Help the compiler and put everything that can be looked up beforehand into
a separate variable:
hhi0, hhi1 := bufferHexHash[i], bufferHexHash[i+1]
for j = 0; j < lenBufferHexSearch; j++ {
hsj0, hsj1 := bufferHexSearch[j][0], bufferHexSearch[j][1]
for k = 0; k < lenMaskHex; k++ {
if hsj0 == hhi0&maskHex[k][0] && hsj1 ==
hhi1&maskHex[k][1] {
bFind = true
break LoopSearch
}
}
}
2017. november 15., szerda 18:15:32 UTC+1 időpontban Christian LeMoussel a
következőt írta:
>
> Hi,
>
> I have this program (https://play.golang.org/p/qHPzjj2uj3) that take a
> decent amount of time for computing.
> Let’s open pprof and see what it spent its time on.
> Type: cpu
> Time: Nov 15, 2017 at 5:48pm (CET)
> Duration: 9.92s, Total samples = 9.78s (98.54%)
> Entering interactive mode (type "help" for commands, "o" for options)
> (pprof) list main.main
> Total: 9.78s
> ROUTINE ======================== main.main in
> c:\Users\lemoussel\go\src\C-Libraries\main.go
> 80ms 9.78s (flat, cum) 100% of Total
> . . 170: bufferHexHash, err := HexToUint32(hash,
> binary.BigEndian)
> . . 171: /*for i, val := range bufferHexHash {
> . . 172: fmt.Printf("bufferHexHash[%d]:
> %08x \n", i, val)
> . . 173: }*/
> . . 174: startTime = time.Now()
> 20ms 20ms 175: for i := 0; i < 10000000; i++ {
> 60ms 9.76s 176: result = findHex(bufferHexSearch,
> bufferHexHash)
> . . 177: }
> . . 178: fmt.Printf("findHex() Find:
> %t Time : %.2f sec.\n", result, time.Now().Sub(startTime).Seconds())
> . . 179:}
>
> Ok, so it seems we spent most of the time in findHex, makes sense!
>
> (pprof) list main.findHex
> Total: 9.78s
> ROUTINE ======================== main.findHex in
> c:\Users\lemoussel\go\src\C-Libraries\main.go
> 9.52s 9.52s (flat, cum) 97.34% of Total
> . . 72: {0x00000fff, 0xfffffff0, 0x0}, // 5
> . . 73: {0x000000ff, 0xffffffff, 0x0}, // 6
> . . 74: {0x0000000f, 0xffffffff, 0xf0000000}, // 7
> . . 75:}
> . . 76:
> 20ms 20ms 77:func findHex(bufferHexSearch [8][3]uint32,
> bufferHexHash []uint32) bool {
> . . 78: var bFind = false
> . . 79: var i, j, k int
> . . 80: var lenBufferHexHash = len(bufferHexHash)
> . . 81: var lenBufferHexSearch =
> len(bufferHexSearch)
> . . 82: var lenMaskHex = len(maskHex)
> . . 83:LoopSearch:
> 300ms 300ms 84: for i = 0; i < lenBufferHexHash; i++ {
> 410ms 410ms 85: for j = 0; j < lenBufferHexSearch;
> j++ {
> 2.53s 2.53s 86: for k = 0; k < lenMaskHex;
> k++ {
> 6.16s 6.16s 87: if
> bufferHexSearch[j][0] == bufferHexHash[i]&maskHex[k][0] &&
> 100ms 100ms 88:
> bufferHexSearch[j][1] == bufferHexHash[i+1]&maskHex[k][1] {
> . . 89: bFind =
> true
> . . 90: break
> LoopSearch
> . . 91: }
> . . 92: }
> . . 93: }
>
> Oh ! most of the time is in the line if bufferHexSearch[j][0] ==
> bufferHexHash[i]&maskHex[k][0] &&
>
> I don't understand why?
> Should I use goroutine to compute concurrently?
> I'm interested in any recommendations to optimize this program.
>
>
>
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