import Mesa 11.0.6

1 files changed, 161 insertions, 0 deletions

diff --git a/lib/mesa/src/gallium/drivers/vc4/vc4_opt_dead_code.c b/lib/mesa/src/gallium/drivers/vc4/vc4_opt_dead_code.c
new file mode 100644
index 000000000..ffd42422d
--- /dev/null
+++ b/lib/mesa/src/gallium/drivers/vc4/vc4_opt_dead_code.c
@@ -0,0 +1,161 @@
+/*
+ * Copyright © 2014 Broadcom
+ *
+ * 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.
+ */
+
+/**
+ * @file vc4_opt_dead_code.c
+ *
+ * This is a simmple dead code eliminator for QIR with no control flow.
+ *
+ * It walks from the bottom of the instruction list, removing instructions
+ * with a destination that is never used, and marking the sources of non-dead
+ * instructions as used.
+ */
+
+#include "vc4_qir.h"
+
+static bool debug;
+
+static void
+dce(struct vc4_compile *c, struct qinst *inst)
+{
+        if (debug) {
+                fprintf(stderr, "Removing: ");
+                qir_dump_inst(c, inst);
+                fprintf(stderr, "\n");
+        }
+        assert(!inst->sf);
+        qir_remove_instruction(c, inst);
+}
+
+static bool
+has_nonremovable_reads(struct vc4_compile *c, struct qinst *inst)
+{
+        for (int i = 0; i < qir_get_op_nsrc(inst->op); i++) {
+                if (inst->src[i].file == QFILE_VPM) {
+                        uint32_t attr = inst->src[i].index / 4;
+                        uint32_t offset = (inst->src[i].index % 4) * 4;
+
+                        if (c->vattr_sizes[attr] != offset + 4)
+                                return true;
+
+                        /* Can't get rid of the last VPM read, or the
+                         * simulator (at least) throws an error.
+                         */
+                        uint32_t total_size = 0;
+                        for (uint32_t i = 0; i < ARRAY_SIZE(c->vattr_sizes); i++)
+                                total_size += c->vattr_sizes[i];
+                        if (total_size == 4)
+                                return true;
+                }
+
+                if (inst->src[i].file == QFILE_VARY &&
+                    c->input_semantics[inst->src[i].index].semantic == 0xff) {
+                        return true;
+                }
+        }
+
+        return false;
+}
+
+bool
+qir_opt_dead_code(struct vc4_compile *c)
+{
+        bool progress = false;
+        bool *used = calloc(c->num_temps, sizeof(bool));
+        bool sf_used = false;
+        /* Whether we're eliminating texture setup currently. */
+        bool dce_tex = false;
+
+        struct list_head *node, *t;
+        for (node = c->instructions.prev, t = node->prev;
+             &c->instructions != node;
+             node = t, t = t->prev) {
+                struct qinst *inst = (struct qinst *)node;
+
+                if (inst->dst.file == QFILE_TEMP &&
+                    !used[inst->dst.index] &&
+                    !inst->sf &&
+                    (!qir_has_side_effects(c, inst) ||
+                     inst->op == QOP_TEX_RESULT) &&
+                    !has_nonremovable_reads(c, inst)) {
+                        if (inst->op == QOP_TEX_RESULT) {
+                                dce_tex = true;
+                                c->num_texture_samples--;
+                        }
+
+                        for (int i = 0; i < qir_get_op_nsrc(inst->op); i++) {
+                                if (inst->src[i].file != QFILE_VPM)
+                                        continue;
+                                uint32_t attr = inst->src[i].index / 4;
+                                uint32_t offset = (inst->src[i].index % 4) * 4;
+
+                                if (c->vattr_sizes[attr] == offset + 4) {
+                                        c->num_inputs--;
+                                        c->vattr_sizes[attr] -= 4;
+                                }
+                        }
+
+                        dce(c, inst);
+                        progress = true;
+                        continue;
+                }
+
+                if (qir_depends_on_flags(inst))
+                        sf_used = true;
+                if (inst->sf) {
+                        if (!sf_used) {
+                                if (debug) {
+                                        fprintf(stderr, "Removing SF on: ");
+                                        qir_dump_inst(c, inst);
+                                        fprintf(stderr, "\n");
+                                }
+
+                                inst->sf = false;
+                                progress = true;
+                        }
+                        sf_used = false;
+                }
+
+                if (inst->op == QOP_TEX_RESULT)
+                        dce_tex = false;
+
+                if (dce_tex && (inst->op == QOP_TEX_S ||
+                                inst->op == QOP_TEX_T ||
+                                inst->op == QOP_TEX_R ||
+                                inst->op == QOP_TEX_B ||
+                                inst->op == QOP_TEX_DIRECT)) {
+                        dce(c, inst);
+                        progress = true;
+                        continue;
+                }
+
+                for (int i = 0; i < qir_get_op_nsrc(inst->op); i++) {
+                        if (inst->src[i].file == QFILE_TEMP)
+                                used[inst->src[i].index] = true;
+                }
+        }
+
+        free(used);
+
+        return progress;
+}