https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98694
--- Comment #4 from Hongtao.liu <crazylht at gmail dot com> --- > It seems to be be handled here. > > cut from copy_value in regcprop.c: > ---- > /* If SRC had been assigned a mode narrower than the copy, we can't > link DEST into the chain, because not all of the pieces of the > copy came from oldest_regno. */ > else if (sn > hard_regno_nregs (sr, vd->e[sr].mode)) > return; > ---- > > here we have %edi set as HImode, but use as SImode and be copied to %xmm2, > but the condition failed to check this beacuase both SImode and HImode has > nregs as 1, since the upper part could be garbage, it can't link DEST into > the chain. > > kmovw %k0, %edi # 69 [c=4 l=4] *movhi_internal/6 <----HI > kmovd %k0, %edx # 487 [c=4 l=3] *movsi_internal/16 > vmovd %edi, %xmm2 # 489 [c=4 l=6] *movsi_internal/13 <----SI > sall $16, %edx # 73 [c=4 l=3] *ashlsi3_1/0 > kmovw %k0, %r8d # 74 [c=4 l=5] *zero_extendhisi2/1 > vpshuflw $0, %xmm2, %xmm0 # 78 [c=4 l=5] > *vec_dupv4hi/1 > orl %edx, %r8d # 75 [c=4 l=3] *iorsi_1/0 > testw %di, %di # 82 [c=4 l=3] *cmphi_ccno_1/0 > jle .L52 # 83 [c=12 l=6] *jcc > kmovd %k0, %r9d # 85 [c=4 l=4] *movsi_internal/16 <----SI > testl %r9d, %r9d # 88 [c=4 l=3] *cmpsi_ccno_1/0 and it looks like a generic code bug.
