Thread (5 messages) flat view 5 messages, 3 authors, 2003-01-15

Re: Re: [PATCH]: cfb_imageblit() fix: handle widths not divisible by 8

From: Geert Uytterhoeven <geert@linux-m68k.org>
Date: 2003-01-15 09:29:50

On 15 Jan 2003, Antonino Daplas wrote:
On Wed, 2003-01-15 at 08:26, James Simmons wrote:
quoted
Applied.
quoted
c. Fix for fast_imageblit() so it always refer to mask tables in 32-bits
which should make it work for 64-bit machines.
Ug. I rather try yo take advantge of using the full 64 bits of data to 
pass across the bus. What I was think is treat the 64 bit case as two 32 
bit cases. The 64 bit data comes in and we run the data twice at tabs[].
Hi James,

Yes, I was trying to find a way to make fast_imageblit() be fast for all
machine architectures.  With the patch attached, there's
fast_imageblit32() and fast_imageblit64().  fast_imageblit32() is
probably slower than fast_imageblit64 on 64-bit machines and, on the
other hand, fast_imageblit64() is 20% slower on 32-bit machines, but is
probably faster on 64-bit and higher machines.  So, the only way I can
think of doing this on all machine architectures is to have them go
separate paths.
Can't you merge fast_imageblit32() and fast_imageblit64() a bit more (with some
#ifdef's), and just call the result fast_imageblit()? Then the definition of
FAST_IMAGEBLIT can go away.

u32 is the same as unsigned long if BITS_PER_LONG == 32.

Gr{oetje,eeting}s,

						Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
							    -- Linus Torvalds




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