diff options
Diffstat (limited to 'sysdeps/alpha/alphaev6')
| -rw-r--r-- | sysdeps/alpha/alphaev6/stxncpy.S | 85 |
1 files changed, 42 insertions, 43 deletions
diff --git a/sysdeps/alpha/alphaev6/stxncpy.S b/sysdeps/alpha/alphaev6/stxncpy.S index 21e94ba7e2..f39c23a886 100644 --- a/sysdeps/alpha/alphaev6/stxncpy.S +++ b/sysdeps/alpha/alphaev6/stxncpy.S @@ -1,4 +1,4 @@ -/* Copyright (C) 2000 Free Software Foundation, Inc. +/* Copyright (C) 2000, 2002 Free Software Foundation, Inc. Contributed by Richard Henderson (rth@tamu.edu) EV6 optimized by Rick Gorton <rick.gorton@alpha-processor.com>. This file is part of the GNU C Library. @@ -210,35 +210,30 @@ $u_head: cmpbge zero, t6, t7 # E : beq a2, $u_eocfin # U : - nop + lda t6, -1 # E : nop bne t7, $u_final # U : - lda t6, -1 # E : mask out the bits we have - mskql t6, a1, t6 # U : already seen (stall) + mskql t6, a1, t6 # U : mask out bits already seen stq_u t0, 0(a0) # L : store first output word + or t6, t2, t2 # E : - or t6, t2, t2 # E : - cmpbge zero, t2, t7 # E : find nulls in second partial (stall) - addq a0, 8, a0 # E : - subq a2, 1, a2 # E : - + cmpbge zero, t2, t7 # E : find nulls in second partial + addq a0, 8, a0 # E : + subq a2, 1, a2 # E : bne t7, $u_late_head_exit # U : + /* Finally, we've got all the stupid leading edge cases taken care of and we can set up to enter the main loop. */ extql t2, a1, t1 # U : position hi-bits of lo word + beq a2, $u_eoc # U : ldq_u t2, 8(a1) # L : read next high-order source word addq a1, 8, a1 # E : - cmpbge zero, t2, t7 # E : (stall) - beq a2, $u_eoc # U : - nop - nop - - bne t7, $u_eos # e1 : - nop - nop - nop + extqh t2, a1, t0 # U : position lo-bits of hi word (stall) + cmpbge zero, t2, t7 # E : + nop + bne t7, $u_eos # U : /* Unaligned copy main loop. In order to avoid reading too much, the loop is structured to detect zeros in aligned source words. @@ -248,6 +243,7 @@ $u_head: to run as fast as possible. On entry to this basic block: + t0 == the shifted low-order bits from the current source word t1 == the shifted high-order bits from the previous source word t2 == the unshifted current source word @@ -255,25 +251,20 @@ $u_head: .align 4 $u_loop: - extqh t2, a1, t0 # U : extract high bits for current word - addq a1, 8, a1 # E : - extql t2, a1, t3 # U : extract low bits for next time + or t0, t1, t0 # E : current dst word now complete + subq a2, 1, a2 # E : decrement word count + extql t2, a1, t1 # U : extract high bits for next time addq a0, 8, a0 # E : - or t0, t1, t0 # E : current dst word now complete - ldq_u t2, 0(a1) # U : Latency=3 load high word for next time - stq_u t0, -8(a0) # U : save the current word (stall) - mov t3, t1 # E : + stq_u t0, -8(a0) # L : save the current word + beq a2, $u_eoc # U : + ldq_u t2, 8(a1) # L : Latency=3 load high word for next time + addq a1, 8, a1 # E : - subq a2, 1, a2 # E : - cmpbge zero, t2, t7 # E : test new word for eos (2 cycle stall for data) - beq a2, $u_eoc # U : (stall) + extqh t2, a1, t0 # U : extract low bits (2 cycle stall) + cmpbge zero, t2, t7 # E : test new word for eos nop - beq t7, $u_loop # U : - nop - nop - nop /* We've found a zero somewhere in the source word we just read. If it resides in the lower half, we have one (probably partial) @@ -281,11 +272,12 @@ $u_loop: have one full and one partial word left to write out. On entry to this basic block: + t0 == the shifted low-order bits from the current source word t1 == the shifted high-order bits from the previous source word t2 == the unshifted current source word. */ $u_eos: - extqh t2, a1, t0 # U : - or t0, t1, t0 # E : first (partial) source word complete (stall) + or t0, t1, t0 # E : first (partial) source word complete + nop cmpbge zero, t0, t7 # E : is the null in this first bit? (stall) bne t7, $u_final # U : (stall) @@ -323,17 +315,26 @@ $u_final: 1: stq_u t0, 0(a0) # L : ret (t9) # L0 : Latency=3 -$u_eoc: # end-of-count - extqh t2, a1, t0 # U : - or t0, t1, t0 # E : (stall) - cmpbge zero, t0, t7 # E : (stall) + /* Got to end-of-count before end of string. + On entry to this basic block: + t1 == the shifted high-order bits from the previous source word */ +$u_eoc: + and a1, 7, t6 # E : + sll t10, t6, t6 # U : (stall) + and t6, 0xff, t6 # E : (stall) + bne t6, 1f # U : (stall) + + ldq_u t2, 8(a1) # L : load final src word nop + extqh t2, a1, t0 # U : extract low bits for last word (stall) + or t1, t0, t1 # E : (stall) + +1: cmpbge zero, t1, t7 # E : + mov t1, t0 $u_eocfin: # end-of-count, final word or t10, t7, t7 # E : br $u_final # L0 : Latency=3 - nop - nop /* Unaligned copy entry point. */ .align 4 @@ -354,9 +355,7 @@ $unaligned: mskql t6, a0, t6 # U : nop nop - nop -1: - subq a1, t4, a1 # E : sub dest misalignment from src addr +1: subq a1, t4, a1 # E : sub dest misalignment from src addr /* If source misalignment is larger than dest misalignment, we need extra startup checks to avoid SEGV. */ |