S/390: Increase register move costs for CC_REGS

This increases the move costs for moves involving the CC register which saves us some instructions in SPEC CPU2006. gcc/ChangeLog: 2018-11-05 Robin Dapp <[email protected]> * config/s390/s390.c (s390_register_move_cost): Increase costs for moves involving the CC reg. From-SVN: r265814
R-macos · Nov 5, 2018 · b14dfa9 · b14dfa9
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diff --git a/gcc/ChangeLog b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2018-11-05  Robin Dapp  <[email protected]>
+
+	* config/s390/s390.c (s390_register_move_cost): Increase costs for
+        moves involving the CC reg.
+
 2018-11-05  Richard Biener  <[email protected]>
 
 	PR tree-optimization/87873

diff --git a/gcc/config/s390/s390.c b/gcc/config/s390/s390.c
@@ -3416,6 +3416,11 @@ s390_register_move_cost (machine_mode mode,
 	  && reg_classes_intersect_p (to, GENERAL_REGS)))
     return 10;
 
+  /* We usually do not want to copy via CC.  */
+  if (reg_classes_intersect_p (from, CC_REGS)
+       || reg_classes_intersect_p (to, CC_REGS))
+    return 5;
+
   return 1;
 }