/*
- * Copyright (C) 1995-2007 University of Karlsruhe. All right reserved.
+ * Copyright (C) 1995-2008 University of Karlsruhe. All right reserved.
*
* This file is part of libFirm.
*
* @author Matthias Braun, Christoph Mallon
* @date 27.09.2006
* @version $Id$
+ *
+ * The goals of the greedy (and ILP) algorithm here works by assuming that
+ * we want to change as many jumps to fallthroughs as possible (executed jumps
+ * actually, we have to look at the execution frequencies). The algorithms
+ * do this by collecting execution frequencies of all branches (which is easily
+ * possible when all critical edges are split) then removes critical edges where
+ * possible as we don't need and want them anymore now. The algorithms then try
+ * to change as many edges to fallthroughs as possible, this is done by setting
+ * a next and prev pointers on blocks. The greedy algorithm sorts the edges by
+ * execution frequencies and tries to transform them to fallthroughs in this order
*/
-#ifdef HAVE_CONFIG_H
#include "config.h"
-#endif
#include "beblocksched.h"
#include "iredges.h"
#include "irgwalk.h"
+#include "irnode_t.h"
#include "irgraph_t.h"
#include "irloop.h"
#include "irprintf.h"
+#include "execfreq.h"
#include "irdump_t.h"
#include "irtools.h"
#include "debug.h"
#include "beirgmod.h"
#include "bemodule.h"
#include "be.h"
+#include "error.h"
-#include <libcore/lc_opts.h>
-#include <libcore/lc_opts_enum.h>
-#include <libcore/lc_timing.h>
+#include "lc_opts.h"
+#include "lc_opts_enum.h"
#ifdef WITH_ILP
#include <lpp/lpp.h>
DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
-typedef enum _blocksched_algos_t {
- BLOCKSCHED_NAIV, BLOCKSCHED_EXTBB, BLOCKSCHED_GREEDY, BLOCKSCHED_ILP
+typedef enum blocksched_algos_t {
+ BLOCKSCHED_NAIV, BLOCKSCHED_GREEDY, BLOCKSCHED_ILP
} blocksched_algos_t;
static int algo = BLOCKSCHED_GREEDY;
static const lc_opt_enum_int_items_t blockschedalgo_items[] = {
- { "naiv", BLOCKSCHED_NAIV },
- { "extbb", BLOCKSCHED_EXTBB },
+ { "naiv", BLOCKSCHED_NAIV },
{ "greedy", BLOCKSCHED_GREEDY },
#ifdef WITH_ILP
{ "ilp", BLOCKSCHED_ILP },
};
static const lc_opt_table_entry_t be_blocksched_options[] = {
- LC_OPT_ENT_ENUM_INT ("algo", "the block scheduling algorithm", &algo_var),
- { NULL }
+ LC_OPT_ENT_ENUM_INT ("blockscheduler", "the block scheduling algorithm", &algo_var),
+ LC_OPT_LAST
};
/*
* |___/
*/
-typedef struct _blocksched_entry_t {
- ir_node *block;
- struct _blocksched_entry_t *next;
- struct _blocksched_entry_t *prev;
-} blocksched_entry_t;
+typedef struct blocksched_entry_t blocksched_entry_t;
+struct blocksched_entry_t {
+ ir_node *block;
+ blocksched_entry_t *next;
+ blocksched_entry_t *prev;
+};
-typedef struct _edge_t {
+typedef struct edge_t edge_t;
+struct edge_t {
ir_node *block; /**< source block */
int pos; /**< number of cfg predecessor (target) */
double execfreq; /**< the frequency */
- int highest_execfreq; /**< flag that indicates wether this edge is the edge with the highest
- execfreq pointing away from this block */
-} edge_t;
+ double outedge_penalty_freq; /**< for edges leaving the loop this is the
+ penality when we make them a
+ fallthrough. */
+ int highest_execfreq; /**< flag that indicates whether this edge is
+ the edge with the highest execfreq pointing
+ away from this block */
+};
-typedef struct _blocksched_env_t {
+typedef struct blocksched_env_t blocksched_env_t;
+struct blocksched_env_t {
ir_graph *irg;
struct obstack *obst;
ir_exec_freq *execfreqs;
edge_t *edges;
pdeq *worklist;
int blockcount;
-} blocksched_env_t;
+};
/**
* Collect cfg frequencies of all edges between blocks.
