Hi,
This is a follow up patch for
https://gcc.gnu.org/ml/gcc-patches/2016-11/msg01898.html
It moves remaining simplification for (A == C1) ? A : C2 in
fold_cond_expr_with_comparison
to match.pd. Bootstrap and test on x86_64 and AArch64, is it OK?
Thanks,
bin
2016-11-17 Bin Cheng <bin.ch...@arm.com>
* fold-const.c (fold_cond_expr_with_comparison): Move simplification
for A == C1 ? A : C2 to below.
* match.pd: Move from above to here:
(cond (eq (convert1? x) c1) (convert2? x) c2)
-> (cond (eq x c1) c1 c2).diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index 1e61ccf..1877dac 100644
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -5210,19 +5210,6 @@ fold_cond_expr_with_comparison (location_t loc, tree
type,
}
}
- /* If this is A == C1 ? A : C2 with C1 and C2 constant integers,
- we simplify it into A == C1 ? C1 : C2. */
-
- if (comp_code == EQ_EXPR
- && INTEGRAL_TYPE_P (type)
- && TREE_CODE (arg01) == INTEGER_CST
- && TREE_CODE (arg1) != INTEGER_CST
- && TREE_CODE (arg2) == INTEGER_CST)
- {
- arg1 = fold_convert_loc (loc, type, arg01);
- return fold_build3_loc (loc, COND_EXPR, type, arg0, arg1, arg2);
- }
-
return NULL_TREE;
}
diff --git a/gcc/match.pd b/gcc/match.pd
index 4beac4e..a8d94de 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -1939,15 +1939,21 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
/* Simplification moved from fold_cond_expr_with_comparison. It may also
be extended. */
-/* (cond (cmp (convert1? x) c1) (convert2? x) c2) -> (minmax (x c)) if:
+/* This pattern implements two kinds simplification:
+
+ Case 1)
+ (cond (cmp (convert1? x) c1) (convert2? x) c2) -> (minmax (x c)) if:
1) Conversions are type widening from smaller type.
2) Const c1 equals to c2 after canonicalizing comparison.
3) Comparison has tree code LT, LE, GT or GE.
This specific pattern is needed when (cmp (convert x) c) may not
be simplified by comparison patterns because of multiple uses of
x. It also makes sense here because simplifying across multiple
- referred var is always benefitial for complicated cases. */
-(for cmp (lt le gt ge)
+ referred var is always benefitial for complicated cases.
+
+ Case 2)
+ (cond (eq (convert1? x) c1) (convert2? x) c2) -> (cond (eq x c1) c1 c2). */
+(for cmp (lt le gt ge eq)
(simplify
(cond (cmp@0 (convert1? @1) INTEGER_CST@3) (convert2? @1) INTEGER_CST@2)
(with
@@ -1966,37 +1972,45 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
&& (TYPE_UNSIGNED (from_type)
|| TYPE_SIGN (c2_type) == TYPE_SIGN (from_type)))))
{
- if (wi::to_widest (@3) == (wi::to_widest (@2) - 1))
- {
- /* X <= Y - 1 equals to X < Y. */
- if (cmp_code == LE_EXPR)
- code = LT_EXPR;
- /* X > Y - 1 equals to X >= Y. */
- if (cmp_code == GT_EXPR)
- code = GE_EXPR;
- }
- if (wi::to_widest (@3) == (wi::to_widest (@2) + 1))
- {
- /* X < Y + 1 equals to X <= Y. */
- if (cmp_code == LT_EXPR)
- code = LE_EXPR;
- /* X >= Y + 1 equals to X > Y. */
- if (cmp_code == GE_EXPR)
- code = GT_EXPR;
- }
- if (code != cmp_code || wi::to_widest (@2) == wi::to_widest (@3))
+ if (code != EQ_EXPR)
{
- if (cmp_code == LT_EXPR || cmp_code == LE_EXPR)
- code = MIN_EXPR;
- if (cmp_code == GT_EXPR || cmp_code == GE_EXPR)
- code = MAX_EXPR;
+ if (wi::to_widest (@3) == (wi::to_widest (@2) - 1))
+ {
+ /* X <= Y - 1 equals to X < Y. */
+ if (cmp_code == LE_EXPR)
+ code = LT_EXPR;
+ /* X > Y - 1 equals to X >= Y. */
+ if (cmp_code == GT_EXPR)
+ code = GE_EXPR;
+ }
+ if (wi::to_widest (@3) == (wi::to_widest (@2) + 1))
+ {
+ /* X < Y + 1 equals to X <= Y. */
+ if (cmp_code == LT_EXPR)
+ code = LE_EXPR;
+ /* X >= Y + 1 equals to X > Y. */
+ if (cmp_code == GE_EXPR)
+ code = GT_EXPR;
+ }
+ if (code != cmp_code || wi::to_widest (@2) == wi::to_widest (@3))
+ {
+ if (cmp_code == LT_EXPR || cmp_code == LE_EXPR)
+ code = MIN_EXPR;
+ if (cmp_code == GT_EXPR || cmp_code == GE_EXPR)
+ code = MAX_EXPR;
+ }
}
+ /* Can do A == C1 ? A : C2 -> A == C1 ? C1 : C2? */
+ else if (!int_fits_type_p (@3, from_type))
+ code = ERROR_MARK;
}
}
(if (code == MAX_EXPR)
(convert (max @1 (convert:from_type @2)))
(if (code == MIN_EXPR)
- (convert (min @1 (convert:from_type @2))))))))
+ (convert (min @1 (convert:from_type @2)))
+ (if (code == EQ_EXPR)
+ (cond (cmp @1 (convert:from_type @3)) (convert:from_type @3) @2)))))))
(for cnd (cond vec_cond)
/* A ? B : (A ? X : C) -> A ? B : C. */
