, function, test_vals in tuple_functions:
print(function_name)
for value in test_vals:
x, y = function(value)
print("{:.5g} {:.5g}".format(x, y))
binary_functions = [('copysign', copysign, [(23., 42.), (-23., 42.), (23., -42.),
(-23., -42.), (1., 0.0), (1., -0.0)])
]