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Date: Mon, 19 Apr 2010 12:59:00 -0000
Subject: [Bug c/43798]  New: attribute((aligned(x))) not honored for array element types?
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From: "rguenth at gcc dot gnu dot org" <gcc-bugzilla@gcc.gnu.org>
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in libbid we have

typedef __attribute__((aligned(16)))
struct {
    unsigned long long w[3];
} UINT192;

UINT192 bid_Kx192[32];

thus we request 16-byte alignment for UINT192 (whose elements add
up to a size of 24).  Now the array ends up with elements of size 24
and thus the elements are _not_ aligned to a 16-byte boundary, still
the element type is not adjusted to reflect that leading to inconsistencies
when one for example tries to set operand 3 of an ARRAY_REF
(which is specified in units of the alignment of the element).

This causes PR43783.

This is also at least a documentation bug as I can't find anything
that documents the above behavior.


-- 
           Summary: attribute((aligned(x))) not honored for array element
                    types?
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Keywords: wrong-code, documentation
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: rguenth at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43798