ivy: update to math/rand/v2

Because math/big is not updated to v2, we must do a bit more of the lifting ourselves, but the word-stuffing interface to big.Int makes it pretty easy. One minor annoyance, probably not worth fixing, is that the Seed for PCG is two words, but the UI we have only allows one. Fixes #174
robpike · Jan 2, 2025 · eb57228 · eb57228
1 parent 16f847d
commit eb57228
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Showing 11 changed files with 58 additions and 50 deletions.
diff --git a/config/config.go b/config/config.go
@@ -8,7 +8,7 @@ import (
 	"fmt"
 	"io"
 	"math/big"
-	"math/rand"
+	"math/rand/v2"
 	"os"
 	"path/filepath"
 	"strconv"
@@ -40,10 +40,10 @@ type Config struct {
 	formatFloat bool // Whether format is floating-point.
 	origin      int
 	bigOrigin   *big.Int
-	seed        int64
+	seed        uint64
 	debug       [len(DebugFlags)]int
 	traceLevel  int
-	source      rand.Source
+	source      *rand.PCG
 	random      *rand.Rand
 	randLock    sync.Mutex
 	maxBits     uint           // Maximum length of an integer; 0 means no limit.
@@ -66,9 +66,9 @@ func (c *Config) init() {
 		c.output = os.Stdout
 		c.errOutput = os.Stderr
 		c.origin = 1
-		c.seed = time.Now().UnixNano()
+		c.seed = uint64(time.Now().UnixNano())
 		c.bigOrigin = big.NewInt(1)
-		c.source = rand.NewSource(c.seed)
+		c.source = rand.NewPCG(c.seed, c.seed) // Need two words. Oh well.
 		c.random = rand.New(c.source)
 		c.maxBits = 1e6
 		c.maxDigits = 1e4
@@ -222,19 +222,19 @@ func (c *Config) Random() *rand.Rand {
 }
 
 // RandomSeed returns the seed used to initialize the random number generator.
-func (c *Config) RandomSeed() int64 {
+func (c *Config) RandomSeed() uint64 {
 	c.LockRandom()
 	seed := c.seed
 	c.UnlockRandom()
 	return seed
 }
 
 // SetRandomSeed sets the seed for the random number generator.
-func (c *Config) SetRandomSeed(seed int64) {
+func (c *Config) SetRandomSeed(seed uint64) {
 	c.init()
 	c.LockRandom()
 	c.seed = seed
-	c.source.Seed(seed)
+	c.source.Seed(seed, seed) // All we can do for now.
 	c.UnlockRandom()
 }
 

