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From: "Maciej W. Rozycki" <>
To: Joseph Faulls <>
Cc: "" <>,
	 "" <>,
	 "" <>
Subject: RE: [EXTERNAL] Re: [PATCH] RISC-V: Do not gp relax against an ABS symbol if it is far away.
Date: Tue, 8 Aug 2023 13:04:05 +0100 (BST)	[thread overview]
Message-ID: <> (raw)
In-Reply-To: <LO4P265MB59144C9A915B70461B7A7012800DA@LO4P265MB5914.GBRP265.PROD.OUTLOOK.COM>

On Tue, 8 Aug 2023, Joseph Faulls wrote:

> > What's the use case for using AUIPC/LW to load an absolute symbol?  
> > Such symbols are not used in contexts where an address could 
> > alternatively be expected, so the correct sequence, and in PIC or PIE 
> > code indeed the only valid, for direct references from code is 
> For my clarification, are you saying that the AUIPC/LW should never have 
> been generated? If so, how is it possible for the compiler to know that 
> the symbol referenced will be an absolute symbol?

 No, the compiler won't ever know that a reference will ultimately resolve 
to an absolute symbol; I don't think there's a way to tell it.  Then such 
symbols aren't usually used in compiled code as they are awkward to refer 
to (e.g. in C you'll only ever use `&symbol' to get at one).  Most often 
I'd expect them to be referred in handcoded assembly, via the LI macro, 
and possibly defined via the GAS's or LD's `--defsym' command-line option, 
or in a linker script.


  reply	other threads:[~2023-08-08 12:04 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-07-27 16:48 Joseph Faulls
2023-07-27 17:02 ` Andreas Schwab
2023-07-27 21:08 ` Palmer Dabbelt
2023-07-28  1:02   ` Nelson Chu
2023-07-28  1:15     ` Nelson Chu
2023-07-28  9:18       ` [EXTERNAL] " Joseph Faulls
2023-07-28 15:03         ` Palmer Dabbelt
2023-07-28 15:52           ` Joseph Faulls
2023-07-28 16:12             ` Palmer Dabbelt
2023-08-08  9:49 ` Maciej W. Rozycki
2023-08-08 10:38   ` [EXTERNAL] " Joseph Faulls
2023-08-08 12:04     ` Maciej W. Rozycki [this message]
2023-08-23 11:16     ` Joseph Faulls

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