changeset 25919:d4e4f72b49fc

8049043: Load variable through a pointer of an incompatible type in hotspot/src/share/vm/runtime/sharedRuntimeMath.hpp Summary: Fixed parfait warnings caused by __HI and __LO macros in sharedRuntimeMath.hpp by using a union. Reviewed-by: kvn, drchase
author thartmann
date Tue, 29 Jul 2014 13:56:29 +0200
parents 79e4c4d9f5c9
children 3e0e9399c3ac
files hotspot/src/share/vm/runtime/sharedRuntimeMath.hpp hotspot/src/share/vm/runtime/sharedRuntimeTrans.cpp hotspot/src/share/vm/runtime/sharedRuntimeTrig.cpp
diffstat 3 files changed, 89 insertions(+), 60 deletions(-) [+]
line wrap: on
line diff
--- a/hotspot/src/share/vm/runtime/sharedRuntimeMath.hpp	Tue Jul 29 13:54:16 2014 +0200
+++ b/hotspot/src/share/vm/runtime/sharedRuntimeMath.hpp	Tue Jul 29 13:56:29 2014 +0200
@@ -27,20 +27,46 @@
 
 #include <math.h>
 
-// VM_LITTLE_ENDIAN is #defined appropriately in the Makefiles
-// [jk] this is not 100% correct because the float word order may different
-// from the byte order (e.g. on ARM FPA)
+// Used to access the lower/higher 32 bits of a double
+typedef union {
+    double d;
+    struct {
 #ifdef VM_LITTLE_ENDIAN
-# define __HI(x) *(1+(int*)&x)
-# define __LO(x) *(int*)&x
+      int lo;
+      int hi;
 #else
-# define __HI(x) *(int*)&x
-# define __LO(x) *(1+(int*)&x)
+      int hi;
+      int lo;
 #endif
+    } split;
+} DoubleIntConv;
+
+static inline int high(double d) {
+  DoubleIntConv x = { d };
+  return x.split.hi;
+}
+
+static inline int low(double d) {
+  DoubleIntConv x = { d };
+  return x.split.lo;
+}
+
+static inline void set_high(double* d, int high) {
+  DoubleIntConv conv = { *d };
+  conv.split.hi = high;
+  *d = conv.d;
+}
+
+static inline void set_low(double* d, int low) {
+  DoubleIntConv conv = { *d };
+  conv.split.lo = low;
+  *d = conv.d;
+}
 
 static double copysignA(double x, double y) {
-  __HI(x) = (__HI(x)&0x7fffffff)|(__HI(y)&0x80000000);
-  return x;
+  DoubleIntConv convX = { x };
+  convX.split.hi = (convX.split.hi & 0x7fffffff) | (high(y) & 0x80000000);
+  return convX.d;
 }
 
 /*
@@ -67,30 +93,32 @@
 hugeX  = 1.0e+300,
 tiny   = 1.0e-300;
 
-static double scalbnA (double x, int n) {
+static double scalbnA(double x, int n) {
   int  k,hx,lx;
-  hx = __HI(x);
-  lx = __LO(x);
+  hx = high(x);
+  lx = low(x);
   k = (hx&0x7ff00000)>>20;              /* extract exponent */
   if (k==0) {                           /* 0 or subnormal x */
     if ((lx|(hx&0x7fffffff))==0) return x; /* +-0 */
     x *= two54;
-    hx = __HI(x);
+    hx = high(x);
     k = ((hx&0x7ff00000)>>20) - 54;
     if (n< -50000) return tiny*x;       /*underflow*/
   }
   if (k==0x7ff) return x+x;             /* NaN or Inf */
   k = k+n;
-  if (k >  0x7fe) return hugeX*copysignA(hugeX,x); /* overflow  */
-  if (k > 0)                            /* normal result */
-    {__HI(x) = (hx&0x800fffff)|(k<<20); return x;}
+  if (k > 0x7fe) return hugeX*copysignA(hugeX,x); /* overflow  */
+  if (k > 0) {                          /* normal result */
+    set_high(&x, (hx&0x800fffff)|(k<<20));
+    return x;
+  }
   if (k <= -54) {
     if (n > 50000)      /* in case integer overflow in n+k */
       return hugeX*copysignA(hugeX,x);  /*overflow*/
     else return tiny*copysignA(tiny,x); /*underflow*/
   }
   k += 54;                              /* subnormal result */
-  __HI(x) = (hx&0x800fffff)|(k<<20);
+  set_high(&x, (hx&0x800fffff)|(k<<20));
   return x*twom54;
 }
 
