move one math utils function

NethermindEth · Sep 26, 2024 · 96d5623 · 96d5623
1 parent 8a63ad6
commit 96d5623
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Showing 5 changed files with 20 additions and 12 deletions.
diff --git a/pkg/hintrunner/utils/math_utils.go b/pkg/hintrunner/utils/math_utils.go
@@ -66,16 +66,6 @@ func Divmod(n, m, p *big.Int) (big.Int, error) {
  return *res, nil
 }
 
-func SafeDiv(x, y *big.Int) (big.Int, error) {
- if y.Cmp(big.NewInt(0)) == 0 {
- return *big.NewInt(0), fmt.Errorf("division by zero")
- }
- if new(big.Int).Mod(x, y).Cmp(big.NewInt(0)) != 0 {
- return *big.NewInt(0), fmt.Errorf("%v is not divisible by %v", x, y)
- }
- return *new(big.Int).Div(x, y), nil
-}
-
 func IsQuadResidue(x *fp.Element) bool {
  // Implementation adapted from sympy implementation which can be found here :
  // https://github.com/sympy/sympy/blob/d91b8ad6d36a59a879cc70e5f4b379da5fdd46ce/sympy/ntheory/residue_ntheory.py#L689

diff --git a/pkg/hintrunner/zero/zerohint_ec.go b/pkg/hintrunner/zero/zerohint_ec.go
@@ -257,7 +257,7 @@ func newDivModNSafeDivPlusOneHint() hinter.Hinter {
  valueBig.Mul(resBig, bBig)
  valueBig.Sub(valueBig, aBig)
 
- newValueBig, err := secp_utils.SafeDiv(valueBig, nBig)
+ newValueBig, err := utils.SafeDiv(valueBig, nBig)
  if err != nil {
  return err
  }

diff --git a/pkg/hintrunner/zero/zerohint_signature.go b/pkg/hintrunner/zero/zerohint_signature.go
@@ -6,6 +6,7 @@ import (
 
  "github.com/NethermindEth/cairo-vm-go/pkg/hintrunner/hinter"
  secp_utils "github.com/NethermindEth/cairo-vm-go/pkg/hintrunner/utils"
+ "github.com/NethermindEth/cairo-vm-go/pkg/utils"
  VM "github.com/NethermindEth/cairo-vm-go/pkg/vm"
  "github.com/NethermindEth/cairo-vm-go/pkg/vm/builtins"
  mem "github.com/NethermindEth/cairo-vm-go/pkg/vm/memory"
@@ -372,7 +373,7 @@ func newDivModSafeDivHint() hinter.Hinter {
  }
 
  divisor := new(big.Int).Sub(new(big.Int).Mul(res, b), a)
- value, err := secp_utils.SafeDiv(divisor, N)
+ value, err := utils.SafeDiv(divisor, N)
  if err != nil {
  return err
  }

diff --git a/pkg/utils/math.go b/pkg/utils/math.go
@@ -220,3 +220,13 @@ func sign(n *big.Int) (int, big.Int) {
  }
  return 1, *new(big.Int).Set(n)
 }
+
+func SafeDiv(x, y *big.Int) (big.Int, error) {
+ if y.Cmp(big.NewInt(0)) == 0 {
+ return *big.NewInt(0), fmt.Errorf("division by zero")
+ }
+ if new(big.Int).Mod(x, y).Cmp(big.NewInt(0)) != 0 {
+ return *big.NewInt(0), fmt.Errorf("%v is not divisible by %v", x, y)
+ }
+ return *new(big.Int).Div(x, y), nil
+}
diff --git a/pkg/vm/builtins/modulo.go b/pkg/vm/builtins/modulo.go
@@ -411,6 +411,13 @@ func (m *ModBuiltin) fillValue(mem *memory.Memory, inputs ModBuiltinInputs, inde
  }
  }
  } else {
+ x, _, gcd := utils.Igcdex(b, &inputs.p)
+ if gcd.Cmp(big.NewInt(1)) != 0 {
+ value = *new(big.Int).Div(&inputs.p, &gcd)
+ } else {
+ value = *new(big.Int).Mul(c, &x)
+ value = *value.Mod(&value, &inputs.p)
+ }
  value = *new(big.Int).Div(c, b)
  }
  if err := m.writeNWordsValue(mem, addresses[0], value); err != nil {