patch-2.4.20 linux-2.4.20/arch/alpha/lib/ev6-stxncpy.S
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- Lines: 154
- Date:
Thu Nov 28 15:53:08 2002
- Orig file:
linux-2.4.19/arch/alpha/lib/ev6-stxncpy.S
- Orig date:
Mon Dec 11 13:46:26 2000
diff -urN linux-2.4.19/arch/alpha/lib/ev6-stxncpy.S linux-2.4.20/arch/alpha/lib/ev6-stxncpy.S
@@ -205,35 +205,30 @@
cmpbge zero, t6, t8 # E :
beq a2, $u_eocfin # U :
- nop
+ lda t6, -1 # E :
nop
bne t8, $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 : (stall)
- or t6, t2, t2 # E :
- cmpbge zero, t2, t8 # E : find nulls in second partial (stall)
- addq a0, 8, a0 # E :
- subq a2, 1, a2 # E :
-
+ cmpbge zero, t2, t8 # E : find nulls in second partial
+ addq a0, 8, a0 # E :
+ subq a2, 1, a2 # E :
bne t8, $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, t8 # E : (stall)
- beq a2, $u_eoc # U :
- nop
- nop
-
- bne t8, $u_eos # e1 :
- nop
- nop
+ extqh t2, a1, t0 # U : position lo-bits of hi word (stall)
+ cmpbge zero, t2, t8 # E :
nop
+ bne t8, $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.
@@ -243,6 +238,7 @@
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
@@ -250,25 +246,20 @@
.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 low 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) # U : save the current word
+ beq a2, $u_eoc # U :
+ ldq_u t2, 8(a1) # U : Latency=3 load high word for next time
+ addq a1, 8, a1 # E :
- subq a2, 1, a2 # E :
- cmpbge zero, t2, t8 # 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, t8 # E : test new word for eos
nop
-
beq t8, $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)
@@ -276,11 +267,12 @@
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, t8 # E : is the null in this first bit? (stall)
bne t8, $u_final # U : (stall)
@@ -318,17 +310,26 @@
1: stq_u t0, 0(a0) # L :
ret (t9) # L0 : Latency=3
-$u_eoc: # end-of-count
- extqh t2, a1, t0 # U :
- or t0, t1, t0 # E : (stall)
- cmpbge zero, t0, t8 # 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 : avoid final load if possible
+ 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)
+
+ cmpbge zero, t1, t8 # E :
+ mov t1, t0 # E :
$u_eocfin: # end-of-count, final word
or t10, t8, t8 # E :
br $u_final # L0 : Latency=3
- nop
- nop
/* Unaligned copy entry point. */
.align 4
@@ -349,9 +350,7 @@
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. */
@@ -396,4 +395,3 @@
nop
.end __stxncpy
-
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