+dnl ARM mpn_sub_n -- Subtract two limb vectors of the same length > 0 and
+dnl store difference in a third limb vector.
+dnl Contributed by Robert Harley.
+
+dnl Copyright 1997, 2000, 2001 Free Software Foundation, Inc.
+
+dnl This file is part of the GNU MP Library.
+
+dnl The GNU MP Library is free software; you can redistribute it and/or modify
+dnl it under the terms of the GNU Lesser General Public License as published
+dnl by the Free Software Foundation; either version 3 of the License, or (at
+dnl your option) any later version.
+
+dnl The GNU MP Library is distributed in the hope that it will be useful, but
+dnl WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+dnl or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
+dnl License for more details.
+
+dnl You should have received a copy of the GNU Lesser General Public License
+dnl along with the GNU MP Library. If not, see http://www.gnu.org/licenses/.
+
+include(`../config.m4')
+
+C This code runs at 5 cycles/limb.
+
+define(`rp',`r0')
+define(`up',`r1')
+define(`vp',`r2')
+define(`n',`r3')
+
+
+ASM_START()
+PROLOGUE(mpn_sub_n)
+ stmfd sp!, { r8, r9, lr }
+ subs r12, r12, r12
+ tst n, #1
+ beq L(skip1)
+ ldr r12, [up], #4
+ ldr lr, [vp], #4
+ subs r12, r12, lr
+ str r12, [rp], #4
+L(skip1):
+ tst n, #2
+ beq L(skip2)
+ ldmia up!, { r8, r9 }
+ ldmia vp!, { r12, lr }
+ sbcs r8, r8, r12
+ sbcs r9, r9, lr
+ stmia rp!, { r8, r9 }
+L(skip2):
+ bics n, n, #3
+ beq L(return)
+ stmfd sp!, { r4, r5, r6, r7 }
+L(sub_n_loop):
+ ldmia up!, { r4, r5, r6, r7 }
+ ldmia vp!, { r8, r9, r12, lr }
+ sbcs r4, r4, r8
+ ldr r8, [rp, #12] C cache allocate
+ sbcs r5, r5, r9
+ sbcs r6, r6, r12
+ sbcs r7, r7, lr
+ stmia rp!, { r4, r5, r6, r7 }
+ sub n, n, #4
+ teq n, #0
+ bne L(sub_n_loop)
+ ldmfd sp!, { r4, r5, r6, r7 }
+L(return):
+ sbc r0, r0, r0
+ and r0, r0, #1
+ ldmfd sp!, { r8, r9, pc }
+EPILOGUE(mpn_sub_n)