From eb30820f268608cf451da32de69723036dddbc62 Mon Sep 17 00:00:00 2001 From: Eric Anholt Date: Fri, 22 Jul 2011 15:56:46 -0700 Subject: [PATCH] i965/fs: Port texture projection avoidance optimization from the old backend. This is part of fixing a ~1% performance regression in OpenArena when changing the fixed function fragment shader to using the new backend. Right now this just avoids the LINTERP of the projector, not the math using it. --- src/mesa/drivers/dri/i965/brw_fs.cpp | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp index 15475fbae2f..9c3180fbc1c 100644 --- a/src/mesa/drivers/dri/i965/brw_fs.cpp +++ b/src/mesa/drivers/dri/i965/brw_fs.cpp @@ -463,9 +463,21 @@ fs_visitor::emit_general_interpolation(ir_variable *ir) } else { /* Perspective interpolation case. */ for (unsigned int k = 0; k < type->vector_elements; k++) { - struct brw_reg interp = interp_reg(location, k); - emit(FS_OPCODE_LINTERP, attr, - this->delta_x, this->delta_y, fs_reg(interp)); + /* FINISHME: At some point we probably want to push + * this farther by giving similar treatment to the + * other potentially constant components of the + * attribute, as well as making brw_vs_constval.c + * handle varyings other than gl_TexCoord. + */ + if (location >= FRAG_ATTRIB_TEX0 && + location <= FRAG_ATTRIB_TEX7 && + k == 3 && !(c->key.proj_attrib_mask & (1 << location))) { + emit(BRW_OPCODE_MOV, attr, fs_reg(1.0f)); + } else { + struct brw_reg interp = interp_reg(location, k); + emit(FS_OPCODE_LINTERP, attr, + this->delta_x, this->delta_y, fs_reg(interp)); + } attr.reg_offset++; } -- 2.30.2