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-rw-r--r--sysdeps/rs6000/add_n.s41
1 files changed, 34 insertions, 7 deletions
diff --git a/sysdeps/rs6000/add_n.s b/sysdeps/rs6000/add_n.s
index e2536d5887..9e1c948974 100644
--- a/sysdeps/rs6000/add_n.s
+++ b/sysdeps/rs6000/add_n.s
@@ -1,6 +1,6 @@
# IBM POWER __mpn_add_n -- Add two limb vectors of equal, non-zero length.
-# Copyright (C) 1992, 1994, 1995 Free Software Foundation, Inc.
+# Copyright (C) 1992, 1994, 1995, 1996 Free Software Foundation, Inc.
# This file is part of the GNU MP Library.
@@ -16,7 +16,8 @@
# You should have received a copy of the GNU Library General Public License
# along with the GNU MP Library; see the file COPYING.LIB. If not, write to
-# the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+# the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+# MA 02111-1307, USA.
# INPUT PARAMETERS
@@ -37,18 +38,44 @@ __mpn_add_n:
.long .__mpn_add_n, TOC[tc0], 0
.csect [PR]
.__mpn_add_n:
- mtctr 6 # copy size into CTR
+ andil. 10,6,1 # odd or even number of limbs?
l 8,0(4) # load least significant s1 limb
l 0,0(5) # load least significant s2 limb
- cal 3,-4(3) # offset res_ptr, it's updated before used
+ cal 3,-4(3) # offset res_ptr, it's updated before it's used
+ sri 10,6,1 # count for unrolled loop
a 7,0,8 # add least significant limbs, set cy
+ mtctr 10 # copy count into CTR
+ beq 0,Leven # branch if even # of limbs (# of limbs >= 2)
+
+# We have an odd # of limbs. Add the first limbs separately.
+ cmpi 1,10,0 # is count for unrolled loop zero?
+ bne 1,L1 # branch if not
+ st 7,4(3)
+ aze 3,10 # use the fact that r10 is zero...
+ br # return
+
+# We added least significant limbs. Now reload the next limbs to enter loop.
+L1: lu 8,4(4) # load s1 limb and update s1_ptr
+ lu 0,4(5) # load s2 limb and update s2_ptr
+ stu 7,4(3)
+ ae 7,0,8 # add limbs, set cy
+Leven: lu 9,4(4) # load s1 limb and update s1_ptr
+ lu 10,4(5) # load s2 limb and update s2_ptr
bdz Lend # If done, skip loop
+
Loop: lu 8,4(4) # load s1 limb and update s1_ptr
lu 0,4(5) # load s2 limb and update s2_ptr
- stu 7,4(3) # store previous limb in load latency slot
- ae 7,0,8 # add new limbs with cy, set cy
+ ae 11,9,10 # add previous limbs with cy, set cy
+ stu 7,4(3) #
+ lu 9,4(4) # load s1 limb and update s1_ptr
+ lu 10,4(5) # load s2 limb and update s2_ptr
+ ae 7,0,8 # add previous limbs with cy, set cy
+ stu 11,4(3) #
bdn Loop # decrement CTR and loop back
-Lend: st 7,4(3) # store ultimate result limb
+
+Lend: ae 11,9,10 # add limbs with cy, set cy
+ st 7,4(3) #
+ st 11,8(3) #
lil 3,0 # load cy into ...
aze 3,3 # ... return value register
br