diff options
Diffstat (limited to '')
-rw-r--r-- | arch/sh/lib/memcpy-sh4.S | 800 |
1 files changed, 800 insertions, 0 deletions
diff --git a/arch/sh/lib/memcpy-sh4.S b/arch/sh/lib/memcpy-sh4.S new file mode 100644 index 000000000..a2435c0f6 --- /dev/null +++ b/arch/sh/lib/memcpy-sh4.S @@ -0,0 +1,800 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * "memcpy" implementation of SuperH + * + * Copyright (C) 1999 Niibe Yutaka + * Copyright (c) 2002 STMicroelectronics Ltd + * Modified from memcpy.S and micro-optimised for SH4 + * Stuart Menefy (stuart.menefy@st.com) + * + */ +#include <linux/linkage.h> + +/* + * void *memcpy(void *dst, const void *src, size_t n); + * + * It is assumed that there is no overlap between src and dst. + * If there is an overlap, then the results are undefined. + */ + + ! + ! GHIJ KLMN OPQR --> ...G HIJK LMNO PQR. + ! + + ! Size is 16 or greater, and may have trailing bytes + + .balign 32 +.Lcase1: + ! Read a long word and write a long word at once + ! At the start of each iteration, r7 contains last long load + add #-1,r5 ! 79 EX + mov r4,r2 ! 5 MT (0 cycles latency) + + mov.l @(r0,r5),r7 ! 21 LS (2 cycles latency) + add #-4,r5 ! 50 EX + + add #7,r2 ! 79 EX + ! +#ifdef CONFIG_CPU_LITTLE_ENDIAN + ! 6 cycles, 4 bytes per iteration +3: mov.l @(r0,r5),r1 ! 21 LS (latency=2) ! NMLK + mov r7, r3 ! 5 MT (latency=0) ! RQPO + + cmp/hi r2,r0 ! 57 MT + shll16 r3 ! 103 EX + + mov r1,r6 ! 5 MT (latency=0) + shll8 r3 ! 102 EX ! Oxxx + + shlr8 r6 ! 106 EX ! xNML + mov r1, r7 ! 5 MT (latency=0) + + or r6,r3 ! 82 EX ! ONML + bt/s 3b ! 109 BR + + mov.l r3,@-r0 ! 30 LS +#else +3: mov.l @(r0,r5),r1 ! 21 LS (latency=2) ! KLMN + mov r7,r3 ! 5 MT (latency=0) ! OPQR + + cmp/hi r2,r0 ! 57 MT + shlr16 r3 ! 107 EX + + shlr8 r3 ! 106 EX ! xxxO + mov r1,r6 ! 5 MT (latency=0) + + shll8 r6 ! 102 EX ! LMNx + mov r1,r7 ! 5 MT (latency=0) + + or r6,r3 ! 82 EX ! LMNO + bt/s 3b ! 109 BR + + mov.l r3,@-r0 ! 30 LS +#endif + ! Finally, copy a byte at once, if necessary + + add #4,r5 ! 50 EX + cmp/eq r4,r0 ! 54 MT + + add #-6,r2 ! 50 EX + bt 9f ! 109 BR + +8: cmp/hi r2,r0 ! 57 MT + mov.b @(r0,r5),r1 ! 20 LS (latency=2) + + bt/s 8b ! 109 BR + + mov.b r1,@-r0 ! 29 LS + +9: rts + nop + + + ! + ! GHIJ KLMN OPQR --> .GHI JKLM NOPQ R... + ! + + ! Size is 16 or greater, and may have trailing bytes + + .balign 32 +.Lcase3: + ! Read a long word and write a long word at once + ! At the start of each iteration, r7 contains last long load + add #-3,r5 ! 79 EX + mov r4,r2 ! 5 MT (0 cycles latency) + + mov.l @(r0,r5),r7 ! 21 LS (2 cycles latency) + add #-4,r5 ! 50 EX + + add #7,r2 ! 79 EX + ! +#ifdef CONFIG_CPU_LITTLE_ENDIAN + ! 