@@ -25,20 +25,15 @@
*
*/
-#define L2_SIZE (8*1024*1024)/2 // L2 8MB/2
-#define CACHE_LINE_SIZE 256
-#define ZF_DIST (CACHE_LINE_SIZE * 21) // Zerofill distance
-#define dest x0
-#define src x1
-#define n x2 // size
-#define tmp1 x3
-#define tmp2 x4
-#define tmp3 x5
-#define rest x6
-#define dest_ptr x7
-#define src_ptr x8
-#define vector_length x9
-#define cl_remainder x10 // CACHE_LINE_SIZE remainder
+#define dstin x0
+#define src x1
+#define n x2
+#define dst x3
+#define dstend x4
+#define srcend x5
+#define tmp x6
+#define vlen x7
+#define vlen8 x8
#if HAVE_AARCH64_SVE_ASM
# if IS_IN (libc)
@@ -47,45 +42,37 @@
.arch armv8.2-a+sve
- .macro dc_zva times
- dc zva, tmp1
- add tmp1, tmp1, CACHE_LINE_SIZE
- .if \times-1
- dc_zva "(\times-1)"
- .endif
- .endm
-
.macro ld1b_unroll8
- ld1b z0.b, p0/z, [src_ptr, #0, mul vl]
- ld1b z1.b, p0/z, [src_ptr, #1, mul vl]
- ld1b z2.b, p0/z, [src_ptr, #2, mul vl]
- ld1b z3.b, p0/z, [src_ptr, #3, mul vl]
- ld1b z4.b, p0/z, [src_ptr, #4, mul vl]
- ld1b z5.b, p0/z, [src_ptr, #5, mul vl]
- ld1b z6.b, p0/z, [src_ptr, #6, mul vl]
- ld1b z7.b, p0/z, [src_ptr, #7, mul vl]
+ ld1b z0.b, p0/z, [src, 0, mul vl]
+ ld1b z1.b, p0/z, [src, 1, mul vl]
+ ld1b z2.b, p0/z, [src, 2, mul vl]
+ ld1b z3.b, p0/z, [src, 3, mul vl]
+ ld1b z4.b, p0/z, [src, 4, mul vl]
+ ld1b z5.b, p0/z, [src, 5, mul vl]
+ ld1b z6.b, p0/z, [src, 6, mul vl]
+ ld1b z7.b, p0/z, [src, 7, mul vl]
.endm
.macro stld1b_unroll4a
- st1b z0.b, p0, [dest_ptr, #0, mul vl]
- st1b z1.b, p0, [dest_ptr, #1, mul vl]
- ld1b z0.b, p0/z, [src_ptr, #0, mul vl]
- ld1b z1.b, p0/z, [src_ptr, #1, mul vl]
- st1b z2.b, p0, [dest_ptr, #2, mul vl]
- st1b z3.b, p0, [dest_ptr, #3, mul vl]
- ld1b z2.b, p0/z, [src_ptr, #2, mul vl]
- ld1b z3.b, p0/z, [src_ptr, #3, mul vl]
+ st1b z0.b, p0, [dst, 0, mul vl]
+ st1b z1.b, p0, [dst, 1, mul vl]
+ ld1b z0.b, p0/z, [src, 0, mul vl]
+ ld1b z1.b, p0/z, [src, 1, mul vl]
+ st1b z2.b, p0, [dst, 2, mul vl]
+ st1b z3.b, p0, [dst, 3, mul vl]
+ ld1b z2.b, p0/z, [src, 2, mul vl]
+ ld1b z3.b, p0/z, [src, 3, mul vl]
.endm
.macro stld1b_unroll4b
- st1b z4.b, p0, [dest_ptr, #4, mul vl]
- st1b z5.b, p0, [dest_ptr, #5, mul vl]
- ld1b z4.b, p0/z, [src_ptr, #4, mul vl]
- ld1b z5.b, p0/z, [src_ptr, #5, mul vl]
- st1b z6.b, p0, [dest_ptr, #6, mul vl]
- st1b z7.b, p0, [dest_ptr, #7, mul vl]
