re PR rtl-optimization/64110 (ICE: Max. number of generated reload insns per insn is achieved (90))

2014-12-12  Vladimir Makarov  <vmakarov@redhat.com>

	PR target/64110
	* lra-constraints.c (process_alt_operands): Refuse alternative
	when reload pseudo of given class can not hold value of given
	mode.

2014-12-12  Vladimir Makarov  <vmakarov@redhat.com>

	PR target/64110
	* gcc.target/i386/pr64110.c: New.

From-SVN: r218688

gcc/ChangeLog

+2014-12-12  Vladimir Makarov  <vmakarov@redhat.com>
+
+	PR target/64110
+	* lra-constraints.c (process_alt_operands): Refuse alternative
+	when reload pseudo of given class can not hold value of given
+	mode.
+
 2014-12-12  Thomas Schwinge  <thomas@codesourcery.com>
 
 	* gimple-walk.c (walk_gimple_op) <GIMPLE_OMP_FOR>: Also check

gcc/lra-constraints.c

@@ -2267,6 +2267,29 @@ process_alt_operands (int only_alternative)
 		  goto fail;
 		}
 
+	      /* Alternative loses if it required class pseudo can not
+		 hold value of required mode.  Such insns can be
+		 described by insn definitions with mode iterators.
+		 Don't use ira_prohibited_class_mode_regs here as it
+		 is common practice for constraints to use a class
+		 which does not have actually enough regs to hold the
+		 value (e.g. x86 AREG for mode requiring more one
+		 general reg).  */
+	      if (GET_MODE (*curr_id->operand_loc[nop]) != VOIDmode
+		  && ! hard_reg_set_empty_p (this_alternative_set)
+		  && ! HARD_REGNO_MODE_OK (ira_class_hard_regs
+					   [this_alternative][0],
+					   GET_MODE (*curr_id->operand_loc[nop])))
+		{
+		  if (lra_dump_file != NULL)
+		    fprintf
+		      (lra_dump_file,
+		       "            alt=%d: reload pseudo for op %d "
+		       " can not hold the mode value -- refuse\n",
+		       nalt, nop);
+		  goto fail;
+		}
+
 	      /* Check strong discouragement of reload of non-constant
 		 into class THIS_ALTERNATIVE.  */
 	      if (! CONSTANT_P (op) && ! no_regs_p

gcc/testsuite/ChangeLog

+2014-12-12  Vladimir Makarov  <vmakarov@redhat.com>
+
+	PR target/64110
+	* gcc.target/i386/pr64110.c: New.
+
 2014-12-12  Thomas Schwinge  <thomas@codesourcery.com>
 
 	* c-c++-common/gomp/nesting-1.c: New file.

gcc/testsuite/gcc.target/i386/pr64110.c

+/* { dg-do compile } */
+/* { dg-options "-O3 -march=core-avx2" } */
+
+int foo (void);
+int a;
+short *b;
+
+void
+bar (short x)
+{
+  while (a--)
+    {
+      int i, j = foo ();
+      for (i = 0; i < j; ++i)
+	*b++ = x;
+    }
+}