Re: ICE on m68k-linux in 3_4-branch

[Jim Wilson <wilson at specifixinc dot com>]

Bernardo Innocenti wrote:
> This RTL expression should match the pattern and select the
> !TARGET_COLDFIRE insn:

Yes.  Perhaps the stage2 compiler was miscompiled, causing the pattern 
match to fail.  Try stepping through the code in recog().

> I'm still wondering why the documentation for strict_low_part
> in gccint.texi doesn't look like this RTX.

The pattern is buggy, technically, since it does not create the SUBREG. 
 However, the passes that actually check for and use the SUBREG are 
very limited.  I would guess that it is only combine, and I would also 
guess that when combine fails to see the required subreg, all it does is 
reject a potential combination.  Thus the lack of the subreg is 
harmless.  Maybe you will lose a bit of optimization, but this is likely 
rare.
--
Jim Wilson, GNU Tools Support, http://www.SpecifixInc.com