1.1 --- a/src/share/vm/runtime/sharedRuntimeMath.hpp Tue Jul 29 13:54:16 2014 +0200
1.2 +++ b/src/share/vm/runtime/sharedRuntimeMath.hpp Tue Jul 29 13:56:29 2014 +0200
1.3 @@ -27,20 +27,46 @@
1.4
1.5 #include <math.h>
1.6
1.7 -// VM_LITTLE_ENDIAN is #defined appropriately in the Makefiles
1.8 -// [jk] this is not 100% correct because the float word order may different
1.9 -// from the byte order (e.g. on ARM FPA)
1.10 +// Used to access the lower/higher 32 bits of a double
1.11 +typedef union {
1.12 + double d;
1.13 + struct {
1.14 #ifdef VM_LITTLE_ENDIAN
1.15 -# define __HI(x) *(1+(int*)&x)
1.16 -# define __LO(x) *(int*)&x
1.17 + int lo;
1.18 + int hi;
1.19 #else
1.20 -# define __HI(x) *(int*)&x
1.21 -# define __LO(x) *(1+(int*)&x)
1.22 + int hi;
1.23 + int lo;
1.24 #endif
1.25 + } split;
1.26 +} DoubleIntConv;
1.27 +
1.28 +static inline int high(double d) {
1.29 + DoubleIntConv x = { d };
1.30 + return x.split.hi;
1.31 +}
1.32 +
1.33 +static inline int low(double d) {
1.34 + DoubleIntConv x = { d };
1.35 + return x.split.lo;
1.36 +}
1.37 +
1.38 +static inline void set_high(double* d, int high) {
1.39 + DoubleIntConv conv = { *d };
1.40 + conv.split.hi = high;
1.41 + *d = conv.d;
1.42 +}
1.43 +
1.44 +static inline void set_low(double* d, int low) {
1.45 + DoubleIntConv conv = { *d };
1.46 + conv.split.lo = low;
1.47 + *d = conv.d;
1.48 +}
1.49
1.50 static double copysignA(double x, double y) {
1.51 - __HI(x) = (__HI(x)&0x7fffffff)|(__HI(y)&0x80000000);
1.52 - return x;
1.53 + DoubleIntConv convX = { x };
1.54 + convX.split.hi = (convX.split.hi & 0x7fffffff) | (high(y) & 0x80000000);
1.55 + return convX.d;
1.56 }
1.57
1.58 /*
1.59 @@ -67,30 +93,32 @@
1.60 hugeX = 1.0e+300,
1.61 tiny = 1.0e-300;
1.62
1.63 -static double scalbnA (double x, int n) {
1.64 +static double scalbnA(double x, int n) {
1.65 int k,hx,lx;
1.66 - hx = __HI(x);
1.67 - lx = __LO(x);
1.68 + hx = high(x);
1.69 + lx = low(x);
1.70 k = (hx&0x7ff00000)>>20; /* extract exponent */
1.71 if (k==0) { /* 0 or subnormal x */
1.72 if ((lx|(hx&0x7fffffff))==0) return x; /* +-0 */
1.73 x *= two54;
1.74 - hx = __HI(x);
1.75 + hx = high(x);
1.76 k = ((hx&0x7ff00000)>>20) - 54;
1.77 if (n< -50000) return tiny*x; /*underflow*/
1.78 }
1.79 if (k==0x7ff) return x+x; /* NaN or Inf */
1.80 k = k+n;
1.81 - if (k > 0x7fe) return hugeX*copysignA(hugeX,x); /* overflow */
1.82 - if (k > 0) /* normal result */
1.83 - {__HI(x) = (hx&0x800fffff)|(k<<20); return x;}
1.84 + if (k > 0x7fe) return hugeX*copysignA(hugeX,x); /* overflow */
1.85 + if (k > 0) { /* normal result */
1.86 + set_high(&x, (hx&0x800fffff)|(k<<20));
1.87 + return x;
1.88 + }
1.89 if (k <= -54) {
1.90 if (n > 50000) /* in case integer overflow in n+k */
1.91 return hugeX*copysignA(hugeX,x); /*overflow*/
1.92 else return tiny*copysignA(tiny,x); /*underflow*/
1.93 }
1.94 k += 54; /* subnormal result */
1.95 - __HI(x) = (hx&0x800fffff)|(k<<20);
1.96 + set_high(&x, (hx&0x800fffff)|(k<<20));
1.97 return x*twom54;
1.98 }
1.99
