------- Comment #1 from matz at gcc dot gnu dot org 2009-05-02 02:34 -------
The assert triggers because of a real pre-existing bug. local variables
with DECL_HARD_REGISTER set must not be put into SSA form. is_gimple_reg
has to return false for them. It doesn't anymore since some changes by richi
(CCed), I think.
Te update_address_taken pass sets DECL_GIMPLE_REG_P on the sp_r1 variable.
This is because of the special handling of vector modes. But it doesn't take
into account variables which can't be gimple_reg for other reasons than simply
being of wrong type.
I think the 2009-03-31 change in is_gimple_reg that moved the DECL_GIMPLE_REG_P
handling earlier might be the cause. But fixing it there
probably is not enough, it's better to not set DECL_GIMPLE_REG_P at all
on this VAR_DECL.
The same is true for volatile decl (in this example it has a hardreg _and_
is volatile even), which also seems to be ignored in the address_taken
pass.
This whole business of special-casing COMPLEX_TYPE and VECTOR_TYPE regarding
gimple regs seems highly dubious to me. The different places setting this
flag freely use a random mixture of tests on
!TREE_THIS_VOLATILE (t)
and/or
(TREE_CODE (t) == VAR_DECL && !DECL_HARD_REGISTER (t))
and/or
!needs_to_live_in_memory (t))
or sometimes nothing at all. In fact at least all three of these tests
are required everywhere, except where it's clear that we just created a
completely new temporary.
Meanwhile the immediate problem can be fixed by the below patch:
Index: tree-ssa.c
===================================================================
--- tree-ssa.c (Revision 147044)
+++ tree-ssa.c (Arbeitskopie)
@@ -1573,7 +1573,10 @@ execute_update_addresses_taken (bool do_
if (!DECL_GIMPLE_REG_P (var)
&& !bitmap_bit_p (not_reg_needs, DECL_UID (var))
&& (TREE_CODE (TREE_TYPE (var)) == COMPLEX_TYPE
- || TREE_CODE (TREE_TYPE (var)) == VECTOR_TYPE))
+ || TREE_CODE (TREE_TYPE (var)) == VECTOR_TYPE)
+ && !TREE_THIS_VOLATILE (var)
+ && (TREE_CODE (var) == VAR_DECL && !DECL_HARD_REGISTER (var))
+ && !needs_to_live_in_memory (var))
{
DECL_GIMPLE_REG_P (var) = 1;
mark_sym_for_renaming (var);
--
matz at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |rguenth at gcc dot gnu dot
| |org
Summary|[4.5 Regression] r1467817 |[4.5 Regression] r146817
|broke libgloss build for SPU|broke libgloss build for SPU
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40001
