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// +build amd64,!noasm
package p751
import (
. "github.com/cloudflare/sidh/internal/isogeny"
cpu "github.com/cloudflare/sidh/internal/utils"
"reflect"
"testing"
"testing/quick"
)
type OptimFlag uint
const (
// Indicates that optimisation which uses MUL instruction should be used
kUse_MUL OptimFlag = 1 << 0
// Indicates that optimisation which uses MULX instruction should be used
kUse_MULX = 1 << 1
// Indicates that optimisation which uses MULX, ADOX and ADCX instructions should be used
kUse_MULXandADxX = 1 << 2
)
func resetCpuFeatures() {
HasBMI2 = cpu.X86.HasBMI2
HasADXandBMI2 = cpu.X86.HasBMI2 && cpu.X86.HasADX
}
// Utility function used for testing REDC implementations. Tests caller provided
// redcFunc against redc()
func testRedc(t *testing.T, f1, f2 OptimFlag) {
doRedcTest := func(aRR FpElementX2) bool {
defer resetCpuFeatures()
var resRedcF1, resRedcF2 FpElement
var aRRcpy = aRR
// Compute redc with first implementation
HasBMI2 = (kUse_MULX & f1) == kUse_MULX
HasADXandBMI2 = (kUse_MULXandADxX & f1) == kUse_MULXandADxX
fp751MontgomeryReduce(&resRedcF1, &aRR)
// Compute redc with second implementation
HasBMI2 = (kUse_MULX & f2) == kUse_MULX
HasADXandBMI2 = (kUse_MULXandADxX & f2) == kUse_MULXandADxX
fp751MontgomeryReduce(&resRedcF2, &aRRcpy)
// Compare results
return reflect.DeepEqual(resRedcF2, resRedcF1)
}
if err := quick.Check(doRedcTest, quickCheckConfig); err != nil {
t.Error(err)
}
}
// Ensures correctness of Montgomery reduction implementation which uses MULX
func TestRedcWithMULX(t *testing.T) {
defer resetCpuFeatures()
if !HasBMI2 {
t.Skip("MULX not supported by the platform")
}
testRedc(t, kUse_MULX, kUse_MUL)
}
// Ensures correctness of Montgomery reduction implementation which uses MULX
// and ADCX/ADOX.
func TestRedcWithMULXADxX(t *testing.T) {
defer resetCpuFeatures()
if !HasADXandBMI2 {
t.Skip("MULX, ADCX and ADOX not supported by the platform")
}
testRedc(t, kUse_MULXandADxX, kUse_MUL)
}
// Ensures correctness of Montgomery reduction implementation which uses MULX
// and ADCX/ADOX.
func TestRedcWithMULXADxXAgainstMULX(t *testing.T) {
defer resetCpuFeatures()
if !HasADXandBMI2 {
t.Skip("MULX, ADCX and ADOX not supported by the platform")
}
testRedc(t, kUse_MULXandADxX, kUse_MULX)
}
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