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ceph-csi/vendor/github.com/pierrec/lz4/decode_amd64.s
Niels de Vos 91774fc936 rebase: vendor dependencies for Vault API
Uses github.com/libopenstorage/secrets to communicate with Vault. This
removes the need for maintaining our own limited Vault APIs.

By adding the new dependency, several other packages got updated in the
process. Unused indirect dependencies have been removed from go.mod.

Signed-off-by: Niels de Vos <ndevos@redhat.com>
2020-11-29 04:03:59 +00:00

376 lines
6.0 KiB
ArmAsm

// +build !appengine
// +build gc
// +build !noasm
#include "textflag.h"
// AX scratch
// BX scratch
// CX scratch
// DX token
//
// DI &dst
// SI &src
// R8 &dst + len(dst)
// R9 &src + len(src)
// R11 &dst
// R12 short output end
// R13 short input end
// func decodeBlock(dst, src []byte) int
// using 50 bytes of stack currently
TEXT ·decodeBlock(SB), NOSPLIT, $64-56
MOVQ dst_base+0(FP), DI
MOVQ DI, R11
MOVQ dst_len+8(FP), R8
ADDQ DI, R8
MOVQ src_base+24(FP), SI
MOVQ src_len+32(FP), R9
ADDQ SI, R9
// shortcut ends
// short output end
MOVQ R8, R12
SUBQ $32, R12
// short input end
MOVQ R9, R13
SUBQ $16, R13
loop:
// for si < len(src)
CMPQ SI, R9
JGE end
// token := uint32(src[si])
MOVBQZX (SI), DX
INCQ SI
// lit_len = token >> 4
// if lit_len > 0
// CX = lit_len
MOVQ DX, CX
SHRQ $4, CX
// if lit_len != 0xF
CMPQ CX, $0xF
JEQ lit_len_loop_pre
CMPQ DI, R12
JGE lit_len_loop_pre
CMPQ SI, R13
JGE lit_len_loop_pre
// copy shortcut
// A two-stage shortcut for the most common case:
// 1) If the literal length is 0..14, and there is enough space,
// enter the shortcut and copy 16 bytes on behalf of the literals
// (in the fast mode, only 8 bytes can be safely copied this way).
// 2) Further if the match length is 4..18, copy 18 bytes in a similar
// manner; but we ensure that there's enough space in the output for
// those 18 bytes earlier, upon entering the shortcut (in other words,
// there is a combined check for both stages).
// copy literal
MOVOU (SI), X0
MOVOU X0, (DI)
ADDQ CX, DI
ADDQ CX, SI
MOVQ DX, CX
ANDQ $0xF, CX
// The second stage: prepare for match copying, decode full info.
// If it doesn't work out, the info won't be wasted.
// offset := uint16(data[:2])
MOVWQZX (SI), DX
ADDQ $2, SI
MOVQ DI, AX
SUBQ DX, AX
CMPQ AX, DI
JGT err_short_buf
// if we can't do the second stage then jump straight to read the
// match length, we already have the offset.
CMPQ CX, $0xF
JEQ match_len_loop_pre
CMPQ DX, $8
JLT match_len_loop_pre
CMPQ AX, R11
JLT err_short_buf
// memcpy(op + 0, match + 0, 8);
MOVQ (AX), BX
MOVQ BX, (DI)
// memcpy(op + 8, match + 8, 8);
MOVQ 8(AX), BX
MOVQ BX, 8(DI)
// memcpy(op +16, match +16, 2);
MOVW 16(AX), BX
MOVW BX, 16(DI)
ADDQ $4, DI // minmatch
ADDQ CX, DI
// shortcut complete, load next token
JMP loop
lit_len_loop_pre:
// if lit_len > 0
CMPQ CX, $0
JEQ offset
CMPQ CX, $0xF
JNE copy_literal
lit_len_loop:
// for src[si] == 0xFF
CMPB (SI), $0xFF
JNE lit_len_finalise
// bounds check src[si+1]
MOVQ SI, AX
ADDQ $1, AX
CMPQ AX, R9
JGT err_short_buf
// lit_len += 0xFF
ADDQ $0xFF, CX
INCQ SI
JMP lit_len_loop
lit_len_finalise:
// lit_len += int(src[si])
// si++
MOVBQZX (SI), AX
ADDQ AX, CX
