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better float parsing

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This commit is contained in:
dtookey 2024-08-01 07:19:58 -04:00
parent 803dae7a11
commit d7e78e6371
2 changed files with 84 additions and 26 deletions
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50
1brc.go
View File

@ -19,7 +19,7 @@ const testFile = "dummy.txt"
const resultFile = "my_results.txt"
const benchFile = "results.txt"
const profile = false
const profile = true
var nGoRoutine = 64
@ -192,35 +192,41 @@ func workerComputePartition(aData []byte, wPart partitionRange, workerNumber int
}
func fParseFloat(str []byte) float64 {
//kick everything off by computing the remainder
v := float64(fCharToInt(str[len(str)-1])) / 10.0
positive := true
end := 0
switch len(str) {
case 3:
//x.x
a := float64(fCharToInt(str[0]))
b := float64(fCharToInt(str[2])) * 0.1
return a + b
case 4:
//either xx.x or -x.x
if str[0] == '-' {
positive = false
end = 1
}
start := len(str) - 3
oom := 0.0
for i := start; i >= end; i-- {
v += float64(fCharToInt(str[i])) * math.Pow(10.0, oom)
oom += 1.0
}
if positive {
return v
//-x.x
a := float64(fCharToInt(str[1]))
b := float64(fCharToInt(str[3])) * 0.1
return -(a + b)
} else {
return -v
//xx.x
a := float64(f2CharToInt(str[0], str[1]))
b := float64(fCharToInt(str[3])) * 0.1
return a + b
}
case 5:
//-xx.x
a := float64(f2CharToInt(str[1], str[2]))
b := float64(fCharToInt(str[4])) * 0.1
return -(a + b)
default:
panic(fmt.Errorf("bad float string: %s", string(str)))
}
}
func fCharToInt(b byte) int {
if b >= '0' && b <= '9' {
return int(b - '0')
}
panic(fmt.Errorf("couldn't parse: %v", string(b)))
func f2CharToInt(b1 byte, b2 byte) int {
return int(((b1 - '0') * 10) + (b2 - '0'))
}
func seekNextNewLine(b []byte, part partitionRange, last int64) int64 {

52
benchmark Normal file
View File

@ -0,0 +1,52 @@
Showing nodes accounting for 84.49s, 99.24% of 85.14s total
Dropped 35 nodes (cum <= 0.43s)
flat flat% sum% cum cum%
29.91s 35.13% 35.13% 80.51s 94.56% main.workerComputePartition
14.55s 17.09% 52.22% 20.92s 24.57% runtime.mapaccess2_fast64
7.65s 8.99% 61.21% 9.47s 11.12% runtime.mapassign_fast64
7.50s 8.81% 70.01% 7.50s 8.81% hash/fnv.(*sum64).Write (inline)
6.55s 7.69% 77.71% 6.55s 7.69% main.seekNextNewLine (inline)
4.58s 5.38% 83.09% 4.58s 5.38% runtime.memhash64
4.48s 5.26% 88.35% 4.48s 5.26% runtime.cgocall
3.61s 4.24% 92.59% 6.16s 7.24% main.fParseFloat
2.76s 3.24% 95.83% 2.76s 3.24% runtime.add (inline)
2.55s 3.00% 98.83% 2.55s 3.00% main.fCharToInt (inline)
0.35s 0.41% 99.24% 0.66s 0.78% runtime.bucketMask (inline)
0 0% 99.24% 4.48s 5.26% internal/poll.(*FD).Read
0 0% 99.24% 4.48s 5.26% main.main
0 0% 99.24% 4.48s 5.26% main.oneBRC
0 0% 99.24% 4.48s 5.26% os.(*File).Read
0 0% 99.24% 4.48s 5.26% os.(*File).read (inline)
0 0% 99.24% 4.48s 5.26% os.ReadFile
0 0% 99.24% 4.48s 5.26% runtime.main
0 0% 99.24% 4.48s 5.26% syscall.Read
0 0% 99.24% 4.48s 5.26% syscall.ReadFile (inline)
0 0% 99.24% 4.48s 5.26% syscall.Syscall6
0 0% 99.24% 4.48s 5.26% syscall.SyscallN
0 0% 99.24% 4.48s 5.26% syscall.readFile
flat flat% sum% cum cum%
29.18s 34.19% 34.19% 80.72s 94.58% main.workerComputePartition
14.53s 17.02% 51.21% 21.08s 24.70% runtime.mapaccess2_fast64
8.30s 9.72% 60.94% 10.42s 12.21% runtime.mapassign_fast64
7.39s 8.66% 69.60% 7.39s 8.66% hash/fnv.(*sum64).Write (inline)
6.36s 7.45% 77.05% 6.36s 7.45% main.seekNextNewLine (inline)
4.73s 5.54% 82.59% 4.73s 5.54% runtime.memhash64
4.48s 5.25% 87.84% 4.48s 5.25% runtime.cgocall
3.76s 4.41% 92.24% 6.28s 7.36% main.fParseFloat
3s 3.51% 95.76% 3s 3.51% runtime.add (inline)
2.52s 2.95% 98.71% 2.52s 2.95% main.fCharToInt (inline)
0.34s 0.4% 99.11% 0.68s 0.8% runtime.bucketMask (inline)
0 0% 99.11% 4.48s 5.25% internal/poll.(*FD).Read
0 0% 99.11% 4.48s 5.25% main.main
0 0% 99.11% 4.48s 5.25% main.oneBRC
0 0% 99.11% 4.48s 5.25% os.(*File).Read
0 0% 99.11% 4.48s 5.25% os.(*File).read (inline)
0 0% 99.11% 4.48s 5.25% os.ReadFile
0 0% 99.11% 4.48s 5.25% runtime.main
0 0% 99.11% 4.48s 5.25% syscall.Read
0 0% 99.11% 4.48s 5.25% syscall.ReadFile (inline)
0 0% 99.11% 4.48s 5.25% syscall.Syscall6
0 0% 99.11% 4.48s 5.25% syscall.SyscallN
0 0% 99.11% 4.48s 5.25% syscall.readFile