- ld1b z6.b, p0/z, [src_ptr, #6, mul vl]
- ld1b z7.b, p0/z, [src_ptr, #7, mul vl]
+ st1b z4.b, p0, [dst, 4, mul vl]
+ st1b z5.b, p0, [dst, 5, mul vl]
+ ld1b z4.b, p0/z, [src, 4, mul vl]
+ ld1b z5.b, p0/z, [src, 5, mul vl]
+ st1b z6.b, p0, [dst, 6, mul vl]
+ st1b z7.b, p0, [dst, 7, mul vl]
+ ld1b z6.b, p0/z, [src, 6, mul vl]
+ ld1b z7.b, p0/z, [src, 7, mul vl]
.endm
.macro stld1b_unroll8
@@ -94,87 +81,18 @@
.endm
.macro st1b_unroll8
- st1b z0.b, p0, [dest_ptr, #0, mul vl]
- st1b z1.b, p0, [dest_ptr, #1, mul vl]
- st1b z2.b, p0, [dest_ptr, #2, mul vl]
- st1b z3.b, p0, [dest_ptr, #3, mul vl]
- st1b z4.b, p0, [dest_ptr, #4, mul vl]
- st1b z5.b, p0, [dest_ptr, #5, mul vl]
- st1b z6.b, p0, [dest_ptr, #6, mul vl]
- st1b z7.b, p0, [dest_ptr, #7, mul vl]
+ st1b z0.b, p0, [dst, 0, mul vl]
+ st1b z1.b, p0, [dst, 1, mul vl]
+ st1b z2.b, p0, [dst, 2, mul vl]
+ st1b z3.b, p0, [dst, 3, mul vl]
+ st1b z4.b, p0, [dst, 4, mul vl]
+ st1b z5.b, p0, [dst, 5, mul vl]
+ st1b z6.b, p0, [dst, 6, mul vl]
+ st1b z7.b, p0, [dst, 7, mul vl]
.endm
- .macro shortcut_for_small_size exit
- // if rest <= vector_length * 2
- whilelo p0.b, xzr, n
- whilelo p1.b, vector_length, n
- b.last 1f
- ld1b z0.b, p0/z, [src, #0, mul vl]
- ld1b z1.b, p1/z, [src, #1, mul vl]
- st1b z0.b, p0, [dest, #0, mul vl]
- st1b z1.b, p1, [dest, #1, mul vl]
- ret
-1: // if rest > vector_length * 8
- cmp n, vector_length, lsl 3 // vector_length * 8
- b.hi \exit
- // if rest <= vector_length * 4
- lsl tmp1, vector_length, 1 // vector_length * 2
- whilelo p2.b, tmp1, n
- incb tmp1
- whilelo p3.b, tmp1, n
- b.last 1f
- ld1b z0.b, p0/z, [src, #0, mul vl]
- ld1b z1.b, p1/z, [src, #1, mul vl]
- ld1b z2.b, p2/z, [src, #2, mul vl]
- ld1b z3.b, p3/z, [src, #3, mul vl]
- st1b z0.b, p0, [dest, #0, mul vl]
- st1b z1.b, p1, [dest, #1, mul vl]
- st1b z2.b, p2, [dest, #2, mul vl]
- st1b z3.b, p3, [dest, #3, mul vl]
- ret
-1: // if rest <= vector_length * 8
- lsl tmp1, vector_length, 2 // vector_length * 4
- whilelo p4.b, tmp1, n
- incb tmp1
- whilelo p5.b, tmp1, n
- b.last 1f
- ld1b z0.b, p0/z, [src, #0, mul vl]
- ld1b z1.b, p1/z, [src, #1, mul vl]
- ld1b z2.b, p2/z, [src, #2, mul vl]
- ld1b z3.b, p3/z, [src, #3, mul vl]
- ld1b z4.b, p4/z, [src, #4, mul vl]
- ld1b z5.b, p5/z, [src, #5, mul vl]
- st1b z0.b, p0, [dest, #0, mul vl]
- st1b z1.b, p1, [dest, #1, mul vl]