6 cycles, 4 bytes per iteration +3: mov.l @(r0,r5),r1 ! 21 LS (latency=2) ! NMLK + mov r7, r3 ! 5 MT (latency=0) ! RQPO + + cmp/hi r2,r0 ! 57 MT + shll8 r3 ! 102 EX ! QPOx + + mov r1,r6 ! 5 MT (latency=0) + shlr16 r6 ! 107 EX + + shlr8 r6 ! 106 EX ! xxxN + mov r1, r7 ! 5 MT (latency=0) + + or r6,r3 ! 82 EX ! QPON + bt/s 3b ! 109 BR + + mov.l r3,@-r0 ! 30 LS +#else +3: mov r7,r3 ! OPQR + shlr8 r3 ! xOPQ + mov.l @(r0,r5),r7 ! KLMN + mov r7,r6 + shll16 r6 + shll8 r6 ! Nxxx + or r6,r3 ! NOPQ + cmp/hi r2,r0 + bt/s 3b + mov.l r3,@-r0 +#endif + + ! Finally, copy a byte at once, if necessary + + add #6,r5 ! 50 EX + cmp/eq r4,r0 ! 54 MT + + add #-6,r2 ! 50 EX + bt 9f ! 109 BR + +8: cmp/hi r2,r0 ! 57 MT + mov.b @(r0,r5),r1 ! 20 LS (latency=2) + + bt/s 8b ! 109 BR + + mov.b r1,@-r0 ! 29 LS + +9: rts + nop + +ENTRY(memcpy) + + ! Calculate the invariants which will be used in the remainder + ! of the code: + ! + ! r4 --> [ ... ] DST [ ... ] SRC + ! [ ... ] [ ... ] + ! : : + ! r0 --> [ ... ] r0+r5 --> [ ... ] + ! + ! + + ! Short circuit the common case of src, dst and len being 32 bit aligned + ! and test for zero length move + + mov r6, r0 ! 5 MT (0 cycle latency) + or r4, r0 ! 82 EX + + or r5, r0 ! 82 EX + tst r6, r6 ! 86 MT + + bt/s 99f ! 111 BR (zero len) + tst #3, r0 ! 87 MT + + mov r4, r0 ! 5 MT (0 cycle latency) + add r6, r0 ! 49 EX + + mov #16, r1 ! 6 EX + bt/s .Lcase00 ! 111 BR (aligned) + + sub r4, r5 ! 75 EX + + ! Arguments are not nicely long word aligned or zero len. + ! Check for small copies, and if so do a simple byte at a time copy. + ! + ! Deciding on an exact value of 'small' is not easy, as the point at which + ! using the optimised routines become worthwhile varies (these are the + ! cycle counts for differnet sizes using byte-at-a-time vs. optimised): + ! size byte-at-time long word byte + ! 16 42 39-40 46-50 50-55 + ! 24 58 43-44 54-58 62-67 + ! 36 82 49-50 66-70 80-85 + ! However the penalty for getting it 'wrong' is much higher for long word + ! aligned data (and this is more common), so use a value of 16. + + cmp/gt r6,r1 ! 56 MT + + add #-1,r5 ! 50 EX + bf/s 6f ! 108 BR (not small) + + mov r5, r3 ! 5 MT (latency=0) + shlr r6 ! 104 EX + + mov.b @(r0,r5),r1 ! 20 LS (latency=2) + bf/s 4f ! 111 BR + + add #-1,r3 ! 50 EX + tst r6, r6 ! 86 MT + + bt/s 98f ! 110 BR + mov.b r1,@-r0 ! 29 LS + + ! 4 cycles, 2 bytes per iteration +3: mov.b @(r0,r5),r1 ! 20 LS (latency=2) + +4: mov.b @(r0,r3),r2 ! 20 LS (latency=2) + dt r6 ! 67 EX + + mov.b r1,@-r0 ! 29 LS + bf/s 3b ! 111 BR + + mov.b r2,@-r0 ! 29 LS +98: + rts + nop + +99: rts + mov r4, r0 + + ! Size is not small, so its worthwhile looking for optimisations. + ! First align destination to a long word boundary. + ! + ! r5 = normal value -1 + +6: tst #3, r0 ! 