Remove fold_strip_sign_ops

This patch deletes fold_strip_sign_ops in favour of the
gimple-ssa-backprop.c pass.

Tested on x86_64-linux-gnu, aarch64-linux-gnu and arm-linux-gnueabi.

gcc/
	* fold-const.h (fold_strip_sign_ops): Delete.
	* fold-const.c (fold_strip_sign_ops): Likewise.
	(fold_unary_loc, fold_binary_loc): Remove calls to it.
	* builtins.c (fold_builtin_cos, fold_builtin_cosh)
	(fold_builtin_ccos): Delete.
	(fold_builtin_pow): Don't call fold_strip_sign_ops.
	(fold_builtin_hypot, fold_builtin_copysign): Likewise.
	Remove fndecl argument.
	(fold_builtin_1): Update calls accordingly.  Handle constant
	cos, cosh, ccos and ccosh here.

gcc/testsuite/
	* gcc.dg/torture/builtin-symmetric-1.c: Don't run at -O0.

From-SVN: r229140

gcc/ChangeLog

 2015-10-21  Richard Sandiford  <richard.sandiford@arm.com>
 
+	* fold-const.h (fold_strip_sign_ops): Delete.
+	* fold-const.c (fold_strip_sign_ops): Likewise.
+	(fold_unary_loc, fold_binary_loc): Remove calls to it.
+	* builtins.c (fold_builtin_cos, fold_builtin_cosh)
+	(fold_builtin_ccos): Delete.
+	(fold_builtin_pow): Don't call fold_strip_sign_ops.
+	(fold_builtin_hypot, fold_builtin_copysign): Likewise.
+	Remove fndecl argument.
+	(fold_builtin_1): Update calls accordingly.  Handle constant
+	cos, cosh, ccos and ccosh here.
+
+2015-10-21  Richard Sandiford  <richard.sandiford@arm.com>
+
 	* doc/invoke.texi (-fdump-tree-backprop, -fssa-backprop): Document.
 	* Makefile.in (OBJS): Add gimple-ssa-backprop.o.
 	* common.opt (fssa-backprop): New option.

gcc/builtins.c

@@ -160,8 +160,6 @@ static rtx expand_builtin_fabs (tree, rtx, rtx);
 static rtx expand_builtin_signbit (tree, rtx);
 static tree fold_builtin_pow (location_t, tree, tree, tree, tree);
 static tree fold_builtin_powi (location_t, tree, tree, tree, tree);
-static tree fold_builtin_cos (location_t, tree, tree, tree);
-static tree fold_builtin_cosh (location_t, tree, tree, tree);
 static tree fold_builtin_tan (tree, tree);
 static tree fold_builtin_trunc (location_t, tree, tree);
 static tree fold_builtin_floor (location_t, tree, tree);
@@ -175,7 +173,6 @@ static tree fold_builtin_memcmp (location_t, tree, tree, tree);
 static tree fold_builtin_strcmp (location_t, tree, tree);
 static tree fold_builtin_strncmp (location_t, tree, tree, tree);
 static tree fold_builtin_signbit (location_t, tree, tree);
-static tree fold_builtin_copysign (location_t, tree, tree, tree, tree);
 static tree fold_builtin_isascii (location_t, tree);
 static tree fold_builtin_toascii (location_t, tree);
 static tree fold_builtin_isdigit (location_t, tree);
@@ -7661,77 +7658,6 @@ fold_builtin_cproj (location_t loc, tree arg, tree type)
   return NULL_TREE;
 }
 
