mirror of
https://gitlab.freedesktop.org/mesa/mesa.git
synced 2025-12-27 08:20:12 +01:00
read-only mirror of https://gitlab.freedesktop.org/mesa/mesa
83dedb6354
When working on tessellation shaders, I created some vec4 virtual
opcodes for creating message headers through a sequence like:
mov(8) g7<1>UD 0x00000000UD { align1 WE_all 1Q compacted };
mov(1) g7.5<1>UD 0x00000100UD { align1 WE_all };
mov(1) g7<1>UD g0<0,1,0>UD { align1 WE_all compacted };
mov(1) g7.3<1>UD g8<0,1,0>UD { align1 WE_all };
This is done in the generator since the vec4 backend can't handle align1
regioning. From the visitor's point of view, this is a single opcode:
hs_set_output_urb_offsets vgrf7.0:UD, 1U, vgrf8.xxxx:UD
Normally, there's no hazard between sources and destinations - an
instruction (naturally) reads its sources, then writes the result to the
destination. However, when the virtual instruction generates multiple
hardware instructions, we can get into trouble.
In the above example, if the register allocator assigned vgrf7 and vgrf8
to the same hardware register, then we'd clobber the source with 0 in
the first instruction, and read back the wrong value in the last one.
It occured to me that this is exactly the same problem we have with
SIMD16 instructions that use W/UW or B/UB types with 0 stride. The
hardware implicitly decodes them as two SIMD8 instructions, and with
the overlapping regions, the first would clobber the second.
Previously, we handled that by incrementing the live range end IP by 1,
which works, but is excessive: the next instruction doesn't actually
care about that. It might also be the end of control flow. This might
keep values alive too long. What we really want is to say "my source
and destinations interfere".
This patch creates new infrastructure for doing just that, and teaches
the register allocator to add interference when there's a hazard. For
my vec4 case, we can determine this by switching on opcodes. For the
SIMD16 case, we just move the existing code there.
I audited our existing virtual opcodes that generate multiple
instructions; I believe FS_OPCODE_PACK_HALF_2x16_SPLIT needs this
treatment as well, but no others.
v2: Rebased by mattst88.
Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Matt Turner <mattst88@gmail.com>
|
||
|---|---|---|
| bin | ||
| docs | ||
| doxygen | ||
| include | ||
| m4 | ||
| scons | ||
| src | ||
| .dir-locals.el | ||
| .gitattributes | ||
| .gitignore | ||
| Android.common.mk | ||
| Android.mk | ||
| autogen.sh | ||
| CleanSpec.mk | ||
| common.py | ||
| configure.ac | ||
| install-gallium-links.mk | ||
| install-lib-links.mk | ||
| Makefile.am | ||
| SConstruct | ||
| VERSION | ||
File: docs/README.WIN32 Last updated: 21 June 2013 Quick Start ----- ----- Windows drivers are build with SCons. Makefiles or Visual Studio projects are no longer shipped or supported. Run scons libgl-gdi to build gallium based GDI driver. This will work both with MSVS or Mingw. Windows Drivers ------- ------- At this time, only the gallium GDI driver is known to work. Source code also exists in the tree for other drivers in src/mesa/drivers/windows, but the status of this code is unknown. Recipe ------ Building on windows requires several open-source packages. These are steps that work as of this writing. - install python 2.7 - install scons (latest) - install mingw, flex, and bison - install pywin32 from here: http://www.lfd.uci.edu/~gohlke/pythonlibs get pywin32-218.4.win-amd64-py2.7.exe - install git - download mesa from git see http://www.mesa3d.org/repository.html - run scons General ------- After building, you can copy the above DLL files to a place in your PATH such as $SystemRoot/SYSTEM32. If you don't like putting things in a system directory, place them in the same directory as the executable(s). Be careful about accidentially overwriting files of the same name in the SYSTEM32 directory. The DLL files are built so that the external entry points use the stdcall calling convention. Static LIB files are not built. The LIB files that are built with are the linker import files associated with the DLL files. The si-glu sources are used to build the GLU libs. This was done mainly to get the better tessellator code. If you have a Windows-related build problem or question, please post to the mesa-dev or mesa-users list.