On Wed, 29 Jul 2015, Richard Biener wrote:
The following fixes PR67053 by more closely mirror what fold_binary()s
STRIP_NOPS does to avoid the C++ FE constexpr code to regress.
Bootstrapped on x86_64-unknown-linux-gnu, testing in progress.
Yes, I'm thinking on an automated way to more closely mirror
STRIP_[SIGN_]NOPS behavior (on toplevel args).
As far as I can see, you are not currently checking that these conversions
are NOPs. I didn't test, but I am afraid this may simplify
(char)p1==(char)p2 to false a bit too quickly.
Richard.
2015-07-29 Richard Biener <rguent...@suse.de>
PR middle-end/67053
* match.pd: Allow both operands to independently have conversion
when simplifying compares of addresses.
Index: gcc/match.pd
===================================================================
--- gcc/match.pd (revision 226345)
+++ gcc/match.pd (working copy)
@@ -1814,7 +1814,7 @@ (define_operator_list CBRT BUILT_IN_CBRT
enough to make fold_stmt not regress when not dispatching to fold_binary. */
(for cmp (simple_comparison)
(simplify
- (cmp (convert?@2 addr@0) (convert? addr@1))
+ (cmp (convert1?@2 addr@0) (convert2? addr@1))
(with
{
HOST_WIDE_INT off0, off1;
--
Marc Glisse
