From 4dc7e6dcbf0d9c360e257c704774c9b083511b47 Mon Sep 17 00:00:00 2001 From: Eric Anholt Date: Wed, 6 Mar 2013 17:50:50 -0800 Subject: [PATCH] i965/fs: Also do the gen4 SEND dependency workaround against other SENDs. We were handling the the dependency workaround for the first written reg of a send preceding the one we're fixing up, but didn't consider the other regs. Thus if you had two sampler calls that got allocated to the same set of regs, one might, rarely, ovewrite the other. This was occurring in XBMC's GLSL shaders. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=44567 NOTE: This is a candidate for the stable branches. Reviewed-by: Kenneth Graunke --- src/mesa/drivers/dri/i965/brw_fs.cpp | 24 +++++++++++++++--------- 1 file changed, 15 insertions(+), 9 deletions(-) diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp index 5380abfe2f4..8ce39543002 100644 --- a/src/mesa/drivers/dri/i965/brw_fs.cpp +++ b/src/mesa/drivers/dri/i965/brw_fs.cpp @@ -2300,7 +2300,8 @@ clear_deps_for_inst_src(fs_inst *inst, int dispatch_width, bool *deps, void fs_visitor::insert_gen4_pre_send_dependency_workarounds(fs_inst *inst) { - int write_len = inst->regs_written() * dispatch_width / 8; + int reg_size = dispatch_width / 8; + int write_len = inst->regs_written() * reg_size; int first_write_grf = inst->dst.reg; bool needs_dep[BRW_MAX_MRF]; assert(write_len < (int)sizeof(needs_dep) - 1); @@ -2339,14 +2340,19 @@ fs_visitor::insert_gen4_pre_send_dependency_workarounds(fs_inst *inst) * instruction but a MOV that might have left us an outstanding * dependency has more latency than a MOV. */ - if (scan_inst->dst.file == GRF && - scan_inst->dst.reg >= first_write_grf && - scan_inst->dst.reg < first_write_grf + write_len && - needs_dep[scan_inst->dst.reg - first_write_grf]) { - inst->insert_before(DEP_RESOLVE_MOV(scan_inst->dst.reg)); - needs_dep[scan_inst->dst.reg - first_write_grf] = false; - if (scan_inst_16wide) - needs_dep[scan_inst->dst.reg - first_write_grf + 1] = false; + if (scan_inst->dst.file == GRF) { + for (int i = 0; i < scan_inst->regs_written(); i++) { + int reg = scan_inst->dst.reg + i * reg_size; + + if (reg >= first_write_grf && + reg < first_write_grf + write_len && + needs_dep[reg - first_write_grf]) { + inst->insert_before(DEP_RESOLVE_MOV(reg)); + needs_dep[reg - first_write_grf] = false; + if (scan_inst_16wide) + needs_dep[reg - first_write_grf + 1] = false; + } + } } /* Clear the flag for registers that actually got read (as expected). */ -- 2.30.2