-/* Fold function call to builtin cos, cosf, or cosl with argument ARG.
-   TYPE is the type of the return value.  Return NULL_TREE if no
-   simplification can be made.  */
-
-static tree
-fold_builtin_cos (location_t loc,
-		  tree arg, tree type, tree fndecl)
-{
-  tree res, narg;
-
-  if (!validate_arg (arg, REAL_TYPE))
-    return NULL_TREE;
-
-  /* Calculate the result when the argument is a constant.  */
-  if ((res = do_mpfr_arg1 (arg, type, mpfr_cos, NULL, NULL, 0)))
-    return res;
-
-  /* Optimize cos(-x) into cos (x).  */
-  if ((narg = fold_strip_sign_ops (arg)))
-    return build_call_expr_loc (loc, fndecl, 1, narg);
-
-  return NULL_TREE;
-}
-
-/* Fold function call to builtin cosh, coshf, or coshl with argument ARG.
-   Return NULL_TREE if no simplification can be made.  */
-
-static tree
-fold_builtin_cosh (location_t loc, tree arg, tree type, tree fndecl)
-{
-  if (validate_arg (arg, REAL_TYPE))
-    {
-      tree res, narg;
-
-      /* Calculate the result when the argument is a constant.  */
-      if ((res = do_mpfr_arg1 (arg, type, mpfr_cosh, NULL, NULL, 0)))
-	return res;
-
-      /* Optimize cosh(-x) into cosh (x).  */
-      if ((narg = fold_strip_sign_ops (arg)))
-	return build_call_expr_loc (loc, fndecl, 1, narg);
-    }
-
-  return NULL_TREE;
-}
-
-/* Fold function call to builtin ccos (or ccosh if HYPER is TRUE) with
-   argument ARG.  TYPE is the type of the return value.  Return
-   NULL_TREE if no simplification can be made.  */
-
-static tree
-fold_builtin_ccos (location_t loc, tree arg, tree type, tree fndecl,
-		   bool hyper)
-{
-  if (validate_arg (arg, COMPLEX_TYPE)
-      && TREE_CODE (TREE_TYPE (TREE_TYPE (arg))) == REAL_TYPE)
-    {
-      tree tmp;
-
-      /* Calculate the result when the argument is a constant.  */
-      if ((tmp = do_mpc_arg1 (arg, type, (hyper ? mpc_cosh : mpc_cos))))
-	return tmp;
-
-      /* Optimize fn(-x) into fn(x).  */
-      if ((tmp = fold_strip_sign_ops (arg)))
-	return build_call_expr_loc (loc, fndecl, 1, tmp);
-    }
-
-  return NULL_TREE;
-}
-
 /* Fold function call to builtin tan, tanf, or tanl with argument ARG.
    Return NULL_TREE if no simplification can be made.  */
 
@@ -8147,10 +8073,9 @@ fold_builtin_bswap (tree fndecl, tree arg)
    NULL_TREE if no simplification can be made.  */
 
 static tree
-fold_builtin_hypot (location_t loc, tree fndecl,
-		    tree arg0, tree arg1, tree type)
+fold_builtin_hypot (location_t loc, tree arg0, tree arg1, tree type)
 {
-  tree res, narg0, narg1;
+  tree res;
 
   if (!validate_arg (arg0, REAL_TYPE)
       || !validate_arg (arg1, REAL_TYPE))
@@ -8160,16 +8085,6 @@ fold_builtin_hypot (location_t loc, tree fndecl,
   if ((res = do_mpfr_arg2 (arg0, arg1, type, mpfr_hypot)))
     return res;
 
-  /* If either argument to hypot has a negate or abs, strip that off.
-     E.g. hypot(-x,fabs(y)) -> hypot(x,y).  */
-  narg0 = fold_strip_sign_ops (arg0);
-  narg1 = fold_strip_sign_ops (arg1);
-  if (narg0 || narg1)
-    {
-      return build_call_expr_loc (loc, fndecl, 2, narg0 ? narg0 : arg0,
-			      narg1 ? narg1 : arg1);
-    }
-
   /* If either argument is zero, hypot is fabs of the other.  */
   if (real_zerop (arg0))
     return fold_build1_loc (loc, ABS_EXPR, type, arg1);
@@ -8274,14 +8189,6 @@ fold_builtin_pow (location_t loc, tree fndecl, tree arg0, tree arg1, tree type)
 	      if (flag_unsafe_math_optimizations || !inexact)
 		return build_real (type, x);
 	    }
-
-	  /* Strip sign ops from even integer powers.  */
-	  if ((n & 1) == 0 && flag_unsafe_math_optimizations)
-	    {
-	      tree narg0 = fold_strip_sign_ops (arg0);
-	      if (narg0)
-		return build_call_expr_loc (loc, fndecl, 2, narg0, arg1);
-	    }
 	}
     }
 
@@ -8729,11 +8636,8 @@ fold_builtin_signbit (location_t loc, tree arg, tree type)
    be made.  */
 
 static tree
-fold_builtin_copysign (location_t loc, tree fndecl,
-		       tree arg1, tree arg2, tree type)
+fold_builtin_copysign (location_t loc, tree arg1, tree arg2, tree type)
 {
-  tree tem;
-
   if (!validate_arg (arg1, REAL_TYPE)
       || !validate_arg (arg2, REAL_TYPE))
     return NULL_TREE;
@@ -8764,11 +8668,6 @@ fold_builtin_copysign (location_t loc, tree fndecl,
 			     fold_build1_loc (loc, ABS_EXPR, type, arg1),
 			     arg2);
 
-  /* Strip sign changing operations for the first argument.  */
-  tem = fold_strip_sign_ops (arg1);
-  if (tem)
-    return build_call_expr_loc (loc, fndecl, 2, tem, arg2);
-
   return NULL_TREE;
 }
 
@@ -9669,10 +9568,16 @@ fold_builtin_1 (location_t loc, tree fndecl, tree arg0)
     break;
 
