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Re: -mfmovd enabled by default for SH2A but not for SH4


> --- ORIG/trunk/gcc/config/sh/sh.h	2007-12-07 09:11:38.000000000 +0900
> +++ LOCAL/trunk/gcc/config/sh/sh.h	2008-02-25 19:09:48.000000000 +0900
> @@ -553,7 +553,7 @@ do {									\
>      {									\
>        sh_cpu = CPU_SH2A;						\
>        if (TARGET_SH2A_DOUBLE)						\
> -        target_flags |= MASK_FMOVD;					\
> +        target_flags |= MASK_FMOVD | MASK_ALIGN_DOUBLE;			\

I've played with this patch and recognize that it's not that
simple, unfortunately.  -mdalign changes not only alignment
of doubles but also calling conventions.  If you compile

void foo () { bar (1, 0x12345678abcd5555LL); }

with/without -mdalign, for example, you can see that effect.
This behavior with -mdalign is consistent from 3.4.
It seems that such change is too big for SH2A users.  Perhaps
this was one reason of not defaulting -mdalign for SH2A.

Regards,
	kaz


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