Mercurial > hg > xemacs-beta
annotate src/alloca.s @ 5676:dede3f658f8e
Sanity check package roots in configure.
| author | Stephen J. Turnbull <stephen@xemacs.org> |
|---|---|
| date | Sat, 04 Aug 2012 23:26:26 +0900 |
| parents | 308d34e9f07d |
| children |
| rev | line source |
|---|---|
| 428 | 1 /* `alloca' standard 4.2 subroutine for 68000's and 16000's and others. |
| 2 Copyright (C) 1985, 1986, 1988 Free Software Foundation, Inc. | |
| 3 | |
| 4 This file is part of XEmacs. | |
| 5 | |
|
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Mats Lidell <matsl@xemacs.org>
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6 XEmacs is free software: you can redistribute it and/or modify it |
| 428 | 7 under the terms of the GNU General Public License as published by the |
|
5402
308d34e9f07d
Changed bulk of GPLv2 or later files identified by script
Mats Lidell <matsl@xemacs.org>
parents:
4759
diff
changeset
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8 Free Software Foundation, either version 3 of the License, or (at your |
|
308d34e9f07d
Changed bulk of GPLv2 or later files identified by script
Mats Lidell <matsl@xemacs.org>
parents:
4759
diff
changeset
|
9 option) any later version. |
| 428 | 10 |
| 11 XEmacs is distributed in the hope that it will be useful, but WITHOUT | |
| 12 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
| 13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
| 14 for more details. | |
| 15 | |
| 16 You should have received a copy of the GNU General Public License | |
|
5402
308d34e9f07d
Changed bulk of GPLv2 or later files identified by script
Mats Lidell <matsl@xemacs.org>
parents:
4759
diff
changeset
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17 along with XEmacs. If not, see <http://www.gnu.org/licenses/>. */ |
| 428 | 18 |
| 19 /* Synched up with: FSF 19.30. */ | |
| 20 | |
| 21 /* Both 68000 systems I have run this on have had broken versions of alloca. | |
| 22 Also, I am told that non-berkeley systems do not have it at all. | |
| 23 So replace whatever system-provided alloca there may be | |
| 24 on all 68000 systems. */ | |
| 25 | |
| 26 #define NOT_C_CODE | |
| 27 #ifdef emacs | |
| 28 #include <config.h> | |
| 29 #else | |
| 30 #include "config.h" | |
| 31 #endif | |
| 32 | |
| 33 #ifndef HAVE_ALLOCA /* define this to use system's alloca */ | |
| 34 | |
| 35 #ifndef m68k | |
| 36 #ifndef m68000 | |
| 37 you | |
| 38 lose!! | |
| 39 #endif /* m68000 */ | |
| 40 #endif /* m68k */ | |
| 41 | |
| 42 | |
| 43 #ifdef m68k /* SGS assembler totally different */ | |
| 44 file "alloca.s" | |
| 45 global alloca | |
| 46 alloca: | |
| 47 mov.l (%sp)+,%a1 # pop return addr from top of stack | |
| 48 mov.l (%sp)+,%d0 # pop size in bytes from top of stack | |
| 49 add.l &R%1,%d0 # round size up to long word | |
| 50 and.l &-4,%d0 # mask out lower two bits of size | |
| 51 sub.l %d0,%sp # allocate by moving stack pointer | |
| 52 tst.b P%1(%sp) # stack probe to allocate pages | |
| 53 mov.l %sp,%a0 # return pointer as pointer | |
| 54 mov.l %sp,%d0 # return pointer as int to avoid disaster | |
| 55 add.l &-4,%sp # new top of stack | |
| 56 jmp (%a1) # not a normal return | |
| 57 set S%1,64 # safety factor for C compiler scratch | |
| 58 set R%1,3+S%1 # add to size for rounding | |
| 59 set P%1,-132 # probe this far below current top of stack | |
| 60 | |
| 61 #else /* not m68k */ | |
| 62 | |
| 63 #ifdef m68000 | |
| 64 | |
| 65 /* Some systems want the _, some do not. Win with both kinds. */ | |
| 66 .globl _alloca | |
| 67 _alloca: | |
| 68 .globl alloca | |
| 69 alloca: | |
| 70 movl sp@+,a0 | |
| 71 movl a7,d0 | |
| 72 subl sp@,d0 | |
| 73 andl #~3,d0 | |
| 74 movl d0,sp | |
| 75 tstb sp@(0) /* Make stack pages exist */ | |
| 76 /* Needed on certain systems | |
| 77 that lack true demand paging */ | |
| 78 addql #4,d0 | |
| 79 jmp a0@ | |
| 80 | |
| 81 #endif /* m68000 */ | |
| 82 #endif /* not m68k */ | |
| 83 | |
| 84 #endif /* not HAVE_ALLOCA */ |