Imported gcc-4.4.3

[msp430-gcc.git] / gmp / mpn / alpha / ev67 / popcount.asm

diff --git a/gmp/mpn/alpha/ev67/popcount.asm b/gmp/mpn/alpha/ev67/popcount.asm
new file mode 100644 (file)
index 0000000..6ed79cf
--- /dev/null
+++ b/gmp/mpn/alpha/ev67/popcount.asm
@@ -0,0 +1,90 @@
+dnl  Alpha ev67 mpn_popcount -- mpn bit population count.
+
+dnl  Copyright 2003, 2005 Free Software Foundation, Inc.
+
+dnl  This file is part of the GNU MP Library.
+dnl
+dnl  The GNU MP Library is free software; you can redistribute it and/or
+dnl  modify it under the terms of the GNU Lesser General Public License as
+dnl  published by the Free Software Foundation; either version 3 of the
+dnl  License, or (at your option) any later version.
+dnl
+dnl  The GNU MP Library is distributed in the hope that it will be useful,
+dnl  but WITHOUT ANY WARRANTY; without even the implied warranty of
+dnl  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+dnl  Lesser General Public License for more details.
+dnl
+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 ev67: 1.5 cycles/limb
+
+
+C unsigned long mpn_popcount (mp_srcptr src, mp_size_t size);
+C
+C This schedule seems necessary for the full 1.5 c/l, the IQ can't quite hide
+C all latencies, the addq's must be deferred to the next iteration.
+C
+C Since we need just 3 instructions per limb, further unrolling could approach
+C 1.0 c/l.
+C
+C The main loop processes two limbs at a time.  An odd size is handled by
+C processing src[0] at the start.  If the size is even that result is
+C discarded, and src[0] is repeated by the main loop.
+C
+
+ASM_START()
+PROLOGUE(mpn_popcount)
+
+       C r16   src
+       C r17   size
+
+       ldq     r0, 0(r16)              C L0  src[0]
+       and     r17, 1, r8              C U1  1 if size odd
+       srl     r17, 1, r17             C U0  size, limb pairs
+
+       s8addq  r8, r16, r16            C L1  src++ if size odd
+       ctpop   r0, r0                  C U0
+       beq     r17, L(one)             C U1  if size==1
+
+       cmoveq  r8, r31, r0             C L   discard first limb if size even
+       clr     r3                      C L
+
+       clr     r4                      C L
+       unop                            C U
+       unop                            C L
+       unop                            C U
+
+
+       ALIGN(16)
+L(top):
+       C r0    total accumulating
+       C r3    pop 0
+       C r4    pop 1
+       C r16   src, incrementing
+       C r17   size, decrementing
+
+       ldq     r1, 0(r16)              C L
+       ldq     r2, 8(r16)              C L
+       lda     r16, 16(r16)            C U
+       lda     r17, -1(r17)            C U
+
+       addq    r0, r3, r0              C L
+       addq    r0, r4, r0              C L
+       ctpop   r1, r3                  C U0
+       ctpop   r2, r4                  C U0
+
+       ldl     r31, 512(r16)           C L     prefetch
+       bne     r17, L(top)             C U
+
+
+       addq    r0, r3, r0              C L
+       addq    r0, r4, r0              C U
+L(one):
+       ret     r31, (r26), 1           C L0
+
+EPILOGUE()
+ASM_END()