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Editing: memmove_riscv64.s
// Copyright 2016 The Go Authors. All rights reserved. // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. #include "textflag.h" // See memmove Go doc for important implementation constraints. // void runtime·memmove(void*, void*, uintptr) TEXT runtime·memmove<ABIInternal>(SB),NOSPLIT,$-0-24 // X10 = to // X11 = from // X12 = n BEQ X10, X11, done BEQZ X12, done // If the destination is ahead of the source, start at the end of the // buffer and go backward. BGTU X10, X11, backward // If less than 8 bytes, do single byte copies. MOV $8, X9 BLT X12, X9, f_loop4_check // Check alignment - if alignment differs we have to do one byte at a time. AND $7, X10, X5 AND $7, X11, X6 BNE X5, X6, f_loop8_unaligned_check BEQZ X5, f_loop_check // Move one byte at a time until we reach 8 byte alignment. SUB X5, X9, X5 SUB X5, X12, X12 f_align: SUB $1, X5 MOVB 0(X11), X14 MOVB X14, 0(X10) ADD $1, X10 ADD $1, X11 BNEZ X5, f_align f_loop_check: MOV $16, X9 BLT X12, X9, f_loop8_check MOV $32, X9 BLT X12, X9, f_loop16_check MOV $64, X9 BLT X12, X9, f_loop32_check f_loop64: MOV 0(X11), X14 MOV 8(X11), X15 MOV 16(X11), X16 MOV 24(X11), X17 MOV 32(X11), X18 MOV 40(X11), X19 MOV 48(X11), X20 MOV 56(X11), X21 MOV X14, 0(X10) MOV X15, 8(X10) MOV X16, 16(X10) MOV X17, 24(X10) MOV X18, 32(X10) MOV X19, 40(X10) MOV X20, 48(X10) MOV X21, 56(X10) ADD $64, X10 ADD $64, X11 SUB $64, X12 BGE X12, X9, f_loop64 BEQZ X12, done f_loop32_check: MOV $32, X9 BLT X12, X9, f_loop16_check f_loop32: MOV 0(X11), X14 MOV 8(X11), X15 MOV 16(X11), X16 MOV 24(X11), X17 MOV X14, 0(X10) MOV X15, 8(X10) MOV X16, 16(X10) MOV X17, 24(X10) ADD $32, X10 ADD $32, X11 SUB $32, X12 BGE X12, X9, f_loop32 BEQZ X12, done f_loop16_check: MOV $16, X9 BLT X12, X9, f_loop8_check f_loop16: MOV 0(X11), X14 MOV 8(X11), X15 MOV X14, 0(X10) MOV X15, 8(X10) ADD $16, X10 ADD $16, X11 SUB $16, X12 BGE X12, X9, f_loop16 BEQZ X12, done f_loop8_check: MOV $8, X9 BLT X12, X9, f_loop4_check f_loop8: MOV 0(X11), X14 MOV X14, 0(X10) ADD $8, X10 ADD $8, X11 SUB $8, X12 BGE X12, X9, f_loop8 BEQZ X12, done JMP f_loop4_check f_loop8_unaligned_check: MOV $8, X9 BLT X12, X9, f_loop4_check f_loop8_unaligned: MOVB 0(X11), X14 MOVB 1(X11), X15 MOVB 2(X11), X16 MOVB 3(X11), X17 MOVB 4(X11), X18 MOVB 5(X11), X19 MOVB 6(X11), X20 MOVB 7(X11), X21 MOVB X14, 0(X10) MOVB X15, 1(X10) MOVB X16, 2(X10) MOVB X17, 3(X10) MOVB X18, 4(X10) MOVB X19, 5(X10) MOVB X20, 6(X10) MOVB X21, 7(X10) ADD $8, X10 ADD $8, X11 SUB $8, X12 BGE X12, X9, f_loop8_unaligned f_loop4_check: MOV $4, X9 BLT X12, X9, f_loop1 f_loop4: MOVB 0(X11), X14 MOVB 1(X11), X15 MOVB 2(X11), X16 MOVB 