[Mesa-dev] Bug in 48157b904a9 found by Coverity

[Ilia Mirkin]

Hey guys,

Just got around to looking at the Coverity email about newly
introduced bugs, and this seems like a legit issue. Based on the
context of the code, I'm guessing you meant to do (input_index - 16)
<< 1.

Cheers,

  -ilia

** CID 1251308:  Bad bit shift operation  (BAD_SHIFT)
/src/mesa/drivers/dri/i965/gen8_sf_state.c: 99 in upload_sbe()

________________________________________________________________________________________________________
*** CID 1251308:  Bad bit shift operation  (BAD_SHIFT)
/src/mesa/drivers/dri/i965/gen8_sf_state.c: 99 in upload_sbe()
93              if (!(brw->fragment_program->Base.InputsRead &
BITFIELD64_BIT(attr)))
94                 continue;
95
96              if (input_index < 16)
97                 dw4 |= (GEN9_SBE_ACTIVE_COMPONENT_XYZW <<
(input_index << 1));
98              else
>>>     CID 1251308:  Bad bit shift operation  (BAD_SHIFT)
>>>     In expression "3 << (input_index << 1)", left shifting by more than 31 bits has undefined behavior.  The shift amount, "input_index << 1", is 32.
99                 dw5 |= (GEN9_SBE_ACTIVE_COMPONENT_XYZW <<
(input_index << 1));
100
101              ++input_index;
102           }
103        }
104        BEGIN_BATCH(sbe_cmd_length);