This patch (also applicable to trunk) makes us canoncialize operand
order for comparisons at the same time we canonicalize other
operand order, in particular before dispatching to generic_simplify.
It also adds operand canonicalization to ternary ops and adds
FMA_EXPR and DOT_PROD_EXPR to the list of ternary commutative ops.
Bootstrap and regtest running on match-and-simplify branch and
x86_64-unknown-linux-gnu.
Richard.
2014-10-16 Richard Biener <rguent...@suse.de>
* fold-const.c (fold_comparison): Remove redundant constant
folding and operand swapping.
(fold_binary_loc): Do comparison operand swapping here,
dispatch to generic_simplify after operand canonicalization.
(fold_ternary_loc): Canonicalize operand order for
commutative ternary operations.
* tree.c (commutative_ternary_tree_code): Add DOT_PROD_EXPR
and FMA_EXPR.
Index: gcc/fold-const.c
===================================================================
--- gcc/fold-const.c (revision 216262)
+++ gcc/fold-const.c (working copy)
@@ -8726,14 +8726,6 @@ fold_comparison (location_t loc, enum tr
STRIP_SIGN_NOPS (arg0);
STRIP_SIGN_NOPS (arg1);
- tem = fold_relational_const (code, type, arg0, arg1);
- if (tem != NULL_TREE)
- return tem;
-
- /* If one arg is a real or integer constant, put it last. */
- if (tree_swap_operands_p (arg0, arg1, true))
- return fold_build2_loc (loc, swap_tree_comparison (code), type, op1, op0);
-
/* Transform comparisons of the form X +- C1 CMP C2 to X CMP C2 -+ C1. */
if ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
&& (equality_code || TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg0)))
@@ -9914,17 +9906,23 @@ fold_binary_loc (location_t loc,
}
}
- extern tree generic_simplify (enum tree_code, tree, tree, tree);
- tem = generic_simplify (code, type, op0, op1);
- if (tem)
- return tem;
-
/* If this is a commutative operation, and ARG0 is a constant, move it
to ARG1 to reduce the number of tests below. */
if (commutative_tree_code (code)
&& tree_swap_operands_p (arg0, arg1, true))
return fold_build2_loc (loc, code, type, op1, op0);
+ /* Likewise if this is a comparison, and ARG0 is a constant, move it
+ to ARG1 to reduce the number of tests below. */
+ if (kind == tcc_comparison
+ && tree_swap_operands_p (arg0, arg1, true))
+ return fold_build2_loc (loc, swap_tree_comparison (code), type, op1, op0);
+
+ extern tree generic_simplify (enum tree_code, tree, tree, tree);
+ tem = generic_simplify (code, type, op0, op1);
+ if (tem)
+ return tem;
+
/* ARG0 is the first operand of EXPR, and ARG1 is the second operand.
First check for cases where an arithmetic operation is applied to a
@@ -13809,6 +13807,12 @@ fold_ternary_loc (location_t loc, enum t
gcc_assert (IS_EXPR_CODE_CLASS (kind)
&& TREE_CODE_LENGTH (code) == 3);
+ /* If this is a commutative operation, and OP0 is a constant, move it
+ to OP1 to reduce the number of tests below. */
+ if (commutative_ternary_tree_code (code)
+ && tree_swap_operands_p (op0, op1, true))
+ return fold_build3_loc (loc, code, type, op1, op0, op2);
+
extern tree generic_simplify (enum tree_code, tree, tree, tree, tree);
tem = generic_simplify (code, type, op0, op1, op2);
if (tem)
Index: gcc/tree.c
===================================================================
--- gcc/tree.c (revision 216244)
+++ gcc/tree.c (working copy)
@@ -7380,6 +7380,8 @@ commutative_ternary_tree_code (enum tree
{
case WIDEN_MULT_PLUS_EXPR:
case WIDEN_MULT_MINUS_EXPR:
+ case DOT_PROD_EXPR:
+ case FMA_EXPR:
return true;
default:
