about summary refs log tree commit diff
path: root/REORG.TODO/sysdeps/powerpc/powerpc32/add_n.S
diff options
context:
space:
mode:
Diffstat (limited to 'REORG.TODO/sysdeps/powerpc/powerpc32/add_n.S')
-rw-r--r--REORG.TODO/sysdeps/powerpc/powerpc32/add_n.S68
1 files changed, 68 insertions, 0 deletions
diff --git a/REORG.TODO/sysdeps/powerpc/powerpc32/add_n.S b/REORG.TODO/sysdeps/powerpc/powerpc32/add_n.S
new file mode 100644
index 0000000000..0687be6236
--- /dev/null
+++ b/REORG.TODO/sysdeps/powerpc/powerpc32/add_n.S
@@ -0,0 +1,68 @@
+/* Add two limb vectors of equal, non-zero length for PowerPC.
+   Copyright (C) 1997-2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C 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 C 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 C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <sysdep.h>
+
+/* mp_limb_t mpn_add_n (mp_ptr res_ptr, mp_srcptr s1_ptr, mp_srcptr s2_ptr,
+                        mp_size_t size)
+   Calculate s1+s2 and put result in res_ptr; return carry, 0 or 1.  */
+
+/* Note on optimisation: This code is optimal for the 601.  Almost every other
+   possible 2-unrolled inner loop will not be.  Also, watch out for the
+   alignment...  */
+
+EALIGN (__mpn_add_n, 3, 0)
+
+/* Set up for loop below.  */
+	mtcrf 0x01,r6
+	srwi. r7,r6,1
+	li    r10,0
+	mtctr r7
+	bt    31,L(2)
+
+/* Clear the carry.  */
+	addic r0,r0,0
+/* Adjust pointers for loop.  */
+	addi  r3,r3,-4
+	addi  r4,r4,-4
+	addi  r5,r5,-4
+	b     L(0)
+
+L(2):	lwz  r7,0(r5)
+	lwz  r6,0(r4)
+	addc r6,r6,r7
+	stw  r6,0(r3)
+        beq  L(1)
+
+/* The loop.  */
+
+/* Align start of loop to an odd word boundary to guarantee that the
+   last two words can be fetched in one access (for 601).  */
+L(0):	lwz  r9,4(r4)
+	lwz  r8,4(r5)
+	lwzu r6,8(r4)
+	lwzu r7,8(r5)
+	adde r8,r9,r8
+	stw  r8,4(r3)
+	adde r6,r6,r7
+	stwu r6,8(r3)
+	bdnz L(0)
+/* Return the carry.  */
+L(1):	addze r3,r10
+	blr
+END (__mpn_add_n)