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flate: Simplify l4-6 loading
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We already calculate the buffer offset. Reuse in case the compiler doesn't pick it up.
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@klauspost
klauspost committed Jan 20, 2025
1 parent 4fa2036 commit c354cf5
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Showing 3 changed files with 21 additions and 21 deletions.
6 changes: 3 additions & 3 deletions flate/level4.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -98,19 +98,19 @@ func (e *fastEncL4) Encode(dst *tokens, src []byte) {
e.bTable[nextHashL] = entry

t = lCandidate.offset - e.cur
if s-t < maxMatchOffset && uint32(cv) == load3232(src, lCandidate.offset-e.cur) {
if s-t < maxMatchOffset && uint32(cv) == load3232(src, t) {
// We got a long match. Use that.
break
}

t = sCandidate.offset - e.cur
if s-t < maxMatchOffset && uint32(cv) == load3232(src, sCandidate.offset-e.cur) {
if s-t < maxMatchOffset && uint32(cv) == load3232(src, t) {
// Found a 4 match...
lCandidate = e.bTable[hash7(next, tableBits)]

// If the next long is a candidate, check if we should use that instead...
lOff := nextS - (lCandidate.offset - e.cur)
if lOff < maxMatchOffset && load3232(src, lCandidate.offset-e.cur) == uint32(next) {
if lOff < maxMatchOffset && load3232(src, lOff) == uint32(next) {
l1, l2 := matchLen(src[s+4:], src[t+4:]), matchLen(src[nextS+4:], src[nextS-lOff+4:])
if l2 > l1 {
s = nextS
Expand Down
24 changes: 12 additions & 12 deletions flate/level5.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -111,14 +111,14 @@ func (e *fastEncL5) Encode(dst *tokens, src []byte) {

t = lCandidate.Cur.offset - e.cur
if s-t < maxMatchOffset {
if uint32(cv) == load3232(src, lCandidate.Cur.offset-e.cur) {
if uint32(cv) == load3232(src, t) {
// Store the next match
e.table[nextHashS] = tableEntry{offset: nextS + e.cur}
eLong := &e.bTable[nextHashL]
eLong.Cur, eLong.Prev = tableEntry{offset: nextS + e.cur}, eLong.Cur

t2 := lCandidate.Prev.offset - e.cur
if s-t2 < maxMatchOffset && uint32(cv) == load3232(src, lCandidate.Prev.offset-e.cur) {
if s-t2 < maxMatchOffset && uint32(cv) == load3232(src, t2) {
l = e.matchlen(s+4, t+4, src) + 4
ml1 := e.matchlen(s+4, t2+4, src) + 4
if ml1 > l {
Expand All @@ -130,7 +130,7 @@ func (e *fastEncL5) Encode(dst *tokens, src []byte) {
break
}
t = lCandidate.Prev.offset - e.cur
if s-t < maxMatchOffset && uint32(cv) == load3232(src, lCandidate.Prev.offset-e.cur) {
if s-t < maxMatchOffset && uint32(cv) == load3232(src, t) {
// Store the next match
e.table[nextHashS] = tableEntry{offset: nextS + e.cur}
eLong := &e.bTable[nextHashL]
Expand All @@ -140,7 +140,7 @@ func (e *fastEncL5) Encode(dst *tokens, src []byte) {
}

t = sCandidate.offset - e.cur
if s-t < maxMatchOffset && uint32(cv) == load3232(src, sCandidate.offset-e.cur) {
if s-t < maxMatchOffset && uint32(cv) == load3232(src, t) {
// Found a 4 match...
l = e.matchlen(s+4, t+4, src) + 4
lCandidate = e.bTable[nextHashL]
Expand All @@ -153,7 +153,7 @@ func (e *fastEncL5) Encode(dst *tokens, src []byte) {
// If the next long is a candidate, use that...
t2 := lCandidate.Cur.offset - e.cur
if nextS-t2 < maxMatchOffset {
if load3232(src, lCandidate.Cur.offset-e.cur) == uint32(next) {
if load3232(src, t2) == uint32(next) {
ml := e.matchlen(nextS+4, t2+4, src) + 4
if ml > l {
t = t2
Expand All @@ -164,7 +164,7 @@ func (e *fastEncL5) Encode(dst *tokens, src []byte) {
}
// If the previous long is a candidate, use that...
t2 = lCandidate.Prev.offset - e.cur
if nextS-t2 < maxMatchOffset && load3232(src, lCandidate.Prev.offset-e.cur) == uint32(next) {
if nextS-t2 < maxMatchOffset && load3232(src, t2) == uint32(next) {
ml := e.matchlen(nextS+4, t2+4, src) + 4
if ml > l {
t = t2
Expand Down Expand Up @@ -423,14 +423,14 @@ func (e *fastEncL5Window) Encode(dst *tokens, src []byte) {

t = lCandidate.Cur.offset - e.cur
if s-t < maxMatchOffset {
if uint32(cv) == load3232(src, lCandidate.Cur.offset-e.cur) {
if uint32(cv) == load3232(src, t) {
// Store the next match
e.table[nextHashS] = tableEntry{offset: nextS + e.cur}
eLong := &e.bTable[nextHashL]
eLong.Cur, eLong.Prev = tableEntry{offset: nextS + e.cur}, eLong.Cur