*/
static void collect_egde_frequency(ir_node *block, void *data)
{
- blocksched_env_t *env = data;
+ blocksched_env_t *env = (blocksched_env_t*)data;
int arity;
edge_t edge;
blocksched_entry_t *entry;
+ ir_loop *loop;
+
+ memset(&edge, 0, sizeof(edge));
- entry = obstack_alloc(env->obst, sizeof(entry[0]));
+ entry = OALLOCZ(env->obst, blocksched_entry_t);
entry->block = block;
- entry->next = NULL;
- entry->prev = NULL;
set_irn_link(block, entry);
- if (block == get_irg_start_block(env->irg))
- return;
+ loop = get_irn_loop(block);
- arity = get_irn_arity(block);
+ arity = get_Block_n_cfgpreds(block);
+
+ if (arity == 0) {
+ /* must be the start block (or end-block for endless loops),
+ * everything else is dead code and should be removed by now */
+ assert(block == get_irg_start_block(env->irg)
+ || block == get_irg_end_block(env->irg));
+ /* nothing to do here */
+ return;
+ } else if (arity == 1) {
+ ir_node *pred_block = get_Block_cfgpred_block(block, 0);
+ ir_loop *pred_loop = get_irn_loop(pred_block);
+ float freq = (float)get_block_execfreq(env->execfreqs, block);
+
+ /* is it an edge leaving a loop */
+ if (get_loop_depth(pred_loop) > get_loop_depth(loop)) {
+ float pred_freq = (float)get_block_execfreq(env->execfreqs, pred_block);
+ edge.outedge_penalty_freq = -(pred_freq - freq);
+ }
- if (arity == 1) {
edge.block = block;
edge.pos = 0;
- edge.execfreq = get_block_execfreq(env->execfreqs, block);
+ edge.execfreq = freq;
edge.highest_execfreq = 1;
ARR_APP1(edge_t, env->edges, edge);
} else {
}
}
- if(highest_edge_num >= 0)
+ if (highest_edge_num >= 0)
env->edges[highest_edge_num].highest_execfreq = 1;
}
}
static int cmp_edges(const void *d1, const void *d2)
{
- const edge_t *e1 = d1;
- const edge_t *e2 = d2;
+ const edge_t *e1 = (const edge_t*)d1;
+ const edge_t *e2 = (const edge_t*)d2;
return QSORT_CMP(e2->execfreq, e1->execfreq);
}
+static int cmp_edges_outedge_penalty(const void *d1, const void *d2)
+{
+ const edge_t *e1 = (const edge_t*)d1;
+ const edge_t *e2 = (const edge_t*)d2;
+ /* reverse sorting as penalties are negative */
+ return QSORT_CMP(e1->outedge_penalty_freq, e2->outedge_penalty_freq);
+}
+
+static void clear_loop_links(ir_loop *loop)
+{
+ int i, n;
+
+ set_loop_link(loop, NULL);
+ n = get_loop_n_elements(loop);
+ for (i = 0; i < n; ++i) {
+ loop_element elem = get_loop_element(loop, i);
+ if (*elem.kind == k_ir_loop) {
+ clear_loop_links(elem.son);
+ }
+ }
+}
+
static void coalesce_blocks(blocksched_env_t *env)
{
int i;
int edge_count = ARR_LEN(env->edges);
+ edge_t *edges = env->edges;
+
+ /* sort interblock edges by execution frequency */
+ qsort(edges, ARR_LEN(edges), sizeof(edges[0]), cmp_edges);
/* run1: only look at jumps */
for (i = 0; i < edge_count; ++i) {
- const edge_t *edge = &env->edges[i];
+ const edge_t *edge = &edges[i];
ir_node *block = edge->block;
+ int pos = edge->pos;
ir_node *pred_block;
blocksched_entry_t *entry, *pred_entry;
- /* the block might have been removed already... */
- if (is_Bad(get_Block_cfgpred(block, 0)))
- continue;
-
/* only check edge with highest frequency */
if (! edge->highest_execfreq)
continue;
- pred_block = get_Block_cfgpred_block(block, edge->pos);
- entry = get_irn_link(block);
- pred_entry = get_irn_link(pred_block);
