Re: i386-G++ ICE in output_operand with static and -fPIC

[Michael Eager <eager at eagercon dot com>]

Jim Wilson wrote:
> Michael Eager wrote:
>
> > the following error is generated:
> >   x.cpp: In function `int ListNextX()':
> >   x.cpp:19: output_operand: Wrong address expression or operand 
> > constraint
> >
> > Can someone help me out here?  Where should I be looking?
>
>
> Use -da to get all of the debugging dumps, and then search them to find 
> where the error first occurs, then debug that optimization pass to 
> figure out why it creates bad RTL.  Also check the 
> GO_IF_LEGITIMATE_ADDRESS macro to make sure it is correct.  This might 
> be a problem with a pseudo being accepted someplace where only hard 
> registers are OK.  If a pseudo doesn't get allocated to a hard register 
> by the register allocator, then it becomes a stack slot reference, and 
> then you have an address that isn't valid.

Thanks for the suggestions.  I have been comparing the RTL generated
with and without static.  Unfortunately, nothing has looked obviously in
error.  I'll look for a pseudo and stack ref.

> If the problem doesn't exist in current sources, then you might be able 
> to find the patch that fixed it by doing a binary search over time. This 
> assumes that it is a relatively simple problem that was fixed by a 
> single patch.  This doesn't work in every case.

Yep, that's my next step -- see what the current sources generate for
the same code and track down what is different.


--
Michael Eager	 Eager Consulting     eager@eagercon.com
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