[Bug rtl-optimization/9240] weird scheduling on v850 unless -fno-sched-spec specified

["law at redhat dot com" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #8 from law at redhat dot com  2010-02-24 21:20 -------
This was fixed at some point; I don't know if it was the patch referenced in
comment #6, or some other patch or some combination thereof.

You can see that probabilities are being propagated down through to the
scheduler by looking at the .sched dump:

(insn 9 7 10 2 j.c:8 (set (cc0)
        (compare (reg:SI 39 [ prephitmp___4 ])
            (reg:SI 42))) 8 {*cmpsi} (expr_list:REG_DEAD (reg:SI 42)
        (expr_list:REG_EQUAL (compare (reg:SI 39 [ prephitmp___4 ])
                (const_int -125 [0xffffffffffffff83]))
            (nil))))

(jump_insn 10 9 11 2 j.c:8 (set (pc)
        (if_then_else (lt (cc0)
                (const_int 0 [0x0]))
            (label_ref 15)
            (pc))) 41 {*branch_normal} (expr_list:REG_BR_PROB (const_int 9996
[0x270c])
        (nil))
 -> 15)
;; End of basic block 2 -> ( 3 4)
;; lr  out       3 [sp] 29 [r29] 32 [.fp] 33 [.ap] 39
;; live  out     3 [sp] 29 [r29] 32 [.fp] 33 [.ap] 39


;; Succ edge  3 [0.0%]  (fallthru)
;; Succ edge  4 [100.0%]

Note how the probability of the edge 2->3 is now zero, reflecting the unlikely
attribute while the edge 2->4 is 100%.  With the correct probabilities the
scheduler naturally does the right thing.


-- 

law at redhat dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=9240