githaven-fork/vendor/github.com/pierrec/lz4/v3/decode_amd64.s
6543 12a1f914f4
Vendor Update Go Libs (#13166)
* update github.com/alecthomas/chroma v0.8.0 -> v0.8.1

* github.com/blevesearch/bleve v1.0.10 -> v1.0.12

* editorconfig-core-go v2.1.1 -> v2.3.7

* github.com/gliderlabs/ssh v0.2.2 -> v0.3.1

* migrate editorconfig.ParseBytes to Parse

* github.com/shurcooL/vfsgen to 0d455de96546

* github.com/go-git/go-git/v5 v5.1.0 -> v5.2.0

* github.com/google/uuid v1.1.1 -> v1.1.2

* github.com/huandu/xstrings v1.3.0 -> v1.3.2

* github.com/klauspost/compress v1.10.11 -> v1.11.1

* github.com/markbates/goth v1.61.2 -> v1.65.0

* github.com/mattn/go-sqlite3 v1.14.0 -> v1.14.4

* github.com/mholt/archiver v3.3.0 -> v3.3.2

* github.com/microcosm-cc/bluemonday 4f7140c49acb -> v1.0.4

* github.com/minio/minio-go v7.0.4 -> v7.0.5

* github.com/olivere/elastic v7.0.9 -> v7.0.20

* github.com/urfave/cli v1.20.0 -> v1.22.4

* github.com/prometheus/client_golang v1.1.0 -> v1.8.0

* github.com/xanzy/go-gitlab v0.37.0 -> v0.38.1

* mvdan.cc/xurls v2.1.0 -> v2.2.0

Co-authored-by: Lauris BH <lauris@nix.lv>
2020-10-16 01:06:27 -04:00

376 lines
6.0 KiB
ArmAsm
Vendored

// +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