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From: "Weiming Zhao" <weimingz@codeaurora.org>
To: <musl@lists.openwall.com>
Cc: <weimingz@codeaurora.org>
Subject: question about malloc's bin_index
Date: Wed, 19 Nov 2014 18:43:23 -0800	[thread overview]
Message-ID: <003001d0046b$c0d0de30$42729a90$@codeaurora.org> (raw)

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Hi,

 

I'm trying to use MUSL on a hardware without floating point unit, however,
the "union" in the bin_index brings some issues.

I'm using -mgeneral-regs-only and gcc refuses to compile it due to the
floating point conversion.

 

I'm wondering what's the purpose of the union? How should I rewrite it to
use integer only?

 

static int bin_index(size_t x)

{

                x = x / SIZE_ALIGN - 1;

                if (x <= 32) return x;

                if (x > 0x1c00) return 63;

                return ((union { float v; uint32_t r; }){(int)x}.r>>21) -
496;  

}

 

Thanks a lot,

Weiming

 

Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, 
a Linux Foundation Collaborative Project

 


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             reply	other threads:[~2014-11-20  2:43 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-11-20  2:43 Weiming Zhao [this message]
2014-11-20  4:06 ` Rich Felker
2014-11-20  6:32   ` Szabolcs Nagy
2014-11-20  4:47 ` weimingz

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