INCQ SI
copy_literal:
// bounds check src and dst
MOVQ SI, AX
ADDQ CX, AX
CMPQ AX, R9
JGT err_short_buf
MOVQ DI, AX
ADDQ CX, AX
CMPQ AX, R8
JGT err_short_buf
// whats a good cut off to call memmove?
CMPQ CX, $16
JGT memmove_lit
// if len(dst[di:]) < 16
MOVQ R8, AX
SUBQ DI, AX
CMPQ AX, $16
JLT memmove_lit
// if len(src[si:]) < 16
MOVQ R9, AX
SUBQ SI, AX
CMPQ AX, $16
JLT memmove_lit
MOVOU (SI), X0
MOVOU X0, (DI)
JMP finish_lit_copy
memmove_lit:
// memmove(to, from, len)
MOVQ DI, 0(SP)
MOVQ SI, 8(SP)
MOVQ CX, 16(SP)
// spill
MOVQ DI, 24(SP)
MOVQ SI, 32(SP)
MOVQ CX, 40(SP) // need len to inc SI, DI after
MOVB DX, 48(SP)
CALL runtime·memmove(SB)
// restore registers
MOVQ 24(SP), DI
MOVQ 32(SP), SI
MOVQ 40(SP), CX
MOVB 48(SP), DX
// recalc initial values
MOVQ dst_base+0(FP), R8
MOVQ R8, R11
ADDQ dst_len+8(FP), R8
MOVQ src_base+24(FP), R9
ADDQ src_len+32(FP), R9
MOVQ R8, R12
SUBQ $32, R12
MOVQ R9, R13
SUBQ $16, R13
finish_lit_copy:
ADDQ CX, SI
ADDQ CX, DI
CMPQ SI, R9
JGE end
offset:
// CX := mLen
// free up DX to use for offset
MOVQ DX, CX
MOVQ SI, AX
ADDQ $2, AX
CMPQ AX, R9
JGT err_short_buf
// offset
// DX := int(src[si]) | int(src[si+1])<<8
MOVWQZX (SI), DX
ADDQ $2, SI
// 0 offset is invalid
CMPQ DX, $0
JEQ err_corrupt
ANDB $0xF, CX
match_len_loop_pre:
// if mlen != 0xF
CMPB CX, $0xF
JNE copy_match
match_len_loop:
// for src[si] == 0xFF
// lit_len += 0xFF
CMPB (SI), $0xFF
JNE match_len_finalise
// bounds check src[si+1]
MOVQ SI, AX
ADDQ $1, AX
CMPQ AX, R9
JGT err_short_buf
ADDQ $0xFF, CX
INCQ SI
JMP match_len_loop
match_len_finalise:
// lit_len += int(src[si])
// si++
MOVBQZX (SI), AX
ADDQ AX, CX
INCQ SI
copy_match:
// mLen += minMatch
ADDQ $4, CX
// check we have match_len bytes left in dst
// di+match_len < len(dst)
MOVQ DI, AX
ADDQ CX, AX
CMPQ AX, R8
JGT err_short_buf
// DX = offset
// CX = match_len
// BX = &dst + (di - offset)
MOVQ DI, BX
SUBQ DX, BX
// check BX is within dst
// if BX < &dst
CMPQ BX, R11
JLT err_short_buf
// if offset + match_len < di
MOVQ BX, AX
ADDQ CX, AX
CMPQ DI, AX
JGT copy_interior_match
// AX := len(dst[:di])
// MOVQ DI, AX
// SUBQ R11, AX
// copy 16 bytes at a time
// if di-offset < 16 copy 16-(di-offset) bytes to di
// then do the remaining
copy_match_loop:
// for match_len >= 0
// dst[di] = dst[i]
// di++
// i++
MOVB (BX), AX
MOVB AX, (DI)
INCQ DI
INCQ BX
DECQ CX
CMPQ CX, $0
JGT copy_match_loop
JMP loop
copy_interior_match:
CMPQ CX, $16
JGT memmove_match
// if len(dst[di:]) < 16
MOVQ R8, AX
SUBQ DI, AX
CMPQ AX, $16
JLT memmove_match
MOVOU (BX), X0
MOVOU X0, (DI)
ADDQ CX, DI
JMP loop
memmove_match:
// memmove(to, from, len)
MOVQ DI, 0(SP)
MOVQ BX, 8(SP)
MOVQ CX, 16(SP)
// spill
MOVQ DI, 24(SP)
MOVQ SI, 32(SP)
MOVQ CX, 40(SP) // need len to inc SI, DI after
CALL runtime·memmove(SB)
// restore registers
MOVQ 24(SP), DI
MOVQ 32(SP), SI
MOVQ 40(SP), CX
// recalc initial values
MOVQ dst_base+0(FP), R8
MOVQ R8, R11 // TODO: make these sensible numbers
ADDQ dst_len+8(FP), R8
MOVQ src_base+24(FP), R9
ADDQ src_len+32(FP), R9
MOVQ R8, R12
SUBQ $32, R12
MOVQ R9, R13
SUBQ $16, R13
ADDQ CX, DI
JMP loop
err_corrupt:
MOVQ $-1, ret+48(FP)
RET
err_short_buf:
MOVQ $-2, ret+48(FP)
RET
end:
SUBQ R11, DI
MOVQ DI, ret+48(FP)
RET