- Implement goto support
- Register allocator bug fixes.
* coalesce_live_ranges now also updates the interference graph of live instructions
* resolve_tangle now avoids copies to phi
* correct_tangles is now called in a loop so that all tangles get fixed
- Bug the version of romcc to 0.30
git-svn-id: svn://svn.coreboot.org/coreboot/trunk@886 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1
diff --git a/util/romcc/romcc.c b/util/romcc/romcc.c
index 5c784fc..1f5c91a 100644
--- a/util/romcc/romcc.c
+++ b/util/romcc/romcc.c
@@ -14,7 +14,7 @@
#define DEBUG_ERROR_MESSAGES 0
#define DEBUG_COLOR_GRAPH 0
#define DEBUG_SCC 0
-#define DEBUG_CONSISTENCY 1
+#define DEBUG_CONSISTENCY 2
#warning "FIXME boundary cases with small types in larger registers"
#warning "FIXME give clear error messages about unused variables"
@@ -858,11 +858,7 @@
#define MAX_REGISTERS 75
#define MAX_REG_EQUIVS 16
-#if 1
#define REGISTER_BITS 16
-#else
-#define REGISTER_BITS 28
-#endif
#define MAX_VIRT_REGISTERS (1<<REGISTER_BITS)
#define TEMPLATE_BITS 6
#define MAX_TEMPLATES (1<<TEMPLATE_BITS)
@@ -881,7 +877,6 @@
#define REG_VIRT9 (MAX_REGISTERS + 5)
/* Provision for 8 register classes */
-#if 1
#define REG_SHIFT 0
#define REGC_SHIFT REGISTER_BITS
#define REGC_MASK (((1 << MAX_REGC) - 1) << REGISTER_BITS)
@@ -892,11 +887,6 @@
#define SET_REGCM(ID, REGCM) ((ID) = (((ID) & ~REGC_MASK) | (((REGCM) << REGC_SHIFT) & REGC_MASK)))
#define SET_INFO(ID, INFO) ((ID) = (((ID) & ~(REG_MASK | REGC_MASK)) | \
(((INFO).reg) & REG_MASK) | ((((INFO).regcm) << REGC_SHIFT) & REGC_MASK)))
-#else
-#define REG_MASK (MAX_VIRT_REGISTERS -1)
-#define ID_REG(ID) ((ID) & REG_MASK)
-#define SET_REG(ID, REG) ((ID) = (((ID) & ~REG_MASK) | ((REG) & REG_MASK)))
-#endif
static unsigned arch_reg_regcm(struct compile_state *state, int reg);
static unsigned arch_regcm_normalize(struct compile_state *state, unsigned regcm);
@@ -933,7 +923,8 @@
#define DEBUG_CODE_ELIMINATION 0x0200
#define DEBUG_INSERTED_COPIES 0x0400
-#define GLOBAL_SCOPE_DEPTH 1
+#define GLOBAL_SCOPE_DEPTH 1
+#define FUNCTION_SCOPE_DEPTH (GLOBAL_SCOPE_DEPTH + 1)
static void compile_file(struct compile_state *old_state, const char *filename, int local);
@@ -2169,6 +2160,22 @@
*chain = sym;
}
+static void label_symbol(struct compile_state *state,
+ struct hash_entry *ident, struct triple *label)
+{
+ struct symbol *sym;
+ if (ident->sym_label) {
+ error(state, 0, "label %s already defined", ident->name);
+ }
+ sym = xcmalloc(sizeof(*sym), "label");
+ sym->ident = ident;
+ sym->def = label;
+ sym->type = &void_type;
+ sym->scope_depth = FUNCTION_SCOPE_DEPTH;
+ sym->next = 0;
+ ident->sym_label = sym;
+}
+
static void start_scope(struct compile_state *state)
{
state->scope_depth++;
@@ -7793,22 +7800,46 @@
static void goto_statement(struct compile_state *state, struct triple *first)
{
- FINISHME();
+ struct hash_entry *ident;
eat(state, TOK_GOTO);
eat(state, TOK_IDENT);
+ ident = state->token[0].ident;
+ if (!ident->sym_label) {
+ /* If this is a forward branch allocate the label now,
+ * it will be flattend in the appropriate location later.
