math.unsigned: fix rotate_left() for uint256, add test (#24872)

tankf33der · web-flow · commit 03e72a4856e4 · 2025-07-10T08:45:34.000+03:00
diff --git a/vlib/math/unsigned/uint256.v b/vlib/math/unsigned/uint256.v
@@ -348,7 +348,7 @@ pub fn (u Uint256) rotate_left(k int) Uint256 {
 			return Uint256{u.hi, u.lo}
 		}
 
-		return Uint256{Uint128{u.hi.lo << n | u.lo.hi >> (64 - n), u.hi.hi << n | u.hi.lo >> (64 - n)}, Uint128{}}
+		return Uint256{Uint128{u.hi.lo << n | u.lo.hi >> (64 - n), u.hi.hi << n | u.hi.lo >> (64 - n)}, Uint128{u.lo.lo << n | u.hi.hi >> (64 - n), u.lo.hi << n | u.lo.lo >> (64 - n)}}
 	}
 	n -= 64
 	if n == 0 {
diff --git a/vlib/math/unsigned/uint256_test.v b/vlib/math/unsigned/uint256_test.v
@@ -303,3 +303,8 @@ fn test_lsh() {
 	assert a.lsh(200).str() == '197653379443855803891661337357963000110230968235283518742069248'
 	assert a.lsh(300) == unsigned.uint256_zero
 }
+
+fn test_rotate_left() {
+	a := unsigned.uint256_from_dec_str('25514942427378518882041616545065271187265095759155217686057363902268374351523')!
+	assert a.rotate_left(182).str() == '88706376393829417451765793453791860419270208590599379720310994108668904859637'
+}

Original file line number	Diff line number	Diff line change
`@@ -348,7 +348,7 @@ pub fn (u Uint256) rotate_left(k int) Uint256 {`
`348`	`348`	`return Uint256{u.hi, u.lo}`
`349`	`349`	`}`
`350`	`350`
`351`		`- return Uint256{Uint128{u.hi.lo << n \| u.lo.hi >> (64 - n), u.hi.hi << n \| u.hi.lo >> (64 - n)}, Uint128{}}`
	`351`	`+ return Uint256{Uint128{u.hi.lo << n \| u.lo.hi >> (64 - n), u.hi.hi << n \| u.hi.lo >> (64 - n)}, Uint128{u.lo.lo << n \| u.hi.hi >> (64 - n), u.lo.hi << n \| u.lo.lo >> (64 - n)}}`
`352`	`352`	`}`
`353`	`353`	`n -= 64`
`354`	`354`	`if n == 0 {`
Original file line number	Diff line number	Diff line change
`@@ -303,3 +303,8 @@ fn test_lsh() {`
`303`	`303`	`assert a.lsh(200).str() == '197653379443855803891661337357963000110230968235283518742069248'`
`304`	`304`	`assert a.lsh(300) == unsigned.uint256_zero`
`305`	`305`	`}`
	`306`	`+`
	`307`	`+fn test_rotate_left() {`
	`308`	`+ a := unsigned.uint256_from_dec_str('25514942427378518882041616545065271187265095759155217686057363902268374351523')!`
	`309`	`+ assert a.rotate_left(182).str() == '88706376393829417451765793453791860419270208590599379720310994108668904859637'`
	`310`	`+}`