87 MT + mov #3, r3 ! 6 EX + + bt/s 2f ! 111 BR + and r0,r3 ! 78 EX + + ! 3 cycles, 1 byte per iteration +1: dt r3 ! 67 EX + mov.b @(r0,r5),r1 ! 19 LS (latency=2) + + add #-1, r6 ! 79 EX + bf/s 1b ! 109 BR + + mov.b r1,@-r0 ! 28 LS + +2: add #1, r5 ! 79 EX + + ! Now select the appropriate bulk transfer code based on relative + ! alignment of src and dst. + + mov r0, r3 ! 5 MT (latency=0) + + mov r5, r0 ! 5 MT (latency=0) + tst #1, r0 ! 87 MT + + bf/s 1f ! 111 BR + mov #64, r7 ! 6 EX + + ! bit 0 clear + + cmp/ge r7, r6 ! 55 MT + + bt/s 2f ! 111 BR + tst #2, r0 ! 87 MT + + ! small + bt/s .Lcase0 + mov r3, r0 + + bra .Lcase2 + nop + + ! big +2: bt/s .Lcase0b + mov r3, r0 + + bra .Lcase2b + nop + + ! bit 0 set +1: tst #2, r0 ! 87 MT + + bt/s .Lcase1 + mov r3, r0 + + bra .Lcase3 + nop + + + ! + ! GHIJ KLMN OPQR --> GHIJ KLMN OPQR + ! + + ! src, dst and size are all long word aligned + ! size is non-zero + + .balign 32 +.Lcase00: + mov #64, r1 ! 6 EX + mov r5, r3 ! 5 MT (latency=0) + + cmp/gt r6, r1 ! 56 MT + add #-4, r5 ! 50 EX + + bf .Lcase00b ! 108 BR (big loop) + shlr2 r6 ! 105 EX + + shlr r6 ! 104 EX + mov.l @(r0, r5), r1 ! 21 LS (latency=2) + + bf/s 4f ! 111 BR + add #-8, r3 ! 50 EX + + tst r6, r6 ! 86 MT + bt/s 5f ! 110 BR + + mov.l r1,@-r0 ! 30 LS + + ! 4 cycles, 2 long words per iteration +3: mov.l @(r0, r5), r1 ! 21 LS (latency=2) + +4: mov.l @(r0, r3), r2 ! 21 LS (latency=2) + dt r6 ! 67 EX + + mov.l r1, @-r0 ! 30 LS + bf/s 3b ! 109 BR + + mov.l r2, @-r0 ! 30 LS + +5: rts + nop + + + ! Size is 16 or greater and less than 64, but may have trailing bytes + + .balign 32 +.Lcase0: + add #-4, r5 ! 50 EX + mov r4, r7 ! 5 MT (latency=0) + + mov.l @(r0, r5), r1 ! 21 LS (latency=2) + mov #4, r2 ! 6 EX + + add #11, r7 ! 50 EX + tst r2, r6 ! 86 MT + + mov r5, r3 ! 5 MT (latency=0) + bt/s 4f ! 111 BR + + add #-4, r3 ! 50 EX + mov.l r1,@-r0 ! 30 LS + + ! 4 cycles, 2 long words per iteration +3: mov.l @(r0, r5), r1 ! 21 LS (latency=2) + +4: mov.l @(r0, r3), r2 ! 21 LS (latency=2) + cmp/hi r7, r0 + + mov.l r1, @-r0 ! 30 LS + bt/s 3b ! 109 BR + + mov.l r2, @-r0 ! 30 LS + + ! Copy the final 0-3 bytes + + add #3,r5 ! 50 EX + + cmp/eq r0, r4 ! 54 MT + add #-10, r7 ! 50 EX + + bt 9f ! 110 BR + + ! 3 cycles, 1 byte per iteration +1: mov.b @(r0,r5),r1 ! 19 LS + cmp/hi r7,r0 ! 57 MT + + bt/s 1b ! 111 BR + mov.b r1,@-r0 ! 28 LS + +9: rts + nop + + ! Size is at least 64 bytes, so will be going round the big loop at least once. + ! + ! r2 = rounded up r4 + ! r3 = rounded down r0 + + .balign 32 +.Lcase0b: + add #-4, r5 ! 50 EX + +.Lcase00b: + mov r0, r3 ! 