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Re: [Qemu-devel] 64-bit target
From: |
Johan Rydberg |
Subject: |
Re: [Qemu-devel] 64-bit target |
Date: |
Mon, 30 Jun 2003 16:35:43 +0200 |
Johan Rydberg <address@hidden> wrote:
: Fabrice Bellard <address@hidden> wrote:
:
: : You can just use two parameters and load two 32 bit values.
:
: Declaring T0 as a long long, and trying to set it to an immediate
: value results in the following code: Which is a bit of an overhead
: I think :)
Using an union like this;
union fast_move { struct { USI hi; USI lo; } s; UDI d; } x;
And a macro like this;
#define GET_UDI_FROM_PARAMS(p1, p2) (((union fast_move) { { (USI) p1, (USI) p2
} }).d)
Reduces the code:
void OPPROTO
op_movdi_t0_uimm (void)
{
T0 = GET_UDI_FROM_PARAMS (PARAM1, PARAM2);
}
To:
00000034 <op_movdi_t0_uimm>:
34: b8 00 00 00 00 mov $0x0,%eax
35: R_386_32 __op_param1
39: ba 00 00 00 00 mov $0x0,%edx
3a: R_386_32 __op_param2
3e: 89 c6 mov %eax,%esi
40: 89 d7 mov %edx,%edi
Can you figure out how to make it move to %esi and %edi directly?
I can, for one, not.
--
Johan Rydberg, Free Software Developer, Sweden
http://rtmk.sf.net | http://www.nongnu.org/guss/
Playing Various Artists - Deftones / My Own Summer (Shove It)