+ /* the block might have been removed already... */
+ if (is_Bad(get_Block_cfgpred(block, 0)))
+ continue;
+
+ pred_block = get_Block_cfgpred_block(block, pos);
+ entry = (blocksched_entry_t*)get_irn_link(block);
+ pred_entry = (blocksched_entry_t*)get_irn_link(pred_block);
if (pred_entry->next != NULL || entry->prev != NULL)
continue;
continue;
/* schedule the 2 blocks behind each other */
- DBG((dbg, LEVEL_1, "Coalesce (Jump) %+F -> %+F (%.3g)\n",
+ DB((dbg, LEVEL_1, "Coalesce (Jump) %+F -> %+F (%.3g)\n",
pred_entry->block, entry->block, edge->execfreq));
pred_entry->next = entry;
entry->prev = pred_entry;
}
- /* run2: remaining edges */
+ /* run2: pick loop fallthroughs */
+ clear_loop_links(get_irg_loop(env->irg));
+
+ qsort(edges, ARR_LEN(edges), sizeof(edges[0]), cmp_edges_outedge_penalty);
for (i = 0; i < edge_count; ++i) {
- const edge_t *edge = &env->edges[i];
+ const edge_t *edge = &edges[i];
ir_node *block = edge->block;
+ int pos = edge->pos;
ir_node *pred_block;
blocksched_entry_t *entry, *pred_entry;
+ ir_loop *loop;
+ ir_loop *outer_loop;
+
+ /* already seen all loop outedges? */
+ if (edge->outedge_penalty_freq == 0)
+ break;
/* the block might have been removed already... */
- if (is_Bad(get_Block_cfgpred(block, 0)))
+ if (is_Bad(get_Block_cfgpred(block, pos)))
continue;
- pred_block = get_Block_cfgpred_block(block, edge->pos);
- entry = get_irn_link(block);
- pred_entry = get_irn_link(pred_block);
+ pred_block = get_Block_cfgpred_block(block, pos);
+ entry = (blocksched_entry_t*)get_irn_link(block);
+ pred_entry = (blocksched_entry_t*)get_irn_link(pred_block);
+
+ if (pred_entry->next != NULL || entry->prev != NULL)
+ continue;
+
+ /* we want at most 1 outedge fallthrough per loop */
+ loop = get_irn_loop(pred_block);
+ if (get_loop_link(loop) != NULL)
+ continue;
+
+ /* schedule the 2 blocks behind each other */
+ DB((dbg, LEVEL_1, "Coalesce (Loop Outedge) %+F -> %+F (%.3g)\n",
+ pred_entry->block, entry->block, edge->execfreq));
+ pred_entry->next = entry;
+ entry->prev = pred_entry;
+
+ /* all loops left have an outedge now */
+ outer_loop = get_irn_loop(block);
+ do {
+ /* we set loop link to loop to mark it */
+ set_loop_link(loop, loop);
+ loop = get_loop_outer_loop(loop);
+ } while (loop != outer_loop);
+ }
+
+ /* sort interblock edges by execution frequency */
+ qsort(edges, ARR_LEN(edges), sizeof(edges[0]), cmp_edges);
+
+ /* run3: remaining edges */
+ for (i = 0; i < edge_count; ++i) {
+ const edge_t *edge = &edges[i];
+ ir_node *block = edge->block;
+ int pos = edge->pos;
+ ir_node *pred_block;
+ blocksched_entry_t *entry, *pred_entry;
+
+ /* the block might have been removed already... */
+ if (is_Bad(get_Block_cfgpred(block, pos)))
+ continue;
+
+ pred_block = get_Block_cfgpred_block(block, pos);
+ entry = (blocksched_entry_t*)get_irn_link(block);
+ pred_entry = (blocksched_entry_t*)get_irn_link(pred_block);
/* is 1 of the blocks already attached to another block? */
if (pred_entry->next != NULL || entry->prev != NULL)
continue;
/* schedule the 2 blocks behind each other */
- DBG((dbg, LEVEL_1, "Coalesce (CondJump) %+F -> %+F (%.3g)\n",
+ DB((dbg, LEVEL_1, "Coalesce (CondJump) %+F -> %+F (%.3g)\n",
pred_entry->block, entry->block, edge->execfreq));