     CASE_FLT_FN (BUILT_IN_CCOS):
-      return fold_builtin_ccos (loc, arg0, type, fndecl, /*hyper=*/ false);
+      if (validate_arg (arg0, COMPLEX_TYPE)
+	  && TREE_CODE (TREE_TYPE (TREE_TYPE (arg0))) == REAL_TYPE)
+	return do_mpc_arg1 (arg0, type, mpc_cos);
+      break;
 
     CASE_FLT_FN (BUILT_IN_CCOSH):
-      return fold_builtin_ccos (loc, arg0, type, fndecl, /*hyper=*/ true);
+      if (validate_arg (arg0, COMPLEX_TYPE)
+	  && TREE_CODE (TREE_TYPE (TREE_TYPE (arg0))) == REAL_TYPE)
+	return do_mpc_arg1 (arg0, type, mpc_cosh);
+      break;
 
     CASE_FLT_FN (BUILT_IN_CPROJ):
       return fold_builtin_cproj (loc, arg0, type);
@@ -9805,7 +9710,9 @@ fold_builtin_1 (location_t loc, tree fndecl, tree arg0)
     break;
 
     CASE_FLT_FN (BUILT_IN_COS):
-      return fold_builtin_cos (loc, arg0, type, fndecl);
+      if (validate_arg (arg0, REAL_TYPE))
+	return do_mpfr_arg1 (arg0, type, mpfr_cos, NULL, NULL, 0);
+      break;
 
     CASE_FLT_FN (BUILT_IN_TAN):
       return fold_builtin_tan (arg0, type);
@@ -9824,7 +9731,9 @@ fold_builtin_1 (location_t loc, tree fndecl, tree arg0)
     break;
 
     CASE_FLT_FN (BUILT_IN_COSH):
-      return fold_builtin_cosh (loc, arg0, type, fndecl);
+      if (validate_arg (arg0, REAL_TYPE))
+	return do_mpfr_arg1 (arg0, type, mpfr_cosh, NULL, NULL, 0);
+      break;
 
     CASE_FLT_FN (BUILT_IN_TANH):
       if (validate_arg (arg0, REAL_TYPE))
@@ -10078,7 +9987,7 @@ fold_builtin_2 (location_t loc, tree fndecl, tree arg0, tree arg1)
     break;
 
     CASE_FLT_FN (BUILT_IN_HYPOT):
-      return fold_builtin_hypot (loc, fndecl, arg0, arg1, type);
+      return fold_builtin_hypot (loc, arg0, arg1, type);
 
     CASE_FLT_FN (BUILT_IN_CPOW):
       if (validate_arg (arg0, COMPLEX_TYPE)
@@ -10134,7 +10043,7 @@ fold_builtin_2 (location_t loc, tree fndecl, tree arg0, tree arg1)
       return fold_builtin_powi (loc, fndecl, arg0, arg1, type);
 
     CASE_FLT_FN (BUILT_IN_COPYSIGN):
-      return fold_builtin_copysign (loc, fndecl, arg0, arg1, type);
+      return fold_builtin_copysign (loc, arg0, arg1, type);
 
     CASE_FLT_FN (BUILT_IN_FMIN):
       return fold_builtin_fmin_fmax (loc, arg0, arg1, type, /*max=*/false);

gcc/fold-const.c

@@ -7803,15 +7803,6 @@ fold_unary_loc (location_t loc, enum tree_code code, tree type, tree op0)
 						  TREE_TYPE (targ0),
 						  targ0));
 	}
-
-      /* Strip sign ops from argument.  */
-      if (TREE_CODE (type) == REAL_TYPE)
-	{
-	  tem = fold_strip_sign_ops (arg0);
-	  if (tem)
-	    return fold_build1_loc (loc, ABS_EXPR, type,
-				fold_convert_loc (loc, type, tem));
-	}
       return NULL_TREE;
 
     case BIT_NOT_EXPR:
@@ -9859,17 +9850,6 @@ fold_binary_loc (location_t loc,
 	}
       else
 	{
-          /* Strip sign operations from X in X*X, i.e. -Y*-Y -> Y*Y.  */
-	  if (operand_equal_p (arg0, arg1, 0))
-	    {
-	      tree tem = fold_strip_sign_ops (arg0);
-	      if (tem != NULL_TREE)
-		{
-		  tem = fold_convert_loc (loc, type, tem);
-		  return fold_build2_loc (loc, MULT_EXPR, type, tem, tem);
-		}
-	    }
-
 	  /* Fold z * +-I to __complex__ (-+__imag z, +-__real z).
 	     This is not the same for NaNs or if signed zeros are
 	     involved.  */
@@ -14252,82 +14232,6 @@ ptr_difference_const (tree e1, tree e2, HOST_WIDE_INT *diff)
   return true;
 }
 
