/*

 * Written by J.T. Conklin <jtc@netbsd.org>.

 * Public domain.

 *

 * Adapted for `long double' by Ulrich Drepper <drepper@cygnus.com>.

 * Adapted for x86-64 by Andreas Jaeger <aj@suse.de>.

 */

#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##(%rip)

#else

# define MO(op) op

#endif

	.text

ENTRY(__ieee754_logl)

	fldln2			// log(2)

	fldt	8(%rsp)		// x : log(2)

	fxam

	fnstsw

	fld	%st		// x : x : log(2)

	testb	$1, %ah

	jnz	3f		// in case x is NaN or +-Inf

	movzwl	8+8(%rsp), %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:	testb	$4, %ah

	jnz	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	8(%rsp)		// x : log(2)

	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)