#include "vc4_qir.h"
-bool
-qir_opt_copy_propagation(struct vc4_compile *c)
+static bool
+is_copy_mov(struct qinst *inst)
{
- bool progress = false;
- struct simple_node *node;
- bool debug = false;
- struct qreg *movs = calloc(c->num_temps, sizeof(struct qreg));
- struct qinst **defs = calloc(c->num_temps, sizeof(struct qreg));
+ if (!inst)
+ return false;
- foreach(node, &c->instructions) {
- struct qinst *inst = (struct qinst *)node;
+ if (inst->op != QOP_MOV &&
+ inst->op != QOP_FMOV &&
+ inst->op != QOP_MMOV) {
+ return false;
+ }
+
+ if (inst->dst.file != QFILE_TEMP)
+ return false;
- if (inst->dst.file == QFILE_TEMP)
- defs[inst->dst.index] = inst;
+ if (inst->src[0].file != QFILE_TEMP &&
+ inst->src[0].file != QFILE_UNIF) {
+ return false;
+ }
- /* A single instruction can only read one uniform value. (It
- * could maybe read the same uniform value in two operands,
- * but that doesn't seem important to do).
+ if (inst->dst.pack || inst->cond != QPU_COND_ALWAYS)
+ return false;
+
+ return true;
+
+}
+
+static bool
+try_copy_prop(struct vc4_compile *c, struct qinst *inst, struct qinst **movs)
+{
+ bool debug = false;
+ bool progress = false;
+
+ for (int i = 0; i < qir_get_nsrc(inst); i++) {
+ if (inst->src[i].file != QFILE_TEMP)
+ continue;
+
+ /* We have two ways of finding MOVs we can copy propagate
+ * from. One is if it's an SSA def: then we can reuse it from
+ * any block in the program, as long as its source is also an
+ * SSA def. Alternatively, if it's in the "movs" array
+ * tracked within the block, then we know the sources for it
+ * haven't been changed since we saw the instruction within
+ * our block.
*/
- bool reads_a_uniform = false;
- for (int i = 0; i < qir_get_op_nsrc(inst->op); i++) {
- if (inst->src[i].file == QFILE_UNIF)
- reads_a_uniform = true;
+ struct qinst *mov = movs[inst->src[i].index];
+ if (!mov) {
+ if (!is_copy_mov(c->defs[inst->src[i].index]))
+ continue;
+ mov = c->defs[inst->src[i].index];
+
+ if (mov->src[0].file == QFILE_TEMP &&
+ !c->defs[mov->src[0].index])
+ continue;
}
- for (int i = 0; i < qir_get_op_nsrc(inst->op); i++) {
- int index = inst->src[i].index;
- if (inst->src[i].file == QFILE_TEMP &&
- (movs[index].file == QFILE_TEMP ||
- (movs[index].file == QFILE_UNIF &&
- !reads_a_uniform))) {
- if (debug) {
- fprintf(stderr, "Copy propagate: ");
- qir_dump_inst(c, inst);
- fprintf(stderr, "\n");
- }
-
- inst->src[i] = movs[index];
- if (movs[index].file == QFILE_UNIF)
- reads_a_uniform = true;
-
- if (debug) {
- fprintf(stderr, "to: ");
- qir_dump_inst(c, inst);
- fprintf(stderr, "\n");
- }
-
- progress = true;
+ /* Mul rotation's source needs to be in an r0-r3 accumulator,
+ * so no uniforms or regfile-a/r4 unpacking allowed.
+ */
+ if (inst->op == QOP_ROT_MUL &&
+ (mov->src[0].file != QFILE_TEMP ||
+ mov->src[0].pack))
+ continue;
+
+ uint8_t unpack;
+ if (mov->src[0].pack) {
+ /* Make sure that the meaning of the unpack
+ * would be the same between the two
+ * instructions.
+ */
+ if (qir_is_float_input(inst) !=
+ qir_is_float_input(mov)) {
+ continue;
}
+
+ /* There's only one unpack field, so make sure
+ * this instruction doesn't already use it.
+ */
+ bool already_has_unpack = false;
+ for (int j = 0; j < qir_get_nsrc(inst); j++) {
+ if (inst->src[j].pack)
+ already_has_unpack = true;
+ }
+ if (already_has_unpack)
+ continue;
+
+ /* A destination pack requires the PM bit to
+ * be set to a specific value already, which
+ * may be different from ours.
+ */
+ if (inst->dst.pack)
+ continue;
+
+ unpack = mov->src[0].pack;
+ } else {
+ unpack = inst->src[i].pack;
+ }
+
+ if (debug) {
+ fprintf(stderr, "Copy propagate: ");
+ qir_dump_inst(c, inst);
+ fprintf(stderr, "\n");
}
- if (inst->op == QOP_MOV &&
- inst->dst.file == QFILE_TEMP &&
- inst->src[0].file != QFILE_VPM &&
- !(inst->src[0].file == QFILE_TEMP &&
- (defs[inst->src[0].index]->op == QOP_TEX_RESULT ||
- defs[inst->src[0].index]->op == QOP_TLB_COLOR_READ))) {
- movs[inst->dst.index] = inst->src[0];
+ inst->src[i] = mov->src[0];
+ inst->src[i].pack = unpack;
+
+ if (debug) {
+ fprintf(stderr, "to: ");
+ qir_dump_inst(c, inst);
+ fprintf(stderr, "\n");
}
+
+ progress = true;
}
- free(movs);
- free(defs);
+ return progress;
+}
+
+static void
+apply_kills(struct vc4_compile *c, struct qinst **movs, struct qinst *inst)
+{
+ if (inst->dst.file != QFILE_TEMP)
+ return;
+
+ for (int i = 0; i < c->num_temps; i++) {
+ if (movs[i] &&
+ (movs[i]->dst.index == inst->dst.index ||
+ (movs[i]->src[0].file == QFILE_TEMP &&
+ movs[i]->src[0].index == inst->dst.index))) {
+ movs[i] = NULL;
+ }
+ }
+}
+
+bool
+qir_opt_copy_propagation(struct vc4_compile *c)
+{
+ bool progress = false;
+ struct qinst **movs;
+
+ movs = ralloc_array(c, struct qinst *, c->num_temps);
+ if (!movs)
+ return false;
+
+ qir_for_each_block(block, c) {
+ /* The MOVs array tracks only available movs within the
+ * block.
+ */
+ memset(movs, 0, sizeof(struct qinst *) * c->num_temps);
+
+ qir_for_each_inst(inst, block) {
+ progress = try_copy_prop(c, inst, movs) || progress;
+
+ apply_kills(c, movs, inst);
+
+ if (is_copy_mov(inst))
+ movs[inst->dst.index] = inst;
+ }
+ }
+
+ ralloc_free(movs);
+
return progress;
}
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