Eric Botcazou <ebotca...@adacore.com> writes:
>> Seems like the thread might have died down, so just wanted to ping it.
>> As Marcus says, this is holding up other patches so it'd be good to get
>> something in soon. Would it be OK to commit the original patch or should
>> we wait?
>
> Yes, go ahead, but add a FIXME or ??? comment.
Thanks, here's what I installed.
Richard
gcc/
2015-01-25 Alan Hayward <alan.hayw...@arm.com>
* rtlanal.c (subreg_get_info): Exit early for simple and common
cases.
Index: gcc/rtlanal.c
===================================================================
--- gcc/rtlanal.c 2015-01-21 17:06:33.594664514 +0000
+++ gcc/rtlanal.c 2015-01-21 17:10:22.863830284 +0000
@@ -3440,6 +3440,22 @@ subreg_get_info (unsigned int xregno, ma
info->offset = offset / regsize_xmode;
return;
}
+ /* Quick exit for the simple and common case of extracting whole
+ subregisters from a multiregister value. */
+ /* ??? It would be better to integrate this into the code below,
+ if we can generalize the concept enough and figure out how
+ odd-sized modes can coexist with the other weird cases we support. */
+ if (!rknown
+ && WORDS_BIG_ENDIAN == REG_WORDS_BIG_ENDIAN
+ && regsize_xmode == regsize_ymode
+ && (offset % regsize_ymode) == 0)
+ {
+ info->representable_p = true;
+ info->nregs = nregs_ymode;
+ info->offset = offset / regsize_ymode;
+ gcc_assert (info->offset + info->nregs <= nregs_xmode);
+ return;
+ }
}
/* Lowpart subregs are otherwise valid. */
