[Mesa-dev] [PATCH 14/16] freedreno: a2xx: add ir2 copy propagation
Jonathan Marek
jonathan at marek.ca
Wed Dec 19 16:40:03 UTC 2018
Two cases:
* replacing srcs which refer to MOV instructions
* replacing MOVs used to write to exports
Signed-off-by: Jonathan Marek <jonathan at marek.ca>
---
.../drivers/freedreno/Makefile.sources | 1 +
src/gallium/drivers/freedreno/a2xx/ir2.c | 6 +
src/gallium/drivers/freedreno/a2xx/ir2_cp.c | 225 ++++++++++++++++++
.../drivers/freedreno/a2xx/ir2_private.h | 3 +
src/gallium/drivers/freedreno/meson.build | 1 +
5 files changed, 236 insertions(+)
create mode 100644 src/gallium/drivers/freedreno/a2xx/ir2_cp.c
diff --git a/src/gallium/drivers/freedreno/Makefile.sources b/src/gallium/drivers/freedreno/Makefile.sources
index 8421318081..f4979953e8 100644
--- a/src/gallium/drivers/freedreno/Makefile.sources
+++ b/src/gallium/drivers/freedreno/Makefile.sources
@@ -71,6 +71,7 @@ a2xx_SOURCES := \
a2xx/ir2.c \
a2xx/ir2.h \
a2xx/ir2_assemble.c \
+ a2xx/ir2_cp.c \
a2xx/ir2_nir.c \
a2xx/ir2_private.h \
a2xx/ir2_ra.c
diff --git a/src/gallium/drivers/freedreno/a2xx/ir2.c b/src/gallium/drivers/freedreno/a2xx/ir2.c
index 344f62defe..bc1d7c23b8 100644
--- a/src/gallium/drivers/freedreno/a2xx/ir2.c
+++ b/src/gallium/drivers/freedreno/a2xx/ir2.c
@@ -422,9 +422,15 @@ ir2_compile(struct fd2_shader_stateobj *so, unsigned variant,
/* convert nir to internal representation */
ir2_nir_compile(&ctx, binning);
+ /* copy propagate srcs */
+ cp_src(&ctx);
+
/* get ref_counts and kill non-needed instructions */
ra_count_refs(&ctx);
+ /* remove movs used to write outputs */
+ cp_export(&ctx);
+
/* instruction order.. and vector->scalar conversions */
schedule_instrs(&ctx);
diff --git a/src/gallium/drivers/freedreno/a2xx/ir2_cp.c b/src/gallium/drivers/freedreno/a2xx/ir2_cp.c
new file mode 100644
index 0000000000..fa155887f8
--- /dev/null
+++ b/src/gallium/drivers/freedreno/a2xx/ir2_cp.c
@@ -0,0 +1,225 @@
+/*
+ * Copyright (C) 2018 Jonathan Marek <jonathan at marek.ca>
+ *
+ * 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.
+ *
+ * Authors:
+ * Jonathan Marek <jonathan at marek.ca>
+ */
+
+#include "ir2_private.h"
+
+static bool is_mov(struct ir2_instr *instr)
+{
+ return instr->type == IR2_ALU && instr->alu.vector_opc == MAXv &&
+ instr->src_count == 1;
+}
+
+static void src_combine(struct ir2_src *src, struct ir2_src b)
+{
+ src->num = b.num;
+ src->type = b.type;
+ src->swizzle = swiz_merge(b.swizzle, src->swizzle);
+ if (!src->abs) /* if we have abs we don't care about previous negate */
+ src->negate ^= b.negate;
+ src->abs |= b.abs;
+}
+
+/* cp_src: replace src regs when they refer to a mov instruction
+ * example:
+ * ALU: MAXv R7 = C7, C7
+ * ALU: MULADDv R7 = R7, R10, R0.xxxx
+ * becomes:
+ * ALU: MULADDv R7 = C7, R10, R0.xxxx
+ */
+void cp_src(struct ir2_context *ctx)
+{
+ struct ir2_instr *p;
+
+ ir2_foreach_instr(instr, ctx) {
+ ir2_foreach_src(src, instr) {
+ /* loop to replace recursively */
+ do {
+ if (src->type != IR2_SRC_SSA)
+ break;
+
+ p = &ctx->instr[src->num];
+ /* don't work across blocks to avoid possible issues */
+ if (p->block_idx != instr->block_idx)
+ break;
+
+ if (!is_mov(p))
+ break;
+
+ /* cant apply abs to const src, const src only for alu */
+ if (p->src[0].type == IR2_SRC_CONST &&
+ (src->abs || instr->type != IR2_ALU))
+ break;
+
+ src_combine(src, p->src[0]);
+ } while (1);
+ }
+ }
+}
+
+/* cp_export: replace mov to export when possible
+ * in the cp_src pass we bypass any mov instructions related
+ * to the src registers, but for exports for need something different
+ * example:
+ * ALU: MAXv R3.x___ = C9.x???, C9.x???
+ * ALU: MAXv R3._y__ = R0.?x??, C8.?x??
+ * ALU: MAXv export0 = R3.yyyx, R3.yyyx
+ * becomes:
+ * ALU: MAXv export0.___w = C9.???x, C9.???x
+ * ALU: MAXv export0.xyz_ = R0.xxx?, C8.xxx?
