[Mesa-dev] [PATCH 11/16] i965/fs: Add pass to propagate conditional modifiers.
Kenneth Graunke
kenneth at whitecape.org
Fri Jan 23 14:50:15 PST 2015
On Monday, January 19, 2015 03:31:10 PM Matt Turner wrote:
> total instructions in shared programs: 5974160 -> 5959463 (-0.25%)
> instructions in affected programs: 1743737 -> 1729040 (-0.84%)
> GAINED: 0
> LOST: 12
> ---
> src/mesa/drivers/dri/i965/Makefile.sources | 1 +
> src/mesa/drivers/dri/i965/brw_fs.cpp | 1 +
> src/mesa/drivers/dri/i965/brw_fs.h | 1 +
> .../drivers/dri/i965/brw_fs_cmod_propagation.cpp | 97 ++++++++++++++++++++++
> 4 files changed, 100 insertions(+)
> create mode 100644 src/mesa/drivers/dri/i965/brw_fs_cmod_propagation.cpp
>
> diff --git a/src/mesa/drivers/dri/i965/Makefile.sources b/src/mesa/drivers/dri/i965/Makefile.sources
> index 3b72955..da48455 100644
> --- a/src/mesa/drivers/dri/i965/Makefile.sources
> +++ b/src/mesa/drivers/dri/i965/Makefile.sources
> @@ -39,6 +39,7 @@ i965_FILES = \
> brw_ff_gs_emit.c \
> brw_ff_gs.h \
> brw_fs_channel_expressions.cpp \
> + brw_fs_cmod_propagation.cpp \
> brw_fs_copy_propagation.cpp \
> brw_fs.cpp \
> brw_fs_cse.cpp \
> diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp
> index 73d722e..994d457 100644
> --- a/src/mesa/drivers/dri/i965/brw_fs.cpp
> +++ b/src/mesa/drivers/dri/i965/brw_fs.cpp
> @@ -3581,6 +3581,7 @@ fs_visitor::optimize()
> OPT(opt_cse);
> OPT(opt_copy_propagate);
> OPT(opt_peephole_predicated_break);
> + OPT(opt_cmod_propagation);
> OPT(dead_code_eliminate);
> OPT(opt_peephole_sel);
> OPT(dead_control_flow_eliminate, this);
> diff --git a/src/mesa/drivers/dri/i965/brw_fs.h b/src/mesa/drivers/dri/i965/brw_fs.h
> index 9c125a6..e1bc7d7 100644
> --- a/src/mesa/drivers/dri/i965/brw_fs.h
> +++ b/src/mesa/drivers/dri/i965/brw_fs.h
> @@ -539,6 +539,7 @@ public:
> bool opt_peephole_sel();
> bool opt_peephole_predicated_break();
> bool opt_saturate_propagation();
> + bool opt_cmod_propagation();
> void emit_bool_to_cond_code(ir_rvalue *condition);
> void emit_if_gen6(ir_if *ir);
> void emit_unspill(bblock_t *block, fs_inst *inst, fs_reg reg,
> diff --git a/src/mesa/drivers/dri/i965/brw_fs_cmod_propagation.cpp b/src/mesa/drivers/dri/i965/brw_fs_cmod_propagation.cpp
> new file mode 100644
> index 0000000..5ba2fd6
> --- /dev/null
> +++ b/src/mesa/drivers/dri/i965/brw_fs_cmod_propagation.cpp
> @@ -0,0 +1,97 @@
> +/*
> + * Copyright © 2014 Intel Corporation
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a
> + * copy of this software and associated documentation files (the "Software"),
> + * to deal in the Software without restriction, including without limitation
> + * the rights to use, copy, modify, merge, publish, distribute, sublicense,
> + * and/or sell copies of the Software, and to permit persons to whom the
> + * Software is furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice (including the next
> + * paragraph) shall be included in all copies or substantial portions of the
> + * Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
> + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
> + * IN THE SOFTWARE.
> + */
> +
> +#include "brw_fs.h"
> +#include "brw_fs_live_variables.h"
> +#include "brw_cfg.h"
> +
> +/** @file brw_fs_cmod_propagation.cpp
> + *
> + * Implements a pass that propagates the conditional modifier from a CMP x 0.0
> + * instruction into the instruction that generated x. For instance, in this
> + * sequence
> + *
> + * add(8) g70<1>F g69<8,8,1>F 4096F
> + * cmp.ge.f0(8) null g70<8,8,1>F 0F
> + *
> + * we can do the comparison as part of the ADD instruction directly:
> + *
> + * add.ge.f0(8) g70<1>F g69<8,8,1>F 4096F
> + */
> +
> +static bool
> +opt_cmod_propagation_local(fs_visitor *v, bblock_t *block)
> +{
> + bool progress = false;
> + int ip = block->end_ip + 1;
> +
> + foreach_inst_in_block_reverse_safe(fs_inst, inst, block) {
> + ip--;
> +
> + if (inst->opcode != BRW_OPCODE_CMP ||
> + inst->predicate != BRW_PREDICATE_NONE ||
> + !inst->dst.is_null() ||
> + inst->src[0].file != GRF ||
> + inst->src[0].abs ||
> + inst->src[0].negate ||
> + !inst->src[1].is_zero())
> + continue;
> +
> + foreach_inst_in_block_reverse_starting_from(fs_inst, scan_inst, inst,
> + block) {
> + if (scan_inst->dst.file == GRF &&
> + scan_inst->dst.reg == inst->src[0].reg &&
> + scan_inst->dst.reg_offset == inst->src[0].reg_offset &&
Although unlikely, I think you'll fail to detect writes to large VGRFs:
add vgrf3+2 ... ...
tex vgrf3 ...
cmp.ge.f0(8) null vgrf3+2 0F
Here, the tex clobbers vgrf3+0..3, including your register, but doesn't
have reg_offset == 2, so you'll miss that.
Perhaps you want:
if (scan_inst->overwrites_reg(inst->src[0].reg)) {
if (scan_inst->is_partial_write() ||
scan_inst->dst.reg_offset != inst->src[0].reg_offset)
break;
if (scan_inst->can_do_cmod() &&
(scan_inst->conditional_mod == BRW_CONDITIONAL_NONE ||
scan_inst->conditional_mod == inst->conditional_mod)) {
scan_inst->conditional_mod = inst->conditional_mod;
inst->remove(block);
progress = true;
}
break;
}
or something like that?
With that fixed or refuted, this is:
Reviewed-by: Kenneth Graunke <kenneth at whitecape.org>
> + !scan_inst->is_partial_write()) {
> + if (scan_inst->can_do_cmod() &&
> + (scan_inst->conditional_mod == BRW_CONDITIONAL_NONE ||
> + scan_inst->conditional_mod == inst->conditional_mod)) {
> + scan_inst->conditional_mod = inst->conditional_mod;
> + inst->remove(block);
> + progress = true;
> + }
> + break;
> + }
> +
> + if (scan_inst->reads_flag() || scan_inst->writes_flag())
> + break;
> + }
> + }
> +
> + return progress;
> +}
> +
> +bool
> +fs_visitor::opt_cmod_propagation()
> +{
> + bool progress = false;
> +
> + foreach_block_reverse(block, cfg) {
> + progress = opt_cmod_propagation_local(this, block) || progress;
> + }
> +
> + if (progress)
> + invalidate_live_intervals();
> +
> + return progress;
> +}
>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 819 bytes
Desc: This is a digitally signed message part.
URL: <http://lists.freedesktop.org/archives/mesa-dev/attachments/20150123/33c5db9a/attachment.sig>
More information about the mesa-dev
mailing list