5 MT (latency=0) + mov #(~0x1f), r1 ! 6 EX + + and r1, r3 ! 78 EX + mov r4, r2 ! 5 MT (latency=0) + + cmp/eq r3, r0 ! 54 MT + add #0x1f, r2 ! 50 EX + + bt/s 1f ! 110 BR + and r1, r2 ! 78 EX + + ! copy initial words until cache line aligned + + mov.l @(r0, r5), r1 ! 21 LS (latency=2) + tst #4, r0 ! 87 MT + + mov r5, r6 ! 5 MT (latency=0) + add #-4, r6 ! 50 EX + + bt/s 4f ! 111 BR + add #8, r3 ! 50 EX + + tst #0x18, r0 ! 87 MT + + bt/s 1f ! 109 BR + mov.l r1,@-r0 ! 30 LS + + ! 4 cycles, 2 long words per iteration +3: mov.l @(r0, r5), r1 ! 21 LS (latency=2) + +4: mov.l @(r0, r6), r7 ! 21 LS (latency=2) + cmp/eq r3, r0 ! 54 MT + + mov.l r1, @-r0 ! 30 LS + bf/s 3b ! 109 BR + + mov.l r7, @-r0 ! 30 LS + + ! Copy the cache line aligned blocks + ! + ! In use: r0, r2, r4, r5 + ! Scratch: r1, r3, r6, r7 + ! + ! We could do this with the four scratch registers, but if src + ! and dest hit the same cache line, this will thrash, so make + ! use of additional registers. + ! + ! We also need r0 as a temporary (for movca), so 'undo' the invariant: + ! r5: src (was r0+r5) + ! r1: dest (was r0) + ! this can be reversed at the end, so we don't need to save any extra + ! state. + ! +1: mov.l r8, @-r15 ! 30 LS + add r0, r5 ! 49 EX + + mov.l r9, @-r15 ! 30 LS + mov r0, r1 ! 5 MT (latency=0) + + mov.l r10, @-r15 ! 30 LS + add #-0x1c, r5 ! 50 EX + + mov.l r11, @-r15 ! 30 LS + + ! 16 cycles, 32 bytes per iteration +2: mov.l @(0x00,r5),r0 ! 18 LS (latency=2) + add #-0x20, r1 ! 50 EX + mov.l @(0x04,r5),r3 ! 18 LS (latency=2) + mov.l @(0x08,r5),r6 ! 18 LS (latency=2) + mov.l @(0x0c,r5),r7 ! 18 LS (latency=2) + mov.l @(0x10,r5),r8 ! 18 LS (latency=2) + mov.l @(0x14,r5),r9 ! 18 LS (latency=2) + mov.l @(0x18,r5),r10 ! 18 LS (latency=2) + mov.l @(0x1c,r5),r11 ! 18 LS (latency=2) + movca.l r0,@r1 ! 40 LS (latency=3-7) + mov.l r3,@(0x04,r1) ! 33 LS + mov.l r6,@(0x08,r1) ! 33 LS + mov.l r7,@(0x0c,r1) ! 33 LS + + mov.l r8,@(0x10,r1) ! 33 LS + add #-0x20, r5 ! 50 EX + + mov.l r9,@(0x14,r1) ! 33 LS + cmp/eq r2,r1 ! 54 MT + + mov.l r10,@(0x18,r1) ! 33 LS + bf/s 2b ! 109 BR + + mov.l r11,@(0x1c,r1) ! 33 LS + + mov r1, r0 ! 5 MT (latency=0) + + mov.l @r15+, r11 ! 15 LS + sub r1, r5 ! 75 EX + + mov.l @r15+, r10 ! 15 LS + cmp/eq r4, r0 ! 54 MT + + bf/s 1f ! 109 BR + mov.l @r15+, r9 ! 15 LS + + rts +1: mov.l @r15+, r8 ! 15 LS + sub r4, r1 ! 75 EX (len remaining) + + ! number of trailing bytes is non-zero + ! + ! invariants restored (r5 already decremented by 4) + ! also r1=num bytes remaining + + mov #4, r2 ! 6 EX + mov r4, r7 ! 5 MT (latency=0) + + add #0x1c, r5 ! 50 EX (back to -4) + cmp/hs r2, r1 ! 58 MT + + bf/s 5f ! 108 BR + add #11, r7 ! 50 EX + + mov.l @(r0, r5), r6 ! 