[PATCH v5 02/14] canonicalize binops before simplification

[Luc Van Oostenryck <luc.vanoostenryck@gmail.com>]

Currently, canonicalization of binops (more specifically
insuring that the operands of binops are in canonical order)
is only done after simplify_binop(). But the goal of
canonicalization is to limit the number of cases/patterns
we need to check/handle during ... simplification.
So canonicalization need to be done before simplification.

Fix this by moving (this part of) canonicalization before
doing simplification.

Note 1: the motivation of this patch is to prepare code for
        the canonicalization of compare instructions

Note 2: this patch allow now some simplification of ...
        the simplification code (simplify_binop()), this
	will be done in a later serie.

Note 3: this patch changes slightly the cost of the CSE/
	simplification, positively or negatively, depending
	on the ration of simplification/canonicalization
	that can be done.

Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
---
 simplify.c | 20 +++++++++-----------
 1 file changed, 9 insertions(+), 11 deletions(-)

diff --git a/simplify.c b/simplify.c
index 5d00937f1..66035bbce 100644
--- a/simplify.c
+++ b/simplify.c
@@ -735,13 +735,13 @@ static int canonical_order(pseudo_t p1, pseudo_t p2)
 	return 1;
 }
 
-static int simplify_commutative_binop(struct instruction *insn)
+static int canonicalize_commutative(struct instruction *insn)
 {
-	if (!canonical_order(insn->src1, insn->src2)) {
-		switch_pseudo(insn, &insn->src1, insn, &insn->src2);
-		return REPEAT_CSE;
-	}
-	return 0;
+	if (canonical_order(insn->src1, insn->src2))
+		return 0;
+
+	switch_pseudo(insn, &insn->src1, insn, &insn->src2);
+	return repeat_phase |= REPEAT_CSE;
 }
 
 static inline int simple_pseudo(pseudo_t pseudo)
@@ -1129,17 +1129,15 @@ int simplify_instruction(struct instruction *insn)
 	case OP_ADD: case OP_MULS:
 	case OP_AND: case OP_OR: case OP_XOR:
 	case OP_AND_BOOL: case OP_OR_BOOL:
+		canonicalize_commutative(insn);
 		if (simplify_binop(insn))
 			return REPEAT_CSE;
-		if (simplify_commutative_binop(insn))
-			return REPEAT_CSE;
 		return simplify_associative_binop(insn);
 
 	case OP_MULU:
 	case OP_SET_EQ: case OP_SET_NE:
-		if (simplify_binop(insn))
-			return REPEAT_CSE;
-		return simplify_commutative_binop(insn);
+		canonicalize_commutative(insn);
+		return simplify_binop(insn);
 
 	case OP_SUB:
 	case OP_DIVU: case OP_DIVS:
-- 
2.12.0