https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94133
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Component|rtl-optimization |target
Target| |x86_64-*-*-*
--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Actually it is done by combine though the target cost model says it is not
profitable:
Trying 10 -> 15:
10: {r84:SI=r115:SI&0x3f;clobber flags:CC;}
REG_DEAD r115:SI
REG_UNUSED flags:CC
15: {r101:TI=r100:TI<<r84:SI#0;clobber flags:CC;}
REG_DEAD r100:TI
REG_UNUSED flags:CC
Failed to match this instruction:
(parallel [
(set (reg:TI 101)
(ashift:TI (reg:TI 100 [ w1 ])
(subreg:QI (and:SI (reg:SI 115)
(const_int 63 [0x3f])) 0)))
(clobber (reg:CC 17 flags))
(set (reg:SI 84 [ _5 ])
(and:SI (reg:SI 115)
(const_int 63 [0x3f])))
])
Failed to match this instruction:
(parallel [
(set (reg:TI 101)
(ashift:TI (reg:TI 100 [ w1 ])
(subreg:QI (and:SI (reg:SI 115)
(const_int 63 [0x3f])) 0)))
(set (reg:SI 84 [ _5 ])
(and:SI (reg:SI 115)
(const_int 63 [0x3f])))
])
Successfully matched this instruction:
(set (reg:SI 84 [ _5 ])
(and:SI (reg:SI 115)
(const_int 63 [0x3f])))
Successfully matched this instruction:
(set (reg:TI 101)
(ashift:TI (reg:TI 100 [ w1 ])
(subreg:QI (and:SI (reg:SI 115)
(const_int 63 [0x3f])) 0)))
rejecting combination of insns 10 and 15
original costs 4 + 32 = 36
replacement costs 4 + 36 = 40