- st1b z2.b, p2, [dest, #2, mul vl]
- st1b z3.b, p3, [dest, #3, mul vl]
- st1b z4.b, p4, [dest, #4, mul vl]
- st1b z5.b, p5, [dest, #5, mul vl]
- ret
-1: lsl tmp1, vector_length, 2 // vector_length * 4
- incb tmp1 // vector_length * 5
- incb tmp1 // vector_length * 6
- whilelo p6.b, tmp1, n
- incb tmp1
- whilelo p7.b, tmp1, n
- ld1b z0.b, p0/z, [src, #0, mul vl]
- ld1b z1.b, p1/z, [src, #1, mul vl]
- ld1b z2.b, p2/z, [src, #2, mul vl]
- ld1b z3.b, p3/z, [src, #3, mul vl]
- ld1b z4.b, p4/z, [src, #4, mul vl]
- ld1b z5.b, p5/z, [src, #5, mul vl]
- ld1b z6.b, p6/z, [src, #6, mul vl]
- ld1b z7.b, p7/z, [src, #7, mul vl]
- st1b z0.b, p0, [dest, #0, mul vl]
- st1b z1.b, p1, [dest, #1, mul vl]
- st1b z2.b, p2, [dest, #2, mul vl]
- st1b z3.b, p3, [dest, #3, mul vl]
- st1b z4.b, p4, [dest, #4, mul vl]
- st1b z5.b, p5, [dest, #5, mul vl]
- st1b z6.b, p6, [dest, #6, mul vl]
- st1b z7.b, p7, [dest, #7, mul vl]
- ret
- .endm
+#undef BTI_C
+#define BTI_C
ENTRY (MEMCPY)
@@ -182,223 +100,209 @@ ENTRY (MEMCPY)
PTR_ARG (1)
SIZE_ARG (2)
-L(memcpy):
- cntb vector_length
- // shortcut for less than vector_length * 8
- // gives a free ptrue to p0.b for n >= vector_length
- shortcut_for_small_size L(vl_agnostic)
- // end of shortcut
-
-L(vl_agnostic): // VL Agnostic
- mov rest, n
- mov dest_ptr, dest
- mov src_ptr, src
- // if rest >= L2_SIZE && vector_length == 64 then L(L2)
- mov tmp1, 64
- cmp rest, L2_SIZE
- ccmp vector_length, tmp1, 0, cs
- b.eq L(L2)
-
-L(unroll8): // unrolling and software pipeline
- lsl tmp1, vector_length, 3 // vector_length * 8
- .p2align 3
- cmp rest, tmp1
- b.cc L(last)
+ cntb vlen
+ cmp n, vlen, lsl 1
+ b.hi L(copy_small)
+ whilelo p1.b, vlen, n
+ whilelo p0.b, xzr, n
+ ld1b z0.b, p0/z, [src, 0, mul vl]
+ ld1b z1.b, p1/z, [src, 1, mul vl]
+ st1b z0.b, p0, [dstin, 0, mul vl]
+ st1b z1.b, p1, [dstin, 1, mul vl]
+ ret
+
+ .p2align 4
+
+L(copy_small):
+ cmp n, vlen, lsl 3
+ b.hi L(copy_large)
+ add dstend, dstin, n
+ add srcend, src, n
+ cmp n, vlen, lsl 2
+ b.hi 1f
+
+ /* Copy 2-4 vectors. */
+ ptrue p0.b
+ ld1b z0.b, p0/z, [src, 0, mul vl]
+ ld1b z1.b, p0/z, [src, 1, mul vl]
+ ld1b z2.b, p0/z, [srcend, -2, mul vl]
+ ld1b z3.b, p0/z, [srcend, -1, mul vl]
+ st1b z0.b, p0, [dstin, 0, mul vl]
+ st1b z1.b, p0, [dstin, 1, mul vl]
+ st1b z2.b, p0, [dstend, -2, mul vl]
+ st1b z3.b, p0, [dstend, -1, mul vl]
