From: Russ Cox <rsc@golang.org>
Date: Wed, 27 Jul 2022 03:34:15 +0000 (-0400)
Subject: math/big: add benchmark of Exp with large modulus
X-Git-Tag: go1.20rc1~462
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=d8541aa8d5d09042cff39ba064b2e09b772f0ae0;p=gostls13.git

math/big: add benchmark of Exp with large modulus

Setting up for improving even modulus.

name                   time/op
ExpMont/Odd-16          240µs ± 2%
ExpMont/Even1-16        757µs ± 3%
ExpMont/Even2-16        755µs ± 1%
ExpMont/Even3-16        771µs ± 3%
ExpMont/Even4-16        775µs ± 3%
ExpMont/Even8-16        779µs ± 2%
ExpMont/Even32-16       778µs ± 3%
ExpMont/Even64-16       774µs ± 6%
ExpMont/Even96-16       776µs ± 4%
ExpMont/Even128-16      764µs ± 2%
ExpMont/Even255-16      761µs ± 3%
ExpMont/SmallEven1-16  45.6µs ± 1%
ExpMont/SmallEven2-16  44.3µs ± 2%
ExpMont/SmallEven3-16  44.1µs ± 5%
ExpMont/SmallEven4-16  47.1µs ± 6%

name                   alloc/op
ExpMont/Odd-16         2.53kB ± 0%
ExpMont/Even1-16       2.57kB ± 0%
ExpMont/Even2-16       2.57kB ± 0%
ExpMont/Even3-16       2.57kB ± 0%
ExpMont/Even4-16       2.57kB ± 0%
ExpMont/Even8-16       2.57kB ± 0%
ExpMont/Even32-16      2.57kB ± 0%
ExpMont/Even64-16      2.57kB ± 0%
ExpMont/Even96-16      2.57kB ± 0%
ExpMont/Even128-16     2.57kB ± 0%
ExpMont/Even255-16     2.57kB ± 0%
ExpMont/SmallEven1-16    872B ± 0%
ExpMont/SmallEven2-16    872B ± 0%
ExpMont/SmallEven3-16    872B ± 0%
ExpMont/SmallEven4-16    872B ± 0%

name                   allocs/op
ExpMont/Odd-16           21.0 ± 0%
ExpMont/Even1-16         24.0 ± 0%
ExpMont/Even2-16         24.0 ± 0%
ExpMont/Even3-16         24.0 ± 0%
ExpMont/Even4-16         24.0 ± 0%
ExpMont/Even8-16         24.0 ± 0%
ExpMont/Even32-16        24.0 ± 0%
ExpMont/Even64-16        24.0 ± 0%
ExpMont/Even96-16        24.0 ± 0%
ExpMont/Even128-16       24.0 ± 0%
ExpMont/Even255-16       24.0 ± 0%
ExpMont/SmallEven1-16    16.0 ± 0%
ExpMont/SmallEven2-16    16.0 ± 0%
ExpMont/SmallEven3-16    16.0 ± 0%
ExpMont/SmallEven4-16    16.0 ± 0%

Change-Id: I5278378b4209a97b16273be581533310e0e4110b
Reviewed-on: https://go-review.googlesource.com/c/go/+/420896
Reviewed-by: Roland Shoemaker <roland@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
Auto-Submit: Russ Cox <rsc@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
---

diff --git a/src/math/big/int_test.go b/src/math/big/int_test.go
index 75831e5215..53cd399b1f 100644
--- a/src/math/big/int_test.go
+++ b/src/math/big/int_test.go
@@ -661,6 +661,41 @@ func BenchmarkExp(b *testing.B) {
 	}
 }
 
+func BenchmarkExpMont(b *testing.B) {
+	x, _ := new(Int).SetString("297778224889315382157302278696111964193", 0)
+	y, _ := new(Int).SetString("2548977943381019743024248146923164919440527843026415174732254534318292492375775985739511369575861449426580651447974311336267954477239437734832604782764979371984246675241012538135715981292390886872929238062252506842498360562303324154310849745753254532852868768268023732398278338025070694508489163836616810661033068070127919590264734220833816416141878688318329193389865030063416339367925710474801991305827284114894677717927892032165200876093838921477120036402410731159852999623461591709308405270748511350289172153076023215", 0)
+	var mods = []struct {
+		name string
+		val  string
+	}{
+		{"Odd", "0x82828282828200FFFF28FF2B218281FF82828282828200FFFF28FF2B218281FF82828282828200FFFF28FF2B218281FF"},
+		{"Even1", "0x82828282828200FFFF28FF2B218281FF82828282828200FFFF28FF2B218281FF82828282828200FFFF28FF2B218281FE"},
+		{"Even2", "0x82828282828200FFFF28FF2B218281FF82828282828200FFFF28FF2B218281FF82828282828200FFFF28FF2B218281FC"},
+		{"Even3", "0x82828282828200FFFF28FF2B218281FF82828282828200FFFF28FF2B218281FF82828282828200FFFF28FF2B218281F8"},
+		{"Even4", "0x82828282828200FFFF28FF2B218281FF82828282828200FFFF28FF2B218281FF82828282828200FFFF28FF2B218281F0"},
+		{"Even8", "0x82828282828200FFFF28FF2B218281FF82828282828200FFFF28FF2B218281FF82828282828200FFFF28FF2B21828100"},
+		{"Even32", "0x82828282828200FFFF28FF2B218281FF82828282828200FFFF28FF2B218281FF82828282828200FFFF28FF2B00000000"},
+		{"Even64", "0x82828282828200FFFF28FF2B218281FF82828282828200FFFF28FF2B218281FF82828282828200FF0000000000000000"},
+		{"Even96", "0x82828282828200FFFF28FF2B218281FF82828282828200FFFF28FF2B218281FF82828283000000000000000000000000"},
+		{"Even128", "0x82828282828200FFFF28FF2B218281FF82828282828200FFFF28FF2B218281FF00000000000000000000000000000000"},
+		{"Even255", "0x82828282828200FFFF28FF2B218281FF8000000000000000000000000000000000000000000000000000000000000000"},
+		{"SmallEven1", "0x7E"},
+		{"SmallEven2", "0x7C"},
+		{"SmallEven3", "0x78"},
+		{"SmallEven4", "0x70"},
+	}
+	for _, mod := range mods {
+		n, _ := new(Int).SetString(mod.val, 0)
+		out := new(Int)
+		b.Run(mod.name, func(b *testing.B) {
+			b.ReportAllocs()
+			for i := 0; i < b.N; i++ {
+				out.Exp(x, y, n)
+			}
+		})
+	}
+}
+
 func BenchmarkExp2(b *testing.B) {
 	x, _ := new(Int).SetString("2", 0)
 	y, _ := new(Int).SetString("0xAC6BDB41324A9A9BF166DE5E1389582FAF72B6651987EE07FC3192943DB56050A37329CBB4A099ED8193E0757767A13DD52312AB4B03310DCD7F48A9DA04FD50E8083969EDB767B0CF6095179A163AB3661A05FBD5FAAAE82918A9962F0B93B855F97993EC975EEAA80D740ADBF4FF747359D041D5C33EA71D281E446B14773BCA97B43A23FB801676BD207A436C6481F1D2B9078717461A5B9D32E688F87748544523B524B0D57D5EA77A2775D2ECFA032CFBDBF52FB3786160279004E57AE6AF874E7303CE53299CCC041C7BC308D82A5698F3A8D0C38271AE35F8E9DBFBB694B5C803D89F7AE435DE236D525F54759B65E372FCD68EF20FA7111F9E4AFF72", 0)