[project @ 2000-01-28 18:07:55 by sewardj]
Modifications to make x86 register spilling to work reasonably. It should work ok most of the time, although there is still a remote possibility that the allocator simply will be unable to complete spilling, and will just give up. -- Incrementally try with 0, 1, 2 and 3 spill regs, so as not to unduly restrict the supply of regs in code which doesn't need spilling. -- Remove the use of %ecx for shift values, so it is always available as the first-choice spill temporary. For code which doesn't do int division, make %edx and %eax available for spilling too. Shifts by a non-constant amount (very rare) are now done by a short test-and-jump sequence, so that %ecx is not tied up. -- x86 FP: do sin, cos, tan in-line so we get the same answers as gcc. -- Moved a little code around to remove recursive dependencies. -- Fix a subtle bug in x86 regUsage, which could cause underestimation of live ranges.