+ ret
+
+ .p2align 4
+ /* Copy 4-8 vectors. */
+1: ptrue p0.b
+ ld1b z0.b, p0/z, [src, 0, mul vl]
+ ld1b z1.b, p0/z, [src, 1, mul vl]
+ ld1b z2.b, p0/z, [src, 2, mul vl]
+ ld1b z3.b, p0/z, [src, 3, mul vl]
+ ld1b z4.b, p0/z, [srcend, -4, mul vl]
+ ld1b z5.b, p0/z, [srcend, -3, mul vl]
+ ld1b z6.b, p0/z, [srcend, -2, mul vl]
+ ld1b z7.b, p0/z, [srcend, -1, mul vl]
+ st1b z0.b, p0, [dstin, 0, mul vl]
+ st1b z1.b, p0, [dstin, 1, mul vl]
+ st1b z2.b, p0, [dstin, 2, mul vl]
+ st1b z3.b, p0, [dstin, 3, mul vl]
+ st1b z4.b, p0, [dstend, -4, mul vl]
+ st1b z5.b, p0, [dstend, -3, mul vl]
+ st1b z6.b, p0, [dstend, -2, mul vl]
+ st1b z7.b, p0, [dstend, -1, mul vl]
+ ret
+
+ .p2align 4
+ /* At least 8 vectors - always align to vector length for
+ higher and consistent write performance. */
+L(copy_large):
+ sub tmp, vlen, 1
+ and tmp, dstin, tmp
+ sub tmp, vlen, tmp
+ whilelo p1.b, xzr, tmp
+ ld1b z1.b, p1/z, [src]
+ st1b z1.b, p1, [dstin]
+ add dst, dstin, tmp
+ add src, src, tmp
+ sub n, n, tmp
+ ptrue p0.b
+
+ lsl vlen8, vlen, 3
+ subs n, n, vlen8
+ b.ls 3f
ld1b_unroll8
- add src_ptr, src_ptr, tmp1
- sub rest, rest, tmp1
- cmp rest, tmp1
- b.cc 2f
- .p2align 3
+ add src, src, vlen8
+ subs n, n, vlen8
+ b.ls 2f
+
+ .p2align 4
+ /* 8x unrolled and software pipelined loop. */
1: stld1b_unroll8
- add dest_ptr, dest_ptr, tmp1
- add src_ptr, src_ptr, tmp1
- sub rest, rest, tmp1
- cmp rest, tmp1
- b.ge 1b
+ add dst, dst, vlen8
+ add src, src, vlen8
+ subs n, n, vlen8
+ b.hi 1b
2: st1b_unroll8
- add dest_ptr, dest_ptr, tmp1
-
- .p2align 3
-L(last):
- whilelo p0.b, xzr, rest
- whilelo p1.b, vector_length, rest
- b.last 1f
- ld1b z0.b, p0/z, [src_ptr, #0, mul vl]
- ld1b z1.b, p1/z, [src_ptr, #1, mul vl]
- st1b z0.b, p0, [dest_ptr, #0, mul vl]
- st1b z1.b, p1, [dest_ptr, #1, mul vl]
- ret
-1: lsl tmp1, vector_length, 1 // vector_length * 2
- whilelo p2.b, tmp1, rest
- incb tmp1
- whilelo p3.b, tmp1, rest
- b.last 1f
- ld1b z0.b, p0/z, [src_ptr, #0, mul vl]
- ld1b z1.b, p1/z, [src_ptr, #1, mul vl]
- ld1b z2.b, p2/z, [src_ptr, #2, mul vl]
- ld1b z3.b, p3/z, [src_ptr, #3, mul vl]
- st1b z0.b, p0, [dest_ptr, #0, mul vl]
- st1b z1.b, p1, [dest_ptr, #1, mul vl]
- st1b z2.b, p2, [dest_ptr, #2, mul vl]
- st1b z3.b, p3, [dest_ptr, #3, mul vl]
+ add dst, dst, vlen8
+3: add n, n, vlen8
+
