Imported gcc-4.4.3

[msp430-gcc.git] / gmp / mpn / m88k / sub_n.s

diff --git a/gmp/mpn/m88k/sub_n.s b/gmp/mpn/m88k/sub_n.s
new file mode 100644 (file)
index 0000000..9ea78ff
--- /dev/null
+++ b/gmp/mpn/m88k/sub_n.s
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+; mc88100 mpn_sub_n -- Subtract two limb vectors of the same length > 0 and
+; store difference in a third limb vector.
+
+; Copyright 1992, 1994, 1996, 2000 Free Software Foundation, Inc.
+
+; This file is part of the GNU MP Library.
+
+; The GNU MP Library is free software; you can redistribute it and/or modify
+; it under the terms of the GNU Lesser General Public License as published by
+; the Free Software Foundation; either version 3 of the License, or (at your
+; option) any later version.
+
+; The GNU MP Library is distributed in the hope that it will be useful, but
+; WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+; or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
+; License for more details.
+
+; You should have received a copy of the GNU Lesser General Public License
+; along with the GNU MP Library.  If not, see http://www.gnu.org/licenses/.
+
+
+; INPUT PARAMETERS
+; res_ptr      r2
+; s1_ptr       r3
+; s2_ptr       r4
+; size         r5
+
+; This code has been optimized to run one instruction per clock, avoiding
+; load stalls and writeback contention.  As a result, the instruction
+; order is not always natural.
+
+; The speed is about 4.6 clocks/limb + 18 clocks/limb-vector on an 88100,
+; but on the 88110, it seems to run much slower, 6.6 clocks/limb.
+
+       text
+       align    16
+       global   ___gmpn_sub_n
+___gmpn_sub_n:
+       ld      r6,r3,0                 ; read first limb from s1_ptr
+       extu    r10,r5,3
+       ld      r7,r4,0                 ; read first limb from s2_ptr
+
+       subu    r5,r0,r5
+       mak     r5,r5,3<4>
+       bcnd.n  eq0,r5,Lzero
+       subu.co r0,r0,r0                ; initialize carry
+
+       or      r12,r0,lo16(Lbase)
+       or.u    r12,r12,hi16(Lbase)
+       addu    r12,r12,r5              ; r12 is address for entering in loop
+
+       extu    r5,r5,2                 ; divide by 4
+       subu    r2,r2,r5                ; adjust res_ptr
+       subu    r3,r3,r5                ; adjust s1_ptr
+       subu    r4,r4,r5                ; adjust s2_ptr
+
+       or      r8,r6,r0
+
+       jmp.n   r12
+        or     r9,r7,r0
+
+Loop:  addu    r3,r3,32
+       st      r8,r2,28
+       addu    r4,r4,32
+       ld      r6,r3,0
+       addu    r2,r2,32
+       ld      r7,r4,0
+Lzero: subu    r10,r10,1               ; subtract 0 + 8r limbs (adj loop cnt)
+Lbase: ld      r8,r3,4
+       subu.cio r6,r6,r7
+       ld      r9,r4,4
+       st      r6,r2,0
+       ld      r6,r3,8                 ; subtract 7 + 8r limbs
+       subu.cio r8,r8,r9
+       ld      r7,r4,8
+       st      r8,r2,4
+       ld      r8,r3,12                ; subtract 6 + 8r limbs
+       subu.cio r6,r6,r7
+       ld      r9,r4,12
+       st      r6,r2,8
+       ld      r6,r3,16                ; subtract 5 + 8r limbs
+       subu.cio r8,r8,r9
+       ld      r7,r4,16
+       st      r8,r2,12
+       ld      r8,r3,20                ; subtract 4 + 8r limbs
+       subu.cio r6,r6,r7
+       ld      r9,r4,20
+       st      r6,r2,16
+       ld      r6,r3,24                ; subtract 3 + 8r limbs
+       subu.cio r8,r8,r9
+       ld      r7,r4,24
+       st      r8,r2,20
+       ld      r8,r3,28                ; subtract 2 + 8r limbs
+       subu.cio r6,r6,r7
+       ld      r9,r4,28
+       st      r6,r2,24
+       bcnd.n  ne0,r10,Loop            ; subtract 1 + 8r limbs
+        subu.cio r8,r8,r9
+
+       st      r8,r2,28                ; store most significant limb
+
+       addu.ci r2,r0,r0                ; return carry-out from most sign. limb
+       jmp.n    r1
+        xor    r2,r2,1