From 20dee82a75ac7415fba0b3540a1f99d60b2325db Mon Sep 17 00:00:00 2001 From: Matt Turner Date: Tue, 1 Apr 2014 14:05:39 -0700 Subject: [PATCH] i965/vec4: Consider sources of non-GRF-dst instructions for dead channels. Previously we'd ignore the sources of instructions with non-GRF destinations when calculating calculating the dead channels. This would lead to us incorrectly removing the first instruction in this sequence: mov vgrf11, ... cmp.ne.f0 null, vgrf11, 1.0 mov vgrf11, ... Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=76616 --- src/mesa/drivers/dri/i965/brw_vec4.cpp | 20 ++++++++------------ 1 file changed, 8 insertions(+), 12 deletions(-) diff --git a/src/mesa/drivers/dri/i965/brw_vec4.cpp b/src/mesa/drivers/dri/i965/brw_vec4.cpp index a86d42c..740d9ff 100644 --- a/src/mesa/drivers/dri/i965/brw_vec4.cpp +++ b/src/mesa/drivers/dri/i965/brw_vec4.cpp @@ -325,6 +325,9 @@ static bool try_eliminate_instruction(vec4_instruction *inst, int new_writemask, const struct brw_context *brw) { + if (inst->has_side_effects()) + return false; + if (new_writemask == 0) { /* Don't dead code eliminate instructions that write to the * accumulator as a side-effect. Instead just set the destination @@ -387,9 +390,6 @@ vec4_visitor::dead_code_eliminate() seen_control_flow = inst->is_control_flow() || seen_control_flow; - if (inst->has_side_effects()) - continue; - bool inst_writes_flag = false; if (inst->dst.file != GRF) { if (inst->dst.is_null() && inst->writes_flag()) { @@ -443,22 +443,18 @@ vec4_visitor::dead_code_eliminate() node = prev, prev = prev->prev) { vec4_instruction *scan_inst = (vec4_instruction *)node; - if (scan_inst->has_side_effects()) - continue; - if (inst_writes_flag) { if (scan_inst->dst.is_null() && scan_inst->writes_flag()) { scan_inst->remove(); progress = true; + continue; } else if (scan_inst->reads_flag()) { - dead_channels = 0; + break; } - continue; - } else if (scan_inst->dst.file != GRF) { - continue; } - if (inst->dst.reg == scan_inst->dst.reg) { + if (inst->dst.file == scan_inst->dst.file && + inst->dst.reg == scan_inst->dst.reg) { int new_writemask = scan_inst->dst.writemask & ~dead_channels; progress = try_eliminate_instruction(scan_inst, new_writemask, brw) || @@ -466,7 +462,7 @@ vec4_visitor::dead_code_eliminate() } for (int i = 0; i < 3; i++) { - if (scan_inst->src[i].file != GRF || + if (scan_inst->src[i].file != inst->dst.file || scan_inst->src[i].reg != inst->dst.reg) continue; -- 2.7.4