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Re: [PATCH] integer overflow checking builtins in constant expressions

From: Martin Sebor <msebor at gmail dot com>
To: Jakub Jelinek <jakub at redhat dot com>
Cc: Gcc Patch List <gcc-patches at gcc dot gnu dot org>, Jason Merrill <jason at redhat dot com>, "Joseph S. Myers" <joseph at codesourcery dot com>
Date: Fri, 3 Jun 2016 09:29:48 -0600
Subject: Re: [PATCH] integer overflow checking builtins in constant expressions
Authentication-results: sourceware.org; auth=none
References: <57263154 dot 5080401 at gmail dot com> <20160531215025 dot GK28550 at tucnak dot redhat dot com> <574E13DD dot 9040401 at gmail dot com> <20160601075212 dot GL28550 at tucnak dot redhat dot com> <574EFC8F dot 2040400 at gmail dot com> <574FA3BC dot 8090603 at gmail dot com> <20160602072316 dot GY28550 at tucnak dot redhat dot com> <5750BF82 dot 5030203 at gmail dot com> <5750CF25 dot 1080801 at gmail dot com> <20160603070637 dot GA7387 at tucnak dot redhat dot com>

+	{
+	  tree type = TREE_TYPE (TREE_TYPE (t));
+	  tree vflow = arith_overflowed_p (opcode, type, arg0, arg1)
+	               ? integer_one_node : integer_zero_node;


This looks incorrect, the return type is TREE_TYPE (t), some complex integer
type, therefore vflow needs to be
       tree vflow = build_int_cst (TREE_TYPE (TREE_TYPE (t)),
				  arith_overflowed_p (opcode, type, arg0, arg1)
				  ? 1 : 0);
no?


I guess it didn't think it mattered since the complex type specifies
the types of the two members.  I don't mind changing it if it does
but I'd like to have a test case to go with it.  Maybe Jason can
help with that.

Martin

Follow-Ups:
- Re: [PATCH] integer overflow checking builtins in constant expressions
  - From: Jakub Jelinek

References:
- Re: [PATCH] integer overflow checking builtins in constant expressions
  - From: Jakub Jelinek
- Re: [PATCH] integer overflow checking builtins in constant expressions
  - From: Martin Sebor
- Re: [PATCH] integer overflow checking builtins in constant expressions
  - From: Martin Sebor
- Re: [PATCH] integer overflow checking builtins in constant expressions
  - From: Jakub Jelinek
- Re: [PATCH] integer overflow checking builtins in constant expressions
  - From: Martin Sebor
- Re: [PATCH] integer overflow checking builtins in constant expressions
  - From: Martin Sebor
- Re: [PATCH] integer overflow checking builtins in constant expressions
  - From: Jakub Jelinek

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