+ /* Move last 0-8 vectors. */
+L(last_bytes):
+ cmp n, vlen, lsl 1
+ b.hi 1f
+ whilelo p0.b, xzr, n
+ whilelo p1.b, vlen, n
+ ld1b z0.b, p0/z, [src, 0, mul vl]
+ ld1b z1.b, p1/z, [src, 1, mul vl]
+ st1b z0.b, p0, [dst, 0, mul vl]
+ st1b z1.b, p1, [dst, 1, mul vl]
ret
-1: lsl tmp1, vector_length, 2 // vector_length * 4
- whilelo p4.b, tmp1, rest
- incb tmp1
- whilelo p5.b, tmp1, rest
- incb tmp1
- whilelo p6.b, tmp1, rest
- incb tmp1
- whilelo p7.b, tmp1, rest
- ld1b z0.b, p0/z, [src_ptr, #0, mul vl]
- ld1b z1.b, p1/z, [src_ptr, #1, mul vl]
- ld1b z2.b, p2/z, [src_ptr, #2, mul vl]
- ld1b z3.b, p3/z, [src_ptr, #3, mul vl]
- ld1b z4.b, p4/z, [src_ptr, #4, mul vl]
- ld1b z5.b, p5/z, [src_ptr, #5, mul vl]
- ld1b z6.b, p6/z, [src_ptr, #6, mul vl]
- ld1b z7.b, p7/z, [src_ptr, #7, mul vl]
- st1b z0.b, p0, [dest_ptr, #0, mul vl]
- st1b z1.b, p1, [dest_ptr, #1, mul vl]
- st1b z2.b, p2, [dest_ptr, #2, mul vl]
- st1b z3.b, p3, [dest_ptr, #3, mul vl]
- st1b z4.b, p4, [dest_ptr, #4, mul vl]
- st1b z5.b, p5, [dest_ptr, #5, mul vl]
- st1b z6.b, p6, [dest_ptr, #6, mul vl]
- st1b z7.b, p7, [dest_ptr, #7, mul vl]
+
+ .p2align 4
+
+1: add srcend, src, n
+ add dstend, dst, n
+ ld1b z0.b, p0/z, [src, 0, mul vl]
+ ld1b z1.b, p0/z, [src, 1, mul vl]
+ ld1b z2.b, p0/z, [srcend, -2, mul vl]
+ ld1b z3.b, p0/z, [srcend, -1, mul vl]
+ cmp n, vlen, lsl 2
+ b.hi 1f
+
+ st1b z0.b, p0, [dst, 0, mul vl]
+ st1b z1.b, p0, [dst, 1, mul vl]
+ st1b z2.b, p0, [dstend, -2, mul vl]
+ st1b z3.b, p0, [dstend, -1, mul vl]
ret
-L(L2):
- // align dest address at CACHE_LINE_SIZE byte boundary
- mov tmp1, CACHE_LINE_SIZE
- ands tmp2, dest_ptr, CACHE_LINE_SIZE - 1
- // if cl_remainder == 0
- b.eq L(L2_dc_zva)
- sub cl_remainder, tmp1, tmp2
- // process remainder until the first CACHE_LINE_SIZE boundary
- whilelo p1.b, xzr, cl_remainder // keep p0.b all true
- whilelo p2.b, vector_length, cl_remainder
- b.last 1f
- ld1b z1.b, p1/z, [src_ptr, #0, mul vl]
- ld1b z2.b, p2/z, [src_ptr, #1, mul vl]
- st1b z1.b, p1, [dest_ptr, #0, mul vl]
- st1b z2.b, p2, [dest_ptr, #1, mul vl]
- b 2f
-1: lsl tmp1, vector_length, 1 // vector_length * 2
- whilelo p3.b, tmp1, cl_remainder
- incb tmp1
- whilelo p4.b, tmp1, cl_remainder
- ld1b z1.b, p1/z, [src_ptr, #0, mul vl]
- ld1b z2.b, p2/z, [src_ptr, #1, mul vl]
- ld1b z3.b, p3/z, [src_ptr, #2, mul vl]