pred_entry->next = entry;
entry->prev = pred_entry;
const ir_edge_t *edge;
double best_succ_execfreq;
- if (irn_visited(block))
+ if (irn_visited_else_mark(block))
return;
env->blockcount++;
- mark_irn_visited(block);
- DBG((dbg, LEVEL_1, "Pick succ of %+F\n", block));
+ DB((dbg, LEVEL_1, "Pick succ of %+F\n", block));
/* put all successors into the worklist */
foreach_block_succ(block, edge) {
/* we only need to put the first of a series of already connected
* blocks into the worklist */
- succ_entry = get_irn_link(succ_block);
+ succ_entry = (blocksched_entry_t*)get_irn_link(succ_block);
while (succ_entry->prev != NULL) {
/* break cycles... */
if (succ_entry->prev->block == succ_block) {
if (irn_visited(succ_entry->block))
continue;
- DBG((dbg, LEVEL_1, "Put %+F into worklist\n", succ_entry->block));
+ DB((dbg, LEVEL_1, "Put %+F into worklist\n", succ_entry->block));
pdeq_putr(env->worklist, succ_entry->block);
}
return;
}
- DBG((dbg, LEVEL_1, "deciding...\n"));
+ DB((dbg, LEVEL_1, "deciding...\n"));
best_succ_execfreq = -1;
/* no successor yet: pick the successor block with the highest execution
if (irn_visited(succ_block))
continue;
- succ_entry = get_irn_link(succ_block);
+ succ_entry = (blocksched_entry_t*)get_irn_link(succ_block);
if (succ_entry->prev != NULL)
continue;
}
if (succ == NULL) {
- DBG((dbg, LEVEL_1, "pick from worklist\n"));
+ DB((dbg, LEVEL_1, "pick from worklist\n"));
do {
if (pdeq_empty(env->worklist)) {
- DBG((dbg, LEVEL_1, "worklist empty\n"));
+ DB((dbg, LEVEL_1, "worklist empty\n"));
return;
}
- succ = pdeq_getl(env->worklist);
+ succ = (ir_node*)pdeq_getl(env->worklist);
} while (irn_visited(succ));
}
- succ_entry = get_irn_link(succ);
+ succ_entry = (blocksched_entry_t*)get_irn_link(succ);
entry->next = succ_entry;
succ_entry->prev = entry;
{
ir_graph *irg = env->irg;
ir_node *startblock = get_irg_start_block(irg);
- blocksched_entry_t *entry = get_irn_link(startblock);
+ blocksched_entry_t *entry = (blocksched_entry_t*)get_irn_link(startblock);
- set_using_visited(irg);
+ ir_reserve_resources(irg, IR_RESOURCE_IRN_VISITED);
inc_irg_visited(irg);
env->worklist = new_pdeq();
assert(pdeq_empty(env->worklist));
del_pdeq(env->worklist);
- clear_using_visited(irg);
+ ir_free_resources(irg, IR_RESOURCE_IRN_VISITED);
return entry;
}
int i = 0;
ir_node **block_list;
blocksched_entry_t *entry;
+ (void) env;
block_list = NEW_ARR_D(ir_node *, obst, count);
- DBG((dbg, LEVEL_1, "Blockschedule:\n"));
+ DB((dbg, LEVEL_1, "Blockschedule:\n"));
for (entry = first; entry != NULL; entry = entry->next) {
assert(i < count);
block_list[i++] = entry->block;
- DBG((dbg, LEVEL_1, "\t%+F\n", entry->block));
+ DB((dbg, LEVEL_1, "\t%+F\n", entry->block));
}
assert(i == count);
env.worklist = NULL;
env.blockcount = 0;
+ /* make sure loopinfo is up-to-date */
+ if (! (get_irg_loopinfo_state(irg) & loopinfo_cf_consistent)) {
+ construct_cf_backedges(irg);
+ }
+
// collect edge execution frequencies
irg_block_walk_graph(irg, collect_egde_frequency, NULL, &env);
- // sort interblock edges by execution frequency
- qsort(env.edges, ARR_LEN(env.edges), sizeof(env.edges[0]), cmp_edges);
-
(void)be_remove_empty_blocks(irg);
if (algo != BLOCKSCHED_NAIV)
