From e31f4ca331fe1ed971a86c7ba29174d8ad3c40b4 Mon Sep 17 00:00:00 2001
From: Anna Shaleva <shaleva.ann@nspcc.ru>
Date: Thu, 12 May 2022 14:23:22 +0300
Subject: [PATCH] interop: add interop API for MODMUL, MODPOW opcodes

---
 pkg/compiler/syscall_test.go | 40 ++++++++++++++++++++++++++++++++++++
 pkg/interop/math/math.go     | 11 ++++++++++
 2 files changed, 51 insertions(+)

diff --git a/pkg/compiler/syscall_test.go b/pkg/compiler/syscall_test.go
index 68e948256..f14d8629c 100644
--- a/pkg/compiler/syscall_test.go
+++ b/pkg/compiler/syscall_test.go
@@ -334,4 +334,44 @@ func TestOpcode(t *testing.T) {
 			stackitem.Make(false),
 		})
 	})
+	t.Run("MODMUL", func(t *testing.T) {
+		src := `package foo
+		import "github.com/nspcc-dev/neo-go/pkg/interop/math"
+		func Main() []int {
+			r := make([]int, 5)
+			r[0] = math.ModMul(3, 4, 5)
+			r[1] = math.ModMul(-3, 4, 5)
+			r[2] = math.ModMul(3, 4, -5)
+			r[3] = math.ModMul(-3, 4, -5)
+			r[4] = math.ModMul(0, 4, 5)
+			return r
+		}`
+		eval(t, src, []stackitem.Item{
+			stackitem.Make(2),
+			stackitem.Make(3),
+			stackitem.Make(2),
+			stackitem.Make(3),
+			stackitem.Make(0),
+		})
+	})
+	t.Run("MODPOW", func(t *testing.T) {
+		src := `package foo
+		import "github.com/nspcc-dev/neo-go/pkg/interop/math"
+		func Main() []int {
+			r := make([]int, 5)
+			r[0] = math.ModPow(3, 4, 5)
+			r[1] = math.ModPow(-3, 5, 5)
+			r[2] = math.ModPow(3, 4, -5)
+			r[3] = math.ModPow(-3, 5, -5)
+			r[4] = math.ModPow(19, -1, 141)
+			return r
+		}`
+		eval(t, src, []stackitem.Item{
+			stackitem.Make(1),
+			stackitem.Make(2),
+			stackitem.Make(1),
+			stackitem.Make(2),
+			stackitem.Make(52),
+		})
+	})
 }
diff --git a/pkg/interop/math/math.go b/pkg/interop/math/math.go
index 796a73e57..b77ff0944 100644
--- a/pkg/interop/math/math.go
+++ b/pkg/interop/math/math.go
@@ -44,3 +44,14 @@ func Min(a, b int) int {
 func Within(x, a, b int) bool {
 	return neogointernal.Opcode3("WITHIN", x, a, b).(bool)
 }
+
+// ModMul returns the result of modulus division on a*b.
+func ModMul(a, b, mod int) int {
+	return neogointernal.Opcode3("MODMUL", a, b, mod).(int)
+}
+
+// ModPow returns the result of modulus division on a^b. If b is -1,
+// it returns the modular inverse of a.
+func ModPow(a, b, mod int) int {
+	return neogointernal.Opcode3("MODPOW", a, b, mod).(int)
+}