- ld1b z4.b, p4/z, [src_ptr, #3, mul vl]
- st1b z1.b, p1, [dest_ptr, #0, mul vl]
- st1b z2.b, p2, [dest_ptr, #1, mul vl]
- st1b z3.b, p3, [dest_ptr, #2, mul vl]
- st1b z4.b, p4, [dest_ptr, #3, mul vl]
-2: add dest_ptr, dest_ptr, cl_remainder
- add src_ptr, src_ptr, cl_remainder
- sub rest, rest, cl_remainder
-
-L(L2_dc_zva):
- // zero fill
- and tmp1, dest, 0xffffffffffffff
- and tmp2, src, 0xffffffffffffff
- subs tmp1, tmp1, tmp2 // diff
- b.ge 1f
- neg tmp1, tmp1
-1: mov tmp3, ZF_DIST + CACHE_LINE_SIZE * 2
- cmp tmp1, tmp3
- b.lo L(unroll8)
- mov tmp1, dest_ptr
- dc_zva (ZF_DIST / CACHE_LINE_SIZE) - 1
- // unroll
- ld1b_unroll8 // this line has to be after "b.lo L(unroll8)"
- add src_ptr, src_ptr, CACHE_LINE_SIZE * 2
- sub rest, rest, CACHE_LINE_SIZE * 2
- mov tmp1, ZF_DIST
- .p2align 3
-1: stld1b_unroll4a
- add tmp2, dest_ptr, tmp1 // dest_ptr + ZF_DIST
- dc zva, tmp2
- stld1b_unroll4b
- add tmp2, tmp2, CACHE_LINE_SIZE
- dc zva, tmp2
- add dest_ptr, dest_ptr, CACHE_LINE_SIZE * 2
- add src_ptr, src_ptr, CACHE_LINE_SIZE * 2
- sub rest, rest, CACHE_LINE_SIZE * 2
- cmp rest, tmp3 // ZF_DIST + CACHE_LINE_SIZE * 2
- b.ge 1b
- st1b_unroll8
- add dest_ptr, dest_ptr, CACHE_LINE_SIZE * 2
- b L(unroll8)
+1: ld1b z4.b, p0/z, [src, 2, mul vl]
+ ld1b z5.b, p0/z, [src, 3, mul vl]
+ ld1b z6.b, p0/z, [srcend, -4, mul vl]
+ ld1b z7.b, p0/z, [srcend, -3, mul vl]
+ st1b z0.b, p0, [dst, 0, mul vl]
+ st1b z1.b, p0, [dst, 1, mul vl]
+ st1b z4.b, p0, [dst, 2, mul vl]
+ st1b z5.b, p0, [dst, 3, mul vl]
+ st1b z6.b, p0, [dstend, -4, mul vl]
+ st1b z7.b, p0, [dstend, -3, mul vl]
+ st1b z2.b, p0, [dstend, -2, mul vl]
+ st1b z3.b, p0, [dstend, -1, mul vl]
+ ret
END (MEMCPY)
libc_hidden_builtin_def (MEMCPY)
-ENTRY (MEMMOVE)
+ENTRY_ALIGN (MEMMOVE, 4)
PTR_ARG (0)
PTR_ARG (1)
SIZE_ARG (2)
- // remove tag address
- // dest has to be immutable because it is the return value
- // src has to be immutable because it is used in L(bwd_last)
- and tmp2, dest, 0xffffffffffffff // save dest_notag into tmp2
- and tmp3, src, 0xffffffffffffff // save src_notag intp tmp3
- cmp n, 0
- ccmp tmp2, tmp3, 4, ne
- b.ne 1f
+ /* Fast case for up to 2 vectors. */
+ cntb vlen
+ cmp n, vlen, lsl 1
+ b.hi 1f
+ whilelo p0.b, xzr, n
+ whilelo p1.b, vlen, n
+ ld1b z0.b, p0/z, [src, 0, mul vl]
+ ld1b z1.b, p1/z, [src, 1, mul vl]
+ st1b z0.b, p0, [dstin, 0, mul vl]
