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["Stephen M. Webb" <stephen.webb@xxxxxxxxxxxxx>]

The default 32-bit Intel compile flags in Ubuntu are for Pentium III
(i586) or later, which all provide SSE instructions.  The Sempron line
of GPUs from AMD have all supported SSE instructions, although some of
the earlier ones do not support SSE2/SSE3 extensions.  I myself have a
system with an Athlon 3000+ (predecessor to the Sempron) on which Compiz
runs just peachy, but I run a 64-bit image.

Compiz does not explicitly include any Intel-specific intrinsics or
assembly code, so does not invoke SSE instructions directly.  It's
possible that SSE instructions are introduced by the compiler where the
optimizer says it's advantageous, or linked in from a dynamically-loaded
shared object such as an image decoder library or user-space video
driver.  WIthout examining the core dump it is not possible to say what
the cause of this crash was.

Please try attaching the relevant crash information to this bug by using
the terminal command "apport-collect 1409608".  We might be able to dive
a little deeper with more information.

** Changed in: compiz (Ubuntu)
   Importance: Undecided => Medium

** Changed in: compiz (Ubuntu)
       Status: New => Incomplete

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https://bugs.launchpad.net/bugs/1409608

Title:
  The 32-bit i386 install executes SSE instructions.

Status in compiz package in Ubuntu:
  Incomplete

Bug description:
  I tried to install the 32-bit ubuntu-14.04.1-desktop-i386.iso on an
  older, but working computer with a 2 GHz AMD Sempron processor with 4
  GiB of RAM.  This system would seem to handily exceed the system
  requirements.  By "working", I mean that it has been running Windows
  XP for years.

  The distribution did not install a graphics driver for the integrated
  graphics chip, so I installed an AMD/ATI video card, downloaded the
  latest driver from the AMD web site, and installed the driver.

  On reboot, the system crashed while initializing the desktop.  The
  apport bug report tool was launched, but as far as I can tell it did
  not upload the crash report.  I'm not sure why.

  Before clicking on "send", I browsed thru the report details.   It
  said the internal error was in /usr/bin/compiz.  Further down in the
  report was a disassembly of a code fragment which showed instructions
  from the SSE extensions to the x86 instruction set.

  The AMD Sempron processor does not support SSE extensions to the
  architecture.   Executing code that contains those instructions on
  this type of processor will result in an illegal instruction
  exception.

  I don't know if compiz was compiled with the wrong compiler flags for
  i386, or if it contains optimization that assumed the extensions were
  present instead of checking the appropriate CPUID feature bits.

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