Re: Problem with reloading in a new backend...

[Jim Wilson <wilson at tuliptree dot org>]

Stelian Pop wrote:
> I will still have the problems with the fact that my indirect addressing
> doesn't allow displacements, no ? (so I would need to implement
> LEGITIMIZE_RELOAD_ADDRESS, in which I'll need a special reserved
> register to compute the full address by adding the base and the
> displacement). Or do you imply that I won't need this anymore ?

In your original message, the right thing happens.  The stack slot 
address gets reloaded.

> 	(insn 1117 16 1118 2 ../../../../src/gcc-4.3.0/libgcc/../gcc/libgcc2.c:1090 (set (reg:QI 10 r10)
> 	        (const_int 24 [0x18])) 1 {*movqi_imm} (nil))
> 	(insn 1118 1117 1119 2 ../../../../src/gcc-4.3.0/libgcc/../gcc/libgcc2.c:1090 (set (reg:QI 10 r10)
> 	        (plus:QI (reg:QI 10 r10)
> 	            (reg/f:QI 30 r30))) 13 {addqi3} (expr_list:REG_EQUIV (plus:QI (reg/f:QI 30 r30)
> 	            (const_int 24 [0x18]))
> 	        (nil)))
> 	(insn 1119 1118 21 2 ../../../../src/gcc-4.3.0/libgcc/../gcc/libgcc2.c:1090 (set (mem/c:QI (reg:QI 10 r10) [31 S1 A16])
> 	        (reg:QI 14 r14)) 8 {*movqi_tomem} (nil))

The only problem here is that the register choice is wrong, and I 
already explained why it is wrong.

It is only after you started making some changes that this apparently 
broke.  It isn't clear why.  I can only suggest that you try to debug 
it.  Put a breakpoint in find_reloads() conditional on the instruction 
number.  Then step through to see what happens.  It should call 
finds_reloads_address or find_reloads_toplev at some point, which will 
see that we don't have a strictly valid address, and then reload it.

Jim