2014-02-14 Vladimir Makarov <vmakarov@redhat.com>

	    Richard Earnshaw  <rearnsha@arm.com>

	PR rtl-optimization/59535
	* lra-constraints.c (process_alt_operands): Encourage alternative
	when unassigned pseudo class is superset of the alternative class.
	(inherit_reload_reg): Don't inherit when optimizing for code size.
	* config/arm/arm.h (MODE_BASE_REG_CLASS): Add version for LRA
	returning CORE_REGS for anything but Thumb1 and BASE_REGS for
	modes not less than 4 for Thumb1.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@207787 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 18 insertions, 0 deletions

diff --git a/gcc/lra-constraints.c b/gcc/lra-constraints.c
index 5302321deb7..d3831380fee 100644
--- a/gcc/lra-constraints.c
+++ b/gcc/lra-constraints.c
@@ -2112,6 +2112,21 @@ process_alt_operands (int only_alternative)
 		  goto fail;
 		}
 
+	      /* If not assigned pseudo has a class which a subset of
+		 required reg class, it is a less costly alternative
+		 as the pseudo still can get a hard reg of necessary
+		 class.  */
+	      if (! no_regs_p && REG_P (op) && hard_regno[nop] < 0
+		  && (cl = get_reg_class (REGNO (op))) != NO_REGS
+		  && ira_class_subset_p[this_alternative][cl])
+		{
+		  if (lra_dump_file != NULL)
+		    fprintf
+		      (lra_dump_file,
+		       "            %d Super set class reg: reject-=3\n", nop);
+		  reject -= 3;
+		}
+
 	      this_alternative_offmemok = offmemok;
 	      if (this_costly_alternative != NO_REGS)
 		{
@@ -4391,6 +4406,9 @@ static bool
 inherit_reload_reg (bool def_p, int original_regno,
 		    enum reg_class cl, rtx insn, rtx next_usage_insns)
 {
+  if (optimize_function_for_size_p (cfun))
+    return false;
+
   enum reg_class rclass = lra_get_allocno_class (original_regno);
   rtx original_reg = regno_reg_rtx[original_regno];
   rtx new_reg, new_insns, usage_insn;