+ *
+ */
+void cp_export(struct ir2_context *ctx)
+{
+ struct ir2_instr *c[4], *ins[4];
+ struct ir2_src *src;
+ struct ir2_reg *reg;
+ unsigned ncomp;
+
+ ir2_foreach_instr(instr, ctx) {
+ if (!is_export(instr)) /* TODO */
+ continue;
+
+ if (!is_mov(instr))
+ continue;
+
+ src = &instr->src[0];
+
+ if (src->negate || src->abs) /* TODO handle these cases */
+ continue;
+
+ if (src->type == IR2_SRC_INPUT || src->type == IR2_SRC_CONST)
+ continue;
+
+ reg = get_reg_src(ctx, src);
+ ncomp = dst_ncomp(instr);
+
+ unsigned reswiz[4] = {};
+ unsigned num_instr = 0;
+
+ /* fill array c with pointers to instrs that write each component */
+ if (src->type == IR2_SRC_SSA) {
+ struct ir2_instr *instr = &ctx->instr[src->num];
+
+ if (instr->type != IR2_ALU)
+ continue;
+
+ for (int i = 0; i < ncomp; i++)
+ c[i] = instr;
+
+ ins[num_instr++] = instr;
+ reswiz[0] = src->swizzle;
+ } else {
+ bool ok = true;
+ unsigned write_mask = 0;
+
+ ir2_foreach_instr(instr, ctx) {
+ if (instr->is_ssa || instr->reg != reg)
+ continue;
+
+ /* set by non-ALU */
+ if (instr->type != IR2_ALU) {
+ ok = false;
+ break;
+ }
+
+ /* component written more than once */
+ if (write_mask & instr->alu.write_mask) {
+ ok = false;
+ break;
+ }
+
+ write_mask |= instr->alu.write_mask;
+
+ /* src pointers for components */
+ for (int i = 0, j = 0; i < 4; i++) {
+ unsigned k = swiz_get(src->swizzle, i);
+ if (instr->alu.write_mask & 1 << k) {
+ c[i] = instr;
+
+ /* reswiz = compressed src->swizzle */
+ unsigned x = 0;
+ for (int i = 0; i < k; i++)
+ x += !!(instr->alu.write_mask & 1 << i);
+
+ assert(src->swizzle || x == j);
+ reswiz[num_instr] |= swiz_set(x, j++);
+ }
+ }
+ ins[num_instr++] = instr;
+ }
+ if (!ok)
+ continue;
+ }
+
+ bool redirect = true;
+
+ /* must all be in same block */
+ for (int i = 0; i < ncomp; i++)
+ redirect &= (c[i]->block_idx == instr->block_idx);
+
+ /* no other instr using the value */
+ ir2_foreach_instr(p, ctx) {
+ if (p == instr)
+ continue;
+ ir2_foreach_src(src, p)
+ redirect &= reg != get_reg_src(ctx, src);
+ }
+
+ if (!redirect)
+ continue;
+
+ /* redirect the instructions writing to the register */
+ for (int i = 0; i < num_instr; i++) {
+ struct ir2_instr *p = ins[i];
+
+ p->alu.export = instr->alu.export;
+ p->alu.write_mask = 0;
+ p->is_ssa = true;
+ p->ssa.ncomp = 0;
+ memset(p->ssa.comp, 0, sizeof(p->ssa.comp));
+
+ switch (instr->alu.vector_opc) {
+ case PRED_SETE_PUSHv ... PRED_SETGTE_PUSHv:
+ case DOT2ADDv:
+ case DOT3v:
+ case DOT4v:
+ case CUBEv:
+ continue;
+ default:
+ break;
+ }
+ ir2_foreach_src(s, p)
+ swiz_merge_p(&s->swizzle, reswiz[i]);
+ }
+
+ for (int i = 0; i < ncomp; i++) {
+ c[i]->alu.write_mask |= (1 << i);
+ c[i]->ssa.ncomp++;
+ }
+ instr->type = IR2_NONE;
+ instr->need_emit = false;
+ }
+}
diff --git a/src/gallium/drivers/freedreno/a2xx/ir2_private.h b/src/gallium/drivers/freedreno/a2xx/ir2_private.h
index d1fbacd908..3bb3fe483d 100644
--- a/src/gallium/drivers/freedreno/a2xx/ir2_private.h
+++ b/src/gallium/drivers/freedreno/a2xx/ir2_private.h
@@ -195,6 +195,9 @@ void ra_reg(struct ir2_context *ctx, struct ir2_reg *reg, int force_idx,
void ra_src_free(struct ir2_context *ctx, struct ir2_instr *instr);
void ra_block_free(struct ir2_context *ctx, unsigned block);
+void cp_src(struct ir2_context *ctx);
+void cp_export(struct ir2_context *ctx);
+
/* utils */
enum {
IR2_SWIZZLE_Y = 1 << 0,
diff --git a/src/gallium/drivers/freedreno/meson.build b/src/gallium/drivers/freedreno/meson.build
index 6f8d8bdcc4..3565432512 100644
--- a/src/gallium/drivers/freedreno/meson.build
+++ b/src/gallium/drivers/freedreno/meson.build
@@ -89,6 +89,7 @@ files_libfreedreno = files(
'a2xx/ir2.c',
'a2xx/ir2.h',
'a2xx/ir2_assemble.c',
+ 'a2xx/ir2_cp.c',
'a2xx/ir2_nir.c',
'a2xx/ir2_private.h',
'a2xx/ir2_ra.c',
--
2.17.1
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