http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15596
Richard Guenther <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|WAITING |ASSIGNED
AssignedTo|unassigned at gcc dot |rguenth at gcc dot gnu.org
|gnu.org |
--- Comment #19 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-05-06
13:18:31 UTC ---
Even with bitfield accesses lowered at the tree level we end up with
<bb 2>:
D.1736_2 = (<unnamed-signed:20>) s_1(D);
BF.0_3 = MEM[(struct bitstr *)&<retval>];
D.1741_4 = BF.0_3 & -1048576;
D.1742_5 = (<unnamed-unsigned:20>) D.1736_2;
D.1743_6 = (int) D.1742_5;
BF.0_7 = D.1741_4 | 1048576;
BF.1_9 = BF.0_7 | D.1743_6;
D.1737_13 = (signed char) l_12(D);
D.1738_14 = (<unnamed-signed:1>) D.1737_13;
D.1747_16 = BF.1_9 & -6291457;
D.1748_17 = (<unnamed-unsigned:1>) D.1738_14;
D.1749_18 = (int) D.1748_17;
D.1750_19 = D.1749_18 << 22;
BF.3_20 = D.1750_19 | D.1747_16;
MEM[(struct bitstr *)&<retval>] = BF.3_20;
return <retval>;
there's some optimization possibilities if we can recognize the truncating
and extending conversions as bit manipulations.