3(X11), X17 MOVB X14, 0(X10) MOVB X15, 1(X10) MOVB X16, 2(X10) MOVB X17, 3(X10) ADD $4, X10 ADD $4, X11 SUB $4, X12 BGE X12, X9, f_loop4 f_loop1: BEQZ X12, done MOVB 0(X11), X14 MOVB X14, 0(X10) ADD $1, X10 ADD $1, X11 SUB $1, X12 JMP f_loop1 backward: ADD X10, X12, X10 ADD X11, X12, X11 // If less than 8 bytes, do single byte copies. MOV $8, X9 BLT X12, X9, b_loop4_check // Check alignment - if alignment differs we have to do one byte at a time. AND $7, X10, X5 AND $7, X11, X6 BNE X5, X6, b_loop8_unaligned_check BEQZ X5, b_loop_check // Move one byte at a time until we reach 8 byte alignment. SUB X5, X12, X12 b_align: SUB $1, X5 SUB $1, X10 SUB $1, X11 MOVB 0(X11), X14 MOVB X14, 0(X10) BNEZ X5, b_align b_loop_check: MOV $16, X9 BLT X12, X9, b_loop8_check MOV $32, X9 BLT X12, X9, b_loop16_check MOV $64, X9 BLT X12, X9, b_loop32_check b_loop64: SUB $64, X10 SUB $64, X11 MOV 0(X11), X14 MOV 8(X11), X15 MOV 16(X11), X16 MOV 24(X11), X17 MOV 32(X11), X18 MOV 40(X11), X19 MOV 48(X11), X20 MOV 56(X11), X21 MOV X14, 0(X10) MOV X15, 8(X10) MOV X16, 16(X10) MOV X17, 24(X10) MOV X18, 32(X10) MOV X19, 40(X10) MOV X20, 48(X10) MOV X21, 56(X10) SUB $64, X12 BGE X12, X9, b_loop64 BEQZ X12, done b_loop32_check: MOV $32, X9 BLT X12, X9, b_loop16_check b_loop32: SUB $32, X10 SUB $32, X11 MOV 0(X11), X14 MOV 8(X11), X15 MOV 16(X11), X16 MOV 24(X11), X17 MOV X14, 0(X10) MOV X15, 8(X10) MOV X16, 16(X10) MOV X17, 24(X10) SUB $32, X12 BGE X12, X9, b_loop32 BEQZ X12, done b_loop16_check: MOV $16, X9 BLT X12, X9, b_loop8_check b_loop16: SUB $16, X10 SUB $16, X11 MOV 0(X11), X14 MOV 8(X11), X15 MOV X14, 0(X10) MOV X15, 8(X10) SUB $16, X12 BGE X12, X9, b_loop16 BEQZ X12, done b_loop8_check: MOV $8, X9 BLT X12, X9, b_loop4_check b_loop8: SUB $8, X10 SUB $8, X11 MOV 0(X11), X14 MOV X14, 0(X10) SUB $8, X12 BGE X12, X9, b_loop8 BEQZ X12, done JMP b_loop4_check b_loop8_unaligned_check: MOV $8, X9 BLT X12, X9, b_loop4_check b_loop8_unaligned: SUB $8, X10 SUB $8, X11 MOVB 0(X11), X14 MOVB 1(X11), X15 MOVB 2(X11), X16 MOVB 3(X11), X17 MOVB 4(X11), X18 MOVB 5(X11), X19 MOVB 6(X11), X20 MOVB 7(X11), X21 MOVB X14, 0(X10) MOVB X15, 1(X10) MOVB X16, 2(X10) MOVB X17, 3(X10) MOVB X18, 4(X10) MOVB X19, 5(X10) MOVB X20, 6(X10) MOVB X21, 7(X10) SUB $8, X12 BGE X12, X9, b_loop8_unaligned b_loop4_check: MOV $4, X9 BLT X12, X9, b_loop1 b_loop4: SUB $4, X10 SUB $4, X11 MOVB 0(X11), X14 MOVB 1(X11), X15 MOVB 2(X11), X16 MOVB 3(X11), X17 MOVB X14, 0(X10) MOVB X15, 1(X10) MOVB X16, 2(X10) MOVB X17, 3(X10) SUB $4, X12 BGE X12, X9, b_loop4 b_loop1: BEQZ X12, done SUB $1, X10 SUB $1, X11 MOVB 0(X11), X14 MOVB X14, 0(X10) SUB $1, X12 JMP b_loop1 done: RET
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