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From: Trevor Scroggins <trevor.scroggins@gmail.com>
To: gcc@gcc.gnu.org
Subject: CONSTANT_POOL_BEFORE_FUNCTION has no effect in tm.h?
Date: Sun, 05 Jul 2009 20:56:00 -0000	[thread overview]
Message-ID: <ca05b9360907051356u109be34fo77e478519a5ecc9b@mail.gmail.com> (raw)

Hello, all. I'm attempting to port GCC 4.4.0 to a new m68k target. The
target begins execution in the first byte of the first text section.
Adding '#define CONSTANT_POOL_BEFORE_FUNCTION 0' in my target's tm.h
seems like the simplest way to avoid execution of read-only data;
however, defining the constant has no effect on compilation. (Note,
custom or missing startup code is common, so I can't work around it
there.)

The only references to CONSTANT_POOL_BEFORE_FUNCTION are in varasm.c,
and the only target current using the definition is pdp11--not exactly
current. Is CONSTANT_POOL_BEFORE_FUNCTION still being used, or have I
hit upon a section of dead code? Is there a simple way to relocate
read-only data to the end of a function without writing a
target-specific reorg routine? Jumping over the data in a prologue
might be an easy, quick and dirty solution, but the target is a
memory-constrained system, and that seems wasteful.

Thanks,

Trev

             reply	other threads:[~2009-07-05 20:56 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-07-05 20:56 Trevor Scroggins [this message]
2009-07-06  6:14 ` Ian Lance Taylor
2009-07-06 16:29   ` Trevor Scroggins
2009-07-06 17:01     ` Ian Lance Taylor
2009-07-06 17:11       ` Trevor Scroggins
2009-07-06 18:29         ` Trevor Scroggins
2009-07-06 18:45           ` Ian Lance Taylor
2009-07-10 22:19             ` Trevor Scroggins
2009-07-10 22:20               ` Fwd: " Trevor Scroggins
2009-07-10 23:38               ` Ian Lance Taylor
2009-07-10 23:48                 ` Trevor Scroggins

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