[comp.sys.mips] forcing double word alignment

jordan@aero.org (Larry M. Jordan) (04/13/91)

Is there a compiler directive (c and f77) which guarantees
that all double's will be double word aligned?

I've noticed in some of the symbolic assembly for FORTRAN
things like:

	...
	.align 2
	.align 0
$$13:	.double 1.0e0 : 1
	...

The double is word aligned?! 

--Larry
	

rogerk@mips.com (Roger B.A. Klorese) (04/13/91)

In article <1991Apr12.183201.4296@aero.org> jordan@aero.org (Larry M. Jordan) writes:
>Is there a compiler directive (c and f77) which guarantees
>that all double's will be double word aligned?
>
>I've noticed in some of the symbolic assembly for FORTRAN
>things like:
>
>	...
>	.align 2
>	.align 0
>$$13:	.double 1.0e0 : 1
>	...
>
>The double is word aligned?! 

Yes.  The MIPS-I architecture requires word alignment for doubles.
-- 
ROGER B.A. KLORESE                                  MIPS Computer Systems, Inc.
MS 6-05    930 DeGuigne Dr.   Sunnyvale, CA  94088              +1 408 524-7421
"10 years of Reagan/Bush have brought us to a new place: postconstitutional
America." - Jon Carroll     rogerk@mips.COM | {ames,decwrl,pyramid}!mips!rogerk 

rogerk@mips.com (Roger B.A. Klorese) (04/13/91)

In article <2234@spim.mips.COM> rogerk@mips.com (Roger B.A. Klorese) writes:
>>The double is word aligned?! 
>Yes.  The MIPS-I architecture requires word alignment for doubles.

I meant to say that MIPS-I requires *at least* word-alignment.  MIPS-II
requires double-word alignment, but then again, it wouldn't have generated
that code...
>-- 
>ROGER B.A. KLORESE                                  MIPS Computer Systems, Inc.
>MS 6-05    930 DeGuigne Dr.   Sunnyvale, CA  94088              +1 408 524-7421
>"10 years of Reagan/Bush have brought us to a new place: postconstitutional
>America." - Jon Carroll     rogerk@mips.COM | {ames,decwrl,pyramid}!mips!rogerk 


-- 
ROGER B.A. KLORESE                                  MIPS Computer Systems, Inc.
MS 6-05    930 DeGuigne Dr.   Sunnyvale, CA  94088              +1 408 524-7421
"10 years of Reagan/Bush have brought us to a new place: postconstitutional
America." - Jon Carroll     rogerk@mips.COM | {ames,decwrl,pyramid}!mips!rogerk