Date: Thu, 5 Oct 2006 15:30:51 +0000 (UTC) From: John Baldwin <jhb@FreeBSD.org> To: src-committers@FreeBSD.org, cvs-src@FreeBSD.org, cvs-all@FreeBSD.org Subject: cvs commit: src/sys/boot/i386/btx/btx btx.S Message-ID: <200610051530.k95FUpjE005483@repoman.freebsd.org>
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jhb 2006-10-05 15:30:51 UTC
FreeBSD src repository
Modified files:
sys/boot/i386/btx/btx btx.S
Log:
- Fix a couple of improper uses of leal in the previous space saving
commits. For some reason I thought the scale factor was a shift count
rather than the multiplicand (that is, I thought leal (%eax,%edx,4) was
going to generate %eax + %edx << 4 rather than %eax + %edx * 4). What
I need is to multiply by 16 to convert a real-mode (seg, offset) tuple
into a flat address. However, the max multiplicand for scaled/index
addressing on i386 is 8, so go back to using a shl and an add.
- Convert two more inter-register mov instructions where we don't need to
preserve the source register to xchg instructions to keep our space
savings.
Tested by: Ian FREISLICH if at hetzner.co.za
MFC after: 1 week
Revision Changes Path
1.43 +7 -5 src/sys/boot/i386/btx/btx/btx.S
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