On Fri, Jul 29, 2022 at 3:43 PM Youlin Li <liulin063@xxxxxxxxx> wrote: > > In adjust_scalar_min_max_vals(), let 32bit bounds learn from 64bit bounds > to get more tight bounds tracking. Similar operation can be found in > reg_set_min_max(). > > Also, we can now fold reg_bounds_sync() into zext_32_to_64(). > > Before: > > func#0 @0 > 0: R1=ctx(off=0,imm=0) R10=fp0 > 0: (b7) r0 = 0 ; R0_w=0 > 1: (b7) r1 = 0 ; R1_w=0 > 2: (87) r1 = -r1 ; R1_w=scalar() > 3: (87) r1 = -r1 ; R1_w=scalar() > 4: (c7) r1 s>>= 63 ; R1_w=scalar(smin=-1,smax=0) > 5: (07) r1 += 2 ; R1_w=scalar(umin=1,umax=2,var_off=(0x0; 0xffffffff)) <--- [*] > 6: (95) exit > > It can be seen that even if the 64bit bounds is clear here, the 32bit > bounds is still in the state of 'UNKNOWN'. > > After: > > func#0 @0 > 0: R1=ctx(off=0,imm=0) R10=fp0 > 0: (b7) r0 = 0 ; R0_w=0 > 1: (b7) r1 = 0 ; R1_w=0 > 2: (87) r1 = -r1 ; R1_w=scalar() > 3: (87) r1 = -r1 ; R1_w=scalar() > 4: (c7) r1 s>>= 63 ; R1_w=scalar(smin=-1,smax=0) > 5: (07) r1 += 2 ; R1_w=scalar(umin=1,umax=2,var_off=(0x0; 0x3)) <--- [*] > 6: (95) exit > > Signed-off-by: Youlin Li <liulin063@xxxxxxxxx> Looks good to me. Thanks Youlin. Acked-by: Hao Luo <haoluo@xxxxxxxxxx> Hao
