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aarch64: Use the L() macro for labels in memcmp
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The L() macro makes the assembly a bit more readable.

	* sysdeps/aarch64/memcmp.S: Use L() macro for labels.
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siddhesh committed Feb 2, 2018
1 parent 96e6a71 commit 84c94d2
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2 changes: 2 additions & 0 deletions ChangeLog
Original file line number Diff line number Diff line change
@@ -1,5 +1,7 @@
2018-02-02 Siddhesh Poyarekar <[email protected]>

* sysdeps/aarch64/memcmp.S: Use L() macro for labels.

* benchtests/bench-memcmp.c: Print json instead of plain text.

* benchtests/bench-memcmp.c (do_test): Call realloc_buf for
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32 changes: 16 additions & 16 deletions sysdeps/aarch64/memcmp.S
Original file line number Diff line number Diff line change
Expand Up @@ -44,73 +44,73 @@ ENTRY_ALIGN (memcmp, 6)
DELOUSE (2)

subs limit, limit, 8
b.lo .Lless8
b.lo L(less8)

/* Limit >= 8, so check first 8 bytes using unaligned loads. */
ldr data1, [src1], 8
ldr data2, [src2], 8
and tmp1, src1, 7
add limit, limit, tmp1
cmp data1, data2
bne .Lreturn
bne L(return)

/* Align src1 and adjust src2 with bytes not yet done. */
sub src1, src1, tmp1
sub src2, src2, tmp1

subs limit, limit, 8
b.ls .Llast_bytes
b.ls L(last_bytes)

/* Loop performing 8 bytes per iteration using aligned src1.
Limit is pre-decremented by 8 and must be larger than zero.
Exit if <= 8 bytes left to do or if the data is not equal. */
.p2align 4
.Lloop8:
L(loop8):
ldr data1, [src1], 8
ldr data2, [src2], 8
subs limit, limit, 8
ccmp data1, data2, 0, hi /* NZCV = 0b0000. */
b.eq .Lloop8
b.eq L(loop8)

cmp data1, data2
bne .Lreturn
bne L(return)

/* Compare last 1-8 bytes using unaligned access. */
.Llast_bytes:
L(last_bytes):
ldr data1, [src1, limit]
ldr data2, [src2, limit]

/* Compare data bytes and set return value to 0, -1 or 1. */
.Lreturn:
L(return):
#ifndef __AARCH64EB__
rev data1, data1
rev data2, data2
#endif
cmp data1, data2
.Lret_eq:
L(ret_eq):
cset result, ne
cneg result, result, lo
ret

.p2align 4
/* Compare up to 8 bytes. Limit is [-8..-1]. */
.Lless8:
L(less8):
adds limit, limit, 4
b.lo .Lless4
b.lo L(less4)
ldr data1w, [src1], 4
ldr data2w, [src2], 4
cmp data1w, data2w
b.ne .Lreturn
b.ne L(return)
sub limit, limit, 4
.Lless4:
L(less4):
adds limit, limit, 4
beq .Lret_eq
.Lbyte_loop:
beq L(ret_eq)
L(byte_loop):
ldrb data1w, [src1], 1
ldrb data2w, [src2], 1
subs limit, limit, 1
ccmp data1w, data2w, 0, ne /* NZCV = 0b0000. */
b.eq .Lbyte_loop
b.eq L(byte_loop)
sub result, data1w, data2w
ret

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