glibc/sysdeps/i386/fpu/e_exp2l.S
Wilco Dijkstra 220622dde5 Add libm_alias_finite for _finite symbols
This patch adds a new macro, libm_alias_finite, to define all _finite
symbol.  It sets all _finite symbol as compat symbol based on its first
version (obtained from the definition at built generated first-versions.h).

The <fn>f128_finite symbols were introduced in GLIBC 2.26 and so need
special treatment in code that is shared between long double and float128.
It is done by adding a list, similar to internal symbol redifinition,
on sysdeps/ieee754/float128/float128_private.h.

Alpha also needs some tricky changes to ensure we still emit 2 compat
symbols for sqrt(f).

Passes buildmanyglibc.

Co-authored-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2020-01-03 10:02:04 -03:00

62 lines
1.3 KiB
ArmAsm

/*
* Written by J.T. Conklin <jtc@netbsd.org>.
* Adapted for exp2 by Ulrich Drepper <drepper@cygnus.com>.
* Public domain.
*/
#include <machine/asm.h>
#include <i386-math-asm.h>
#include <libm-alias-finite.h>
DEFINE_LDBL_MIN
#ifdef PIC
# define MO(op) op##@GOTOFF(%ecx)
#else
# define MO(op) op
#endif
.text
ENTRY(__ieee754_exp2l)
#ifdef PIC
LOAD_PIC_REG (cx)
#endif
fldt 4(%esp)
/* I added the following ugly construct because exp(+-Inf) resulted
in NaN. The ugliness results from the bright minds at Intel.
For the i686 the code can be written better.
-- drepper@cygnus.com. */
fxam /* Is NaN or +-Inf? */
fstsw %ax
movb $0x45, %dh
andb %ah, %dh
cmpb $0x05, %dh
je 1f /* Is +-Inf, jump. */
movzwl 4+8(%esp), %eax
andl $0x7fff, %eax
cmpl $0x3fbe, %eax
jge 3f
/* Argument's exponent below -65, result rounds to 1. */
fld1
faddp
ret
3: fld %st
frndint /* int(x) */
fsubr %st,%st(1) /* fract(x) */
fxch
f2xm1 /* 2^(fract(x)) - 1 */
fld1
faddp /* 2^(fract(x)) */
fscale /* e^x */
fstp %st(1)
LDBL_CHECK_FORCE_UFLOW_NONNEG_NAN
ret
1: testl $0x200, %eax /* Test sign. */
jz 2f /* If positive, jump. */
fstp %st
fldz /* Set result to 0. */
2: ret
END (__ieee754_exp2l)
libm_alias_finite (__ieee754_exp2l, __exp2l)