-/* Simplify the floating point expression EXP when the sign of the
-   result is not significant.  Return NULL_TREE if no simplification
-   is possible.  */
-
-tree
-fold_strip_sign_ops (tree exp)
-{
-  tree arg0, arg1;
-  location_t loc = EXPR_LOCATION (exp);
-
-  switch (TREE_CODE (exp))
-    {
-    case ABS_EXPR:
-    case NEGATE_EXPR:
-      arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 0));
-      return arg0 ? arg0 : TREE_OPERAND (exp, 0);
-
-    case MULT_EXPR:
-    case RDIV_EXPR:
-      if (HONOR_SIGN_DEPENDENT_ROUNDING (element_mode (exp)))
-	return NULL_TREE;
-      arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 0));
-      arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
-      if (arg0 != NULL_TREE || arg1 != NULL_TREE)
-	return fold_build2_loc (loc, TREE_CODE (exp), TREE_TYPE (exp),
-			    arg0 ? arg0 : TREE_OPERAND (exp, 0),
-			    arg1 ? arg1 : TREE_OPERAND (exp, 1));
-      break;
-
-    case COMPOUND_EXPR:
-      arg0 = TREE_OPERAND (exp, 0);
-      arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
-      if (arg1)
-	return fold_build2_loc (loc, COMPOUND_EXPR, TREE_TYPE (exp), arg0, arg1);
-      break;
-
-    case COND_EXPR:
-      arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
-      arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 2));
-      if (arg0 || arg1)
-	return fold_build3_loc (loc,
-			    COND_EXPR, TREE_TYPE (exp), TREE_OPERAND (exp, 0),
-			    arg0 ? arg0 : TREE_OPERAND (exp, 1),
-			    arg1 ? arg1 : TREE_OPERAND (exp, 2));
-      break;
-
-    case CALL_EXPR:
-      {
-	const enum built_in_function fcode = builtin_mathfn_code (exp);
-	switch (fcode)
-	{
-	CASE_FLT_FN (BUILT_IN_COPYSIGN):
-	  /* Strip copysign function call, return the 1st argument. */
-	  arg0 = CALL_EXPR_ARG (exp, 0);
-	  arg1 = CALL_EXPR_ARG (exp, 1);
-	  return omit_one_operand_loc (loc, TREE_TYPE (exp), arg0, arg1);
-
-	default:
-	  /* Strip sign ops from the argument of "odd" math functions.  */
-	  if (negate_mathfn_p (fcode))
-            {
-	      arg0 = fold_strip_sign_ops (CALL_EXPR_ARG (exp, 0));
-	      if (arg0)
-		return build_call_expr_loc (loc, get_callee_fndecl (exp), 1, arg0);
-	    }
-	  break;
-	}
-      }
-      break;
-
-    default:
-      break;
-    }
-  return NULL_TREE;
-}
-
 /* Return OFF converted to a pointer offset type suitable as offset for
    POINTER_PLUS_EXPR.  Use location LOC for this conversion.  */
 tree

gcc/fold-const.h

@@ -107,7 +107,6 @@ extern tree build_fold_addr_expr_loc (location_t, tree);
         build_fold_addr_expr_with_type_loc (UNKNOWN_LOCATION, (T), TYPE)
 extern tree build_fold_addr_expr_with_type_loc (location_t, tree, tree);
 extern tree fold_build_cleanup_point_expr (tree type, tree expr);
-extern tree fold_strip_sign_ops (tree);
 #define build_fold_indirect_ref(T)\
         build_fold_indirect_ref_loc (UNKNOWN_LOCATION, T)
 extern tree build_fold_indirect_ref_loc (location_t, tree);

gcc/testsuite/ChangeLog

 2015-10-21  Richard Sandiford  <richard.sandiford@arm.com>
 
+	* gcc.dg/torture/builtin-symmetric-1.c: Don't run at -O0.
+
+2015-10-21  Richard Sandiford  <richard.sandiford@arm.com>
+
 	* gcc.dg/tree-ssa/backprop-1.c, gcc.dg/tree-ssa/backprop-2.c,
 	gcc.dg/tree-ssa/backprop-3.c, gcc.dg/tree-ssa/backprop-4.c,
 	gcc.dg/tree-ssa/backprop-5.c, gcc.dg/tree-ssa/backprop-6.c: New tests.

gcc/testsuite/gcc.dg/torture/builtin-symmetric-1.c

@@ -7,6 +7,7 @@
 
 /* { dg-do link } */
 /* { dg-options "-ffast-math" } */
+/* { dg-skip-if "" { *-*-* } { "-O0" } { "" } } */
 
 /* All references to link_error should go away at compile-time.  */
 extern void link_error(int);