sub_n.asm
上传用户:qaz666999
上传日期:2022-08-06
资源大小:2570k
文件大小:8k
- dnl Alpha ev6 mpn_sub_n -- Subtract two limb vectors of the same length > 0
- dnl and store difference in a third limb vector.
- dnl Copyright 2000, 2003, 2005 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 cycles/limb
- C EV4: ?
- C EV5: 5.4
- C EV6: 2.125
- C INPUT PARAMETERS
- C rp r16
- C up r17
- C vp r18
- C n r19
- C cy r20 (for mpn_add_nc)
- C TODO
- C Finish cleaning up cy registers r22, r23 (make them use cy0/cy1)
- C Use multi-pronged feed-in.
- C Perform additional micro-tuning
- C This code was written in cooperation with ev6 pipeline expert Steve Root.
- C Pair loads and stores where possible
- C Store pairs oct-aligned where possible (didn't need it here)
- C Stores are delayed every third cycle
- C Loads and stores are delayed by fills
- C U stays still, put code there where possible (note alternation of U1 and U0)
- C L moves because of loads and stores
- C Note dampers in L to limit damage
- C This odd-looking optimization expects that were having random bits in our
- C data, so that a pure zero result is unlikely. so we penalize the unlikely
- C case to help the common case.
- define(`u0', `r0') define(`u1', `r3')
- define(`v0', `r1') define(`v1', `r4')
- define(`cy0', `r20') define(`cy1', `r21')
- MULFUNC_PROLOGUE(mpn_sub_n mpn_sub_nc)
- ASM_START()
- PROLOGUE(mpn_sub_nc)
- br r31, $entry
- EPILOGUE()
- PROLOGUE(mpn_sub_n)
- bis r31, r31, cy0 C clear carry in
- $entry: cmpult r19, 5, r22 C L1 move counter
- ldq u1, 0(r17) C L0 get next ones
- ldq v1, 0(r18) C L1
- bne r22, $Lsmall
- ldq u0, 8(r17) C L0 get next ones
- ldq v0, 8(r18) C L1
- subq u1, v1, r5 C U0 sub two data
- cmpult u1, v1, r23 C U0 did it borrow
- ldq u1, 16(r17) C L0 get next ones
- ldq v1, 16(r18) C L1
- subq u0, v0, r8 C U1 sub two data
- subq r5, cy0, r24 C U0 borrow in
- cmpult u0, v0, r22 C U1 did it borrow
- beq r5, $fix5f C U0 fix exact zero
- $ret5f: ldq u0, 24(r17) C L0 get next ones
- ldq v0, 24(r18) C L1
- subq r8, r23, r25 C U1 borrow from last
- subq u1, v1, r7 C U0 sub two data
- beq r8, $fix6f C U1 fix exact zero
- $ret6f: cmpult u1, v1, r23 C U0 did it borrow
- ldq u1, 32(r17) C L0 get next ones
- ldq v1, 32(r18) C L1
- lda r17, 40(r17) C L0 move pointer
- lda r18, 40(r18) C L1 move pointer
- lda r16, -8(r16)
- lda r19, -13(r19) C L1 move counter
- blt r19, $Lend C U1 loop control
- C Main loop. 8-way unrolled.
- ALIGN(16)
- $Loop: subq u0, v0, r2 C U1 sub two data
- stq r24, 8(r16) C L0 put an answer
- subq r7, r22, r24 C U0 borrow from last
- stq r25, 16(r16) C L1 pair
- cmpult u0, v0, cy1 C U1 did it borrow
- beq r7, $fix7 C U0 fix exact 0
- $ret7: ldq u0, 0(r17) C L0 get next ones
- ldq v0, 0(r18) C L1
- bis r31, r31, r31 C L damp out
- subq r2, r23, r25 C U1 borrow from last
- bis r31, r31, r31 C L moves in L !
- subq u1, v1, r5 C U0 sub two data
- beq r2, $fix0 C U1 fix exact zero
- $ret0: cmpult u1, v1, cy0 C U0 did it borrow
- ldq u1, 8(r17) C L0 get next ones
- ldq v1, 8(r18) C L1
- subq u0, v0, r8 C U1 sub two data
- stq r24, 24(r16) C L0 store pair
- subq r5, cy1, r24 C U0 borrow from last
- stq r25, 32(r16) C L1
- cmpult u0, v0, r22 C U1 did it borrow
- beq r5, $fix1 C U0 fix exact zero
- $ret1: ldq u0, 16(r17) C L0 get next ones
- ldq v0, 16(r18) C L1
- lda r16, 64(r16) C L0 move pointer
- subq r8, cy0, r25 C U1 borrow from last
- lda r19, -8(r19) C L1 move counter
- subq u1, v1, r7 C U0 sub two data
- beq r8, $fix2 C U1 fix exact zero
- $ret2: cmpult u1, v1, r23 C U0 did it borrow
- ldq u1, 24(r17) C L0 get next ones
- ldq v1, 24(r18) C L1
- subq u0, v0, r2 C U1 sub two data
- stq r24, -24(r16) C L0 put an answer
- subq r7, r22, r24 C U0 borrow from last
- stq r25, -16(r16) C L1 pair
- cmpult u0, v0, cy1 C U1 did it borrow
- beq r7, $fix3 C U0 fix exact 0
- $ret3: ldq u0, 32(r17) C L0 get next ones
- ldq v0, 32(r18) C L1
- bis r31, r31, r31 C L damp out
- subq r2, r23, r25 C U1 borrow from last
- bis r31, r31, r31 C L moves in L !
