The attached test case produces this RTL sequence after lreg, when compiled at
-O2 -mcpu=m32cm:
(insn 12 11 13 2 ba-bug.ii:24 (set (reg:DI 26 [ p.2 ])
(mem/s:DI (reg/f:PSI 31) [3 S8 A8])) 176 {movdi_splittable}
(expr_list:R
EG_DEAD (reg/f:PSI 31)
(nil)))
(insn 13 12 14 2 ba-bug.ii:24 (set (reg:PSI 25 [ p$second ])
(subreg:PSI (reg:DI 26 [ p.2 ]) 4)) 172 {movpsi_op} (nil))
[For reference, in -mcpu=m32cm mode, this target uses PSImode for 24-bit
pointers, which appear to be being padded to 32 bits in memory.]
During processing of insn 13, reload demands a MODE_PARTIAL_INT mode with at
least 64 bits. There is no such mode, and the compiler aborts in
smallest_mode_for_size.
The test case is simplified from libstdc++ bitmap_alloc.cc. It is extremely
fragile; any further simplification and the problem RTL sequence will be
eliminated by earlier optimizers.
--
Summary: abort during reload on (subreg:PSI (reg:DI ...) 4)
Product: gcc
Version: 4.3.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: zackw at panix dot com
GCC target triplet: m32c-unknown-elf
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32659
