PR target/37939

	* config/cris/cris.c (cris_rtx_costs) <MULT>: Return 0 for an ADDI
	operand.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@141524 138bc75d-0d04-0410-961f-82ee72b054a4

2 files changed, 21 insertions, 0 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index b811061b3df..9e558d35b9c 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2008-11-01  Hans-Peter Nilsson  <hp@axis.com>
+
+	PR target/37939
+	* config/cris/cris.c (cris_rtx_costs) <MULT>: Return 0 for an ADDI
+	operand.
+
 2008-11-01  Richard Guenther  <rguenther@suse.de>
 
 	PR middle-end/37976
diff --git a/gcc/config/cris/cris.c b/gcc/config/cris/cris.c
index 1d0a34b9abb..88d89993a9e 100644
--- a/gcc/config/cris/cris.c
+++ b/gcc/config/cris/cris.c
@@ -1796,6 +1796,21 @@ cris_rtx_costs (rtx x, int code, int outer_code, int *total,
       return true;
 
     case MULT:
+      /* If we have one arm of an ADDI, make sure it gets the cost of
+	 one insn, i.e. zero cost for this operand, and just the cost
+	 of the PLUS, as the insn is created by combine from a PLUS
+	 and an ASHIFT, and the MULT cost below would make the
+	 combined value be larger than the separate insns.  The insn
+	 validity is checked elsewhere by combine.
+
+	 FIXME: this case is a stop-gap for 4.3 and 4.4, this whole
+	 function should be rewritten.  */
+      if (outer_code == PLUS && BIAP_INDEX_P (x))
+	{
+	  *total = 0;
+	  return true;
+	}
+
       /* Identify values that are no powers of two.  Powers of 2 are
          taken care of already and those values should not be changed.  */
       if (!CONST_INT_P (XEXP (x, 1))