Commit 04785d3f authored by Michael Beck's avatar Michael Beck
Browse files

Some improvements:

- use Phi list to speed up algo
- initially clear the links of all nodes (block walker visits only initially reachable ones)
- track resources
- invalidate analysis info at end

[r27386]
parent db593e53
......@@ -41,6 +41,7 @@
#include "irtools.h"
#include "tv.h"
#include "irpass.h"
#include "irmemory.h"
/* TODO:
* - Implement cleared/set bit calculation for Add, Sub, Minus, Mul, Div, Mod, Shl, Shr, Shrs, Rotl
......@@ -127,6 +128,10 @@ typedef struct bitinfo
tarval* o; // safe ones, 0 = bit maybe is zero, 1 = bit is 1
} bitinfo;
typedef struct environment_t {
unsigned modified:1; /**< Set, if the graph was modified. */
} environment_t;
static inline bitinfo* get_bitinfo(ir_node const* const irn)
{
return get_irn_link(irn);
......@@ -542,12 +547,12 @@ static void first_round(ir_node* const irn, void* const env)
}
}
static void apply_result(ir_node* const irn, void* const env)
static void apply_result(ir_node* const irn, void* ctx)
{
bitinfo* const b = get_bitinfo(irn);
tarval* z;
tarval* o;
(void)env;
environment_t* env = ctx;
if (!b) return;
if (is_Const(irn)) return; // It cannot get any better than a Const.
......@@ -583,6 +588,7 @@ static void apply_result(ir_node* const irn, void* const env)
set_irn_link(n, b);
exchange_only:
exchange(irn, n);
env->modified = 1;
}
switch (get_irn_opcode(irn)) {
......@@ -595,11 +601,13 @@ exchange_only:
if (tarval_is_null(tarval_andnot(br->z, bl->z))) {
DB((dbg, LEVEL_2, "%+F(%+F, %+F) is superfluous\n", irn, l, r));
exchange(irn, r);
env->modified = 1;
}
} else if (br->z == br->o) {
if (tarval_is_null(tarval_andnot(bl->z, br->z))) {
DB((dbg, LEVEL_2, "%+F(%+F, %+F) is superfluous\n", irn, l, r));
exchange(irn, l);
env->modified = 1;
}
}
break;
......@@ -614,11 +622,13 @@ exchange_only:
if (tarval_is_null(tarval_andnot(bl->o, br->o))) {
DB((dbg, LEVEL_2, "%+F(%+F, %+F) is superfluous\n", irn, l, r));
exchange(irn, r);
env->modified = 1;
}
} else if (br->z == br->o) {
if (tarval_is_null(tarval_andnot(br->o, bl->o))) {
DB((dbg, LEVEL_2, "%+F(%+F, %+F) is superfluous\n", irn, l, r));
exchange(irn, l);
env->modified = 1;
}
}
break;
......@@ -635,12 +645,12 @@ static void queue_users(pdeq* const q, ir_node* const n)
ir_edge_t const* e;
foreach_out_edge(n, e) {
ir_node* const src = get_edge_src_irn(e);
ir_edge_t const* src_e;
pdeq_putr(q, src);
foreach_out_edge(src, src_e) {
ir_node* const src_src = get_edge_src_irn(src_e);
if (is_Phi(src_src))
pdeq_putr(q, src_src);
/* should always be a block */
if (is_Block(src)) {
ir_node *phi;
for (phi = get_Block_phis(src); phi; phi = get_Phi_next(phi))
pdeq_putr(q, phi);
}
}
} else {
......@@ -656,8 +666,24 @@ static void queue_users(pdeq* const q, ir_node* const n)
}
}
static void clear_links(ir_node *irn, void *env)
{
(void) env;
set_irn_link(irn, NULL);
if (is_Block(irn))
set_Block_phis(irn, NULL);
}
static void build_phi_lists(ir_node *irn, void *env)
{
if (is_Phi(irn))
add_Block_phi(get_nodes_block(irn), irn);
}
void fixpoint_vrp(ir_graph* const irg)
{
environment_t env;
FIRM_DBG_REGISTER(dbg, "firm.opt.fp-vrp");
DB((dbg, LEVEL_1, "===> Performing constant propagation on %+F\n", irg));
......@@ -666,7 +692,14 @@ void fixpoint_vrp(ir_graph* const irg)
edges_assure(irg);
assure_doms(irg);
{ pdeq* const q = new_pdeq();
ir_reserve_resources(irg, IR_RESOURCE_IRN_LINK | IR_RESOURCE_PHI_LIST);
{
pdeq* const q = new_pdeq();
/* We need this extra step because the dom tree does not contain unreachable
blocks in Firm. Moreover build phi list. */
irg_walk_graph(irg, clear_links, build_phi_lists, NULL);
/* TODO Improve iteration order. Best is reverse postorder in data flow
* direction and respecting loop nesting for fastest convergence. */
......@@ -682,7 +715,19 @@ void fixpoint_vrp(ir_graph* const irg)
}
DB((dbg, LEVEL_2, "---> Applying analysis results\n"));
irg_walk_graph(irg, NULL, apply_result, NULL);
env.modified = 0;
irg_walk_graph(irg, NULL, apply_result, &env);
if (env.modified) {
/* control flow might changed */
set_irg_outs_inconsistent(irg);
set_irg_extblk_inconsistent(irg);
set_irg_doms_inconsistent(irg);
set_irg_loopinfo_inconsistent(irg);
set_irg_entity_usage_state(irg, ir_entity_usage_not_computed);
}
ir_free_resources(irg, IR_RESOURCE_IRN_LINK | IR_RESOURCE_PHI_LIST);
obstack_free(&obst, NULL);
}
......
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment