return ins;
}
-static midgard_branch_extended
-midgard_create_branch_extended( midgard_condition cond,
- midgard_jmp_writeout_op op,
- unsigned dest_tag,
- signed quadword_offset)
-{
- /* The condition code is actually a LUT describing a function to
- * combine multiple condition codes. However, we only support a single
- * condition code at the moment, so we just duplicate over a bunch of
- * times. */
-
- uint16_t duplicated_cond =
- (cond << 14) |
- (cond << 12) |
- (cond << 10) |
- (cond << 8) |
- (cond << 6) |
- (cond << 4) |
- (cond << 2) |
- (cond << 0);
-
- midgard_branch_extended branch = {
- .op = op,
- .dest_tag = dest_tag,
- .offset = quadword_offset,
- .cond = duplicated_cond
- };
-
- return branch;
-}
-
static void
attach_constants(compiler_context *ctx, midgard_instruction *ins, void *constants, int name)
{
* stream and in branch targets. An initial block might be empty, so iterate
* until we find one that 'works' */
-static unsigned
+unsigned
midgard_get_first_tag_from_block(compiler_context *ctx, unsigned block_idx)
{
midgard_block *initial_block = mir_get_block(ctx, block_idx);
midgard_schedule_program(ctx);
mir_ra(ctx);
- /* Now that all the bundles are scheduled and we can calculate block
- * sizes, emit actual branch instructions rather than placeholders */
-
- int br_block_idx = 0;
-
- mir_foreach_block(ctx, _block) {
- midgard_block *block = (midgard_block *) _block;
- util_dynarray_foreach(&block->bundles, midgard_bundle, bundle) {
- for (int c = 0; c < bundle->instruction_count; ++c) {
- midgard_instruction *ins = bundle->instructions[c];
-
- if (!midgard_is_branch_unit(ins->unit)) continue;
-
- /* Parse some basic branch info */
- bool is_compact = ins->unit == ALU_ENAB_BR_COMPACT;
- bool is_conditional = ins->branch.conditional;
- bool is_inverted = ins->branch.invert_conditional;
- bool is_discard = ins->branch.target_type == TARGET_DISCARD;
- bool is_tilebuf_wait = ins->branch.target_type == TARGET_TILEBUF_WAIT;
- bool is_special = is_discard || is_tilebuf_wait;
- bool is_writeout = ins->writeout;
-
- /* Determine the block we're jumping to */
- int target_number = ins->branch.target_block;
-
- /* Report the destination tag */
- int dest_tag = is_discard ? 0 :
- is_tilebuf_wait ? bundle->tag :
- midgard_get_first_tag_from_block(ctx, target_number);
-
- /* Count up the number of quadwords we're
- * jumping over = number of quadwords until
- * (br_block_idx, target_number) */
-
- int quadword_offset = 0;
-
- if (is_discard) {
- /* Ignored */
- } else if (is_tilebuf_wait) {
- quadword_offset = -1;
- } else if (target_number > br_block_idx) {
- /* Jump forward */
-
- for (int idx = br_block_idx + 1; idx < target_number; ++idx) {
- midgard_block *blk = mir_get_block(ctx, idx);
- assert(blk);
-
- quadword_offset += blk->quadword_count;
- }
- } else {
- /* Jump backwards */
-
- for (int idx = br_block_idx; idx >= target_number; --idx) {
- midgard_block *blk = mir_get_block(ctx, idx);
- assert(blk);
-
- quadword_offset -= blk->quadword_count;
- }
- }
-
- /* Unconditional extended branches (far jumps)
- * have issues, so we always use a conditional
- * branch, setting the condition to always for
- * unconditional. For compact unconditional
- * branches, cond isn't used so it doesn't
- * matter what we pick. */
-
- midgard_condition cond =
- !is_conditional ? midgard_condition_always :
- is_inverted ? midgard_condition_false :
- midgard_condition_true;
-
- midgard_jmp_writeout_op op =
- is_discard ? midgard_jmp_writeout_op_discard :
- is_tilebuf_wait ? midgard_jmp_writeout_op_tilebuffer_pending :
- is_writeout ? midgard_jmp_writeout_op_writeout :
- (is_compact && !is_conditional) ? midgard_jmp_writeout_op_branch_uncond :
- midgard_jmp_writeout_op_branch_cond;
-
- if (!is_compact) {
- midgard_branch_extended branch =
- midgard_create_branch_extended(
- cond, op,
- dest_tag,
- quadword_offset);
-
- memcpy(&ins->branch_extended, &branch, sizeof(branch));
- } else if (is_conditional || is_special) {
- midgard_branch_cond branch = {
- .op = op,
- .dest_tag = dest_tag,
- .offset = quadword_offset,
- .cond = cond
- };
-
- assert(branch.offset == quadword_offset);
-
- memcpy(&ins->br_compact, &branch, sizeof(branch));
- } else {
- assert(op == midgard_jmp_writeout_op_branch_uncond);
-
- midgard_branch_uncond branch = {
- .op = op,
- .dest_tag = dest_tag,
- .offset = quadword_offset,
- .unknown = 1
- };
-
- assert(branch.offset == quadword_offset);
-
- memcpy(&ins->br_compact, &branch, sizeof(branch));
- }
- }
- }
-
- ++br_block_idx;
- }
-
/* Emit flat binary from the instruction arrays. Iterate each block in
* sequence. Save instruction boundaries such that lookahead tags can
* be assigned easily */