glibc/sysdeps/i386/fpu/e_logl.S
Joseph Myers df179d8808 Fix i386/x86_64 logl (sNaN) (bug 20227).
The i386/x86_64 versions of logl return sNaN for sNaN input.  This
patch fixes them to add a NaN input to itself so that qNaN is returned
in this case.

Tested for x86_64 and x86 (including a build for i586 to cover the
non-i686 logl version).

	[BZ #20227]
	* sysdeps/i386/fpu/e_logl.S (__ieee754_logl): Add NaN input to
	itself.
	* sysdeps/i386/i686/fpu/e_logl.S (__ieee754_logl): Likewise.
	* sysdeps/x86_64/fpu/e_logl.S (__ieee754_logl): Likewise.
	* math/libm-test.inc (log_test_data): Add sNaN tests.
2016-06-08 22:24:06 +00:00

98 lines
1.9 KiB
ArmAsm

/*
* Written by J.T. Conklin <jtc@netbsd.org>.
* Public domain.
*
* Adapted for `long double' by Ulrich Drepper <drepper@cygnus.com>.
*/
#include <machine/asm.h>
.section .rodata.cst8,"aM",@progbits,8
.p2align 3
.type one,@object
one: .double 1.0
ASM_SIZE_DIRECTIVE(one)
/* It is not important that this constant is precise. It is only
a value which is known to be on the safe side for using the
fyl2xp1 instruction. */
.type limit,@object
limit: .double 0.29
ASM_SIZE_DIRECTIVE(limit)
#ifdef PIC
# define MO(op) op##@GOTOFF(%edx)
#else
# define MO(op) op
#endif
.text
ENTRY(__ieee754_logl)
fldln2 // log(2)
fldt 4(%esp) // x : log(2)
fxam
fnstsw
#ifdef PIC
LOAD_PIC_REG (dx)
#endif
fld %st // x : x : log(2)
sahf
jc 3f // in case x is NaN or +-Inf
movzwl 4+8(%esp), %eax
cmpl $0xc000, %eax
jae 6f // x <= -2, avoid overflow from -LDBL_MAX - 1.
4: fsubl MO(one) // x-1 : x : log(2)
6: fld %st // x-1 : x-1 : x : log(2)
fabs // |x-1| : x-1 : x : log(2)
fcompl MO(limit) // x-1 : x : log(2)
fnstsw // x-1 : x : log(2)
andb $0x45, %ah
jz 2f
fxam
fnstsw
andb $0x45, %ah
cmpb $0x40, %ah
jne 5f
fabs // log(1) is +0 in all rounding modes.
5: fstp %st(1) // x-1 : log(2)
fyl2xp1 // log(x)
ret
2: fstp %st(0) // x : log(2)
fyl2x // log(x)
ret
3: jp 4b // in case x is +-Inf
fstp %st(1)
fstp %st(1)
fadd %st(0)
ret
END (__ieee754_logl)
ENTRY(__logl_finite)
fldln2 // log(2)
fldt 4(%esp) // x : log(2)
#ifdef PIC
LOAD_PIC_REG (dx)
#endif
fld %st // x : x : log(2)
fsubl MO(one) // x-1 : x : log(2)
fld %st // x-1 : x-1 : x : log(2)
fabs // |x-1| : x-1 : x : log(2)
fcompl MO(limit) // x-1 : x : log(2)
fnstsw // x-1 : x : log(2)
andb $0x45, %ah
jz 2b
fxam
fnstsw
andb $0x45, %ah
cmpb $0x40, %ah
jne 7f
fabs // log(1) is +0 in all rounding modes.
7: fstp %st(1) // x-1 : log(2)
fyl2xp1 // log(x)
ret
END(__logl_finite)