setjmp.s

用于嵌入式Linux系统的标准C的库函数

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 * Copyright (c) 1993 Intel Corporation
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/******************************************************************************/
/*                                                                            */
/*      setjmp(), longjmp()                                                   */
/*                                                                            */
/******************************************************************************/
	.file "setjmp.as"
	.text
	/* .link_pix */

	.align	4
	.globl	_setjmp
_setjmp:
	flushreg
	andnot	0xf,pfp,g1	/* get pfp, mask out return status bits */
	st	g1, 0x58(g0)	/* save fp of caller*/
   /* save globals not killed by the calling convention */
	stq	g8, 0x40(g0)	/* save g8-g11*/
	st	g12, 0x50(g0)	/* save g12*/
	st	g14, 0x54(g0)	/* save g14*/
   /* save previous frame local registers */
	ldq	(g1), g4	/* get previous frame pfp, sp, rip, r3 */
	stq	g4, (g0)	/* save pfp, sp, rip, r3 */
	ldq	0x10(g1), g4	/* get previous frame r4-r7 */
	stq	g4, 0x10(g0)	/* save r4-r7 */
	ldq	0x20(g1), g4	/* get previous frame r8-r11 */
	stq	g4, 0x20(g0)	/* save r8-r11 */
	ldq	0x30(g1), g4	/* get previous frame r12-r15 */
	stq	g4, 0x30(g0)	/* save r12-r15 */

	mov	0, g0		/* return 0 */
	ret

   /*
    * fake a return to the place that called the corresponding _setjmp
   */
	.align	4
	.globl	_longjmp
_longjmp:
	call	0f		/* ensure there is at least one stack frame */

0:
	flushreg		/* do this before swapping stack */
	ld	0x58(g0), pfp	/* get fp of caller of setjmp */
   /* restore local registers 
    * the following code modifies the frame of the function which originally 
    *  called setjmp.
    */
	ldq	(g0), g4	/* get pfp, sp, rip, r3 */
	stq	g4, (pfp)	/* restore pfp, sp, rip, r3 */
	ldq	0x10(g0), g4	/* get r4-r7 */
	stq	g4, 0x10(pfp)	/* restore r4-r7 */
	ldq	0x20(g0), g4	/* get r8-r11 */
	stq	g4, 0x20(pfp)	/* restore r8-r11 */
	ldq	0x30(g0), g4	/* get r12-r15 */
	stq	g4, 0x30(pfp)	/* restore r12-r15 */
   /* restore global registers */
	ldq	0x40(g0), g8	/* get old g8-g11 values */
	ld	0x50(g0), g12	/* get old g12 value */
	ld	0x54(g0), g14	/* get old g14 value */

	mov	g1, g0		/* get return value */
	cmpo	g0, 0		/* make sure it is not zero */
	bne	0f
	mov	1, g0		/* return 1 by default */
0:
	ret			/* return to caller of _setjmp */