[gcc] GCC 4.5.0=>4.5.1

gcc/gmp/mpn/alpha/ev67/gcd_1.asm

-dnl  Alpha ev67 mpn_gcd_1 -- Nx1 greatest common divisor.
-
-dnl  Copyright 2003, 2004 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: 3.4 cycles/bitpair for 1x1 part
-
-
-C mp_limb_t mpn_gcd_1 (mp_srcptr xp, mp_size_t xsize, mp_limb_t y);
-C
-C In the 1x1 part, the algorithm is to change x,y to abs(x-y),min(x,y) and
-C strip trailing zeros from abs(x-y) to maintain x and y both odd.
-C
-C The trailing zeros are calculated from just x-y, since in twos-complement
-C there's the same number of trailing zeros on d or -d.  This means the cttz
-C runs in parallel with abs(x-y).
-C
-C The loop takes 5 cycles, and at 0.68 iterations per bit for two N-bit
-C operands with this algorithm gives the measured 3.4 c/l.
-C
-C The slottings shown are for SVR4 style systems, Unicos differs in the
-C initial gp setup and the LEA.
-C
-C Enhancement:
-C
-C On the jsr, !lituse_jsr! (when available) would allow the linker to relax
-C it to a bsr, but probably only in a static binary.  Plain "jsr foo" gives
-C the right object code for relaxation, and ought to be available
-C everywhere, but we prefer to schedule the GOT ldq (LEA) back earlier, for
-C the usual case of running in a shared library.
-C
-C bsr could perhaps be used explicitly anyway.  We should be able to assume
-C modexact is in the same module as us (ie. shared library or mainline).
-C Would there be any worries about the size of the displacement?  Could
-C always put modexact and gcd_1 in the same .o to be certain.
-
-ASM_START()
-PROLOGUE(mpn_gcd_1, gp)
-
-        C r16   xp
-        C r17   size
-        C r18   y
-
-        C ldah                          C l
-        C lda                           C u
-
-        ldq     r0, 0(r16)              C L   x = xp[0]
-        lda     r30, -32(r30)           C u   alloc stack
-
-        LEA(  r27, mpn_modexact_1c_odd) C L   modexact addr, ldq (gp)
-        stq     r10, 16(r30)            C L   save r10
-        cttz    r18, r10                C U0  y twos
-        cmpeq   r17, 1, r5              C u   test size==1
-
-        stq     r9, 8(r30)              C L   save r9
-        clr     r19                     C u   zero c for modexact
-        unop
-        unop
-
-        cttz    r0, r6                  C U0  x twos
-        stq     r26, 0(r30)             C L   save ra
-
-        srl     r18, r10, r18           C U   y odd
-
-        mov     r18, r9                 C l   hold y across call
-
-        cmpult  r6, r10, r2             C u   test x_twos < y_twos
-
-        cmovne  r2, r6, r10             C l   common_twos = min(x_twos,y_twos)
-        bne     r5, L(one)              C U   no modexact if size==1
-        jsr     r26, (r27), mpn_modexact_1c_odd   C L0
-
-        LDGP(   r29, 0(r26))            C u,l ldah,lda
-        cttz    r0, r6                  C U0  new x twos
-        ldq     r26, 0(r30)             C L   restore ra
-
-L(one):
-        mov     r9, r1                  C u   y
-        ldq     r9, 8(r30)              C L   restore r9
-        mov     r10, r2                 C u   common twos
-        ldq     r10, 16(r30)            C L   restore r10
-
-        lda     r30, 32(r30)            C l   free stack
-        beq     r0, L(done)             C U   return y if x%y==0
-
-        srl     r0, r6, r0              C U   x odd
-        unop
-
-        ALIGN(16)
-L(top):
-        C r0    x
-        C r1    y
-        C r2    common twos, for use at end
-
-        subq    r0, r1, r7              C l0  d = x - y
-        cmpult  r0, r1, r16             C u0  test x >= y
-
-        subq    r1, r0, r4              C l0  new_x = y - x
-        cttz    r7, r8                  C U0  d twos
-
-        cmoveq  r16, r7, r4             C l0  new_x = d if x>=y
-        cmovne  r16, r0, r1             C u0  y = x if x<y
-        unop                            C l   \ force cmoveq into l0
-        unop                            C u   /
-
-        C                               C cmoveq2 L0, cmovne2 U0
-
-        srl     r4, r8, r0              C U0  x = new_x >> twos
-        bne     r7, L(top)              C U1  stop when d==0
-
-
-L(done):
-        sll     r1, r2, r0              C U0  return y << common_twos
-        ret     r31, (r26), 1           C L0
-
-EPILOGUE()
-ASM_END()