From 94b68109fbe1cb60cc23a4c5a319039ada81ea81 Mon Sep 17 00:00:00 2001 From: Matt Turner Date: Sat, 27 Sep 2014 10:34:56 -0700 Subject: [PATCH] i965/fs: Optimize sqrt+inv into rsq. Transform sqrt a, b rcp c, a into sqrt a, b rsq c, b The improvement here is that we've broken a dependency between these instructions. Leads to 330 fewer INV instructions and 330 more RSQ. Reviewed-by: Anuj Phogat Reviewed-by: Ian Romanick --- src/mesa/drivers/dri/i965/brw_fs.cpp | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp index ab4ee34b41c..19e9cb957e0 100644 --- a/src/mesa/drivers/dri/i965/brw_fs.cpp +++ b/src/mesa/drivers/dri/i965/brw_fs.cpp @@ -2334,6 +2334,17 @@ fs_visitor::opt_algebraic() } } break; + case SHADER_OPCODE_RCP: { + fs_inst *prev = (fs_inst *)inst->prev; + if (prev->opcode == SHADER_OPCODE_SQRT) { + if (inst->src[0].equals(prev->dst)) { + inst->opcode = SHADER_OPCODE_RSQ; + inst->src[0] = prev->src[0]; + progress = true; + } + } + break; + } default: break; } -- 2.30.2