* config/arm/arm.c (arm_size_rtx_costs): Treat a PLUS with a shift

	the same as a PLUS without a shift.  Increase the cost of a
	CONST_INT in MULT.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@146595 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 4218dca..ec64ac2 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2009-04-22  Kazu Hirata  <kazu@codesourcery.com>
+
+       * config/arm/arm.c (arm_size_rtx_costs): Treat a PLUS with a shift
+       the same as a PLUS without a shift.  Increase the cost of a
+       CONST_INT in MULT.
+
 2009-04-22  Manuel Lopez-Ibanez  <manu@gcc.gnu.org>
 
        * Makefile.in: Update dependencies.

diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
index 80d1267..547e760 100644 (file)
--- a/gcc/config/arm/arm.c
+++ b/gcc/config/arm/arm.c
@@ -5681,6 +5681,16 @@ arm_size_rtx_costs (rtx x, enum rtx_code code, enum rtx_code outer_code,
          return false;
        }
 
+      /* A shift as a part of ADD costs nothing.  */
+      if (GET_CODE (XEXP (x, 0)) == MULT
+         && power_of_two_operand (XEXP (XEXP (x, 0), 1), SImode))
+       {
+         *total = COSTS_N_INSNS (TARGET_THUMB2 ? 2 : 1);
+         *total += rtx_cost (XEXP (XEXP (x, 0), 0), code, false);
+         *total += rtx_cost (XEXP (x, 1), code, false);
+         return true;
+       }
+
       /* Fall through */
     case AND: case XOR: case IOR:
       if (mode == SImode)
@@ -5774,7 +5784,10 @@ arm_size_rtx_costs (rtx x, enum rtx_code code, enum rtx_code outer_code,
 
     case CONST_INT:
       if (const_ok_for_arm (INTVAL (x)))
-       *total = COSTS_N_INSNS (outer_code == SET ? 1 : 0);
+       /* A multiplication by a constant requires another instruction
+          to load the constant to a register.  */
+       *total = COSTS_N_INSNS ((outer_code == SET || outer_code == MULT)
+                               ? 1 : 0);
       else if (const_ok_for_arm (~INTVAL (x)))
        *total = COSTS_N_INSNS (outer_code == AND ? 0 : 1);
       else if (const_ok_for_arm (-INTVAL (x)))