Re: [PATCH xserver] On x86 targets, turn off SSE instructions for SlowBcopy

2017-07-30 Thread Matt Turner
On Sun, Jul 30, 2017 at 11:49 AM, Dimitry Andric wrote: > Some compilers (e.g. clang) will recognize the memcpy idiom in > xf86SlowBcopy(), and optimize it into a loop using SSE instructions. > This can cause "Illegal instruction" crashes under virtualization > environments

Re: [PATCH xserver] On x86 targets, turn off SSE instructions for SlowBcopy

2017-07-30 Thread Jonathan A. Kollasch
On Sun, Jul 30, 2017 at 08:49:49PM +0200, Dimitry Andric wrote: > Some compilers (e.g. clang) will recognize the memcpy idiom in > xf86SlowBcopy(), and optimize it into a loop using SSE instructions. > This can cause "Illegal instruction" crashes under virtualization > environments such as

[PATCH xserver] On x86 targets, turn off SSE instructions for SlowBcopy

2017-07-30 Thread Dimitry Andric
Some compilers (e.g. clang) will recognize the memcpy idiom in xf86SlowBcopy(), and optimize it into a loop using SSE instructions. This can cause "Illegal instruction" crashes under virtualization environments such as qemu/kvm. To prevent this, explicitly turn off SSE for SlowBcopy.c, when