coalesce_blocks(&env);
start_entry = finish_block_schedule(&env);
- block_list = create_blocksched_array(&env, start_entry, env.blockcount, get_irg_obstack(irg));
+ block_list = create_blocksched_array(&env, start_entry, env.blockcount,
+ be_get_be_obst(irg));
DEL_ARR_F(env.edges);
obstack_free(&obst, NULL);
*/
#ifdef WITH_ILP
-typedef struct _ilp_edge_t {
+typedef struct ilp_edge_t {
ir_node *block; /**< source block */
int pos; /**< number of cfg predecessor (target) */
int ilpvar;
} ilp_edge_t;
-typedef struct _blocksched_ilp_env_t {
+typedef struct blocksched_ilp_env_t {
blocksched_env_t env;
ilp_edge_t *ilpedges;
lpp_t *lpp;
} blocksched_ilp_env_t;
-typedef struct _blocksched_ilp_entry_t {
+typedef struct blocksched_ilp_entry_t {
ir_node *block;
- struct _blocksched_entry_t *next;
- struct _blocksched_entry_t *prev;
+ struct blocksched_entry_t *next;
+ struct blocksched_entry_t *prev;
int out_cst;
} blocksched_ilp_entry_t;
snprintf(name, sizeof(name), "block_out_constr_%ld", get_irn_node_nr(block));
out_count = get_irn_n_edges_kind(block, EDGE_KIND_BLOCK);
- entry = obstack_alloc(env->env.obst, sizeof(entry[0]));
+ entry = OALLOC(env->env.obst, blocksched_ilp_entry_t);
entry->block = block;
entry->next = NULL;
entry->prev = NULL;
}
else {
int i;
- int *edgenums = alloca(sizeof(edgenums[0]) * arity);
snprintf(name, sizeof(name), "block_in_constr_%ld", get_irn_node_nr(block));
cst = lpp_add_cst_uniq(env->lpp, name, lpp_greater, arity - 1);
static void coalesce_blocks_ilp(blocksched_ilp_env_t *env)
{
- int i;
- int edge_count = ARR_LEN(env->ilpedges);
+ int edge_count = ARR_LEN(env->ilpedges);
+ be_options_t *options = be_get_irg_options(env->env.irg);
+ int i;
/* complete out constraints */
- for(i = 0; i < edge_count; ++i) {
+ for (i = 0; i < edge_count; ++i) {
const ilp_edge_t *edge = &env->ilpedges[i];
ir_node *block = edge->block;
ir_node *pred;
pred = get_Block_cfgpred_block(block, edge->pos);
entry = get_irn_link(pred);
- DBG((dbg, LEVEL_1, "Adding out cst to %+F from %+F,%d\n",
+ DB((dbg, LEVEL_1, "Adding out cst to %+F from %+F,%d\n",
pred, block, edge->pos));
lpp_set_factor_fast(env->lpp, entry->out_cst, edge->ilpvar, 1.0);
}
-#if 0
- {
- FILE *f;
- char fname[256];
- lpp_dump(env->lpp, "lpp.out");
- snprintf(fname, sizeof(fname), "lpp_%s.plain", get_irg_dump_name(env->env.irg));
- f = fopen(fname, "w");
- lpp_dump_plain(env->lpp, f);
- fclose(f);
- }
-#endif
-
- //lpp_solve_net(env->lpp, main_env->options->ilp_server, main_env->options->ilp_solver);
- lpp_solve_net(env->lpp, "i44pc52", "cplex");
+ lpp_solve_net(env->lpp, options->ilp_server, options->ilp_solver);
assert(lpp_is_sol_valid(env->lpp));
/* Apply results to edges */
coalesce_blocks_ilp(&env);
start_entry = finish_block_schedule(&env.env);
- block_list = create_blocksched_array(&env.env, start_entry, env.env.blockcount, get_irg_obstack(irg));
+ block_list = create_blocksched_array(&env.env, start_entry,
+ env.env.blockcount,
+ be_get_be_obst(irg));
DEL_ARR_F(env.ilpedges);
free_lpp(env.lpp);
}
#endif /* WITH_ILP */
-/*
- * _____ _ ____ ____
- * | ____|_ _| |_| __ )| __ )
- * | _| \ \/ / __| _ \| _ \
- * | |___ > <| |_| |_) | |_) |
- * |_____/_/\_\\__|____/|____/
- *
- */
-
-/** A simple forward single linked list. */
