On Fri, 17 Oct 2014, Richard Biener wrote:
> On Thu, 16 Oct 2014, Jeff Law wrote:
>
> > On 10/16/14 05:06, Richard Biener wrote:
> > >
> > > 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.
> > Seems like something we'd want for the trunk independent of the
> > match-and-simplify work
>
> Yes, I am going to test and apply it there today.
Like below. Bootstrapped on x86_64-unknown-linux-gnu, testing in
progress.
Richard.
2014-10-17 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.
(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 216366)
+++ gcc/fold-const.c (working copy)
@@ -8721,14 +8721,6 @@ 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)))
@@ -9915,6 +9907,12 @@ fold_binary_loc (location_t loc,
&& 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);
+
/* 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
@@ -13799,6 +13797,12 @@ 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);
+
/* Strip any conversions that don't change the mode. This is safe
for every expression, except for a comparison expression because
its signedness is derived from its operands. So, in the latter
Index: gcc/tree.c
===================================================================
--- gcc/tree.c (revision 216366)
+++ gcc/tree.c (working copy)
@@ -7385,6 +7385,8 @@ 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:
