From f0aec4ee1e364927f3003cabafa644035bcd803c Mon Sep 17 00:00:00 2001 From: Matt Turner Date: Mon, 12 Jan 2015 13:58:06 -0800 Subject: [PATCH] i965: Don't consider null dst instructions as matching non-null dst. MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit When performing common subexpression elimination on instructions with non-null destinations we emit a MOV to copy the result to a new register that must have no other uses. In the case of: cmp.g.f0.0(8) null:D, vgrf43:F, 0.500000f ... cmp.g.f0.0(8) vgrf113:D, vgrf43:F, 0.500000f we put the first instruction in the AEB and decided that we could reuse its result when we found the second. Unfortunately, that meant that we'd emit a MOV from the first's destination, which is null. Don't do anything if the entry's destination is null and the instruction's destination is non-null. Tested-by: Tapani Pälli --- src/mesa/drivers/dri/i965/brw_fs_cse.cpp | 3 ++- src/mesa/drivers/dri/i965/brw_vec4_cse.cpp | 3 ++- 2 files changed, 4 insertions(+), 2 deletions(-) diff --git a/src/mesa/drivers/dri/i965/brw_fs_cse.cpp b/src/mesa/drivers/dri/i965/brw_fs_cse.cpp index f87601ce0ec..11cb327614c 100644 --- a/src/mesa/drivers/dri/i965/brw_fs_cse.cpp +++ b/src/mesa/drivers/dri/i965/brw_fs_cse.cpp @@ -194,7 +194,8 @@ fs_visitor::opt_cse_local(bblock_t *block) foreach_in_list_use_after(aeb_entry, entry, &aeb) { /* Match current instruction's expression against those in AEB. */ - if (instructions_match(inst, entry->generator)) { + if (!(entry->generator->dst.is_null() && !inst->dst.is_null()) && + instructions_match(inst, entry->generator)) { found = true; progress = true; break; diff --git a/src/mesa/drivers/dri/i965/brw_vec4_cse.cpp b/src/mesa/drivers/dri/i965/brw_vec4_cse.cpp index 30a4098b339..ee50419dc9a 100644 --- a/src/mesa/drivers/dri/i965/brw_vec4_cse.cpp +++ b/src/mesa/drivers/dri/i965/brw_vec4_cse.cpp @@ -157,7 +157,8 @@ vec4_visitor::opt_cse_local(bblock_t *block) foreach_in_list_use_after(aeb_entry, entry, &aeb) { /* Match current instruction's expression against those in AEB. */ - if (instructions_match(inst, entry->generator)) { + if (!(entry->generator->dst.is_null() && !inst->dst.is_null()) && + instructions_match(inst, entry->generator)) { found = true; progress = true; break; -- 2.30.2