On Wed, Jun 26, 2019 at 07:27:20PM +0530, Prathamesh Kulkarni wrote: > combine then does following combinations: > > Trying 7 -> 9: > 7: r90:V2DI=r89:V2DI>r93:V2DI > REG_DEAD r93:V2DI > REG_DEAD r89:V2DI > 9: r91:V2DF=r90:V2DI#0 > REG_DEAD r90:V2DI > Successfully matched this instruction: > (set (subreg:V2DI (reg:V2DF 91) 0) > (gt:V2DI (reg:V2DI 89) > (reg:V2DI 93))) > allowing combination of insns 7 and 9 > > Trying 6, 9 -> 10: > 6: r89:V2DI=const_vector > 9: r91:V2DF#0=r89:V2DI>r93:V2DI > REG_DEAD r89:V2DI > REG_DEAD r93:V2DI > 10: r87:SI=unspec[r91:V2DF] 43 > REG_DEAD r91:V2DF > Successfully matched this instruction: > (set (reg:SI 87) > (unspec:SI [ > (lt:V2DF (reg:V2DI 93) > (const_vector:V2DI [ > (const_int 0 [0]) repeated x2 > ])) > ] UNSPEC_MOVMSK))
Both of these are obviously correct, they are simple substitutions. If this does not do what you want, the problem is elsewhere, not in combine, afaics? > Is the above folding correct, since lt has V2DF mode, > and casting -1 (literally) to DFmode would result in -NaN ? Combine does not introduce any of that, it was there already. > Also, should result of lt be having only integral modes ? Apparently your machine description likes this fine. Combine does not ask questions. Segher