+ */
+ struct triple *ins;
+ ins = label(state);
+ label_symbol(state, ident, ins);
+ }
eat(state, TOK_SEMI);
- error(state, 0, "goto is not implemeted");
- FINISHME();
+
+ flatten(state, first, branch(state, ident->sym_label->def, 0));
}
static void labeled_statement(struct compile_state *state, struct triple *first)
{
- FINISHME();
+ struct triple *ins;
+ struct hash_entry *ident;
eat(state, TOK_IDENT);
+
+ ident = state->token[0].ident;
+ if (ident->sym_label && ident->sym_label->def) {
+ ins = ident->sym_label->def;
+ put_occurance(ins->occurance);
+ ins->occurance = new_occurance(state);
+ }
+ else {
+ ins = label(state);
+ label_symbol(state, ident, ins);
+ }
+ if (ins->id & TRIPLE_FLAG_FLATTENED) {
+ error(state, 0, "label %s already defined", ident->name);
+ }
+ flatten(state, first, ins);
+
eat(state, TOK_COLON);
statement(state, first);
- error(state, 0, "labeled statements are not implemented");
- FINISHME();
}
static void switch_statement(struct compile_state *state, struct triple *first)
@@ -8845,6 +8876,30 @@
return result;
}
+static void resolve_branches(struct compile_state *state)
+{
+ /* Make a second pass and finish anything outstanding
+ * with respect to branches. The only outstanding item
+ * is to see if there are goto to labels that have not
+ * been defined and to error about them.
+ */
+ int i;
+ for(i = 0; i < HASH_TABLE_SIZE; i++) {
+ struct hash_entry *entry;
+ for(entry = state->hash_table[i]; entry; entry = entry->next) {
+ struct triple *ins;
+ if (!entry->sym_label) {
+ continue;
+ }
+ ins = entry->sym_label->def;
+ if (!(ins->id & TRIPLE_FLAG_FLATTENED)) {
+ error(state, ins, "label `%s' used but not defined",
+ entry->name);
+ }
+ }
+ }
+}
+
static struct triple *function_definition(
struct compile_state *state, struct type *type)
{
@@ -8926,8 +8981,12 @@
/* Now get the actual function definition */
compound_statement(state, end);
+ /* Finish anything unfinished with branches */
+ resolve_branches(state);
+
/* Remove the parameter scope */
end_scope(state);
+
#if 0
fprintf(stdout, "\n");
loc(stdout, state, 0);
@@ -10781,6 +10840,9 @@
*/
struct triple *in;
struct triple **expr;
+ if (ins->op == OP_PHI) {
+ internal_error(state, ins, "pre_copy on a phi?");
+ }
expr = &RHS(ins, index);
in = pre_triple(state, ins, OP_COPY, (*expr)->type, *expr, 0);
unuse_triple(*expr, ins);
@@ -11772,6 +11834,19 @@
}
}
+static void transfer_live_edges(struct reg_state *rstate,
+ struct live_range *dest, struct live_range *src)
+{
+ struct live_range_edge *edge, *next;
+ for(edge = src->edges; edge; edge = next) {
+ struct live_range *other;
+ next = edge->next;
+ other = edge->node;
+ remove_live_edge(rstate, src, other);
+ add_live_edge(rstate, dest, other);
+ }
+}
+
/* Interference graph...
*
@@ -11887,7 +11962,7 @@
fprintf(stderr, "lr2 pre\n");
}
#endif
-#if 1
+#if 0
fprintf(stderr, "coalesce color1(%p): %3d color2(%p) %3d\n",
lr1->defs->def,
lr1->color,
@@ -11898,6 +11973,12 @@
lr1->classes = classes;
/* Append lr2 onto lr1 */
#warning "FIXME should this be a merge instead of a splice?"
+ /* This FIXME item applies to the correctness of live_range_end
+ * and to the necessity of making multiple passes of coalesce_live_ranges.
+ * A failure to find some coalesce opportunities in coaleace_live_ranges
+ * does not impact the correct of the compiler just the efficiency with
+ * which registers are allocated.
+ */
head = lr1->defs;
mid1 = lr1->defs->prev;
mid2 = lr2->defs;
@@ -11928,6 +12009,9 @@
lr1->color = color;
lr1->classes = classes;
+ /* Keep the graph in sync by transfering the edges from lr2 to lr1 */
+ transfer_live_edges(rstate, lr1, lr2);
+
return lr1;
}
@@ -12505,6 +12589,7 @@
struct reg_block *blocks, struct triple_reg_set *live,
struct reg_block *rb, struct triple *ins, void *arg)
{
+ int *tangles = arg;
struct triple *tangle;
do {
char used[MAX_REGISTERS];
@@ -12531,6 +12616,13 @@
if (used[info.reg] < 2) {
continue;
}
+ /* Changing copies that feed into phi functions
+ * is incorrect.
