[Mesa-dev] [PATCH 3/9] i965: fix 64-bit immediates in brw_inst(_set)_bits

[Iago Toral Quiroga]

From: Connor Abbott <connor.w.abbott at intel.com>

If we tried to get/set something that was exactly 64 bits, we would
try to do (1 << 64) - 1 to calculate the mask which doesn't give us all
1's like we want.

v2 (Iago)
 - Replace ~0 by ~0ull
 - Removed unnecessary parenthesis

Reviewed-by: Iago Toral Quiroga <itoral at igalia.com>
---
 src/mesa/drivers/dri/i965/brw_inst.h | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/brw_inst.h b/src/mesa/drivers/dri/i965/brw_inst.h
index 4ed95c4..ec08194 100644
--- a/src/mesa/drivers/dri/i965/brw_inst.h
+++ b/src/mesa/drivers/dri/i965/brw_inst.h
@@ -694,7 +694,8 @@ brw_inst_bits(const brw_inst *inst, unsigned high, unsigned low)
    high %= 64;
    low %= 64;
 
-   const uint64_t mask = (1ull << (high - low + 1)) - 1;
+   const uint64_t mask = (high - low == 63) ? ~0ull :
+      (1ull << (high - low + 1)) - 1;
 
    return (inst->data[word] >> low) & mask;
 }
@@ -713,7 +714,8 @@ brw_inst_set_bits(brw_inst *inst, unsigned high, unsigned low, uint64_t value)
    high %= 64;
    low %= 64;
 
-   const uint64_t mask = ((1ull << (high - low + 1)) - 1) << low;
+   const uint64_t mask = (high - low == 63) ? ~0ull :
+      ((1ull << (high - low + 1)) - 1) << low;
 
    /* Make sure the supplied value actually fits in the given bitfield. */
    assert((value & (mask >> low)) == value);
-- 
1.9.1