-typedef struct {
- ir_node *start; /**< start of the list */
- ir_node *end; /**< last block in the list */
- unsigned n_blks; /**< number of blocks in the list */
-} anchor;
-
-static void add_block(anchor *list, ir_node *block) {
- if (list->start == NULL) {
- list->start = block;
- list->end = block;
- } else {
- set_irn_link(list->end, block);
- list->end = block;
- }
-
- list->n_blks++;
-}
-
-static void create_block_list(ir_node *leader_block, anchor *list) {
- int i;
- const ir_edge_t *edge;
- ir_node *block = NULL;
- ir_extblk *extbb = get_Block_extbb(leader_block);
-
- if (extbb_visited(extbb))
- return;
- mark_extbb_visited(extbb);
-
- for (i = 0; i < get_extbb_n_blocks(extbb); ++i) {
- block = get_extbb_block(extbb, i);
- add_block(list, block);
- }
-
- assert(block != NULL);
-
- /* pick successor extbbs */
- foreach_block_succ(block, edge) {
- ir_node *succ = get_edge_src_irn(edge);
- create_block_list(succ, list);
- }
-
- for (i = 0; i < get_extbb_n_blocks(extbb) - 1; ++i) {
- block = get_extbb_block(extbb, i);
-
- foreach_block_succ(block, edge) {
- ir_node *succ = get_edge_src_irn(edge);
- create_block_list(succ, list);
- }
- }
-}
-
-void compute_extbb_execfreqs(ir_graph *irg, ir_exec_freq *execfreqs);
-
-/*
- * Calculates a block schedule. The schedule is stored as a linked
- * list starting at the start_block of the irg.
- */
-static ir_node **create_extbb_block_schedule(ir_graph *irg, ir_exec_freq *execfreqs)
-{
- anchor list;
- ir_node **blk_list, *b, *n;
- unsigned i;
-
- /* schedule extended basic blocks */
- compute_extbb_execfreqs(irg, execfreqs);
- //compute_extbb(irg);
-
- list.start = NULL;
- list.end = NULL;
- list.n_blks = 0;
-
- set_using_irn_link(irg);
- set_using_visited(irg);
- inc_irg_block_visited(irg);
-
- create_block_list(get_irg_start_block(irg), &list);
-
- /** create an array, so we can go forward and backward */
- blk_list = NEW_ARR_D(ir_node *, irg->obst,list.n_blks);
-
- for (i = 0, b = list.start; b; b = n, ++i) {
- n = get_irn_link(b);
- blk_list[i] = b;
- }
-
- clear_using_irn_link(irg);
- clear_using_visited(irg);
-
- return blk_list;
-}
-
/*
* __ __ _
* | \/ | __ _(_)_ __
* |_| |_|\__,_|_|_| |_|
*
*/
+BE_REGISTER_MODULE_CONSTRUCTOR(be_init_blocksched);
void be_init_blocksched(void)
{
lc_opt_entry_t *be_grp = lc_opt_get_grp(firm_opt_get_root(), "be");
- lc_opt_entry_t *blocksched_grp = lc_opt_get_grp(be_grp, "blocksched");
- lc_opt_add_table(blocksched_grp, be_blocksched_options);
+ lc_opt_add_table(be_grp, be_blocksched_options);
FIRM_DBG_REGISTER(dbg, "firm.be.blocksched");
}
-BE_REGISTER_MODULE_CONSTRUCTOR(be_init_blocksched);
-
-ir_node **be_create_block_schedule(ir_graph *irg, ir_exec_freq *execfreqs)
+ir_node **be_create_block_schedule(ir_graph *irg)
{
- switch(algo) {
+ ir_exec_freq *execfreqs = be_get_irg_exec_freq(irg);
+
+ switch (algo) {
case BLOCKSCHED_GREEDY:
case BLOCKSCHED_NAIV:
return create_block_schedule_greedy(irg, execfreqs);
- case BLOCKSCHED_EXTBB:
- return create_extbb_block_schedule(irg, execfreqs);
#ifdef WITH_ILP
case BLOCKSCHED_ILP:
return create_block_schedule_ilp(irg, execfreqs);
#endif /* WITH_ILP */
}
- assert(0 && "unknown blocksched algo");
- return NULL;
+ panic("unknown blocksched algo");
}