+ */
+ if (set->member->use &&
+ (set->member->use->member->op == OP_PHI)) {
+ continue;
+ }
if (!tangle || tdominates(state, set->member, tangle)) {
tangle = set->member;
}
@@ -12538,6 +12630,7 @@
/* If I have found a tangle resolve it */
if (tangle) {
struct triple *post_copy;
+ (*tangles)++;
post_copy = resolve_tangle(state, tangle);
if (post_copy) {
replace_block_use(state, blocks, tangle, post_copy);
@@ -12550,11 +12643,14 @@
return;
}
-static void correct_tangles(
+static int correct_tangles(
struct compile_state *state, struct reg_block *blocks)
{
+ int tangles;
+ tangles = 0;
color_instructions(state);
- walk_variable_lifetimes(state, blocks, fix_tangles, 0);
+ walk_variable_lifetimes(state, blocks, fix_tangles, &tangles);
+ return tangles;
}
struct least_conflict {
@@ -13536,6 +13632,7 @@
rstate->blocks = 0;
}
+static void verify_consistency(struct compile_state *state);
static void allocate_registers(struct compile_state *state)
{
struct reg_state rstate;
@@ -13547,8 +13644,13 @@
do {
struct live_range **point, **next;
+ int tangles;
int coalesced;
+#if 0
+ fprintf(stderr, "pass: %d\n", rstate.passes);
+#endif
+
/* Restore ids */
ids_from_rstate(state, &rstate);
@@ -13562,30 +13664,42 @@
walk_variable_lifetimes(
state, rstate.blocks, fix_coalesce_conflicts, 0);
- /* Fix two simultaneous uses of the same register */
- correct_tangles(state, rstate.blocks);
+ /* Fix two simultaneous uses of the same register.
+ * In a few pathlogical cases a partial untangle moves
+ * the tangle to a part of the graph we won't revisit.
+ * So we keep looping until we have no more tangle fixes
+ * to apply.
+ */
+ do {
+ tangles = correct_tangles(state, rstate.blocks);
+ } while(tangles);
if (state->debug & DEBUG_INSERTED_COPIES) {
printf("After resolve_tangles\n");
print_blocks(state, stdout);
print_control_flow(state);
}
-
+ verify_consistency(state);
/* Allocate and initialize the live ranges */
initialize_live_ranges(state, &rstate);
-
- do {
- /* Forget previous live range edge calculations */
- cleanup_live_edges(&rstate);
+ /* Note current doing coalescing in a loop appears to
+ * buys me nothing. The code is left this way in case
+ * there is some value in it. Or if a future bugfix
+ * yields some benefit.
+ */
+ do {
#if 0
fprintf(stderr, "coalescing\n");
#endif
+ /* Remove any previous live edge calculations */
+ cleanup_live_edges(&rstate);
+
/* Compute the interference graph */
walk_variable_lifetimes(
state, rstate.blocks, graph_ins, &rstate);
-
+
/* Display the interference graph if desired */
if (state->debug & DEBUG_INTERFERENCE) {
printf("\nlive variables by block\n");
@@ -13595,14 +13709,25 @@
state, rstate.blocks,
print_interference_ins, &rstate);
}
-#if DEBUG_CONSISTENCY
- /* Verify the interference graph */
- walk_variable_lifetimes(
- state, rstate.blocks, verify_graph_ins, &rstate);
-#endif
coalesced = coalesce_live_ranges(state, &rstate);
+
+#if 0
+ fprintf(stderr, "coalesced: %d\n", coalesced);
+#endif
} while(coalesced);
+
+#if DEBUG_CONSISTENCY > 1
+# if 0
+ fprintf(stderr, "verify_graph_ins...\n");
+# endif
+ /* Verify the interference graph */
+ walk_variable_lifetimes(
+ state, rstate.blocks, verify_graph_ins, &rstate);
+# if 0
+ fprintf(stderr, "verify_graph_ins done\n");
+#endif
+#endif
/* Build the groups low and high. But with the nodes
* first sorted by degree order.
@@ -14545,7 +14670,7 @@
verify_ins_colors(state);
}
#else
-#define verify_consistency(state) do {} while(0)
+static void verify_consistency(struct compile_state *state) {}
#endif /* DEBUG_USES */
static void optimize(struct compile_state *state)