1 /* Mips implementation of list scheduler selector */
12 #include "mips_scheduler.h"
14 #include "../besched_t.h"
19 #include "gen_mips_regalloc_if.h"
21 #include "mips_new_nodes.h"
23 list_sched_selector_t mips_sched_selector;
26 const arch_env_t* arch_env;
29 * This array holds an entry for each register that specifies how much cycles
30 * have to pass before we can access that register again
31 * (because mips will write the register value back in the WB phase of the pipeline)
33 int busy_registers[N_mips_gp_REGS];
39 static void *mips_scheduler_init_graph(const list_sched_selector_t *vtab, const arch_env_t *arch_env, ir_graph *irg)
41 mips_sched_env_t *sched_env = xmalloc(sizeof(sched_env[0]));
42 memset(sched_env, 0, sizeof(sched_env[0]));
44 sched_env->arch_env = arch_env;
45 sched_env->div_set = new_pset(pset_default_ptr_cmp, 4);
50 static void mips_scheduler_finish_graph(void* graph_env)
52 mips_sched_env_t *sched_env = (mips_sched_env_t*) graph_env;
53 del_pset(sched_env->div_set);
56 static void *mips_scheduler_init_block(void *graph_env, ir_node *block)
58 mips_sched_env_t *sched_env = (mips_sched_env_t*) graph_env;
59 assert(pset_count(sched_env->div_set) == 0);
61 // TODO later we might have blocks that don't end in a jump
62 memset(&sched_env->busy_registers, 0, sizeof(sched_env->busy_registers));
63 sched_env->block = block;
64 sched_env->last_nop = NULL;
68 static void mips_scheduler_finish_block(void* graph_env)
70 mips_sched_env_t *sched_env = (mips_sched_env_t*) graph_env;
71 // attach last nop to end node (so that firm doesn't discard it)
72 if(sched_env->last_nop != NULL) {
73 ir_node* end = get_irg_end(get_irn_irg(sched_env->block));
77 sched_env->block = NULL;
80 static int mips_scheduler_to_appear_in_schedule(void *block_env, const ir_node *irn)
82 return is_mips_irn(irn) && !is_mips_zero(irn) && !is_mips_reinterpret_conv(irn) && !is_mips_fallthrough(irn);
85 static void mips_collect_mflohis(pset* set, ir_node* node) {
86 // construct a list of nodes that need to be scheduled before
87 // we are allowed to schedule another div or mul instruction
88 const ir_edge_t *edge, *edge2;
90 if(is_mips_div(node)) {
91 foreach_out_edge(node, edge) {
92 const ir_node* node2 = get_edge_src_irn(edge);
94 assert(is_Proj(node2));
95 foreach_out_edge(node2, edge2) {
96 const ir_node* node3 = get_edge_src_irn(edge2);
97 if(is_mips_mfhi(node3) || is_mips_mflo(node3))
98 pset_insert_ptr(set, node3);
101 } else if(is_mips_mult(node)) {
102 foreach_out_edge(node, edge) {
103 const ir_node* node2 = get_edge_src_irn(edge);
105 if(is_mips_mfhi(node2) || is_mips_mflo(node2))
106 pset_insert_ptr(set, node2);
111 static int mips_scheduler_node_allowed(mips_sched_env_t *sched_env, ir_node* node)
113 if(pset_count(sched_env->div_set) != 0 && (is_mips_div(node) || is_mips_mult(node))) {
120 static ir_node *mips_scheduler_select(void *block_env, nodeset *ready_set, nodeset *live_set)
122 mips_sched_env_t *sched_env = (mips_sched_env_t*) block_env;
123 const arch_env_t *arch_env = (const arch_env_t*) sched_env->arch_env;
124 ir_node *node = NULL;
125 ir_node *block = sched_env->block;
126 ir_node *condjmp = NULL;
127 ir_graph *irg = get_irn_irg(block);
128 int have_non_branch_nodes = 0;
130 // test all nodes in the ready set and take the first non-branch that
132 for (node = nodeset_first(ready_set); node != NULL; node = nodeset_next(ready_set)) {
133 if (arch_irn_class_is(arch_env, node, branch)) {
134 if (is_irn_forking(node))
139 have_non_branch_nodes = 1;
141 if (mips_scheduler_node_allowed(sched_env, node))
143 nodeset_break(ready_set);
145 // TODO update busy_registers
147 if (is_mips_div(node) || is_mips_mult(node)) {
148 mips_collect_mflohis(sched_env->div_set, node);
149 } else if(is_mips_mflo(node) || is_mips_mfhi(node)) {
150 pset_remove_ptr(sched_env->div_set, node);
157 // if we arrive here no non-branch node was found that we can emit
159 // return a branch if there are just branches left
160 if(!have_non_branch_nodes) {
161 // schedule conditional branches before non-conditional ones
162 if(condjmp != NULL) {
165 node = nodeset_first(ready_set);
166 assert(arch_irn_class_is(arch_env, node, branch));
167 nodeset_break(ready_set);
172 node = new_rd_mips_nop(NULL, irg, block, mode_M);
178 * Returns the reg_pressure scheduler with to_appear_in_schedule() overloaded
180 const list_sched_selector_t *mips_get_list_sched_selector(const void *self, list_sched_selector_t *selector)
182 memset(&mips_sched_selector, 0, sizeof(mips_sched_selector));
183 mips_sched_selector.init_graph = mips_scheduler_init_graph;
184 mips_sched_selector.init_block = mips_scheduler_init_block;
185 mips_sched_selector.select = mips_scheduler_select;
186 mips_sched_selector.to_appear_in_schedule = mips_scheduler_to_appear_in_schedule;
187 mips_sched_selector.finish_block = mips_scheduler_finish_block;
188 mips_sched_selector.finish_graph = mips_scheduler_finish_graph;
189 //return &mips_sched_selector;