t2 := lCandidate.Prev.offset - e.cur
if s-t2 < maxMatchOffset && uint32(cv) == load3232(src, lCandidate.Prev.offset-e.cur) {
if s-t2 < maxMatchOffset && uint32(cv) == load3232(src, t2) {
l = e.matchlen(s+4, t+4, src) + 4
ml1 := e.matchlen(s+4, t2+4, src) + 4
if ml1 > l {
Expand All @@ -442,7 +442,7 @@ func (e *fastEncL5Window) Encode(dst *tokens, src []byte) {
break
}
t = lCandidate.Prev.offset - e.cur
if s-t < maxMatchOffset && uint32(cv) == load3232(src, lCandidate.Prev.offset-e.cur) {
if s-t < maxMatchOffset && uint32(cv) == load3232(src, t) {
// Store the next match
e.table[nextHashS] = tableEntry{offset: nextS + e.cur}
eLong := &e.bTable[nextHashL]
Expand All @@ -452,7 +452,7 @@ func (e *fastEncL5Window) Encode(dst *tokens, src []byte) {
}

t = sCandidate.offset - e.cur
if s-t < maxMatchOffset && uint32(cv) == load3232(src, sCandidate.offset-e.cur) {
if s-t < maxMatchOffset && uint32(cv) == load3232(src, t) {
// Found a 4 match...
l = e.matchlen(s+4, t+4, src) + 4
lCandidate = e.bTable[nextHashL]
Expand All @@ -465,7 +465,7 @@ func (e *fastEncL5Window) Encode(dst *tokens, src []byte) {
// If the next long is a candidate, use that...
t2 := lCandidate.Cur.offset - e.cur
if nextS-t2 < maxMatchOffset {
if load3232(src, lCandidate.Cur.offset-e.cur) == uint32(next) {
if load3232(src, t2) == uint32(next) {
ml := e.matchlen(nextS+4, t2+4, src) + 4
if ml > l {
t = t2
Expand All @@ -476,7 +476,7 @@ func (e *fastEncL5Window) Encode(dst *tokens, src []byte) {
}
// If the previous long is a candidate, use that...
t2 = lCandidate.Prev.offset - e.cur
if nextS-t2 < maxMatchOffset && load3232(src, lCandidate.Prev.offset-e.cur) == uint32(next) {
if nextS-t2 < maxMatchOffset && load3232(src, t2) == uint32(next) {
ml := e.matchlen(nextS+4, t2+4, src) + 4
if ml > l {
t = t2
Expand Down
12 changes: 6 additions & 6 deletions flate/level6.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -113,7 +113,7 @@ func (e *fastEncL6) Encode(dst *tokens, src []byte) {

t = lCandidate.Cur.offset - e.cur
if s-t < maxMatchOffset {
if uint32(cv) == load3232(src, lCandidate.Cur.offset-e.cur) {
if uint32(cv) == load3232(src, t) {
// Long candidate matches at least 4 bytes.

// Store the next match
Expand All @@ -123,7 +123,7 @@ func (e *fastEncL6) Encode(dst *tokens, src []byte) {

// Check the previous long candidate as well.
t2 := lCandidate.Prev.offset - e.cur
if s-t2 < maxMatchOffset && uint32(cv) == load3232(src, lCandidate.Prev.offset-e.cur) {
if s-t2 < maxMatchOffset && uint32(cv) == load3232(src, t2) {
l = e.matchlen(s+4, t+4, src) + 4
ml1 := e.matchlen(s+4, t2+4, src) + 4
if ml1 > l {
Expand All @@ -136,7 +136,7 @@ func (e *fastEncL6) Encode(dst *tokens, src []byte) {
}
// Current value did not match, but check if previous long value does.
t = lCandidate.Prev.offset - e.cur
if s-t < maxMatchOffset && uint32(cv) == load3232(src, lCandidate.Prev.offset-e.cur) {
if s-t < maxMatchOffset && uint32(cv) == load3232(src, t) {
// Store the next match
e.table[nextHashS] = tableEntry{offset: nextS + e.cur}
eLong := &e.bTable[nextHashL]
Expand All @@ -146,7 +146,7 @@ func (e *fastEncL6) Encode(dst *tokens, src []byte) {
}

t = sCandidate.offset - e.cur
if s-t < maxMatchOffset && uint32(cv) == load3232(src, sCandidate.offset-e.cur) {
if s-t < maxMatchOffset && uint32(cv) == load3232(src, t) {
// Found a 4 match...
l = e.matchlen(s+4, t+4, src) + 4

Expand Down Expand Up @@ -175,7 +175,7 @@ func (e *fastEncL6) Encode(dst *tokens, src []byte) {
// If the next long is a candidate, use that...
t2 = lCandidate.Cur.offset - e.cur
if nextS-t2 < maxMatchOffset {
if load3232(src, lCandidate.Cur.offset-e.cur) == uint32(next) {
if load3232(src, t2) == uint32(next) {
ml := e.matchlen(nextS+4, t2+4, src) + 4
if ml > l {
t = t2
Expand All @@ -186,7 +186,7 @@ func (e *fastEncL6) Encode(dst *tokens, src []byte) {
}
// If the previous long is a candidate, use that...
t2 = lCandidate.Prev.offset - e.cur
if nextS-t2 < maxMatchOffset && load3232(src, lCandidate.Prev.offset-e.cur) == uint32(next) {
if nextS-t2 < maxMatchOffset && load3232(src, t2) == uint32(next) {
ml := e.matchlen(nextS+4, t2+4, src) + 4
if ml > l {
t = t2
Expand Down

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