diff --git a/demo/demo.out b/demo/demo.out
@@ -205,32 +205,32 @@ world
 0 0 1 0 0
 0 0 0 1 0
 0 0 0 0 1
-6
-53
-2 3 1 4 4 1 4 1 1 1 4 1 3 4 4 4 2 5 3 5
-2 5 5 3 5 4 5 6 3 5 5 4 2 5 4 2 2 5 3 3
-2
-2 3 5
+23
+68
+3 3 3 1 5 3 5 6 3 2 2 1 5 3 4 5 1 1 2 2
+5 5 2 4 6 4 6 2 1 4 5 2 2 6 5 6 3 3 6 3
+5
+5 6 2
 21 22 23 24 25
 16 17 18 19 20
 11 12 13 14 15
  6  7  8  9 10
  1  2  3  4  5
-1 13 16 17 4 9 19 20 6 12 15 2 3 5 7 10 11 14 18 8
-2 2 2 2 3 3 3 3 4 4 4 5 5 5 5 5 5 5 5 6
-6 5 5 5 5 5 5 5 5 4 4 4 3 3 3 3 2 2 2 2
+9 3 8 12 13 17 18 20 4 6 10 1 2 11 15 5 7 14 16 19
+1 2 2 2 2 3 3 3 4 4 4 5 5 5 5 6 6 6 6 6
+6 6 6 6 6 5 5 5 5 4 4 4 3 3 3 2 2 2 2 1
  dehllloorw
 wroolllhed 
-1 5 1 3 6 5 6 4 6 5
-1 2 5 1 5 1 5 4 4 2
-1 0 0 1 0 1 0 0 0 0
-0 1 0 0 0 0 0 0 0 1
-0 0 0 0 0 0 0 0 0 0
-0 0 0 0 0 0 0 1 1 0
-0 0 1 0 1 0 1 0 0 0
+3 3 5 3 3 3 2 4 6 2
+3 4 1 1 2 1 1 6 2 6
+0 0 1 1 0 1 1 0 0 0
+0 0 0 0 1 0 0 0 1 0
+1 0 0 0 0 0 0 0 0 0
+0 1 0 0 0 0 0 0 0 0
 0 0 0 0 0 0 0 0 0 0
-3 2 0 2 3 0
-10009 10060 10101 10006 9947 9877
+0 0 0 0 0 0 0 1 0 1
+4 2 1 1 0 2
+10003 10005 9943 10003 9936 10110
 93326215443944152681699238856266700490715968264381621468592963895217599993229915608941463976156518286253697920827223758251185210916864000000000000000000000000
 18446744073709551616
 2 4 8 16 32 64 128 256 512 1024 2048 4096 8192 16384 32768 65536 131072 262144 524288 1048576 2097152 4194304 8388608 16777216 33554432 67108864 134217728 268435456 536870912 1073741824 2147483648 4294967296 8589934592 17179869184 34359738368 68719476736 137438953472 274877906944 549755813888 1099511627776 2199023255552 4398046511104 8796093022208 17592186044416 35184372088832 70368744177664 140737488355328 281474976710656 562949953421312 1125899906842624 2251799813685248 4503599627370496 9007199254740992 18014398509481984 36028797018963968 72057594037927936 144115188075855872 288230376151711744 576460752303423488 1152921504606846976 2305843009213693952 4611686018427387904 9223372036854775808 18446744073709551616
@@ -299,7 +299,7 @@ obase	10
 1000000
 20790751712732071385260775389205038176518395689256962640553572190852257598673381784322742265316923818079968268215969189602199756251999333965132909951960289976500893760055198463215219092698883914498589405550491920067455174599775586168862012029023648238127.07022046010735612342287230013067007929306351019435926435028561499747440517352604713511825702766039147857499953727037090383883084362025734950710726648468500009346666636430630292715823581701770581944408657475021305573686463728114465493959674058665751620534257457985005236196057918114857289948561454225538704595167673182840177586048550697493300879332131946404945958668733624356589082017084900781744552767939649882284675393555693897791351239406170600871901402146316763999367014729002406016871658214237371538566964220527856919345434240455587742731759660673744448451839668041045815121881991267912200316539315387310602396711510323411102824513044338894430799360841703725372940892716130795137220663022833926894670773439711904995174455909277266084634431285
 50.5
-999 995 994
+980 979 978
 wroo
 1 1 1
 3
@@ -313,7 +313,7 @@ wroo
 7
 105
 2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89 97
-6 4 7 3 1
+9 5 1 10 6
 (A♠) (A♡) (A♣) (A♢)
 (2♠) (2♡) (2♣) (2♢)
 (3♠) (3♡) (3♣) (3♢)
@@ -327,5 +327,5 @@ wroo
 (J♠) (J♡) (J♣) (J♢)
 (Q♠) (Q♡) (Q♣) (Q♢)
 (K♠) (K♡) (K♣) (K♢)
-(J♠) (6♡) (4♢) (5♢) (4♡) (7♢) (8♡) (2♢) (4♣) (Q♣) (9♡) (3♣) (Q♠) (2♣) (J♡) (J♣) (A♠) (K♡) (3♢) (0♣) (6♢) (8♠) (A♢) (A♣) (0♡) (9♢) (8♣) (K♠) (2♠) (3♡) (Q♡) (J♢) (9♠) (3♠) (K♢) (9♣) (Q♢) (7♡) (0♢) (5♠) (4♠) (0♠) (7♠) (7♣) (5♡) (6♣) (6♠) (5♣) (8♢) (A♡) (K♣) (2♡)
+(A♢) (3♣) (2♢) (3♡) (0♡) (4♢) (8♡) (2♡) (J♢) (K♣) (J♠) (J♡) (5♠) (J♣) (5♢) (8♣) (A♠) (5♣) (K♠) (6♣) (6♠) (2♠) (0♢) (Q♡) (0♠) (4♡) (K♡) (K♢) (Q♢) (9♡) (4♠) (8♠) (7♢) (0♣) (7♣) (5♡) (9♢) (6♡) (9♠) (8♢) (A♡) (9♣) (A♣) (Q♠) (7♠) (3♠) (Q♣) (4♣) (6♢) (2♣) (3♢) (7♡)
 22
diff --git a/parse/special.go b/parse/special.go
@@ -329,7 +329,7 @@ Switch:
 			p.Println(conf.RandomSeed())
 			break Switch
 		}
-		conf.SetRandomSeed(p.nextDecimalNumber64())
+		conf.SetRandomSeed(uint64(p.nextDecimalNumber64()))
 	case "timezone":
 		if p.peek().Type == scan.EOF {
 			_, offset := time.Now().In(conf.Location()).Zone()

diff --git a/testdata/binary_int.ivy b/testdata/binary_int.ivy
@@ -518,7 +518,7 @@
 
 )seed 0
 5?10
-	9 3 4 1 6
+	5 6 9 2 1
 
 2 , 5
 	2 5

diff --git a/testdata/reduce.ivy b/testdata/reduce.ivy
@@ -177,4 +177,4 @@ floor F/%3 4 5 6 rho iota 100
 )seed 0
 throws = ? 10000 rho 6
 +/(iota 6) o.== throws
-	1584 1704 1669 1699 1700 1644
+	1660 1684 1656 1642 1671 1687
diff --git a/testdata/unary_bigfloat.ivy b/testdata/unary_bigfloat.ivy
@@ -204,20 +204,20 @@ first sqrt 2
 # Random numbers
 )seed 0
 rand 3
-	1.96599645204
+	1.32199404393
 
