(Div16 <t> n (Const16 [c])) && isPowerOfTwo16(c) =>
  (Rsh16x64
    (Add16 <t> n (Rsh16Ux64 <t> (Rsh16x64 <t> n (Const64 <typ.UInt64> [15])) (Const64 <typ.UInt64> [int64(16-log16(c))])))
    (Const64 <typ.UInt64> [int64(log16(c))]))
(Div32 <t> n (Const32 [c])) && isPowerOfTwo32(c) =>
  (Rsh32x64
    (Add32 <t> n (Rsh32Ux64 <t> (Rsh32x64 <t> n (Const64 <typ.UInt64> [31])) (Const64 <typ.UInt64> [int64(32-log32(c))])))

//
// Special cases are:
//
//	Log1p(+Inf) = +Inf
//	Log1p(±0) = ±0
//	Log1p(-1) = -Inf
//	Log1p(x < -1) = NaN
//	Log1p(NaN) = NaN
func Log1p(x float64) float64 {
	if haveArchLog1p {
		return archLog1p(x)
	}
	return log1p(x)
}

func log1p(x float64) float64 {
	const (
		Sqrt2M1     = 4.142135623730950488017e-01  // Sqrt(2)-1 = 0x3fda827999fcef34

// license that can be found in the LICENSE file.

package math

// Log10 returns the decimal logarithm of x.
// The special cases are the same as for [Log].
func Log10(x float64) float64 {
	if haveArchLog10 {
		return archLog10(x)
	}
	return log10(x)
}

func log10(x float64) float64 {
	return Log(x) * (1 / Ln10)
}

// Log2 returns the binary logarithm of x.

// license that can be found in the LICENSE file.

package math

// Export internal functions and variable for testing.
var Log10NoVec = log10
var CosNoVec = cos
var CoshNoVec = cosh
var SinNoVec = sin
var SinhNoVec = sinh
var TanhNoVec = tanh
var Log1pNovec = log1p
var AtanhNovec = atanh
var AcosNovec = acos
var AcoshNovec = acosh
var AsinNovec = asin
var AsinhNovec = asinh
var ErfNovec = erf

		a := Abs(vf[i])
		if f := Log10NoVec(a); !veryclose(log10[i], f) {
			t.Errorf("Log10(%g) = %g, want %g", a, f, log10[i])
		}
	}
	if f := Log10NoVec(E); f != Log10E {
		t.Errorf("Log10(%g) = %g, want %g", E, f, Log10E)
	}
	for i := 0; i < len(vflogSC); i++ {
		if f := Log10NoVec(vflogSC[i]); !alike(logSC[i], f) {
			t.Errorf("Log10(%g) = %g, want %g", vflogSC[i], f, logSC[i])
		}
	}
}

	return int64(ntz64(^x))
}

// logX returns logarithm of n base 2.
// n must be a positive power of 2 (isPowerOfTwoX returns true).
func log8(n int8) int64 {
	return int64(bits.Len8(uint8(n))) - 1
}
func log16(n int16) int64 {
	return int64(bits.Len16(uint16(n))) - 1
}
func log32(n int32) int64 {
	return int64(bits.Len32(uint32(n))) - 1
}
func log64(n int64) int64 {
	return int64(bits.Len64(uint64(n))) - 1
}

	// result: (Rsh16Ux64 n (Const64 <typ.UInt64> [log16(c)]))
	for {
		n := v_0
		if v_1.Op != OpConst16 {
			break
		}
		c := auxIntToInt16(v_1.AuxInt)
		if !(isNonNegative(n) && isPowerOfTwo16(c)) {
			break
		}
		v.reset(OpRsh16Ux64)
		v0 := b.NewValue0(v.Pos, OpConst64, typ.UInt64)
		v0.AuxInt = int64ToAuxInt(log16(c))
		v.AddArg2(n, v0)
		return true
	}

GLOBL ·log1ptab<> + 0(SB), RODATA, $128

// Log1p returns the natural logarithm of 1 plus its argument x.
// It is more accurate than Log(1 + x) when x is near zero.
//
// Special cases are:
//      Log1p(+Inf) = +Inf
//      Log1p(±0) = ±0
//      Log1p(-1) = -Inf
//      Log1p(x < -1) = NaN
//      Log1p(NaN) = NaN
// The algorithm used is minimax polynomial approximation

TEXT ·log10TrampolineSetup(SB), NOSPLIT, $0
	MOVB   ·hasVX(SB), R1
	CMPBEQ R1, $1, vectorimpl                 // vectorfacility = 1, vector supported
	MOVD   $·log10vectorfacility+0x00(SB), R1
	MOVD   $·log10(SB), R2
	MOVD   R2, 0(R1)
	BR     ·log10(SB)

vectorimpl:
	MOVD $·log10vectorfacility+0x00(SB), R1
	MOVD $·log10Asm(SB), R2
	MOVD R2, 0(R1)
	BR   ·log10Asm(SB)

GLOBL ·log10vectorfacility+0x00(SB), NOPTR, $8

        assertEquals(BigIntegerMath.log10(valueOf(x), mode), IntMath.log10(x, mode));
      }
    }
  }

  // Relies on the correctness of log10(int, FLOOR) and of pow(int, int).
  @GwtIncompatible // pow()
  public void testLog10Exact() {
    for (int x : POSITIVE_INTEGER_CANDIDATES) {
      int floor = IntMath.log10(x, FLOOR);
      boolean expectSuccess = IntMath.pow(10, floor) == x;