http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56352
Bug #: 56352
Summary: Simplify testing of related conditions in for loop
Classification: Unclassified
Product: gcc
Version: 4.8.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
AssignedTo: unassig...@gcc.gnu.org
ReportedBy: josh.m.con...@gmail.com
If we have a loop like this:
for (i = 0; i < a && i < b; i++)
{
/* Code which cannot affect i, a, or b */
}
gcc should be able to optimize this into:
tmp = MIN(a,b)
for (i = 0; i < tmp; i++)
{
/* Body */
}
But it does not. Similarly, code like:
for (i = 0; i < a; i++)
{
if (i >= b)
break;
/* Code which cannot affect i, a, or b */
}
Should be similarly optimized.
