Hi!
As mentioned in the PR, this optimization can't work if @0's precision
is higher than @1's precision, because originally it compares just some set
of lower bits, but in the new comparison compares all bits.
If @0's precision is smaller than @1's precision (in this case @0 can't be
a pointer, as we disallow such direct casts), then in theory it can be
handled, but will not match what the comment says and we'd need to verify
that the @1 constant can be represented in the @0's precision.
This patch just verifies the precision is the same and does small formatting
cleanup. Bootstrapped/regtested on x86_64-linux and i686-linux, ok for
trunk?
2018-04-18 Jakub Jelinek <ja...@redhat.com>
PR tree-optimization/85446
* match.pd ((intptr_t) x eq/ne CST to x eq/ne (typeof x) cst): Require
the integral and pointer types to have the same precision.
--- gcc/match.pd.jj 2018-04-09 20:15:49.158631652 +0200
+++ gcc/match.pd 2018-04-18 09:55:47.176343913 +0200
@@ -3711,10 +3711,13 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
(for cmp (ne eq)
(simplify
(cmp (convert @0) INTEGER_CST@1)
- (if ((POINTER_TYPE_P (TREE_TYPE (@0)) && !FUNC_OR_METHOD_TYPE_P (TREE_TYPE
(TREE_TYPE (@0)))
- && INTEGRAL_TYPE_P (TREE_TYPE (@1)))
- || (INTEGRAL_TYPE_P (TREE_TYPE (@0)) && POINTER_TYPE_P (TREE_TYPE (@1))
- && !FUNC_OR_METHOD_TYPE_P (TREE_TYPE (TREE_TYPE (@1)))))
+ (if (((POINTER_TYPE_P (TREE_TYPE (@0))
+ && !FUNC_OR_METHOD_TYPE_P (TREE_TYPE (TREE_TYPE (@0)))
+ && INTEGRAL_TYPE_P (TREE_TYPE (@1)))
+ || (INTEGRAL_TYPE_P (TREE_TYPE (@0))
+ && POINTER_TYPE_P (TREE_TYPE (@1))
+ && !FUNC_OR_METHOD_TYPE_P (TREE_TYPE (TREE_TYPE (@1)))))
+ && TYPE_PRECISION (TREE_TYPE (@0)) == TYPE_PRECISION (TREE_TYPE (@1)))
(cmp @0 (convert @1)))))
/* Non-equality compare simplifications from fold_binary */
Jakub
