Re: target/3925: [ARM/Thumb] Assembler chokes on branches with (PLT)

[Philip Blundell <pb@nexus.co.uk>]

The following reply was made to PR target/3925; it has been noted by GNATS.

From: Philip Blundell <pb@nexus.co.uk>
To: Richard Earnshaw <rearnsha@arm.com>
Cc: gcc-gnats@gcc.gnu.org, pb@gcc.gnu.org, fnf@ninemoons.com, 
	gcc-bugs@gcc.gnu.org, rearnsha@gcc.gnu.org
Subject: Re: target/3925: [ARM/Thumb] Assembler chokes on branches with (PLT)
Date: 19 Mar 2002 11:50:08 +0000

 On Tue, 2002-03-19 at 11:09, Richard Earnshaw wrote:
 > Even if it could be shown that the two relocation types must be
 > different, then there is no reason for annotating the label in this
 > way.  When assembling PIC code all BL type instructions should generate
 > a PLT32 relocation (assuming any relocation is required at all) and when
 > not generating PIC code all BL type instructions should generate an
 > arm24 relocation.  Hence it is possible to determine the relocation type
 > required simply by the presence of the -k flag on the assembler command
 > line: no annotation of the labels is required.
 
 Yes, quite.
 
 There's no reason that -k couldn't cause the assembler to emit all
 branches as PLT32 relocs rather than PC24.  It just happens that Pat and
 Scott chose to follow the example of the i386-linux port, where the
 assembler just ignores -k altogether and the compiler adds "@plt"
 decorations to call instructions.
 
 I don't see any particularly compelling arguments for either approach
 over the other, to be honest.  It would be easy enough to make gas take
 notice of -k, and then gcc could do whatever it likes.
 
 p.