stkwmps.asm

来自「开放源码的编译器open watcom 1.6.0版的源代码」· 汇编 代码 · 共 62 行

;*****************************************************************************
;*
;*                            Open Watcom Project
;*
;*    Portions Copyright (c) 1983-2002 Sybase, Inc. All Rights Reserved.
;*
;*  ========================================================================
;*
;*    This file contains Original Code and/or Modifications of Original
;*    Code as defined in and that are subject to the Sybase Open Watcom
;*    Public License version 1.0 (the 'License'). You may not use this file
;*    except in compliance with the License. BY USING THIS FILE YOU AGREE TO
;*    ALL TERMS AND CONDITIONS OF THE LICENSE. A copy of the License is
;*    provided with the Original Code and Modifications, and is also
;*    available at www.sybase.com/developer/opensource.
;*
;*    The Original Code and all software distributed under the License are
;*    distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
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;*  ========================================================================
;*
;* Description:  Fixed size stack crawler for MIPS.
;*
;*****************************************************************************


.text

.globl  _WtcStkCrawlSize

.set noat
.set noreorder

/*
 * Note that this routine is called from function prolog,
 * and so is able to destroy registers which are volatile
 * across standard routines.
 */

/* _WtcStkCrawlSize touches newly allocated stack area page by page.
 * This is required on operating systems that use the guard page
 * mechanism.
 *
 * Input:
 * $sp  - stack pointer (bottom of local storage)
 * $t0  - size of newly allocated frame in bytes
 */

_WtcStkCrawlSize:
        addu    $t0,$sp,$t0     /* make t0 point at top of stack */
L1:     addiu   $t0,$t0,-4096   /* go down a page */
        slt     $t1,$t0,$sp     /* see if t0 < sp */
        bne     $t1,$zero,L1    /* if not, loop */
        lw      $zero,4092($t0) /* touch memory (in delay slot) */
        jr      $v0
        nop