rl78.c (rl78_rtx_costs): Improve cost estimates for multiplication.

	* config/rl78/rl78.c (rl78_rtx_costs): Improve cost estimates for
	multiplication.

From-SVN: r228521

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 6b08c7d196abc2ac5e9aa884837653e0ae1ff667..8ec89e37b013bf425ac1c934cf1bfcc020e23362 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,12 +1,17 @@
+2015-10-06  Nick Clifton  <nickc@redhat.com>
+
+       * config/rl78/rl78.c (rl78_rtx_costs): Improve cost estimates for
+       multiplication.
+
 2015-10-06  Venkataramanan Kumar  <Venkataramanan.kumar@amd.com>
 
        * config.gcc (i[34567]86-*-linux* | ...): Add znver1.
        (case ${target}): Add znver1.
        * config/i386/cpuid.h(bit_CLZERO):  Define.
        * config/i386/driver-i386.c: (host_detect_local_cpu): Let
-       -march=native recognize znver1 processors. 
+       -march=native recognize znver1 processors.
        * config/i386/i386-c.c (ix86_target_macros_internal): Add
-       znver1, clzero def_and_undef. 
+       znver1, clzero def_and_undef.
        * config/i386/i386.c (struct processor_costs znver1_cost): New.
        (m_znver1): New definition.
        (m_AMD_MULTIPLE): Includes m_znver1.
@@ -17,10 +22,10 @@
        (PTA_CLZERO) :  New definition.
        (ix86_option_override_internal): Handle new clzerooption.
        (ix86_issue_rate): Add znver1.
-       (ix86_adjust_cost): Add znver1.                
+       (ix86_adjust_cost): Add znver1.
        (ia32_multipass_dfa_lookahead): Add znver1.
-       (has_dispatch): Add znver1.       
-       * config/i386/i386.h (TARGET_znver1): New definition. 
+       (has_dispatch): Add znver1.
+       * config/i386/i386.h (TARGET_znver1): New definition.
        (TARGET_CLZERO): Define.
        (TARGET_CLZERO_P): Define.
        (struct ix86_size_cost): Add TARGET_ZNVER1.

diff --git a/gcc/config/rl78/rl78.c b/gcc/config/rl78/rl78.c
index e74d6c38a3187773c39ba5ab2bdf672da56f5143..436768295357661c1e4830198cb6c9db957e864e 100644 (file)
--- a/gcc/config/rl78/rl78.c
+++ b/gcc/config/rl78/rl78.c
@@ -4165,21 +4165,42 @@ rl78_rtx_costs (rtx          x,
       return true;
     }
 
+  if (mode == HImode)
+    {
+      if (code == MULT && ! speed)
+       {
+         * total = COSTS_N_INSNS (8);
+         return true;
+       }
+      return false;
+    }
+
   if (mode == SImode)
     {
       switch (code)
        {
        case MULT:
-         if (RL78_MUL_G14)
+         if (! speed)
+           /* If we are compiling for space then we do not want to use the
+              inline SImode multiplication patterns or shift sequences.
+              The cost is not set to 1 or 5 however as we have to allow for
+              the possibility that we might be converting a leaf function
+              into a non-leaf function.  (There is no way to tell here).
+              A value of 13 seems to be a reasonable compromise for the
+              moment.  */
+           * total = COSTS_N_INSNS (13);
+         else if (RL78_MUL_G14)
            *total = COSTS_N_INSNS (14);
          else if (RL78_MUL_G13)
            *total = COSTS_N_INSNS (29);
          else
            *total = COSTS_N_INSNS (500);
          return true;
+
        case PLUS:
          *total = COSTS_N_INSNS (8);
          return true;
+
        case ASHIFT:
        case ASHIFTRT:
        case LSHIFTRT:
@@ -4205,6 +4226,9 @@ rl78_rtx_costs (rtx          x,
          else
            *total = COSTS_N_INSNS (10+4*16);
          return true;
+
+       default:
+         break;
        }
     }
   return false;