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195 lines
5.0 KiB
195 lines
5.0 KiB
// +build !appengine |
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// +build gc |
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// +build !noasm |
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#include "textflag.h" |
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#include "funcdata.h" |
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#include "go_asm.h" |
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#ifdef GOAMD64_v4 |
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#ifndef GOAMD64_v3 |
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#define GOAMD64_v3 |
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#endif |
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#endif |
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#define bufoff 256 // see decompress.go, we're using [4][256]byte table |
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//func decompress4x_main_loop_x86(pbr0, pbr1, pbr2, pbr3 *bitReaderShifted, |
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// peekBits uint8, buf *byte, tbl *dEntrySingle) (int, bool) |
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TEXT ·decompress4x_main_loop_x86(SB), NOSPLIT, $8 |
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#define off R8 |
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#define buffer DI |
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#define table SI |
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#define br_bits_read R9 |
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#define br_value R10 |
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#define br_offset R11 |
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#define peek_bits R12 |
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#define exhausted DX |
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#define br0 R13 |
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#define br1 R14 |
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#define br2 R15 |
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#define br3 BP |
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MOVQ BP, 0(SP) |
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XORQ exhausted, exhausted // exhausted = false |
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XORQ off, off // off = 0 |
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MOVBQZX peekBits+32(FP), peek_bits |
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MOVQ buf+40(FP), buffer |
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MOVQ tbl+48(FP), table |
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MOVQ pbr0+0(FP), br0 |
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MOVQ pbr1+8(FP), br1 |
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MOVQ pbr2+16(FP), br2 |
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MOVQ pbr3+24(FP), br3 |
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main_loop: |
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{{ define "decode_2_values_x86" }} |
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// const stream = {{ var "id" }} |
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// br{{ var "id"}}.fillFast() |
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MOVBQZX bitReaderShifted_bitsRead(br{{ var "id" }}), br_bits_read |
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MOVQ bitReaderShifted_value(br{{ var "id" }}), br_value |
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MOVQ bitReaderShifted_off(br{{ var "id" }}), br_offset |
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// We must have at least 2 * max tablelog left |
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CMPQ br_bits_read, $64-22 |
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JBE skip_fill{{ var "id" }} |
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SUBQ $32, br_bits_read // b.bitsRead -= 32 |
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SUBQ $4, br_offset // b.off -= 4 |
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// v := b.in[b.off-4 : b.off] |
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// v = v[:4] |
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// low := (uint32(v[0])) | (uint32(v[1]) << 8) | (uint32(v[2]) << 16) | (uint32(v[3]) << 24) |
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MOVQ bitReaderShifted_in(br{{ var "id" }}), AX |
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// b.value |= uint64(low) << (b.bitsRead & 63) |
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#ifdef GOAMD64_v3 |
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SHLXQ br_bits_read, 0(br_offset)(AX*1), AX // AX = uint32(b.in[b.off:b.off+4]) << (b.bitsRead & 63) |
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#else |
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MOVL 0(br_offset)(AX*1), AX // AX = uint32(b.in[b.off:b.off+4]) |
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MOVQ br_bits_read, CX |
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SHLQ CL, AX |
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#endif |
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ORQ AX, br_value |
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// exhausted = exhausted || (br{{ var "id"}}.off < 4) |
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CMPQ br_offset, $4 |
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SETLT DL |
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ORB DL, DH |
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// } |
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skip_fill{{ var "id" }}: |
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// val0 := br{{ var "id"}}.peekTopBits(peekBits) |
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#ifdef GOAMD64_v3 |
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SHRXQ peek_bits, br_value, AX // AX = (value >> peek_bits) & mask |
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#else |
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MOVQ br_value, AX |
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MOVQ peek_bits, CX |
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SHRQ CL, AX // AX = (value >> peek_bits) & mask |
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#endif |
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// v0 := table[val0&mask] |
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MOVW 0(table)(AX*2), AX // AX - v0 |
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// br{{ var "id"}}.advance(uint8(v0.entry)) |
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MOVB AH, BL // BL = uint8(v0.entry >> 8) |
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#ifdef GOAMD64_v3 |
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MOVBQZX AL, CX |
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SHLXQ AX, br_value, br_value // value <<= n |
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#else |
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MOVBQZX AL, CX |
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SHLQ CL, br_value // value <<= n |
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#endif |
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ADDQ CX, br_bits_read // bits_read += n |
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#ifdef GOAMD64_v3 |
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SHRXQ peek_bits, br_value, AX // AX = (value >> peek_bits) & mask |
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#else |
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// val1 := br{{ var "id"}}.peekTopBits(peekBits) |
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MOVQ peek_bits, CX |
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MOVQ br_value, AX |
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SHRQ CL, AX // AX = (value >> peek_bits) & mask |
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#endif |
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// v1 := table[val1&mask] |
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MOVW 0(table)(AX*2), AX // AX - v1 |
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// br{{ var "id"}}.advance(uint8(v1.entry)) |
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MOVB AH, BH // BH = uint8(v1.entry >> 8) |
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#ifdef GOAMD64_v3 |
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MOVBQZX AL, CX |
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SHLXQ AX, br_value, br_value // value <<= n |
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#else |
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MOVBQZX AL, CX |
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SHLQ CL, br_value // value <<= n |
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#endif |
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ADDQ CX, br_bits_read // bits_read += n |
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// these two writes get coalesced |
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// buf[stream][off] = uint8(v0.entry >> 8) |
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// buf[stream][off+1] = uint8(v1.entry >> 8) |
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MOVW BX, {{ var "bufofs" }}(buffer)(off*1) |
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// update the bitrader reader structure |
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MOVB br_bits_read, bitReaderShifted_bitsRead(br{{ var "id" }}) |
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MOVQ br_value, bitReaderShifted_value(br{{ var "id" }}) |
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MOVQ br_offset, bitReaderShifted_off(br{{ var "id" }}) |
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{{ end }} |
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{{ set "id" "0" }} |
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{{ set "ofs" "0" }} |
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{{ set "bufofs" "0" }} {{/* id * bufoff */}} |
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{{ template "decode_2_values_x86" . }} |
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{{ set "id" "1" }} |
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{{ set "ofs" "8" }} |
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{{ set "bufofs" "256" }} |
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{{ template "decode_2_values_x86" . }} |
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{{ set "id" "2" }} |
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{{ set "ofs" "16" }} |
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{{ set "bufofs" "512" }} |
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{{ template "decode_2_values_x86" . }} |
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{{ set "id" "3" }} |
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{{ set "ofs" "24" }} |
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{{ set "bufofs" "768" }} |
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{{ template "decode_2_values_x86" . }} |
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ADDQ $2, off // off += 2 |
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TESTB DH, DH // any br[i].ofs < 4? |
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JNZ end |
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CMPQ off, $bufoff |
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JL main_loop |
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end: |
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MOVQ 0(SP), BP |
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MOVB off, ret+56(FP) |
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RET |
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#undef off |
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#undef buffer |
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#undef table |
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#undef br_bits_read |
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#undef br_value |
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#undef br_offset |
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#undef peek_bits |
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#undef exhausted |
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#undef br0 |
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#undef br1 |
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#undef br2 |
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#undef br3
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