reduce conditional compilation for LOAD_EXTEND_OP

Provide a default in files where that is possible, so that everything
else there can be unconditionally compiled.  However rtlanal.c and
reload.c do tricky things that break providing a global default, so we
can't do that yet.

gcc/ChangeLog:

2015-07-08  Trevor Saunders  <tbsaunde+gcc@tbsaunde.org>

	* combine.c (try_combine): Don't check if LOAD_EXTEND_OP is
	defined.
	(simplify_set): Likewise.
	* cse.c (cse_insn): Likewise.
	* fold-const.c (fold_single_bit_test): Likewise.
	(fold_unary_loc): Likewise.
	* postreload.c (reload_cse_simplify_set): Likewise.
	(reload_cse_simplify_operands): Likewise.

From-SVN: r225591

gcc/ChangeLog

+2015-07-08  Trevor Saunders  <tbsaunde+gcc@tbsaunde.org>
+
+	* combine.c (try_combine): Don't check if LOAD_EXTEND_OP is
+	defined.
+	(simplify_set): Likewise.
+	* cse.c (cse_insn): Likewise.
+	* fold-const.c (fold_single_bit_test): Likewise.
+	(fold_unary_loc): Likewise.
+	* postreload.c (reload_cse_simplify_set): Likewise.
+	(reload_cse_simplify_operands): Likewise.
+
 2015-07-08  Jiong Wang  <jiong.wang@arm.com>
 
 	* config/aarch64/aarch64.c (aarch64_unspec_may_trap_p): New function.

gcc/combine.c

@@ -113,6 +113,10 @@ along with GCC; see the file COPYING3.  If not see
 #include "obstack.h"
 #include "rtl-iter.h"
 
+#ifndef LOAD_EXTEND_OP
+#define LOAD_EXTEND_OP(M) UNKNOWN
+#endif
+
 /* Number of attempts to combine instructions in this function.  */
 
 static int combine_attempts;
@@ -3744,7 +3748,6 @@ try_combine (rtx_insn *i3, rtx_insn *i2, rtx_insn *i1, rtx_insn *i0,
 	     be written as a ZERO_EXTEND.  */
 	  if (split_code == SUBREG && MEM_P (SUBREG_REG (*split)))
 	    {
-#ifdef LOAD_EXTEND_OP
 	      /* Or as a SIGN_EXTEND if LOAD_EXTEND_OP says that that's
 		 what it really is.  */
 	      if (LOAD_EXTEND_OP (GET_MODE (SUBREG_REG (*split)))
@@ -3752,7 +3755,6 @@ try_combine (rtx_insn *i3, rtx_insn *i2, rtx_insn *i1, rtx_insn *i0,
 		SUBST (*split, gen_rtx_SIGN_EXTEND (split_mode,
 						    SUBREG_REG (*split)));
 	      else
-#endif
 		SUBST (*split, gen_rtx_ZERO_EXTEND (split_mode,
 						    SUBREG_REG (*split)));
 	    }
@@ -6772,7 +6774,6 @@ simplify_set (rtx x)
 	}
     }
 
-#ifdef LOAD_EXTEND_OP
   /* If we have (set FOO (subreg:M (mem:N BAR) 0)) with M wider than N, this
      would require a paradoxical subreg.  Replace the subreg with a
      zero_extend to avoid the reload that would otherwise be required.  */
@@ -6790,7 +6791,6 @@ simplify_set (rtx x)
 
       src = SET_SRC (x);
     }
-#endif
 
   /* If we don't have a conditional move, SET_SRC is an IF_THEN_ELSE, and we
      are comparing an item known to be 0 or -1 against 0, use a logical

gcc/cse.c

@@ -51,6 +51,10 @@ along with GCC; see the file COPYING3.  If not see
 #include "dbgcnt.h"
 #include "rtl-iter.h"
 
+#ifndef LOAD_EXTEND_OP
+#define LOAD_EXTEND_OP(M) UNKNOWN
+#endif
+
 /* The basic idea of common subexpression elimination is to go
    through the code, keeping a record of expressions that would
    have the same value at the current scan point, and replacing
@@ -4867,7 +4871,6 @@ cse_insn (rtx_insn *insn)
 	    }
 	}
 
-#ifdef LOAD_EXTEND_OP
       /* See if a MEM has already been loaded with a widening operation;
 	 if it has, we can use a subreg of that.  Many CISC machines
 	 also have such operations, but this is only likely to be
@@ -4913,7 +4916,6 @@ cse_insn (rtx_insn *insn)
 		break;
 	    }
 	}
-#endif /* LOAD_EXTEND_OP */
 
       /* Try to express the constant using a register+offset expression
 	 derived from a constant anchor.  */

gcc/fold-const.c

@@ -77,6 +77,10 @@ along with GCC; see the file COPYING3.  If not see
 #include "generic-match.h"
 #include "optabs.h"
 
