/*

	getcpucpuflags: get cpuflags for ia32

	copyright ?-2006 by the mpg123 project - free software under the terms of the LGPL 2.1

	see COPYING and AUTHORS files in distribution or http:#mpg123.org

	initially written by KIMURA Takuhiro (for 3DNow!)

	extended for general use by Thomas Orgis

	 extern int getcpuid(struct cpuflags*)

	or just 

	 extern int getcpuid(unsigned int*)

	where there is memory for 4 ints

	 -> the first set of idflags (basic cpu family info)

	    and the idflags, stdflags, std2flags, extflags written to the parameter

	 -> 0x00000000 (CPUID instruction not supported)

*/

#include "mangle.h"

.text

	ALIGN4

.globl ASM_NAME(getcpuflags)

/*	.type ASM_NAME(getcpuflags),@function */

ASM_NAME(getcpuflags):

	pushl %ebp

	movl %esp,%ebp

	pushl %edx

	pushl %ecx

	pushl %ebx

	pushl %esi

/* get the int pointer for storing the flags */

	movl 8(%ebp), %esi

/* does that one make sense? */

	movl $0x80000000,%eax

/* now save the flags and do a check for cpuid availability */

	pushfl

	pushfl

	popl %eax

	movl %eax,%ebx

/* set that bit... */

	xorl $0x00200000,%eax

	pushl %eax

	popfl

/* ...and read back the flags to see if it is understood */

	pushfl

	popl %eax

	popfl

	cmpl %ebx,%eax

	je .Lnocpuid

/* In principle, I would have to check the CPU's identify first to be sure how to interpret the extended flags. */

/* now get the info, first extended */

	movl $0x0, 12(%esi) /* clear value */

	movl $0x0, 16(%esi) /* clear value */

/* only if supported... */

	movl $0x80000000, %eax

	cpuid

/* IDT CPUs should not change EAX, generally I hope that non-3DNow cpus do not set a bogus support level here. */

	cmpl $0x80000001, %eax

	jb .Lnoextended /* Skip ext check without minimal support level. */

/* is supported, get flags value */

	movl $0x80000001,%eax

	cpuid

	movl %edx,12(%esi)

.Lnoextended:

/* then the other ones, called last to get the id flags in %eax for ret */

	movl $0x00000001,%eax

	cpuid

	movl %eax, (%esi)

	movl %ecx, 4(%esi)

	movl %edx, 8(%esi)

/* check if xgetbv instruction is available */

	test	$0x04000000, %ecx

	jz		.Lend

	test	$0x08000000, %ecx

	jz		.Lend

	xor		%ecx, %ecx

	.byte	0x0f, 0x01, 0xd0 /* xgetbv instruction */

	movl	%eax, 16(%esi)

	movl	(%esi), %eax

	jmp .Lend

	ALIGN4

.Lnocpuid:

/* error: set everything to zero */

	movl $0, %eax

	movl $0, (%esi)

	movl $0, 4(%esi)

	movl $0, 8(%esi)

	movl $0, 12(%esi)

	movl $0, 16(%esi)

	ALIGN4

.Lend:

/* return value are the id flags, still stored in %eax */

	popl %esi

	popl %ebx

	popl %ecx

	popl %edx

	movl %ebp,%esp

	popl %ebp

	ret

NONEXEC_STACK