From: Matt Turner Date: Thu, 7 Nov 2013 23:09:33 +0000 (-0800) Subject: i965/fs: Don't perform CSE on inst HW_REG dests (unless it's null) X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=68349e52194b7eba521b88d42ee8db3bfdf0a877;p=mesa.git i965/fs: Don't perform CSE on inst HW_REG dests (unless it's null) Commit b16b3c87 began performing CSE on CMP instructions with null destinations. I relaxed the restrictions a bit too much, thereby allowing CSE to be performed on instructions with, for instance, an explicit accumulator destination. This broke the arb_gpu_shader5/fs-imulExtended shader tests because they emit MUL instructions with the accumulator as the destination. CSE would instead cause the MUL to write to a GRF, which is lower precision than the accumulator. Reviewed-by: Eric Anholt Cc: 10.0 --- diff --git a/src/mesa/drivers/dri/i965/brw_fs_cse.cpp b/src/mesa/drivers/dri/i965/brw_fs_cse.cpp index 47938744cf6..27541db9be9 100644 --- a/src/mesa/drivers/dri/i965/brw_fs_cse.cpp +++ b/src/mesa/drivers/dri/i965/brw_fs_cse.cpp @@ -129,7 +129,8 @@ fs_visitor::opt_cse_local(bblock_t *block, exec_list *aeb) inst = (fs_inst *) inst->next) { /* Skip some cases. */ - if (is_expression(inst) && !inst->is_partial_write()) + if (is_expression(inst) && !inst->is_partial_write() && + (inst->dst.file != HW_REG || inst->dst.is_null())) { bool found = false;