From 153ea3548f5ac80d30103ace2655faaf05aa2ccb Mon Sep 17 00:00:00 2001 From: Eric Biederman Date: Fri, 20 Jun 2003 14:43:20 +0000 Subject: [PATCH] - 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 --- util/romcc/Makefile | 5 +- util/romcc/romcc.c | 195 ++++++++++++++++++++++++++++++++++++-------- 2 files changed, 163 insertions(+), 37 deletions(-) diff --git a/util/romcc/Makefile b/util/romcc/Makefile index 8df5ce1ad..fbf945f78 100644 --- a/util/romcc/Makefile +++ b/util/romcc/Makefile @@ -1,5 +1,5 @@ -VERSION:=0.29 -RELEASE_DATE:=19 June 2003 +VERSION:=0.30 +RELEASE_DATE:=20 June 2003 PACKAGE:=romcc @@ -57,6 +57,7 @@ TESTS=\ simple_test35.c \ simple_test36.c \ simple_test37.c \ + simple_test38.c \ raminit_test.c \ raminit_test2.c \ raminit_test3.c \ diff --git a/util/romcc/romcc.c b/util/romcc/romcc.c index 5c784fc5e..1f5c91af8 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 @@ struct type { #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<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 continue_statement(struct compile_state *state, struct triple *first 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 @@ static struct triple *initializer( 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 @@ static struct triple *function_definition( /* 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 @@ static struct triple *pre_copy( */ 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 remove_live_edges(struct reg_state *rstate, struct live_range *range } } +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 @@ static struct live_range *coalesce_ranges( 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 @@ static struct live_range *coalesce_ranges( 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 @@ static struct live_range *coalesce_ranges( 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 @@ static void fix_tangles(struct compile_state *state, 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 @@ static void fix_tangles(struct compile_state *state, 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 @@ static void fix_tangles(struct compile_state *state, /* 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 @@ static void fix_tangles(struct compile_state *state, 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 @@ static void cleanup_rstate(struct compile_state *state, struct reg_state *rstate 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 @@ static void allocate_registers(struct compile_state *state) 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 @@ static void allocate_registers(struct compile_state *state) 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 @@ static void allocate_registers(struct compile_state *state) 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 @@ static void verify_consistency(struct compile_state *state) 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) -- 2.25.1