From 2fb58f16eeec8ef3ec2a25e246477aab64e38a7d Mon Sep 17 00:00:00 2001 From: marha Date: Sun, 10 Apr 2011 18:43:19 +0000 Subject: mesa git update --- mesalib/docs/llvmpipe.html | 204 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 204 insertions(+) create mode 100644 mesalib/docs/llvmpipe.html (limited to 'mesalib/docs/llvmpipe.html') diff --git a/mesalib/docs/llvmpipe.html b/mesalib/docs/llvmpipe.html new file mode 100644 index 000000000..5f4e9de3b --- /dev/null +++ b/mesalib/docs/llvmpipe.html @@ -0,0 +1,204 @@ + + +llvmpipe + + + + + +

Introduction

+ +

+The Gallium llvmpipe driver is a software rasterizer that uses LLVM to +do runtime code generation. +Shaders, point/line/triangle rasterization and vertex processing are +implemented with LLVM IR which is translated to x86 or x86-64 machine +code. +Also, the driver is multithreaded to take advantage of multiple CPU cores +(up to 8 at this time). +It's the fastest software rasterizer for Mesa. +

+ + +

Requirements

+ +
+
An x86 or amd64 processor. 64-bit mode is preferred.
+
+

+ Support for sse2 is strongly encouraged. Support for ssse3, and sse4.1 will + yield the most efficient code. The less features the CPU has the more + likely is that you ran into underperforming, buggy, or incomplete code. +

+

+ See /proc/cpuinfo to know what your CPU supports. +

+
+
LLVM. Version 2.8 recommended. 2.6 or later required.
+
+

+ NOTE: LLVM 2.8 and earlier will not work on systems that support the + Intel AVX extensions (e.g. Sandybridge). LLVM's code generator will + fail when trying to emit AVX instructions. This was fixed in LLVM 2.9. +

+

+ For Linux, on a recent Debian based distribution do: +

+
+     aptitude install llvm-dev
+
+ For a RPM-based distribution do: +

+
+     yum install llvm-devel
+
+ +

+ For Windows download pre-built MSVC 9.0 or MinGW binaries from + http://people.freedesktop.org/~jrfonseca/llvm/ and set the LLVM environment + variable to the extracted path. +

+ +

+ For MSVC there are two set of binaries: llvm-x.x-msvc32mt.7z and + llvm-x.x-msvc32mtd.7z . +

+ +

+ You have to set the LLVM=/path/to/llvm-x.x-msvc32mtd env var when passing + debug=yes to scons, and LLVM=/path/to/llvm-x.x-msvc32mt when building with + debug=no. This is necessary as LLVM builds as static library so the chosen + MS CRT must match. +

+
+ +
scons (optional)
+
+ + + +

Building

+ +To build everything on Linux invoke scons as: + +
+  scons build=debug libgl-xlib
+
+ +Alternatively, you can build it with GNU make, if you prefer, by invoking it as + +
+  make linux-llvm
+
+ +but the rest of these instructions assume that scons is used. + +For windows is everything the except except the winsys: + +
+  scons build=debug libgl-gdi
+
+ + +

Using

+ +On Linux, building will create a drop-in alternative for libGL.so into + +
+  build/foo/gallium/targets/libgl-xlib/libGL.so
+
+or +
+  lib/gallium/libGL.so
+
+ +To use it set the LD_LIBRARY_PATH environment variable accordingly. + +For performance evaluation pass debug=no to scons, and use the corresponding +lib directory without the "-debug" suffix. + +On Windows, building will create a drop-in alternative for opengl32.dll. To use +it put it in the same directory as the application. It can also be used by +replacing the native ICD driver, but it's quite an advanced usage, so if you +need to ask, don't even try it. + + +

Profiling

+ +To profile llvmpipe you should pass the options + +
+  scons build=profile 
+
+ +This will ensure that frame pointers are used both in C and JIT functions, and +that no tail call optimizations are done by gcc. + +To better profile JIT code you'll need to build LLVM with oprofile integration. + +
+  ./configure \
+      --prefix=$install_dir \
+      --enable-optimized \
+      --disable-profiling \
+      --enable-targets=host-only \
+      --with-oprofile
+
+  make -C "$build_dir"
+  make -C "$build_dir" install
+
+  find "$install_dir/lib" -iname '*.a' -print0 | xargs -0 strip --strip-debug
+
+ +The you should define + +
+  export LLVM=/path/to/llvm-2.6-profile
+
+ +and rebuild. + + +

Unit testing

+ +

+Building will also create several unit tests in +build/linux-???-debug/gallium/drivers/llvmpipe: +

+ + +
  • lp_test_blend: blending +
  • lp_test_conv: SIMD vector conversion +
  • lp_test_format: pixel unpacking/packing + + +

    +Some of this tests can output results and benchmarks to a tab-separated-file +for posterior analysis, e.g.: +

    +
    +  build/linux-x86_64-debug/gallium/drivers/llvmpipe/lp_test_blend -o blend.tsv
+
    + + +

    Development Notes

    + + -- cgit v1.2.3