target m68k-elf, -m5200, -O2 generates incorrect code for ColdFire

[Peter Jakubek]

Franz Sirl wrote:
> 
> OK, a few hints :-).
> 
> I compiled your code with -save-temps -dap -fverbose-asm added and got 
> this in the .s:
> 
>         moveq.l #1,%d7  | 267   *m68k.md:993/1
>         add.l %d7,-2(%a6)       |  i1   | 186   *addsi3_5200/1
>         move.w -2(%a6),%a0      |  i1,  i1      | 37    extendhisi2/2
>         move.l %a0,%a3  |  i1,  i1      | 234   *m68k.md:993/1
> 
> Checking out m68k.md shows that addsi3_5200 calls output_addsi3 in 
> m68k.c. I'm not sure if the bug is there or maybe in reload, cause if 
> you look at the debug RTL dumps you'll notice that the addsi3_5200 first 
> shows up in the .greg dump. Maybe the HImode add shouldn't be converted 
> to a SImode add?
> 
> Franz.
> 

Thanks for the hint!

It really seems the HImode add is converted incorrectly to SImode add.
But my understanding of gcc/RTL is not sufficient to locate the problem.
Will have to dig deeper into it...

Peter Jakubek
LaserAnimation Sollinger GmbH
pjak@lasergraph-dsp.de