--- a/hotspot/src/share/vm/runtime/sharedRuntimeTrans.cpp	Tue Jul 29 13:54:16 2014 +0200
+++ b/hotspot/src/share/vm/runtime/sharedRuntimeTrans.cpp	Tue Jul 29 13:56:29 2014 +0200
@@ -40,6 +40,7 @@
 // generated; can not figure out how to turn down optimization for one
 // file in the IDE on Windows
 #ifdef WIN32
+# pragma warning( disable: 4748 ) // /GS can not protect parameters and local variables from local buffer overrun because optimizations are disabled in function
 # pragma optimize ( "", off )
 #endif
 
@@ -114,8 +115,8 @@
   int k,hx,i,j;
   unsigned lx;
 
-  hx = __HI(x);               /* high word of x */
-  lx = __LO(x);               /* low  word of x */
+  hx = high(x);               /* high word of x */
+  lx = low(x);                /* low  word of x */
 
   k=0;
   if (hx < 0x00100000) {                   /* x < 2**-1022  */
@@ -123,13 +124,13 @@
       return -two54/zero;             /* log(+-0)=-inf */
     if (hx<0) return (x-x)/zero;   /* log(-#) = NaN */
     k -= 54; x *= two54; /* subnormal number, scale up x */
-    hx = __HI(x);             /* high word of x */
+    hx = high(x);             /* high word of x */
   }
   if (hx >= 0x7ff00000) return x+x;
   k += (hx>>20)-1023;
   hx &= 0x000fffff;
   i = (hx+0x95f64)&0x100000;
-  __HI(x) = hx|(i^0x3ff00000);        /* normalize x or x/2 */
+  set_high(&x, hx|(i^0x3ff00000)); /* normalize x or x/2 */
   k += (i>>20);
   f = x-1.0;
   if((0x000fffff&(2+hx))<3) {  /* |f| < 2**-20 */
@@ -208,8 +209,8 @@
   int i,k,hx;
   unsigned lx;
 
-  hx = __HI(x);       /* high word of x */
-  lx = __LO(x);       /* low word of x */
+  hx = high(x);       /* high word of x */
+  lx = low(x);        /* low word of x */
 
   k=0;
   if (hx < 0x00100000) {                  /* x < 2**-1022  */
@@ -217,14 +218,14 @@
       return -two54/zero;             /* log(+-0)=-inf */
     if (hx<0) return (x-x)/zero;        /* log(-#) = NaN */
     k -= 54; x *= two54; /* subnormal number, scale up x */
-    hx = __HI(x);                /* high word of x */
+    hx = high(x);                /* high word of x */
   }
   if (hx >= 0x7ff00000) return x+x;
   k += (hx>>20)-1023;
   i  = ((unsigned)k&0x80000000)>>31;
   hx = (hx&0x000fffff)|((0x3ff-i)<<20);
   y  = (double)(k+i);
-  __HI(x) = hx;
+  set_high(&x, hx);
   z  = y*log10_2lo + ivln10*__ieee754_log(x);
   return  z+y*log10_2hi;
 }
@@ -319,14 +320,14 @@
   int k=0,xsb;
   unsigned hx;
 
-  hx  = __HI(x);        /* high word of x */
+  hx  = high(x);                /* high word of x */
   xsb = (hx>>31)&1;             /* sign bit of x */
   hx &= 0x7fffffff;             /* high word of |x| */
 
   /* filter out non-finite argument */
   if(hx >= 0x40862E42) {                        /* if |x|>=709.78... */
     if(hx>=0x7ff00000) {
-      if(((hx&0xfffff)|__LO(x))!=0)
+      if(((hx&0xfffff)|low(x))!=0)
         return x+x;             /* NaN */
       else return (xsb==0)? x:0.0;      /* exp(+-inf)={inf,0} */
     }
@@ -357,10 +358,10 @@
   if(k==0)      return one-((x*c)/(c-2.0)-x);
   else          y = one-((lo-(x*c)/(2.0-c))-hi);
   if(k >= -1021) {
-    __HI(y) += (k<<20); /* add k to y's exponent */
+    set_high(&y, high(y) + (k<<20)); /* add k to y's exponent */
     return y;
   } else {
-    __HI(y) += ((k+1000)<<20);/* add k to y's exponent */
+    set_high(&y, high(y) + ((k+1000)<<20)); /* add k to y's exponent */
     return y*twom1000;
   }
 }
@@ -447,8 +448,8 @@
   unsigned lx,ly;
 
   i0 = ((*(int*)&one)>>29)^1; i1=1-i0;
-  hx = __HI(x); lx = __LO(x);
-  hy = __HI(y); ly = __LO(y);
+  hx = high(x); lx = low(x);
+  hy = high(y); ly = low(y);
   ix = hx&0x7fffffff;  iy = hy&0x7fffffff;
 
