[svn:parrot] r41941 - in trunk: include/parrot src/runcore

[cotto at svn.parrot.org]

Author: cotto
Date: Mon Oct 19 15:16:09 2009
New Revision: 41941
URL: https://trac.parrot.org/parrot/changeset/41941

Log:
[profiling] add a pc->line number cache to the profiling runcore
This speeds up oofib.pir profiling by about 13.9% and drastically reduces the
time spent in Parrot_Sub_get_line_from_pc, reducing it from ~38% to ~0%.
(parrot_hash_get is at about 2.74%.) This will cause a slowdown for programs
without many loops, but such programs are not likely to be profiled in the
first place.

Modified:
   trunk/include/parrot/runcore_profiling.h
   trunk/src/runcore/profiling.c

Modified: trunk/include/parrot/runcore_profiling.h
==============================================================================
--- trunk/include/parrot/runcore_profiling.h	Mon Oct 19 14:49:46 2009	(r41940)
+++ trunk/include/parrot/runcore_profiling.h	Mon Oct 19 15:16:09 2009	(r41941)
@@ -45,6 +45,7 @@
     UINTVAL         level;      /* how many nested runloops */
     UINTVAL         time_size;  /* how big is the following array */
     UHUGEINTVAL    *time;       /* time spent between DO_OP and start/end of a runcore */
+    Hash           *line_cache; /* hash for caching pc -> line mapping */
 };
 
 

Modified: trunk/src/runcore/profiling.c
==============================================================================
--- trunk/src/runcore/profiling.c	Mon Oct 19 14:49:46 2009	(r41940)
+++ trunk/src/runcore/profiling.c	Mon Oct 19 15:16:09 2009	(r41941)
@@ -147,6 +147,7 @@
     runcore->runloop_count   = 0;
     runcore->level           = 0;
     runcore->time_size       = 32;
+    runcore->line_cache      = parrot_new_pointer_hash(interp);
     runcore->time            = mem_allocate_n_typed(runcore->time_size,
                                                     UHUGEINTVAL);
     Profiling_first_loop_SET(runcore);
@@ -257,9 +258,13 @@
             Parrot_ex_throw_from_c_args(interp, NULL, 1,
                     "attempt to access code outside of current code segment");
 
-        preop_line = Parrot_Sub_get_line_from_pc(interp,
-                Parrot_pcc_get_sub(interp, CURRENT_CONTEXT(interp)),
-                CONTEXT(interp)->current_pc);
+        preop_line = parrot_hash_get(interp, runcore->line_cache, CONTEXT(interp)->current_pc);
+        if (preop_line == NULL) {
+            preop_line = Parrot_Sub_get_line_from_pc(interp,
+                    Parrot_pcc_get_sub(interp, CURRENT_CONTEXT(interp)),
+                    CONTEXT(interp)->current_pc);
+            parrot_hash_put(interp, runcore->line_cache, CONTEXT(interp)->current_pc, preop_line);
+        }
 
         CONTEXT(interp)->current_pc = pc;
         preop_sub                   = CONTEXT(interp)->current_sub;
@@ -367,6 +372,7 @@
         "output from this file.\n", filename_cstr);
 
     Parrot_str_free_cstring(filename_cstr);
+    parrot_hash_destroy(interp, runcore->line_cache);
 
     fclose(runcore->profile_fd);
     mem_sys_free(runcore->time);