Le 01/11/2016 à 22:29, Richard Henderson a écrit :
> Here's the patch I almost wrote in the email, followed by
> a cleanup that allows cmpm to be written "nicely".
>
> I can test this to some extent with the coldfire kernel,
> but of course coldfire can't excersise any of the tricky
> edge cases that m68000 can.
>
> I'm particularly interested in edge cases like
>
> mov.b a0@+, a0@+
> movea a0@+, a0
> movea a0, a0@-
>
> The first two are not really useful and likely not show up
> in normal code. The third may well do so; I think our
> current code gets it wrong, but this will get it right.
Checked on a real 68040:
stack:
.long 0x3456789a
top:
.text
.globl _start
_start:
lea top,%a0
move.l %a0,-(%a0)
The result is:
%a0 = top - 4
and top is stored in place of "0x3456789a".
[this is also what happens without your patches]
If I try this with you patch, I have a core dump:
m68k-linux-gnu-gcc -g -m68040 -nostartfiles -nodefaultlibs -nostdlib
-o move move.S
./m68k-linux-user/qemu-m68k -singlestep -d in_asm,cpu -cpu m68040
../qemu-m68k/tests/m68k/move
----------------
IN:
0x800000b8: lea 0x800020d0,%a0
D0 = 00000000 A0 = 00000000 F0 = 0000000000000000 ( 0)
D1 = 00000000 A1 = 00000000 F1 = 0000000000000000 ( 0)
D2 = 00000000 A2 = 00000000 F2 = 0000000000000000 ( 0)
D3 = 00000000 A3 = 00000000 F3 = 0000000000000000 ( 0)
D4 = 00000000 A4 = 00000000 F4 = 0000000000000000 ( 0)
D5 = 00000000 A5 = 00000000 F5 = 0000000000000000 ( 0)
D6 = 00000000 A6 = 00000000 F6 = 0000000000000000 ( 0)
D7 = 00000000 A7 = f6fff0a0 F7 = 0000000000000000 ( 0)
PC = 800000b8 SR = 0000 ----- FPRESULT = 0
----------------
IN:
0x800000be: movel %a0,%a0@-
D0 = 00000000 A0 = 800020d0 F0 = 0000000000000000 ( 0)
D1 = 00000000 A1 = 00000000 F1 = 0000000000000000 ( 0)
D2 = 00000000 A2 = 00000000 F2 = 0000000000000000 ( 0)
D3 = 00000000 A3 = 00000000 F3 = 0000000000000000 ( 0)
D4 = 00000000 A4 = 00000000 F4 = 0000000000000000 ( 0)
D5 = 00000000 A5 = 00000000 F5 = 0000000000000000 ( 0)
D6 = 00000000 A6 = 00000000 F6 = 0000000000000000 ( 0)
D7 = 00000000 A7 = f6fff0a0 F7 = 0000000000000000 ( 0)
PC = 800000be SR = 0000 ----- FPRESULT = 0
qemu-m68k: tcg/tcg.c:653: tcg_temp_free_internal: Assertion `idx >=
s->nb_globals && idx < s->nb_temps' failed.
qemu-m68k: translate-all.c:175: tb_lock: Assertion `!have_tb_lock' failed.
Laurent
