Explicitly change a floating point division with a constant into a

multiplication by its inverse.

In optimized builds GCC does this on its own, but this may be useful
when using other compilers.
Review URL: http://codereview.chromium.org/11524

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@805 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This commit is contained in:
ager@chromium.org 2008-11-20 11:33:50 +00:00
parent 40cd237bae
commit 9ee294b302

View File

@ -3163,9 +3163,9 @@ static Object* Runtime_Math_random(Arguments args) {
// double in the range [0, RAND_MAX + 1) obtained by adding the // double in the range [0, RAND_MAX + 1) obtained by adding the
// high-order bits in the range [0, RAND_MAX] with the low-order // high-order bits in the range [0, RAND_MAX] with the low-order
// bits in the range [0, 1). // bits in the range [0, 1).
double lo = static_cast<double>(random()) / (RAND_MAX + 1.0); double lo = static_cast<double>(random()) * (1.0 / (RAND_MAX + 1.0));
double hi = static_cast<double>(random()); double hi = static_cast<double>(random());
double result = (hi + lo) / (RAND_MAX + 1.0); double result = (hi + lo) * (1.0 / (RAND_MAX + 1.0));
ASSERT(result >= 0 && result < 1); ASSERT(result >= 0 && result < 1);
return Heap::AllocateHeapNumber(result); return Heap::AllocateHeapNumber(result);
} }