21 LS (latency=2) + tst r2, r1 ! 86 MT + + mov r5, r3 ! 5 MT (latency=0) + bt/s 4f ! 111 BR + + add #-4, r3 ! 50 EX + cmp/hs r2, r1 ! 58 MT + + bt/s 5f ! 111 BR + mov.l r6,@-r0 ! 30 LS + + ! 4 cycles, 2 long words per iteration +3: mov.l @(r0, r5), r6 ! 21 LS (latency=2) + +4: mov.l @(r0, r3), r2 ! 21 LS (latency=2) + cmp/hi r7, r0 + + mov.l r6, @-r0 ! 30 LS + bt/s 3b ! 109 BR + + mov.l r2, @-r0 ! 30 LS + + ! Copy the final 0-3 bytes + +5: cmp/eq r0, r4 ! 54 MT + add #-10, r7 ! 50 EX + + bt 9f ! 110 BR + add #3,r5 ! 50 EX + + ! 3 cycles, 1 byte per iteration +1: mov.b @(r0,r5),r1 ! 19 LS + cmp/hi r7,r0 ! 57 MT + + bt/s 1b ! 111 BR + mov.b r1,@-r0 ! 28 LS + +9: rts + nop + + ! + ! GHIJ KLMN OPQR --> ..GH IJKL MNOP QR.. + ! + + .balign 32 +.Lcase2: + ! Size is 16 or greater and less then 64, but may have trailing bytes + +2: mov r5, r6 ! 5 MT (latency=0) + add #-2,r5 ! 50 EX + + mov r4,r2 ! 5 MT (latency=0) + add #-4,r6 ! 50 EX + + add #7,r2 ! 50 EX +3: mov.w @(r0,r5),r1 ! 20 LS (latency=2) + + mov.w @(r0,r6),r3 ! 20 LS (latency=2) + cmp/hi r2,r0 ! 57 MT + + mov.w r1,@-r0 ! 29 LS + bt/s 3b ! 111 BR + + mov.w r3,@-r0 ! 29 LS + + bra 10f + nop + + + .balign 32 +.Lcase2b: + ! Size is at least 64 bytes, so will be going round the big loop at least once. + ! + ! r2 = rounded up r4 + ! r3 = rounded down r0 + + mov r0, r3 ! 5 MT (latency=0) + mov #(~0x1f), r1 ! 6 EX + + and r1, r3 ! 78 EX + mov r4, r2 ! 5 MT (latency=0) + + cmp/eq r3, r0 ! 54 MT + add #0x1f, r2 ! 50 EX + + add #-2, r5 ! 50 EX + bt/s 1f ! 110 BR + and r1, r2 ! 78 EX + + ! Copy a short word one at a time until we are cache line aligned + ! Normal values: r0, r2, r3, r4 + ! Unused: r1, r6, r7 + ! Mod: r5 (=r5-2) + ! + add #2, r3 ! 50 EX + +2: mov.w @(r0,r5),r1 ! 20 LS (latency=2) + cmp/eq r3,r0 ! 54 MT + + bf/s 2b ! 111 BR + + mov.w r1,@-r0 ! 29 LS + + ! Copy the cache line aligned blocks + ! + ! In use: r0, r2, r4, r5 (=r5-2) + ! Scratch: r1, r3, r6, r7 + ! + ! We could do this with the four scratch registers, but if src + ! and dest hit the same cache line, this will thrash, so make + ! use of additional registers. + ! + ! We also need r0 as a temporary (for movca), so 'undo' the invariant: + ! r5: src (was r0+r5) + ! r1: dest (was r0) + ! this can be reversed at the end, so we don't need to save any extra + ! state. + ! +1: mov.l r8, @-r15 ! 30 LS + add r0, r5 ! 49 EX + + mov.l r9, @-r15 ! 30 LS + mov r0, r1 ! 5 MT (latency=0) + + mov.l r10, @-r15 ! 30 LS + add #-0x1e, r5 ! 50 EX + + mov.l r11, @-r15 ! 30 LS + + mov.l r12, @-r15 ! 30 LS + + ! 17 cycles, 32 bytes per iteration +#ifdef CONFIG_CPU_LITTLE_ENDIAN +2: mov.w @r5+, r0 ! 