From bcbb7c41b75aa780f93f32937697c2999ff2eb36 Mon Sep 17 00:00:00 2001 From: Matt Turner Date: Sat, 28 Jun 2014 18:00:27 -0700 Subject: [PATCH] i965/fs: Let sat-prop ignore live ranges if producer already has sat. This sequence (where both x and w are used afterwards) wasn't handled. mul.sat x, y, z ... mov.sat w, x We assumed that if x was used after the mov.sat, that we couldn't propagate the saturate modifier, but in fact x was already saturated. So ignore the live range check if the producing instruction already saturates its result. Cuts one instruction from hundreds of TF2 shaders. total instructions in shared programs: 1995631 -> 1994951 (-0.03%) instructions in affected programs: 155248 -> 154568 (-0.44%) Reviewed-by: Kenneth Graunke --- .../drivers/dri/i965/brw_fs_saturate_propagation.cpp | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/src/mesa/drivers/dri/i965/brw_fs_saturate_propagation.cpp b/src/mesa/drivers/dri/i965/brw_fs_saturate_propagation.cpp index 1b3d3b76d13..29c8b2ea318 100644 --- a/src/mesa/drivers/dri/i965/brw_fs_saturate_propagation.cpp +++ b/src/mesa/drivers/dri/i965/brw_fs_saturate_propagation.cpp @@ -49,8 +49,6 @@ opt_saturate_propagation_local(fs_visitor *v, bblock_t *block) int src_var = v->live_intervals->var_from_reg(&inst->src[0]); int src_end_ip = v->live_intervals->end[src_var]; - if (src_end_ip > ip && !inst->dst.equals(inst->src[0])) - continue; int scan_ip = ip; bool interfered = false; @@ -63,10 +61,15 @@ opt_saturate_propagation_local(fs_visitor *v, bblock_t *block) scan_inst->dst.reg == inst->src[0].reg && scan_inst->dst.reg_offset == inst->src[0].reg_offset && !scan_inst->is_partial_write()) { - if (scan_inst->can_do_saturate()) { - scan_inst->saturate = true; + if (scan_inst->saturate) { inst->saturate = false; progress = true; + } else if (src_end_ip <= ip || inst->dst.equals(inst->src[0])) { + if (scan_inst->can_do_saturate()) { + scan_inst->saturate = true; + inst->saturate = false; + progress = true; + } } break; } -- 2.30.2