[FFmpeg-devel] r9017 breaks WMA decoding on Intel Macs

Guillaume POIRIER poirierg
Mon May 28 00:39:22 CEST 2007


On 5/28/07, Trent Piepho <xyzzy at speakeasy.org> wrote:
> On Sun, 27 May 2007, Guillaume POIRIER wrote:
> >On 5/27/07, Zuxy Meng <zuxy.meng at gmail.com> wrote:
> >> 2007/5/27, Guillaume Poirier <gpoirier at mplayerhq.hu>:
> >
> >> > I guess I'm off to reading the other hunk to figure out what may be
> >> > wrong with it. If I can't figure this out, then I'll have to compare
> >> > the assembler emitted by GCC.
> >>
> >> Then please check things like "8+%0" "-16+%1", replace constraints
> >> from "m" to "r" and rewrite using "8(%0)" "-16(%1)". Maybe Apple's
> >> binutils doesn't like such syntax.
> >
> >I guess I suck at doing such things too. Attached patch is an attempt
> >to do what you suggest, be it doesn't assemble, either on Linux x86-64
> >or OSX x86
> When you change from "m" to "r" you're also changing from the lvalue itself
> to a pointer to the lvalue.
> This results in less efficient code, since you preclude using SIB
> addressing and might need an extra register.  If the apple version of gas
> doesn't like the syntax, it should generate an error.

The said syntax seems to be supported, since there's no error
reported. Trent, you mean that it shouldn't be necessary to replace
"8+%0" "-16+%1", to "8(%0)" "-16(%1)" ?

When I do this change, and this change alone (no "m" to "r" contrain),
it doesn't assemble either.

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Imb?cile et meurtri?re
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  -- Renaud (sur "Miss Maggie")

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