Replace aliasing with memcpy

References #4319

git-svn-id: http://svn.osgeo.org/postgis/trunk@17744 b70326c6-7e19-0410-871a-916f4a2858ee

diff --git a/liblwgeom/lwgeom.c b/liblwgeom/lwgeom.c
index a655b616c82268572a24e47991726e935ffe8eaf..a5f5152d8ef4ca3d0abe20a5da996a44a742225e 100644 (file)
--- a/liblwgeom/lwgeom.c
+++ b/liblwgeom/lwgeom.c
@@ -2444,28 +2444,21 @@ bits_for_precision(int32_t significant_digits)
        return bits_needed;
 }
 
-static inline
-double mask_double(double d, uint64_t mask)
-{
-       uint64_t* double_bits = (uint64_t*) (&d);
-
-       (*double_bits) &= mask;
-
-       return *((double*) double_bits);
-}
-
 static double trim_preserve_decimal_digits(double d, int32_t decimal_digits)
 {
-       if (d==0)
+       if (d == 0)
                return 0;
 
        int digits_left_of_decimal = (int) (1 + log10(fabs(d)));
        uint8_t bits_needed = bits_for_precision(decimal_digits + digits_left_of_decimal);
-
-
        uint64_t mask = 0xffffffffffffffff << (52 - bits_needed);
+       uint64_t dint = 0;
+       size_t dsz = sizeof(d) < sizeof(dint) ? sizeof(d) : sizeof(dint);
 
-       return mask_double(d, mask);
+       memcpy(&dint, &d, dsz);
+       dint &= mask;
+       memcpy(&d, &dint, dsz);
+       return d;
 }
 
 void lwgeom_trim_bits_in_place(LWGEOM* geom, int32_t prec_x, int32_t prec_y, int32_t prec_z, int32_t prec_m)