Re: [CVS ci] JIT bug fix

[Leopold Toetsch]

Daniel Grunblatt wrote:

> On Wednesday 13 November 2002 08:06, Leopold Toetsch wrote:
>
>>I could localize a long outstanding bug in JIT causing 4 perl6 tests to
>>fail.

> I wonder who was the #%$# that introduced that bug ..... D'OH! :)

Wow, Daniel, the lost son himself ;-)

So I immediately have a question (or some):

I'm currently studying jit.c and I'm wondering, it it wouldn't be better to allocate registers for a whole basic block, and only store/load the used registers for non JITed sections when necessary. These normally don't have a lot of IRegs, so we could save a bunch of store/load's.

And 2), when doing this, I would change

char intval_map[INT_REGISTERS_TO_MAP] =
{ emit_EDI, emit_EBX, emit_EDX, emit_ECX };

to use callee saved regs first (ebx, edi, esi), and then (edx, ecx), which would mean, that the first 3 registers wouldn't be globbered by external functions. The current usage of esi could be done by ebp, I think. This would need some defines, how many/which registers are callee saved (like CALL_USED_REGISTERS in gcc/config/*).

What do you think of this?
leo