summaryrefslogtreecommitdiff
path: root/rts/gmp/mpn/m88k/sub_n.s
diff options
context:
space:
mode:
Diffstat (limited to 'rts/gmp/mpn/m88k/sub_n.s')
-rw-r--r--rts/gmp/mpn/m88k/sub_n.s106
1 files changed, 106 insertions, 0 deletions
diff --git a/rts/gmp/mpn/m88k/sub_n.s b/rts/gmp/mpn/m88k/sub_n.s
new file mode 100644
index 0000000000..2fd345a135
--- /dev/null
+++ b/rts/gmp/mpn/m88k/sub_n.s
@@ -0,0 +1,106 @@
+; mc88100 __gmpn_sub -- Subtract two limb vectors of the same length > 0 and
+; store difference in a third limb vector.
+
+; Copyright (C) 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 2.1 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; see the file COPYING.LIB. If not, write to
+; the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+; MA 02111-1307, USA.
+
+
+; 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