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Implemented log1p using the new intrinsics. All log functions and atanh, acosh, and asinh are now pure nothrow.

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This commit is contained in:
Don Clugston 2009-04-14 06:51:52 +00:00
parent 7b631c942e
commit 02bfae247a
1 changed files with 30 additions and 17 deletions
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47
std/math.d
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@ -643,7 +643,7 @@ public:
* $(SV +$(INFIN),+$(INFIN))
* )
*/
real acosh(real x)
pure nothrow real acosh(real x)
{
if (x > 1/real.epsilon)
return LN2 + log(x);
@ -651,9 +651,9 @@ real acosh(real x)
return log(x + sqrt(x*x - 1));
}
/// ditto
double acosh(double x) { return acosh(cast(real)x); }
pure nothrow double acosh(double x) { return acosh(cast(real)x); }
/// ditto
float acosh(float x) { return acosh(cast(real)x); }
pure nothrow float acosh(float x) { return acosh(cast(real)x); }
unittest
@ -680,7 +680,7 @@ unittest
* $(SV $(PLUSMN)$(INFIN),$(PLUSMN)$(INFIN))
* )
*/
real asinh(real x)
pure nothrow real asinh(real x)
{
if (fabs(x) > 1 / real.epsilon) { // beyond this point, x*x + 1 == x*x
return copysign(LN2 + log(fabs(x)), x);
@ -690,9 +690,9 @@ real asinh(real x)
}
}
/// ditto
double asinh(double x) { return asinh(cast(real)x); }
pure nothrow double asinh(double x) { return asinh(cast(real)x); }
/// ditto
float asinh(float x) { return asinh(cast(real)x); }
pure nothrow float asinh(float x) { return asinh(cast(real)x); }
unittest
{
@ -720,15 +720,15 @@ unittest
* $(SV -$(INFIN), -0)
* )
*/
real atanh(real x)
pure nothrow real atanh(real x)
{
// log( (1+x)/(1-x) ) == log ( 1 + (2*x)/(1-x) )
return 0.5 * log1p( 2 * x / (1 - x) );
}
/// ditto
double atanh(double x) { return atanh(cast(real)x); }
pure nothrow double atanh(double x) { return atanh(cast(real)x); }
/// ditto
float atanh(float x) { return atanh(cast(real)x); }
pure nothrow float atanh(float x) { return atanh(cast(real)x); }
unittest
@ -1279,7 +1279,7 @@ unittest {
* )
*/
real log(real x)
pure nothrow real log(real x)
{
version (INLINE_YL2X)
return yl2x(x, LN2);
@ -1303,7 +1303,7 @@ unittest
* )
*/
real log10(real x)
pure nothrow real log10(real x)
{
version (INLINE_YL2X)
return yl2x(x, LOG2);
@ -1331,7 +1331,15 @@ unittest
* )
*/
real log1p(real x) { return std.c.math.log1pl(x); }
pure nothrow real log1p(real x) {
version(INLINE_YL2X) {
// On x87, yl2xp1 is valid if and only if -0.5 <= lg(x) <= 0.5,
// ie if -0.29<=x<=0.414
return (fabs(x) <= 0.25) ? yl2xp1(x, LN2) : yl2x(x+1, LN2);
} else {
return std.c.math.log1pl(x);
}
}
/***************************************
* Calculates the base-2 logarithm of x:
@ -1344,7 +1352,7 @@ real log1p(real x) { return std.c.math.log1pl(x); }
* $(TR $(TD +$(INFIN)) $(TD +$(INFIN)) $(TD no) $(TD no) )
* )
*/
real log2(real x)
pure nothrow real log2(real x)
{
version (INLINE_YL2X)
return yl2x(x, 1);
@ -2214,7 +2222,7 @@ pure nothrow real nextUp(real x)
}
/** ditto */
double nextUp(double x)
pure nothrow double nextUp(double x)
{
ulong *ps = cast(ulong *)&x;
@ -2236,7 +2244,7 @@ double nextUp(double x)
}
/** ditto */
float nextUp(float x)
pure nothrow float nextUp(float x)
{
uint *ps = cast(uint *)&x;
@ -2278,13 +2286,13 @@ pure nothrow real nextDown(real x)
}
/** ditto */
double nextDown(double x)
pure nothrow double nextDown(double x)
{
return -nextUp(-x);
}
/** ditto */
float nextDown(float x)
pure nothrow float nextDown(float x)
{
return -nextUp(-x);
}
@ -2627,6 +2635,11 @@ F pow(F)(F x, F y) if (isFloatingPoint!(F))
}
}
}
/*
version(INLINE_YL2X) {
return exp2(yl2x(y, x));
}
*/
return std.c.math.powl(x, y);
}