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Subject: Re: [PATCH] c++/67376 Comparison with pointer to past-the-end, of array fails inside constant expression
To: Martin Sebor <msebor@gmail.com>, Jeff Law <law@redhat.com>,        Gcc Patch List <gcc-patches@gcc.gnu.org>
References: <56E72C33.8000301@gmail.com> <56E9B9C3.5000908@redhat.com> <56EB1ECA.90800@gmail.com> <56EC3500.4030701@redhat.com> <56F03567.8040306@redhat.com> <56F07137.1050400@redhat.com> <56F19456.3030900@redhat.com> <56F1A494.1060407@gmail.com> <56F2EC3C.5000606@redhat.com> <56F9AA63.4090201@gmail.com>
Cc: Marek Polacek <polacek@redhat.com>, Jakub Jelinek <jakub@redhat.com>
From: Jason Merrill <jason@redhat.com>
Message-ID: <56FACF51.5000407@redhat.com>
Date: Tue, 29 Mar 2016 19:07:00 -0000
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On 03/28/2016 06:04 PM, Martin Sebor wrote:
> +	       && compare_tree_int (arg1, 0) == 0)

This can be integer_zerop.

> +	    case GE_EXPR:
> +	    case EQ_EXPR:
> +	    case LE_EXPR:
> +	      return boolean_false_node;
> +	    case GT_EXPR:
> +	    case LT_EXPR:
> +	    case NE_EXPR:
> +	      return boolean_true_node;

EQ and NE make sense, but I would expect both > and >= to be true, < and 
<= to be false.

Are we confident that arr[0] won't make it here as POINTER_PLUS_EXPR or 
some such?

Jason