+ st1b z1.b, p1, [dstin, 1, mul vl]
+L(full_overlap):
ret
-1: cntb vector_length
- // shortcut for less than vector_length * 8
- // gives a free ptrue to p0.b for n >= vector_length
- // tmp2 and tmp3 should not be used in this macro to keep
- // notag addresses
- shortcut_for_small_size L(dispatch)
- // end of shortcut
-
-L(dispatch):
- // tmp2 = dest_notag, tmp3 = src_notag
- // diff = dest_notag - src_notag
- sub tmp1, tmp2, tmp3
- // if diff <= 0 || diff >= n then memcpy
- cmp tmp1, 0
- ccmp tmp1, n, 2, gt
- b.cs L(vl_agnostic)
-
-L(bwd_start):
- mov rest, n
- add dest_ptr, dest, n // dest_end
- add src_ptr, src, n // src_end
-
-L(bwd_unroll8): // unrolling and software pipeline
- lsl tmp1, vector_length, 3 // vector_length * 8
- .p2align 3
- cmp rest, tmp1
- b.cc L(bwd_last)
- sub src_ptr, src_ptr, tmp1
+
+ .p2align 4
+ /* Check for overlapping moves. Return if there is a full overlap.
+ Small moves up to 8 vectors use the overlap-safe copy_small code.
+ Non-overlapping or overlapping moves with dst < src use memcpy.
+ Overlapping moves with dst > src use a backward copy loop. */
+1: sub tmp, dstin, src
+ ands tmp, tmp, 0xffffffffffffff /* Clear special tag bits. */
+ b.eq L(full_overlap)
+ cmp n, vlen, lsl 3
+ b.ls L(copy_small)
+ cmp tmp, n
+ b.hs L(copy_large)
+
+ /* Align to vector length. */
+ add dst, dstin, n
+ sub tmp, vlen, 1
+ ands tmp, dst, tmp
+ csel tmp, tmp, vlen, ne
+ whilelo p1.b, xzr, tmp
+ sub n, n, tmp
+ ld1b z1.b, p1/z, [src, n]
+ st1b z1.b, p1, [dstin, n]
+ add src, src, n
+ add dst, dstin, n
+
+ ptrue p0.b
+ lsl vlen8, vlen, 3
+ subs n, n, vlen8
+ b.ls 3f
+ sub src, src, vlen8
ld1b_unroll8
- sub rest, rest, tmp1
- cmp rest, tmp1
- b.cc 2f
- .p2align 3
-1: sub src_ptr, src_ptr, tmp1
- sub dest_ptr, dest_ptr, tmp1
+ subs n, n, vlen8
+ b.ls 2f
+
+ .p2align 4
+ /* 8x unrolled and software pipelined backward copy loop. */
+1: sub src, src, vlen8
+ sub dst, dst, vlen8
stld1b_unroll8
- sub rest, rest, tmp1
- cmp rest, tmp1
- b.ge 1b
-2: sub dest_ptr, dest_ptr, tmp1
+ subs n, n, vlen8
+ b.hi 1b
+2: sub dst, dst, vlen8
st1b_unroll8
+3: add n, n, vlen8
-L(bwd_last):
- mov dest_ptr, dest
- mov src_ptr, src
- b L(last)
+ /* Adjust src/dst for last 0-8 vectors. */
+ sub src, src, n
+ mov dst, dstin
+ b L(last_bytes)
END (MEMMOVE)
libc_hidden_builtin_def (MEMMOVE)