   /* y==zero: x**0 = 1 */
@@ -548,14 +549,14 @@
     u = ivln2_h*t;      /* ivln2_h has 21 sig. bits */
     v = t*ivln2_l-w*ivln2;
     t1 = u+v;
-    __LO(t1) = 0;
+    set_low(&t1, 0);
     t2 = v-(t1-u);
   } else {
     double ss,s2,s_h,s_l,t_h,t_l;
     n = 0;
     /* take care subnormal number */
     if(ix<0x00100000)
-      {ax *= two53; n -= 53; ix = __HI(ax); }
+      {ax *= two53; n -= 53; ix = high(ax); }
     n  += ((ix)>>20)-0x3ff;
     j  = ix&0x000fffff;
     /* determine interval */
@@ -563,17 +564,17 @@
     if(j<=0x3988E) k=0;         /* |x|<sqrt(3/2) */
     else if(j<0xBB67A) k=1;     /* |x|<sqrt(3)   */
     else {k=0;n+=1;ix -= 0x00100000;}
-    __HI(ax) = ix;
+    set_high(&ax, ix);
 
     /* compute ss = s_h+s_l = (x-1)/(x+1) or (x-1.5)/(x+1.5) */
     u = ax-bp[k];               /* bp[0]=1.0, bp[1]=1.5 */
     v = one/(ax+bp[k]);
     ss = u*v;
     s_h = ss;
-    __LO(s_h) = 0;
+    set_low(&s_h, 0);
     /* t_h=ax+bp[k] High */
     t_h = zeroX;
-    __HI(t_h)=((ix>>1)|0x20000000)+0x00080000+(k<<18);
+    set_high(&t_h, ((ix>>1)|0x20000000)+0x00080000+(k<<18));
     t_l = ax - (t_h-bp[k]);
     s_l = v*((u-s_h*t_h)-s_h*t_l);
     /* compute log(ax) */
@@ -582,32 +583,32 @@
     r += s_l*(s_h+ss);
     s2  = s_h*s_h;
     t_h = 3.0+s2+r;
-    __LO(t_h) = 0;
+    set_low(&t_h, 0);
     t_l = r-((t_h-3.0)-s2);
     /* u+v = ss*(1+...) */
     u = s_h*t_h;
     v = s_l*t_h+t_l*ss;
     /* 2/(3log2)*(ss+...) */
     p_h = u+v;
-    __LO(p_h) = 0;
+    set_low(&p_h, 0);
     p_l = v-(p_h-u);
     z_h = cp_h*p_h;             /* cp_h+cp_l = 2/(3*log2) */
     z_l = cp_l*p_h+p_l*cp+dp_l[k];
     /* log2(ax) = (ss+..)*2/(3*log2) = n + dp_h + z_h + z_l */
     t = (double)n;
     t1 = (((z_h+z_l)+dp_h[k])+t);
-    __LO(t1) = 0;
+    set_low(&t1, 0);
     t2 = z_l-(((t1-t)-dp_h[k])-z_h);
   }
 
   /* split up y into y1+y2 and compute (y1+y2)*(t1+t2) */
   y1  = y;
-  __LO(y1) = 0;
+  set_low(&y1, 0);
   p_l = (y-y1)*t1+y*t2;
   p_h = y1*t1;
   z = p_l+p_h;
-  j = __HI(z);
-  i = __LO(z);
+  j = high(z);
+  i = low(z);
   if (j>=0x40900000) {                          /* z >= 1024 */
     if(((j-0x40900000)|i)!=0)                   /* if z > 1024 */
       return s*hugeX*hugeX;                     /* overflow */
@@ -631,13 +632,13 @@
     n = j+(0x00100000>>(k+1));
     k = ((n&0x7fffffff)>>20)-0x3ff;     /* new k for n */
     t = zeroX;
-    __HI(t) = (n&~(0x000fffff>>k));
+    set_high(&t, (n&~(0x000fffff>>k)));
     n = ((n&0x000fffff)|0x00100000)>>(20-k);
     if(j<0) n = -n;
     p_h -= t;
   }
   t = p_l+p_h;
-  __LO(t) = 0;
+  set_low(&t, 0);
   u = t*lg2_h;
   v = (p_l-(t-p_h))*lg2+t*lg2_l;
   z = u+v;
@@ -646,10 +647,10 @@
   t1  = z - t*(P1+t*(P2+t*(P3+t*(P4+t*P5))));
   r  = (z*t1)/(t1-two)-(w+z*w);
   z  = one-(r-z);
-  j  = __HI(z);
+  j  = high(z);
   j += (n<<20);
   if((j>>20)<=0) z = scalbnA(z,n);       /* subnormal output */
-  else __HI(z) += (n<<20);
+  else set_high(&z, high(z) + (n<<20));
   return s*z;
 }
 
