cfgcleanup.c: Include params.h.

        * cfgcleanup.c: Include params.h.
        (try_crossjump_bb): Use PARAM_MAX_CROSSJUMP_EDGES.  Fix test for
        too many outgoing edges from a block.
        * Makefile.in (cfgcleanup.o): Depend on PARAMS_H.
        * params.def (max-crossjump-edges): New.
        * doc/invoke.texi: Document it.

From-SVN: r62942

5 files changed, 34 insertions, 8 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 2315a03..bba56b8 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,14 @@
 2003-02-15  Richard Henderson  <rth@redhat.com>
 
+	* cfgcleanup.c: Include params.h.
+	(try_crossjump_bb): Use PARAM_MAX_CROSSJUMP_EDGES.  Fix test for
+	too many outgoing edges from a block.
+	* Makefile.in (cfgcleanup.o): Depend on PARAMS_H.
+	* params.def (max-crossjump-edges): New.
+	* doc/invoke.texi: Document it.
+
+2003-02-15  Richard Henderson  <rth@redhat.com>
+
         * recog.c (split_all_insns): Include new blocks in life update;
         do a global life update.
 
diff --git a/gcc/Makefile.in b/gcc/Makefile.in
index f4e26b7..8af0a704 100644
--- a/gcc/Makefile.in
+++ b/gcc/Makefile.in
@@ -1593,9 +1593,10 @@ cfganal.o : cfganal.c $(CONFIG_H) $(SYSTEM_H) coretypes.h $(TM_H) $(RTL_H) \
 cfgbuild.o : cfgbuild.c $(CONFIG_H) $(SYSTEM_H) coretypes.h $(TM_H) $(RTL_H) flags.h \
    insn-config.h $(BASIC_BLOCK_H) $(REGS_H) hard-reg-set.h output.h toplev.h $(RECOG_H) \
    function.h except.h $(GGC_H)
-cfgcleanup.o : cfgcleanup.c $(CONFIG_H) $(SYSTEM_H) coretypes.h $(TM_H) $(RTL_H) \
-   $(TIMEVAR_H) $(BASIC_BLOCK_H) hard-reg-set.h output.h flags.h $(RECOG_H) toplev.h \
-   $(GGC_H) insn-config.h cselib.h $(TARGET_H) $(TM_P_H)
+cfgcleanup.o : cfgcleanup.c $(CONFIG_H) $(SYSTEM_H) coretypes.h $(TM_H) \
+   $(RTL_H) $(TIMEVAR_H) $(BASIC_BLOCK_H) hard-reg-set.h output.h flags.h \
+   $(RECOG_H) toplev.h $(GGC_H) insn-config.h cselib.h $(TARGET_H) $(TM_P_H) \
+   $(PARAMS_H)
 cfgloop.o : cfgloop.c $(CONFIG_H) $(SYSTEM_H) $(RTL_H) coretypes.h $(TM_H) \
    $(BASIC_BLOCK_H) hard-reg-set.h cfgloop.h flags.h
 cfgloopanal.o : cfgloopanal.c $(CONFIG_H) $(SYSTEM_H) $(RTL_H) \
diff --git a/gcc/cfgcleanup.c b/gcc/cfgcleanup.c
index 338281a..3607fc3 100644
--- a/gcc/cfgcleanup.c
+++ b/gcc/cfgcleanup.c
@@ -45,6 +45,7 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA
 #include "recog.h"
 #include "toplev.h"
 #include "cselib.h"
+#include "params.h"
 #include "tm_p.h"
 #include "target.h"
 
@@ -1464,7 +1465,7 @@ try_crossjump_bb (mode, bb)
 {
   edge e, e2, nexte2, nexte, fallthru;
   bool changed;
-  int n = 0;
+  int n = 0, max;
 
   /* Nothing to do if there is not at least two incoming edges.  */
   if (!bb->pred || !bb->pred->pred_next)
@@ -1473,11 +1474,13 @@ try_crossjump_bb (mode, bb)
   /* It is always cheapest to redirect a block that ends in a branch to
      a block that falls through into BB, as that adds no branches to the
      program.  We'll try that combination first.  */
-  for (fallthru = bb->pred; fallthru; fallthru = fallthru->pred_next, n++)
+  fallthru = NULL;
+  max = PARAM_VALUE (PARAM_MAX_CROSSJUMP_EDGES);
+  for (e = bb->pred; e ; e = e->pred_next, n++)
     {
-      if (fallthru->flags & EDGE_FALLTHRU)
-	break;
-      if (n > 100)
+      if (e->flags & EDGE_FALLTHRU)
+	fallthru = e;
+      if (n > max)
 	return false;
     }
 
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 36e1411..0c6f4eb 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -4346,6 +4346,13 @@ In each case, the @var{value} is an integer.  The allowable choices for
 @var{name} are given in the following table:
 
 @table @gcctabopt
+@item max-crossjump-edges
+The maximum number of incoming edges to consider for crossjumping.
+The algorithm used by @option(-fcrossjumping) is @math{O(N^2)} in
+the number of edges incoming to each block.  Increasing values mean
+more aggressive optimization, making the compile time increase with
+probably small improvement in executable size.
+
 @item max-delay-slot-insn-search
 The maximum number of instructions to consider when looking for an
 instruction to fill a delay slot.  If more than this arbitrary number of
diff --git a/gcc/params.def b/gcc/params.def
index 998b40d..66d8231 100644
--- a/gcc/params.def
+++ b/gcc/params.def
@@ -202,6 +202,12 @@ DEFPARAM(TRACER_MIN_BRANCH_PROBABILITY,
 this threshold (in percents). Used when profile feedback is not available",
 	 50)
 
+/* The maximum number of incoming edges to consider for crossjumping.  */
+DEFPARAM(PARAM_MAX_CROSSJUMP_EDGES,
+	 "max-crossjump-edges",
+	 "The maximum number of incoming edges to consider for crossjumping",
+	 100)
+
 #ifdef ENABLE_GC_ALWAYS_COLLECT
 # define GGC_MIN_EXPAND_DEFAULT 0
 # define GGC_MIN_HEAPSIZE_DEFAULT 0