[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Lightning] sse instructions and gcc warnings

From: Paolo Bonzini
Subject: Re: [Lightning] sse instructions and gcc warnings
Date: Mon, 26 Jul 2010 10:34:39 +0200
User-agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv: Gecko/20100621 Fedora/3.0.5-1.fc13 Lightning/1.0b2pre Thunderbird/3.0.5

On 07/26/2010 09:49 AM, Paulo César Pereira de Andrade wrote:
   This started happening when I added calls to jit_str_c, jit_str_uc,
etc, and apparently doesn't happen if there are only calls to
jit_stxi_s, jit_stxi_us, etc, but I am not 100% sure now.

Yes, jit_str_c and jit_str_uc are indeed responsible.

    Also about @subject, I needed to add a global function to check
if a double is zero, because apparently the i387 goes nonsense if
a function using vector instructions was called.

Argument passing in i387 was buggy, it is kind of impossible to get it
right due to the stack-like registers. :(

I think I'm going to change it to use SSE always except for argument
passing.  Would this be a problem?

   I think x86 non sse processors are not manufactured for several
years, but probably better to require SSE2 or lower

Yes, of couse.

As long as it
works, I don't have any objections :-) One thing I noticed is that
on x86_64, -0.0 literal looses sign when loaded/stored using



reply via email to

[Prev in Thread] Current Thread [Next in Thread]