Commit dc7f449d1ac53a66e6efb56ccf2a5953418a26ca introduced a new method for avoiding MOVs: try to rewrite the destination of the instruction that produced the RHS so it writes into the LHS.
Unfortunately, this is not safe for texturing operations, as they return a set of four contiguous registers. Consider the following: SEND g7 ... MOV g15 g7 ADD g8 1.0 Upon seeing the MOV, we would rewrite the SEND to write to g15 (and implicitly g16, g17, and g18), causing the next instruction that references g8 to read garbage. The VS does not need texturing workarounds because sampler results fit in a single register in SIMD4x2 mode. Fixes color distortion in XBMC when using GLSL shaders. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=44333 Signed-off-by: Kenneth Graunke <kenn...@whitecape.org> --- src/mesa/drivers/dri/i965/brw_fs_visitor.cpp | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-) diff --git a/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp b/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp index e670ba7..5d93ba5 100644 --- a/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp +++ b/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp @@ -605,6 +605,9 @@ fs_visitor::try_rewrite_rhs_to_dst(ir_assignment *ir, !src.equals(&last_rhs_inst->dst)) return false; + if (last_rhs_inst->is_tex()) + return false; + /* Success! Rewrite the instruction. */ last_rhs_inst->dst = dst; -- 1.7.9 _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
