c/7696: Spurious shift warning

[Falk Hueffner]

The following reply was made to PR c/7696; it has been noted by GNATS.

From: Falk Hueffner <falk.hueffner@student.uni-tuebingen.de>
To: "Christian Ehrhardt" <ehrhardt@mathematik.uni-ulm.de>
Cc: gcc-gnats@gcc.gnu.org, schwab@suse.de, gcc-bugs@gcc.gnu.org,
   nobody@gcc.gnu.org, gcc-prs@gcc.gnu.org
Subject: Re: c/7696: Spurious shift warning
Date: 06 Apr 2003 16:50:37 +0200

 "Christian Ehrhardt" <ehrhardt@mathematik.uni-ulm.de> writes:
 
 >                struct ia64_psr {
 >                  unsigned long cpl : 2;
 >                } x = {1};
 > 		
 >                  unsigned long y =  ((unsigned long) x.cpl) << 40;
 > 
 > According to gdb the cast is thrown away early (build_binary_op
 > doesn't see it at all), probably because the bitfield is of type
 > unsigned long.
 
 All casts of bit-fields to the same type get discarded. This is a very
 long standing bug and has already been reported as c/3325, c/3326,
 c/6346, c/6515 and target/9620. We also have xfailing
 gcc.c-torture/execute/bitfld-1.c for it.
 
 -- 
 	Falk