+#ifndef LOAD_EXTEND_OP
+#define LOAD_EXTEND_OP(M) UNKNOWN
+#endif
+
 /* Nonzero if we are folding constants inside an initializer; zero
    otherwise.  */
 int folding_initializer = 0;
@@ -6646,12 +6650,8 @@ fold_single_bit_test (location_t loc, enum tree_code code,
       /* If we are going to be able to omit the AND below, we must do our
 	 operations as unsigned.  If we must use the AND, we have a choice.
 	 Normally unsigned is faster, but for some machines signed is.  */
-#ifdef LOAD_EXTEND_OP
       ops_unsigned = (LOAD_EXTEND_OP (operand_mode) == SIGN_EXTEND
 		      && !flag_syntax_only) ? 0 : 1;
-#else
-      ops_unsigned = 1;
-#endif
 
       signed_type = lang_hooks.types.type_for_mode (operand_mode, 0);
       unsigned_type = lang_hooks.types.type_for_mode (operand_mode, 1);
@@ -7815,7 +7815,6 @@ fold_unary_loc (location_t loc, enum tree_code code, tree type, tree op0)
 	      cst &= HOST_WIDE_INT_M1U
 		     << (TYPE_PRECISION (TREE_TYPE (and1)) - 1);
 	      change = (cst == 0);
-#ifdef LOAD_EXTEND_OP
 	      if (change
 		  && !flag_syntax_only
 		  && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0)))
@@ -7825,7 +7824,6 @@ fold_unary_loc (location_t loc, enum tree_code code, tree type, tree op0)
 		  and0 = fold_convert_loc (loc, uns, and0);
 		  and1 = fold_convert_loc (loc, uns, and1);
 		}
-#endif
 	    }
 	  if (change)
 	    {

gcc/postreload.c

@@ -54,6 +54,10 @@ along with GCC; see the file COPYING3.  If not see
 #include "tree-pass.h"
 #include "dbgcnt.h"
 
+#ifndef LOAD_EXTEND_OP
+#define LOAD_EXTEND_OP(M) UNKNOWN
+#endif
+
 static int reload_cse_noop_set_p (rtx);
 static bool reload_cse_simplify (rtx_insn *, rtx);
 static void reload_cse_regs_1 (void);
@@ -254,9 +258,7 @@ reload_cse_simplify_set (rtx set, rtx_insn *insn)
   int old_cost;
   cselib_val *val;
   struct elt_loc_list *l;
-#ifdef LOAD_EXTEND_OP
   enum rtx_code extend_op = UNKNOWN;
-#endif
   bool speed = optimize_bb_for_speed_p (BLOCK_FOR_INSN (insn));
 
   dreg = true_regnum (SET_DEST (set));
@@ -269,7 +271,6 @@ reload_cse_simplify_set (rtx set, rtx_insn *insn)
 
   dclass = REGNO_REG_CLASS (dreg);
 
-#ifdef LOAD_EXTEND_OP
   /* When replacing a memory with a register, we need to honor assumptions
      that combine made wrt the contents of sign bits.  We'll do this by
      generating an extend instruction instead of a reg->reg copy.  Thus
@@ -279,7 +280,6 @@ reload_cse_simplify_set (rtx set, rtx_insn *insn)
       && (extend_op = LOAD_EXTEND_OP (GET_MODE (src))) != UNKNOWN
       && !REG_P (SET_DEST (set)))
     return 0;
-#endif
 
   val = cselib_lookup (src, GET_MODE (SET_DEST (set)), 0, VOIDmode);
   if (! val)
@@ -301,7 +301,6 @@ reload_cse_simplify_set (rtx set, rtx_insn *insn)
 
       if (CONSTANT_P (this_rtx) && ! references_value_p (this_rtx, 0))
 	{
-#ifdef LOAD_EXTEND_OP
 	  if (extend_op != UNKNOWN)
 	    {
 	      wide_int result;
@@ -326,19 +325,17 @@ reload_cse_simplify_set (rtx set, rtx_insn *insn)
 		}
 	      this_rtx = immed_wide_int_const (result, word_mode);
 	    }
-#endif
+
 	  this_cost = set_src_cost (this_rtx, GET_MODE (SET_DEST (set)), speed);
 	}
       else if (REG_P (this_rtx))
 	{
-#ifdef LOAD_EXTEND_OP
 	  if (extend_op != UNKNOWN)
 	    {
 	      this_rtx = gen_rtx_fmt_e (extend_op, word_mode, this_rtx);
 	      this_cost = set_src_cost (this_rtx, word_mode, speed);
 	    }
 	  else
-#endif
 	    this_cost = register_move_cost (GET_MODE (this_rtx),
 					    REGNO_REG_CLASS (REGNO (this_rtx)),
 					    dclass);
@@ -353,7 +350,6 @@ reload_cse_simplify_set (rtx set, rtx_insn *insn)
 	      && REG_P (this_rtx)
 	      && !REG_P (SET_SRC (set))))
 	{
-#ifdef LOAD_EXTEND_OP
 	  if (GET_MODE_BITSIZE (GET_MODE (SET_DEST (set))) < BITS_PER_WORD
 	      && extend_op != UNKNOWN
 #ifdef CANNOT_CHANGE_MODE_CLASS
@@ -367,7 +363,6 @@ reload_cse_simplify_set (rtx set, rtx_insn *insn)
 	      ORIGINAL_REGNO (wide_dest) = ORIGINAL_REGNO (SET_DEST (set));
 	      validate_change (insn, &SET_DEST (set), wide_dest, 1);
 	    }
-#endif
 
 	  validate_unshare_change (insn, &SET_SRC (set), this_rtx, 1);
 	  old_cost = this_cost, did_change = 1;
@@ -439,7 +434,6 @@ reload_cse_simplify_operands (rtx_insn *insn, rtx testreg)
 	continue;
 
       op = recog_data.operand[i];
-#ifdef LOAD_EXTEND_OP
       if (MEM_P (op)
 	  && GET_MODE_BITSIZE (GET_MODE (op)) < BITS_PER_WORD
 	  && LOAD_EXTEND_OP (GET_MODE (op)) != UNKNOWN)
@@ -490,7 +484,7 @@ reload_cse_simplify_operands (rtx_insn *insn, rtx testreg)
 	       safe to optimize, but is it worth the trouble?  */
 	    continue;
 	}
-#endif /* LOAD_EXTEND_OP */
+
       if (side_effects_p (op))
 	continue;
       v = cselib_lookup (op, recog_data.operand_mode[i], 0, VOIDmode);