* movsi on 16-bit machine: how to?
@ 2009-03-27 8:56 Florent DEFAY
2009-03-27 16:38 ` Ian Lance Taylor
0 siblings, 1 reply; 2+ messages in thread
From: Florent DEFAY @ 2009-03-27 8:56 UTC (permalink / raw)
To: gcc-help
Hi,
I am implementing movsi on a 16-bit machine.
I did it this way:
;; ---- movsi
(define_insn "movsi"
[(set (match_operand:SI 0 "nonimmediate_operand" "=r,m,r,r")
(match_operand:SI 1 "general_operand" "r,r,m,i"))]
""
"#"
)
(define_split
[(set (match_operand:SI 0 "nonimmediate_operand" "")
(match_operand:SI 1 "general_operand" ""))]
"reload_completed
&& !extra_constraint (operands[1], 'R')"
[(set (match_dup 2)
(match_dup 3))
(set (match_dup 4)
(match_dup 5))]
{
operands[2] = simplify_gen_subreg(HImode,operands[0],SImode,0);
operands[4] = simplify_gen_subreg(HImode,operands[0],SImode,2);
operands[3] = simplify_gen_subreg(HImode,operands[1],SImode,0);
operands[5] = simplify_gen_subreg(HImode,operands[1],SImode,2);
}
)
And I tried many other code. But each time I have some " insn does not
satisfy its constraints".
../../../gcc-4.3.3/libgcc/../gcc/libgcc2.c: In function ‘__lshrsi3’:
../../../gcc-4.3.3/libgcc/../gcc/libgcc2.c:435: error: insn does not
satisfy its constraints:
(insn 8 98 80 ../../../gcc-4.3.3/libgcc/../gcc/libgcc2.c:415 (set
(mem/c/i:SI (reg:HI 0 r0) [0 <result>+0 S4 A16])
(reg:SI 1 r1)) 6 {movsi} (nil))
I am looking for a great and simple example of movsi for 16-bit
machine or movdi for 32-bit machine (because I think it is the same
mechanism);
or a basic method to do this.
I will be grateful for any advice.
Florent
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: movsi on 16-bit machine: how to?
2009-03-27 8:56 movsi on 16-bit machine: how to? Florent DEFAY
@ 2009-03-27 16:38 ` Ian Lance Taylor
0 siblings, 0 replies; 2+ messages in thread
From: Ian Lance Taylor @ 2009-03-27 16:38 UTC (permalink / raw)
To: Florent DEFAY; +Cc: gcc-help
Florent DEFAY <spira.inhabitant@gmail.com> writes:
> ;; ---- movsi
>
> (define_insn "movsi"
> [(set (match_operand:SI 0 "nonimmediate_operand" "=r,m,r,r")
> (match_operand:SI 1 "general_operand" "r,r,m,i"))]
> ""
> "#"
> )
...
> ../../../gcc-4.3.3/libgcc/../gcc/libgcc2.c: In function ‘__lshrsi3’:
> ../../../gcc-4.3.3/libgcc/../gcc/libgcc2.c:435: error: insn does not
> satisfy its constraints:
> (insn 8 98 80 ../../../gcc-4.3.3/libgcc/../gcc/libgcc2.c:415 (set
> (mem/c/i:SI (reg:HI 0 r0) [0 <result>+0 S4 A16])
> (reg:SI 1 r1)) 6 {movsi} (nil))
As far as I can see, the only way that this insn could fail to satisfy
its constraints would be if (mem:SI (reg:HI 0)) does not satisfy the 'm'
constraint. That implies that that address is not recognized by
GO_IF_LEGITIMATE_ADDRESS. Look there first.
> I am looking for a great and simple example of movsi for 16-bit
> machine or movdi for 32-bit machine (because I think it is the same
> mechanism);
> or a basic method to do this.
There are many examples in the existing gcc backends.
Ian
^ permalink raw reply [flat|nested] 2+ messages in thread
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