--- a/hotspot/src/share/vm/runtime/sharedRuntimeTrig.cpp	Tue Jul 29 13:54:16 2014 +0200
+++ b/hotspot/src/share/vm/runtime/sharedRuntimeTrig.cpp	Tue Jul 29 13:56:29 2014 +0200
@@ -519,7 +519,7 @@
 {
         double z,r,v;
         int ix;
-        ix = __HI(x)&0x7fffffff;        /* high word of x */
+        ix = high(x)&0x7fffffff;                /* high word of x */
         if(ix<0x3e400000)                       /* |x| < 2**-27 */
            {if((int)x==0) return x;}            /* generate inexact */
         z       =  x*x;
@@ -574,9 +574,9 @@
 
 static double __kernel_cos(double x, double y)
 {
-  double a,h,z,r,qx;
+  double a,h,z,r,qx=0;
   int ix;
-  ix = __HI(x)&0x7fffffff;      /* ix = |x|'s high word*/
+  ix = high(x)&0x7fffffff;              /* ix = |x|'s high word*/
   if(ix<0x3e400000) {                   /* if x < 2**27 */
     if(((int)x)==0) return one;         /* generate inexact */
   }
@@ -588,8 +588,8 @@
     if(ix > 0x3fe90000) {               /* x > 0.78125 */
       qx = 0.28125;
     } else {
-      __HI(qx) = ix-0x00200000; /* x/4 */
-      __LO(qx) = 0;
+      set_high(&qx, ix-0x00200000); /* x/4 */
+      set_low(&qx, 0);
     }
     h = 0.5*z-qx;
     a = one-qx;
@@ -654,11 +654,11 @@
 {
   double z,r,v,w,s;
   int ix,hx;
-  hx = __HI(x);   /* high word of x */
+  hx = high(x);           /* high word of x */
   ix = hx&0x7fffffff;     /* high word of |x| */
   if(ix<0x3e300000) {                     /* x < 2**-28 */
     if((int)x==0) {                       /* generate inexact */
-      if (((ix | __LO(x)) | (iy + 1)) == 0)
+      if (((ix | low(x)) | (iy + 1)) == 0)
         return one / fabsd(x);
       else {
         if (iy == 1)
@@ -667,10 +667,10 @@
           double a, t;
 
           z = w = x + y;
-          __LO(z) = 0;
+          set_low(&z, 0);
           v = y - (z - x);
           t = a = -one / w;
-          __LO(t) = 0;
+          set_low(&t, 0);
           s = one + t * z;
           return t + a * (s + t * v);
         }
@@ -705,10 +705,10 @@
     /*  compute -1.0/(x+r) accurately */
     double a,t;
     z  = w;
-    __LO(z) = 0;
+    set_low(&z, 0);
     v  = r-(z - x);     /* z+v = r+x */
     t = a  = -1.0/w;    /* a = -1.0/w */
-    __LO(t) = 0;
+    set_low(&t, 0);
     s  = 1.0+t*z;
     return t+a*(s+t*v);
   }
@@ -757,7 +757,7 @@
   int n, ix;
 
   /* High word of x. */
-  ix = __HI(x);
+  ix = high(x);
 
   /* |x| ~< pi/4 */
   ix &= 0x7fffffff;
@@ -815,7 +815,7 @@
   int n, ix;
 
   /* High word of x. */
-  ix = __HI(x);
+  ix = high(x);
 
   /* |x| ~< pi/4 */
   ix &= 0x7fffffff;
@@ -872,7 +872,7 @@
   int n, ix;
 
   /* High word of x. */
-  ix = __HI(x);
+  ix = high(x);
 
   /* |x| ~< pi/4 */
   ix &= 0x7fffffff;