On 04/02/14 06:08, Anthony Green wrote:
One embarrassing feature of the moxie compiler port is that it really
doesn't understand how to promote integral types. Moxie cores
zero-extend all loads, but the compiler still shifts loaded values back
and forth to zero out the upper bits.
I'm a bit surprised LOAD_EXTEND_OP doesn't cover this for you. Maybe
other aspects of the moxie are getting in the way:
(insn 7 6 8 2 (set (reg:SI 32)
(const_int 24 [0x18])) j.c:4 19 {*movsi}
(nil))
(insn 8 7 10 2 (set (reg:SI 30 [ D.1371 ])
(ashift:SI (subreg:SI (mem:QI (reg:SI 2 $r0 [ c ]) [0 *c_2(D)+0
S1 A8]) 0)
(reg:SI 32))) j.c:4 14 {ashlsi3}
(expr_list:REG_DEAD (reg:SI 2 $r0 [ c ])
(nil)))
(note 10 8 15 2 NOTE_INSN_DELETED)
(insn 15 10 16 2 (set (reg/i:SI 2 $r0)
(lshiftrt:SI (reg:SI 30 [ D.1371 ])
(reg:SI 32))) j.c:5 16 {lshrsi3}
(expr_list:REG_DEAD (reg:SI 32)
(expr_list:REG_DEAD (reg:SI 30 [ D.1371 ])
(nil))))
Looks problematical. The shift count is used twice, so combine's going
to have a bit of a tough time with this.
Perhaps allow constant shift counts then force them into registers after
combine with splitters?
jeff
