create execution frequencies from profile data

diff --git a/ir/be/bemain.c b/ir/be/bemain.c
index fa32cb9..3f30e70 100644 (file)
--- a/ir/be/bemain.c
+++ b/ir/be/bemain.c
@@ -494,7 +494,14 @@ static void be_main_loop(FILE *file_handle, const char *asm_file_name)
                );
                BE_TIMER_PUSH(t_other);   /* t_other */
 
-               birg->execfreqs = compute_execfreq(irg, 10);
+               /**
+                * Create execution frequencies from profile data or estimate some
+                */
+               if(be_profile_has_data()) {
+                       birg->execfreqs = be_create_execfreqs_from_profile(irg);
+               } else {
+                       birg->execfreqs = compute_execfreq(irg, 10);
+               }
 
                BE_TIMER_ONLY(num_nodes_b = get_num_reachable_nodes(irg));
 

diff --git a/ir/be/beprofile.c b/ir/be/beprofile.c
index 829c766..4e0efc9 100644 (file)
--- a/ir/be/beprofile.c
+++ b/ir/be/beprofile.c
@@ -45,6 +45,7 @@
 #include "beutil.h"
 #include "ircons.h"
 #include "irhooks.h"
+#include "iredges.h"
 
 #include "bechordal_t.h"
 
@@ -103,6 +104,10 @@ instrument_block(ir_node * bb, ir_node * address, unsigned int id)
        ir_node  *load, *store, *offset, *add, *projm, *proji, *unknown;
        ir_node  *cnst;
 
+       /**
+        * We can't instrument the start and end block as there are no real
+        * instructions in these blocks
+        */
        if(bb == start_block || bb == get_irg_end_block(irg))
                return;
 
@@ -236,7 +241,7 @@ block_id_walker(ir_node * bb, void * data)
 }
 
 ir_graph *
-be_profile_instrument(char * filename)
+be_profile_instrument(const char *filename)
 {
        int            n, i;
        unsigned int   n_blocks = 0;
@@ -371,7 +376,7 @@ unregister_vcg_hook(void)
  * profile info struct
  */
 void
-be_profile_read(char * filename)
+be_profile_read(const char *filename)
 {
        FILE   *f;
        char    buf[8];
@@ -381,7 +386,7 @@ be_profile_read(char * filename)
        if(f == NULL) {
                return;
        }
-       printf("found profile data.\n");
+       printf("found profile data '%s'.\n", filename);
 
        /* check magic */
        ret = fread(buf, 8, 1, f);
@@ -430,7 +435,7 @@ be_profile_has_data(void)
  * Get block execution count as determined be profiling
  */
 unsigned int
-be_profile_get_block_execcount(const ir_node * block)
+be_profile_get_block_execcount(const ir_node *block)
 {
        execcount_t *ec, query;
 
@@ -440,9 +445,67 @@ be_profile_get_block_execcount(const ir_node * block)
        query.block = get_irn_node_nr(block);
        ec = set_find(profile, &query, sizeof(query), get_irn_node_nr(block));
 
-       if(ec) {
+       if(ec != NULL) {
                return ec->count;
        } else {
+               ir_fprintf(stderr, "Warning: Profile contains no data for %+F\n",
+                          block);
                return 1;
        }
 }
+
+typedef struct _intialize_execfreq_env_t {
+       ir_graph *irg;
+       exec_freq_t *execfreqs;
+       double freq_factor;
+} initialize_execfreq_env_t;
+
+static void initialize_execfreq(ir_node *block, void *data) {
+       initialize_execfreq_env_t *env = data;
+       double freq;
+
+       if(block == get_irg_start_block(env->irg)
+          || block == get_irg_end_block(env->irg)) {
+               freq = 1.0;
+       } else {
+               freq = be_profile_get_block_execcount(block);
+               freq *= env->freq_factor;
+       }
+
+       set_execfreq(env->execfreqs, block, freq);
+}
+
+exec_freq_t *be_create_execfreqs_from_profile(ir_graph *irg)
+{
+       ir_node *block2 = NULL;
+       ir_node *start_block;
+       const ir_edge_t *edge;
+       initialize_execfreq_env_t env;
+       unsigned count;
+
+       env.execfreqs = create_execfreq(irg);
+
+       // find the successor to the start block
+       start_block = get_irg_start_block(irg);
+       foreach_block_succ(start_block, edge) {
+               ir_node *succ = get_edge_src_irn(edge);
+               if(succ != start_block) {
+                       block2 = succ;
+                       break;
+               }
+       }
+       assert(block2 != NULL);
+
+       count = be_profile_get_block_execcount(block2);
+       if(count == 0) {
+               // the function was never executed, so fallback to estimated freqs
+               free_execfreq(env.execfreqs);
+
+               return compute_execfreq(irg, 10);
+       }
+
+       env.freq_factor = 1 / count;
+       irg_block_walk_graph(irg, initialize_execfreq, NULL, &env);
+
+       return env.execfreqs;
+}

diff --git a/ir/be/beprofile.h b/ir/be/beprofile.h
index 542601e..408600f 100644 (file)
--- a/ir/be/beprofile.h
+++ b/ir/be/beprofile.h
@@ -18,14 +18,14 @@
  * @param filename The name of the output file for the profile information
  * @return The irg doing the profile initialization.
  */
-ir_graph * be_profile_instrument(char * filename);
+ir_graph * be_profile_instrument(const char *filename);
 
 /**
  * Reads the corresponding profile info file if it exists and returns a
  * profile info struct
  * @param filename The name of the file containing profile information
  */
-void be_profile_read(char * filename);
+void be_profile_read(const char *filename);
 
 /**
  * Frees the profile info
@@ -37,6 +37,11 @@ void be_profile_free(void);
  */
 unsigned int be_profile_get_block_execcount(const ir_node * block);
 
+/**
+ * Initializes exec_freq structure for an irg based on profile data
+ */
+exec_freq_t *be_create_execfreqs_from_profile(ir_graph *irg);
+
 /**
  * Tells whether profile module has acquired data
  */