http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54342
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Component|rtl-optimization |target
Target Milestone|4.8.0 |---
Summary|[4.8 Regression] Wrong mode |OImode is used for _m256
|of call argument |types when using unions in
| |a function call.
--- Comment #13 from Andrew Pinski <pinskia at gcc dot gnu.org> 2012-11-16
22:58:46 UTC ---
>(insn 10 9 11 3 (set (reg:OI 21 xmm0)
(reg:OI 64)) er.c:14 -1
(nil))
This above is generated by the back-end's call by construct_container. So this
is not a middle-end issue even if the middle-end says the mode on the union is
BLKmode. It is up to the back-end to do the correct thing when it is doing a
function call and converting the BLKmode of the union to the correct mode.
case 4:
gcc_assert (i == 0
&& regclass[1] == X86_64_SSEUP_CLASS
&& regclass[2] == X86_64_SSEUP_CLASS
&& regclass[3] == X86_64_SSEUP_CLASS);
tmpmode = OImode;
Is where the OImode is being generated.
The comment in ix86_hard_regno_mode_ok says:
/* We implement the move patterns for all vector modes into and
out of SSE registers, even when no operation instructions
are available. OImode move is available only when AVX is
enabled. */
So really I don't think this is a bug in the code itself but rather the patch
which you are working on which did not take into account OImode being an AVX
mode.