14 LS (latency=2) ..JI + add #-0x20, r1 ! 50 EX + + mov.l @r5+, r3 ! 15 LS (latency=2) NMLK + + mov.l @r5+, r6 ! 15 LS (latency=2) RQPO + shll16 r0 ! 103 EX JI.. + + mov.l @r5+, r7 ! 15 LS (latency=2) + xtrct r3, r0 ! 48 EX LKJI + + mov.l @r5+, r8 ! 15 LS (latency=2) + xtrct r6, r3 ! 48 EX PONM + + mov.l @r5+, r9 ! 15 LS (latency=2) + xtrct r7, r6 ! 48 EX + + mov.l @r5+, r10 ! 15 LS (latency=2) + xtrct r8, r7 ! 48 EX + + mov.l @r5+, r11 ! 15 LS (latency=2) + xtrct r9, r8 ! 48 EX + + mov.w @r5+, r12 ! 15 LS (latency=2) + xtrct r10, r9 ! 48 EX + + movca.l r0,@r1 ! 40 LS (latency=3-7) + xtrct r11, r10 ! 48 EX + + mov.l r3, @(0x04,r1) ! 33 LS + xtrct r12, r11 ! 48 EX + + mov.l r6, @(0x08,r1) ! 33 LS + + mov.l r7, @(0x0c,r1) ! 33 LS + + mov.l r8, @(0x10,r1) ! 33 LS + add #-0x40, r5 ! 50 EX + + mov.l r9, @(0x14,r1) ! 33 LS + cmp/eq r2,r1 ! 54 MT + + mov.l r10, @(0x18,r1) ! 33 LS + bf/s 2b ! 109 BR + + mov.l r11, @(0x1c,r1) ! 33 LS +#else +2: mov.w @(0x1e,r5), r0 ! 17 LS (latency=2) + add #-2, r5 ! 50 EX + + mov.l @(0x1c,r5), r3 ! 18 LS (latency=2) + add #-4, r1 ! 50 EX + + mov.l @(0x18,r5), r6 ! 18 LS (latency=2) + shll16 r0 ! 103 EX + + mov.l @(0x14,r5), r7 ! 18 LS (latency=2) + xtrct r3, r0 ! 48 EX + + mov.l @(0x10,r5), r8 ! 18 LS (latency=2) + xtrct r6, r3 ! 48 EX + + mov.l @(0x0c,r5), r9 ! 18 LS (latency=2) + xtrct r7, r6 ! 48 EX + + mov.l @(0x08,r5), r10 ! 18 LS (latency=2) + xtrct r8, r7 ! 48 EX + + mov.l @(0x04,r5), r11 ! 18 LS (latency=2) + xtrct r9, r8 ! 48 EX + + mov.l @(0x00,r5), r12 ! 18 LS (latency=2) + xtrct r10, r9 ! 48 EX + + movca.l r0,@r1 ! 40 LS (latency=3-7) + add #-0x1c, r1 ! 50 EX + + mov.l r3, @(0x18,r1) ! 33 LS + xtrct r11, r10 ! 48 EX + + mov.l r6, @(0x14,r1) ! 33 LS + xtrct r12, r11 ! 48 EX + + mov.l r7, @(0x10,r1) ! 33 LS + + mov.l r8, @(0x0c,r1) ! 33 LS + add #-0x1e, r5 ! 50 EX + + mov.l r9, @(0x08,r1) ! 33 LS + cmp/eq r2,r1 ! 54 MT + + mov.l r10, @(0x04,r1) ! 33 LS + bf/s 2b ! 109 BR + + mov.l r11, @(0x00,r1) ! 33 LS +#endif + + mov.l @r15+, r12 + mov r1, r0 ! 5 MT (latency=0) + + mov.l @r15+, r11 ! 15 LS + sub r1, r5 ! 75 EX + + mov.l @r15+, r10 ! 15 LS + cmp/eq r4, r0 ! 54 MT + + bf/s 1f ! 109 BR + mov.l @r15+, r9 ! 15 LS + + rts +1: mov.l @r15+, r8 ! 15 LS + + add #0x1e, r5 ! 50 EX + + ! Finish off a short word at a time + ! r5 must be invariant - 2 +10: mov r4,r2 ! 5 MT (latency=0) + add #1,r2 ! 50 EX + + cmp/hi r2, r0 ! 57 MT + bf/s 1f ! 109 BR + + add #2, r2 ! 50 EX + +3: mov.w @(r0,r5),r1 ! 20 LS + cmp/hi r2,r0 ! 57 MT + + bt/s 3b ! 109 BR + + mov.w r1,@-r0 ! 29 LS +1: + + ! + ! Finally, copy the last byte if necessary + cmp/eq r4,r0 ! 54 MT + bt/s 9b + add #1,r5 + mov.b @(r0,r5),r1 + rts + mov.b r1,@-r0 + |