Annotation of OpenXM_contrib/gmp/mpn/x86/pentium4/sse2/sub_n.asm, Revision 1.1.1.1
1.1 ohara 1: dnl Intel Pentium-4 mpn_sub_n -- mpn subtraction.
2:
3: dnl Copyright 2001, 2002 Free Software Foundation, Inc.
4: dnl
5: dnl This file is part of the GNU MP Library.
6: dnl
7: dnl The GNU MP Library is free software; you can redistribute it and/or
8: dnl modify it under the terms of the GNU Lesser General Public License as
9: dnl published by the Free Software Foundation; either version 2.1 of the
10: dnl License, or (at your option) any later version.
11: dnl
12: dnl The GNU MP Library is distributed in the hope that it will be useful,
13: dnl but WITHOUT ANY WARRANTY; without even the implied warranty of
14: dnl MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15: dnl Lesser General Public License for more details.
16: dnl
17: dnl You should have received a copy of the GNU Lesser General Public
18: dnl License along with the GNU MP Library; see the file COPYING.LIB. If
19: dnl not, write to the Free Software Foundation, Inc., 59 Temple Place -
20: dnl Suite 330, Boston, MA 02111-1307, USA.
21:
22: include(`../config.m4')
23:
24:
25: C P4: 4.0 cycles/limb if dst!=src1 and dst!=src2
26: C 6.0 cycles/limb if dst==src1 or dst==src2
27:
28:
29: C mp_limb_t mpn_sub_n (mp_ptr dst, mp_srcptr src1, mp_srcptr src2,
30: C mp_size_t size);
31: C mp_limb_t mpn_sub_nc (mp_ptr dst, mp_srcptr src1, mp_srcptr src2,
32: C mp_size_t size, mp_limb_t carry);
33: C
34: C The main loop code is 2x unrolled so that the carry bit can alternate
35: C between mm0 and mm1.
36:
37: defframe(PARAM_CARRY,20)
38: defframe(PARAM_SIZE, 16)
39: defframe(PARAM_SRC2, 12)
40: defframe(PARAM_SRC1, 8)
41: defframe(PARAM_DST, 4)
42:
43: dnl re-use parameter space
44: define(SAVE_EBX,`PARAM_SRC1')
45:
46: TEXT
47: ALIGN(8)
48:
49: PROLOGUE(mpn_sub_nc)
50: deflit(`FRAME',0)
51:
52: movd PARAM_CARRY, %mm0
53: jmp L(start_nc)
54:
55: EPILOGUE()
56:
57: ALIGN(8)
58: PROLOGUE(mpn_sub_n)
59: deflit(`FRAME',0)
60: pxor %mm0, %mm0
61: L(start_nc):
62: movl PARAM_SRC1, %eax
63: movl %ebx, SAVE_EBX
64: movl PARAM_SRC2, %ebx
65: movl PARAM_DST, %edx
66: movl PARAM_SIZE, %ecx
67:
68: leal (%eax,%ecx,4), %eax C src1 end
69: leal (%ebx,%ecx,4), %ebx C src2 end
70: leal (%edx,%ecx,4), %edx C dst end
71: negl %ecx C -size
72:
73: L(top):
74: C eax src1 end
75: C ebx src2 end
76: C ecx counter, limbs, negative
77: C edx dst end
78: C mm0 carry bit
79:
80: movd (%eax,%ecx,4), %mm1
81: movd (%ebx,%ecx,4), %mm2
82: psubq %mm2, %mm1
83:
84: psubq %mm0, %mm1
85: movd %mm1, (%edx,%ecx,4)
86:
87: psrlq $63, %mm1
88:
89: addl $1, %ecx
90: jz L(done_mm1)
91:
92: movd (%eax,%ecx,4), %mm0
93: movd (%ebx,%ecx,4), %mm2
94: psubq %mm2, %mm0
95:
96: psubq %mm1, %mm0
97: movd %mm0, (%edx,%ecx,4)
98:
99: psrlq $63, %mm0
100:
101: addl $1, %ecx
102: jnz L(top)
103:
104:
105: movd %mm0, %eax
106: movl SAVE_EBX, %ebx
107: emms
108: ret
109:
110: L(done_mm1):
111: movd %mm1, %eax
112: movl SAVE_EBX, %ebx
113: emms
114: ret
115:
116: EPILOGUE()
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