[Mesa-dev] [PATCH 1/3] i965/fs: Detect multi-register MOVs correctly in register_coalesce.

[Francisco Jerez]

register_coalesce() was considering the exec_size of the MOV
instruction alone to decide whether the register at offset+1 of the
source VGRF was being copied to inst->dst.reg_offset+1 of the
destination VGRF, which is only a valid assumption if the move has a
32-bit execution type.  Use regs_read() instead to find out the number
of registers copied by the instruction.
---
 src/mesa/drivers/dri/i965/brw_fs_register_coalesce.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/mesa/drivers/dri/i965/brw_fs_register_coalesce.cpp b/src/mesa/drivers/dri/i965/brw_fs_register_coalesce.cpp
index a253c81..4544122 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_register_coalesce.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_register_coalesce.cpp
@@ -195,7 +195,7 @@ fs_visitor::register_coalesce()
             continue;
          }
          reg_to_offset[offset] = inst->dst.reg_offset;
-         if (inst->exec_size == 16)
+         if (inst->regs_read(0) > 1)
             reg_to_offset[offset + 1] = inst->dst.reg_offset + 1;
          mov[offset] = inst;
          channels_remaining -= inst->regs_written;
-- 
2.4.6