re PR rtl-optimization/79571 (ICE in Max. number of generated reload insns per insn is achieved (90))

2017-03-06  Vladimir Makarov  <vmakarov@redhat.com>

	PR rtl-optimization/79571
	* lra-constraints.c (process_alt_operands): Claculate static
	reject and subtract it from overal when there will be only address
	reloads.

2017-03-06  Vladimir Makarov  <vmakarov@redhat.com>

	PR rtl-optimization/79571
	* gcc.target/i386/pr79571.c: New.

From-SVN: r245928

1 files changed, 20 insertions, 3 deletions

diff --git a/gcc/lra-constraints.c b/gcc/lra-constraints.c
index c67bd06..630261a 100644
--- a/gcc/lra-constraints.c
+++ b/gcc/lra-constraints.c
@@ -1867,11 +1867,15 @@ process_alt_operands (int only_alternative)
   /* LOSERS counts the operands that don't fit this alternative and
      would require loading.  */
   int losers;
+  int addr_losers;
   /* REJECT is a count of how undesirable this alternative says it is
      if any reloading is required.  If the alternative matches exactly
      then REJECT is ignored, but otherwise it gets this much counted
      against it in addition to the reloading needed.  */
   int reject;
+  /* This is defined by '!' or '?' alternative constraint and added to
+     reject.  But in some cases it can be ignored.  */
+  int static_reject;
   int op_reject;
   /* The number of elements in the following array.  */
   int early_clobbered_regs_num;
@@ -1948,7 +1952,8 @@ process_alt_operands (int only_alternative)
       if (!TEST_BIT (preferred, nalt))
 	continue;
 
-      overall = losers = reject = reload_nregs = reload_sum = 0;
+      overall = losers = addr_losers = 0;
+      static_reject = reject = reload_nregs = reload_sum = 0;
       for (nop = 0; nop < n_operands; nop++)
 	{
 	  int inc = (curr_static_id
@@ -1956,8 +1961,9 @@ process_alt_operands (int only_alternative)
 	  if (lra_dump_file != NULL && inc != 0)
 	    fprintf (lra_dump_file,
 		     "            Staticly defined alt reject+=%d\n", inc);
-	  reject += inc;
+	  static_reject += inc;
 	}
+      reject += static_reject;
       early_clobbered_regs_num = 0;
 
       for (nop = 0; nop < n_operands; nop++)
@@ -2704,6 +2710,9 @@ process_alt_operands (int only_alternative)
 		       nop);
 		  reject++;
 		}
+
+	      if (MEM_P (op) && offmemok)
+		addr_losers++;
 	    }
 
 	  if (early_clobber_p && ! scratch_p)
@@ -2718,7 +2727,8 @@ process_alt_operands (int only_alternative)
 	     Should we update the cost (may be approximately) here
 	     because of early clobber register reloads or it is a rare
 	     or non-important thing to be worth to do it.  */
-	  overall = losers * LRA_LOSER_COST_FACTOR + reject;
+	  overall = (losers * LRA_LOSER_COST_FACTOR + reject
+		     - (addr_losers == losers ? static_reject : 0));
 	  if ((best_losers == 0 || losers != 0) && best_overall < overall)
             {
               if (lra_dump_file != NULL)
@@ -2742,6 +2752,7 @@ process_alt_operands (int only_alternative)
 	  if (early_clobber_p && operand_reg[nop] != NULL_RTX)
 	    early_clobbered_nops[early_clobbered_regs_num++] = nop;
 	}
+
       if (curr_insn_set != NULL_RTX && n_operands == 2
 	  /* Prevent processing non-move insns.  */
 	  && (GET_CODE (SET_SRC (curr_insn_set)) == SUBREG
@@ -2753,9 +2764,15 @@ process_alt_operands (int only_alternative)
 		   || reg_in_class_p (no_subreg_reg_operand[1], curr_alt[0])))
 	      || (! curr_alt_win[0] && curr_alt_win[1]
 		  && REG_P (no_subreg_reg_operand[1])
+		  /* Check that we reload memory not the memory
+		     address.  */
+		  && !curr_alt_offmemok[0]
 		  && reg_in_class_p (no_subreg_reg_operand[1], curr_alt[0]))
 	      || (curr_alt_win[0] && ! curr_alt_win[1]
 		  && REG_P (no_subreg_reg_operand[0])
+		  /* Check that we reload memory not the memory
+		     address.  */
+		  && !curr_alt_offmemok[1]
 		  && reg_in_class_p (no_subreg_reg_operand[0], curr_alt[1])
 		  && (! CONST_POOL_OK_P (curr_operand_mode[1],
 					 no_subreg_reg_operand[1])