[Bug rtl-optimization/47862] Incorrect code for spilling a vector register

[pthaugen at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47862

--- Comment #1 from Pat Haugen <pthaugen at gcc dot gnu.org> 2011-02-24 21:54:00 UTC ---
Looks like the bogus spill/restore insns are being inserted via caller-save.c
routines since IRA assigned volatile regs to pseudos which are live across a
call.


190.sched1 dump for the example above (pseudo 352).

(insn 180 177 182 12 (set (reg:V2DF 352 [ vect_var_.59 ])
        (mult:V2DF (reg:V2DF 343 [ vect_var_.53 ])
            (reg:V2DF 350 [ vect_cst_.60 ]))) spill.c:21 766 {*vsx_mulv2df3}
     (nil))

... call expd2()

(insn 185 184 186 12 (set (reg:V2DF 79 2)
        (reg:V2DF 352 [ vect_var_.59 ])) spill.c:21 756 {*vsx_movv2df}
     (expr_list:REG_DEAD (reg:V2DF 352 [ vect_var_.59 ])
        (nil)))


191.ira dump, along with some additional info I dumped in
caller-save:insert_one_insn() to show insn being inserted

      Popping a139(r352,l0)  -- assign reg 43

(vector save) Inserting insn ...
(set (mem/c:DI (plus:DI (reg/f:DI 113 sfp)
            (const_int 144 [0x90])) [9 S8 A64])
    (reg:DI 43 11))

(vector restore) Inserting insn ...
(set (reg:DI 43 11)
    (mem/c:DI (plus:DI (reg/f:DI 113 sfp)
            (const_int 144 [0x90])) [9 S8 A64]))
... before ...
(insn 185 184 186 12 (set (reg:V2DF 79 2)
        (reg:V2DF 43 11 [orig:352 vect_var_.59 ] [352])) spill.c:21 756
{*vsx_movv2df}
     (expr_list:REG_DEAD (reg:V2DF 43 11 [orig:352 vect_var_.59 ] [352])
        (nil)))


---final ira dump

(insn 180 177 182 12 (set (reg:V2DF 43 11 [orig:352 vect_var_.59 ] [352])
        (mult:V2DF (reg:V2DF 103 26 [orig:343 vect_var_.53 ] [343])
            (reg:V2DF 44 12 [orig:350 vect_cst_.60 ] [350]))) spill.c:21 766
{*vsx_mulv2df3}
     (nil))

(insn 323 322 324 12 (set (mem/c:DI (plus:DI (reg/f:DI 1 1)
                (const_int 144 [0x90])) [9 S8 A64])
        (reg:DI 43 11)) spill.c:21 405 {*movdi_internal64}
     (nil))

... call expd2()

(insn 326 184 185 12 (set (reg:DI 43 11)
        (mem/c:DI (plus:DI (reg/f:DI 1 1)
                (const_int 144 [0x90])) [9 S8 A64])) spill.c:21 405
{*movdi_internal64}
     (nil))

(insn 185 326 186 12 (set (reg:V2DF 79 2)
        (reg:V2DF 43 11 [orig:352 vect_var_.59 ] [352])) spill.c:21 756
{*vsx_movv2df}
     (nil))