some quick & dirty benchmarking

.gitignore

@@ -2,4 +2,5 @@
 !*/
 !*.*
 .nimble
-poseidon2.out
+poseidon2.out
+.DS_store

bench/bench_perm.nim

@@ -0,0 +1,63 @@
+
+#
+# nimble build -d:release
+#
+
+import strformat
+import times, os, strutils
+
+import constantine/math/arithmetic
+import constantine/math/io/io_fields
+import constantine/math/io/io_bigints
+
+import poseidon2/types
+import poseidon2/io
+import poseidon2/permutation
+
+#-------------------------------------------------------------------------------
+
+func seconds*(x: float): string = fmt"{x:.4f} seconds"
+
+func quoted*(s: string): string = fmt"`{s:s}`"
+
+template withMeasureTime*(doPrint: bool, text: string, code: untyped) =
+  block:
+    if doPrint:
+      let t0 = epochTime()
+      code
+      let elapsed = epochTime() - t0
+      let elapsedStr = elapsed.formatFloat(format = ffDecimal, precision = 4)
+      echo ( text & " took " & elapsedStr & " seconds" )
+    else:
+      code
+
+#-------------------------------------------------------------------------------
+
+proc iteratePerm(n: int) = 
+
+  var x: F = toF(0)
+  var y: F = toF(1)
+  var z: F = toF(2)
+
+  for i in 0..<n:
+    permInPlace(x, y, z)
+
+  echo "x = ", toDecimal(x)
+  echo "y = ", toDecimal(y)
+  echo "z = ", toDecimal(z)
+
+#-------------------------------------------------------------------------------
+
+when isMainModule:
+
+  echo "quick & dirty nim-poseidon2-bn254 benchmark"
+  
+  let n: int = 1000000
+
+  let text = fmt"{n} Poseidon2 permutations"
+  withMeasureTime(true,text): 
+    iteratePerm(n)
+
+  let mb = float64(n)*62.0/1024/1024
+  echo fmt"that corresponds to about {mb:.2f} megabytes of linear hashing"
+

bench/nim.cfg

@@ -0,0 +1 @@
+--path:".."

poseidon2.nimble

@@ -4,3 +4,5 @@ description = "Poseidon2 hash function"
 license = "MIT"
 
 requires "https://github.com/mratsim/constantine#bc3845aa492b52f7fef047503b1592e830d1a774"
+
+bin = @["bench/bench_perm"]