------- Comment #11 from rguenth at gcc dot gnu dot org 2007-09-06 12:13 ------- The extra store you still see is caused by -ftracer duplicating it. Optimizations after that don't catch that (because of the intervening possibly aliasing loads I guess):
(insn 25 24 27 4 t.ii:3 (set (mem/s:SI (reg/f:DI 102) [4 <variable>.D.2014.a+0 S4 A64]) (reg:SI 75)) 47 {*movsi_1} (expr_list:REG_DEAD (reg:SI 75) (expr_list:REG_EQUAL (plus:SI (mem/s:SI (reg/f:DI 102) [4 <variable>.D.2014.a+0 S4 A64]) (const_int 4 [0x4])) (nil)))) (insn 27 25 28 4 t.ii:18 (set (reg:DI 78 [ <variable>.addr ]) (zero_extend:DI (mem/s:SI (reg/f:DI 101) [4 <variable>.addr+0 S4 A64]))) 120 {zero_extendsidi2_rex64} (nil)) ... (insn 96 95 97 4 t.ii:3 (parallel [ (set (reg:SI 83) (plus:SI (reg:SI 76 [ <variable>.D.2014.a ]) (const_int 6 [0x6]))) (clobber (reg:CC 17 flags)) ]) 235 {*addsi_1} (expr_list:REG_UNUSED (reg:CC 17 flags) (expr_list:REG_DEAD (reg:SI 84 [ <variable>.D.2014.a ]) (nil)))) (insn 97 96 98 4 t.ii:3 (set (mem/s:SI (reg/f:DI 102) [4 <variable>.D.2014.a+0 S4 A64]) (reg:SI 83)) 47 {*movsi_1} (expr_list:REG_EQUAL (plus:SI (mem/s:SI (reg/f:DI 102) [4 <variable>.D.2014.a+0 S4 A64]) (const_int 2 [0x2])) (expr_list:REG_DEAD (reg:SI 83) (nil)))) If you build without -ftracer or without -fforce-addr it works (but won't combine the add on one path). But.. -ftracer was supposed to be moved to the tree level... -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33302