 # High precision, not float64s.
 )seed 0
 1e1000 * rand 1e-1000
-	0.655332150681
+	0.44066468131
 
 # Test stats. For a uniform distribution, ideally: mean = .5,  𝛔 = 1/√12 = 0.2887
 )seed 0
 x = rand 10000 rho 1
 mean = (+/ x) / 10000
 sigma = sqrt 1/10000 * +/(x - mean) ** 2
 mean sigma
-	0.500853881349 0.288396812059
+	0.499676724781 0.289259555152
 
 # There is a (possible?) but in big.Float.Copy that made this not work.
 # BigFloat.inverse would change the value of floatOne. This is a simple

diff --git a/testdata/unary_bigint.ivy b/testdata/unary_bigint.ivy
@@ -6,7 +6,7 @@
 
 )seed 0
 ?1e10
-	8354553846
+	2226562147
 
 1e10
 	10000000000

diff --git a/testdata/unary_int.ivy b/testdata/unary_int.ivy
@@ -6,7 +6,7 @@
 
 )seed 0
 ?10
-	6
+	3
 
 23
 	23

diff --git a/testdata/unary_matrix.ivy b/testdata/unary_matrix.ivy
@@ -171,8 +171,8 @@ rho rho 1
 
 )seed 0
 ?2 3 rho iota 6
-	1 1 2
-	3 3 4
+	1 2 2
+	4 2 1
 
 + 2 3 rho 23 45 56
 	23 45 56

diff --git a/testdata/unary_vector.ivy b/testdata/unary_vector.ivy
@@ -30,7 +30,7 @@ x = 4
 
 )seed 0
 ?10 10 10
-	6 3 8
+	3 7 4
 
 + 23 45 56
 	23 45 56

diff --git a/value/unary.go b/value/unary.go
@@ -55,10 +55,19 @@ func bigFloatWrap(op func(*big.Float, *big.Float) *big.Float) func(Context, *big
 // bigIntRand sets a to a random number in [origin, origin+b].
 func bigIntRand(c Context, a, b *big.Int) *big.Int {
 	config := c.Config()
+	bWords := b.Bits()
+	words := make([]big.Word, len(bWords))
 	config.LockRandom()
-	a.Rand(config.Random(), b)
+	// Words are in little-endian order.
+	for i := range words {
+		if i < len(words)-1 || words[i] == (1<<bits.UintSize)-1 { // Word is a uint.
+			words[i] = big.Word(c.Config().Random().Uint64())
+		} else {
+			words[i] = big.Word(c.Config().Random().Uint64N(uint64(bWords[i])))
+		}
+	}
 	config.UnlockRandom()
-	return a.Add(a, config.BigOrigin())
+	return a.SetBits(words).Add(a, config.BigOrigin())
 }
 
 func self(c Context, v Value) Value {
@@ -149,13 +158,12 @@ func bigFloatRand(c Context, f *big.Float) Value {
 		maxBits[i] = big.Word(^uint(0))
 	}
 	max := big.NewInt(0).SetBits(maxBits)
-	max.Add(max, bigIntOne.Int) // big.Int.Rand is [0,n)
-	// Now pick a random integer from [0 to max)
-	config.LockRandom()
-	rand := big.NewInt(0).Rand(config.Random(), max)
-	config.UnlockRandom()
+	max.Add(max, bigIntOne.Int) // We want range [0,n) but we have n-1.
+	// Now grab a random integer from [0, max)
+	randInt := big.NewInt(0)
+	bigIntRand(c, randInt, max)
 	// Make it a float and normalize it.
-	x := big.NewFloat(0).SetInt(rand)
+	x := big.NewFloat(0).SetInt(randInt)
 	x.Quo(x, big.NewFloat(0).SetInt(max))
 	// Finally, scale it up to [0, f).
 	x.Mul(x, f)
@@ -174,9 +182,9 @@ func init() {
 						Errorf("illegal roll value %v", v)
 					}
 					c.Config().LockRandom()
-					res := Int(c.Config().Origin()) + Int(c.Config().Random().Int63n(i))
+					res := Int(c.Config().Random().Int64N(int64(i)))
 					c.Config().UnlockRandom()
-					return res
+					return Int(c.Config().Origin()) + res
 				},
 				bigIntType: func(c Context, v Value) Value {
 					if v.(BigInt).Sign() <= 0 {
-Original file line number
+Diff line change
@@ Expand Up / @@ -518,7 +518,7 @@ @@
     )seed 0
 ?10
-3 4 1 6
+6 9 2 1
 , 5
 5
@@ Expand Down @@