- subq u1, v1, r5 C U0 sub two data
- beq r2, $fix4 C U1 fix exact zero
- $ret4: cmpult u1, v1, cy0 C U0 did it borrow
- ldq u1, 40(r17) C L0 get next ones
- ldq v1, 40(r18) C L1
- subq u0, v0, r8 C U1 sub two data
- stq r24, -8(r16) C L0 store pair
- subq r5, cy1, r24 C U0 borrow from last
- stq r25, 0(r16) C L1
- cmpult u0, v0, r22 C U1 did it borrow
- beq r5, $fix5 C U0 fix exact zero
- $ret5: ldq u0, 48(r17) C L0 get next ones
- ldq v0, 48(r18) C L1
- ldl r31, 256(r17) C L0 prefetch
- subq r8, cy0, r25 C U1 borrow from last
- ldl r31, 256(r18) C L1 prefetch
- subq u1, v1, r7 C U0 sub two data
- beq r8, $fix6 C U1 fix exact zero
- $ret6: cmpult u1, v1, r23 C U0 did it borrow
- ldq u1, 56(r17) C L0 get next ones
- ldq v1, 56(r18) C L1
- lda r17, 64(r17) C L0 move pointer
- bis r31, r31, r31 C U
- lda r18, 64(r18) C L1 move pointer
- bge r19, $Loop C U1 loop control
- C ==== main loop end
- $Lend: subq u0, v0, r2 C U1 sub two data
- stq r24, 8(r16) C L0 put an answer
- subq r7, r22, r24 C U0 borrow from last
- stq r25, 16(r16) C L1 pair
- cmpult u0, v0, cy1 C U1 did it borrow
- beq r7, $fix7c C U0 fix exact 0
- $ret7c: subq r2, r23, r25 C U1 borrow from last
- subq u1, v1, r5 C U0 sub two data
- beq r2, $fix0c C U1 fix exact zero
- $ret0c: cmpult u1, v1, cy0 C U0 did it borrow
- stq r24, 24(r16) C L0 store pair
- subq r5, cy1, r24 C U0 borrow from last
- stq r25, 32(r16) C L1
- beq r5, $fix1c C U0 fix exact zero
- $ret1c: stq r24, 40(r16) C L0 put an answer
- lda r16, 48(r16) C L0 move pointer
- lda r19, 8(r19)
- beq r19, $Lret
- ldq u1, 0(r17)
- ldq v1, 0(r18)
- $Lsmall:
- lda r19, -1(r19)
- beq r19, $Lend0
- ALIGN(8)
- $Loop0: subq u1, v1, r2 C main sub
- cmpult u1, v1, r8 C compute bw from last sub
- ldq u1, 8(r17)
- ldq v1, 8(r18)
- subq r2, cy0, r5 C borrow sub
- lda r17, 8(r17)
- lda r18, 8(r18)
- stq r5, 0(r16)
- cmpult r2, cy0, cy0 C compute bw from last sub
- lda r19, -1(r19) C decr loop cnt
- bis r8, cy0, cy0 C combine bw from the two subs
- lda r16, 8(r16)
- bne r19, $Loop0
- $Lend0: subq u1, v1, r2 C main sub
- subq r2, cy0, r5 C borrow sub
- cmpult u1, v1, r8 C compute bw from last sub
- cmpult r2, cy0, cy0 C compute bw from last sub
- stq r5, 0(r16)
- bis r8, cy0, r0 C combine bw from the two subs
- ret r31,(r26),1
- ALIGN(8)
- $Lret: lda r0, 0(cy0) C copy borrow into return register
- ret r31,(r26),1
- $fix5f: bis r23, cy0, r23 C bring forward borrow
- br r31, $ret5f
- $fix6f: bis r22, r23, r22 C bring forward borrow
- br r31, $ret6f
- $fix0: bis cy1, r23, cy1 C bring forward borrow
- br r31, $ret0
- $fix1: bis cy0, cy1, cy0 C bring forward borrow
- br r31, $ret1
- $fix2: bis r22, cy0, r22 C bring forward borrow
- br r31, $ret2
- $fix3: bis r23, r22, r23 C bring forward borrow
- br r31, $ret3
- $fix4: bis cy1, r23, cy1 C bring forward borrow
- br r31, $ret4
- $fix5: bis cy1, cy0, cy0 C bring forward borrow
- br r31, $ret5
- $fix6: bis r22, cy0, r22 C bring forward borrow
- br r31, $ret6
- $fix7: bis r23, r22, r23 C bring forward borrow
- br r31, $ret7
- $fix0c: bis cy1, r23, cy1 C bring forward borrow
- br r31, $ret0c
- $fix1c: bis cy0, cy1, cy0 C bring forward borrow
- br r31, $ret1c
- $fix7c: bis r23, r22, r23 C bring forward borrow
- br r31, $ret7c
- EPILOGUE()
- ASM_END()