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Diffstat (limited to 'llvm')
| -rw-r--r-- | llvm/docs/ReleaseNotes.rst | 112 |
1 files changed, 56 insertions, 56 deletions
diff --git a/llvm/docs/ReleaseNotes.rst b/llvm/docs/ReleaseNotes.rst index c61401f..efceccc 100644 --- a/llvm/docs/ReleaseNotes.rst +++ b/llvm/docs/ReleaseNotes.rst @@ -286,89 +286,89 @@ Changes since the last release: * isl imported into Polly distribution -`isl <http://repo.or.cz/w/isl.git>`_, the math library Polly uses, has been -imported into the source code repository of Polly and is now distributed as part -of Polly. As this was the last external library dependency of Polly, Polly can -now be compiled right after checking out the Polly source code without the need -for any additional libraries to be pre-installed. + `isl <http://repo.or.cz/w/isl.git>`_, the math library Polly uses, has been + imported into the source code repository of Polly and is now distributed as part + of Polly. As this was the last external library dependency of Polly, Polly can + now be compiled right after checking out the Polly source code without the need + for any additional libraries to be pre-installed. * Small integer optimization of isl -The MIT licensed imath backend using in `isl <http://repo.or.cz/w/isl.git>`_ for -arbitrary width integer computations has been optimized to use native integer -operations for the common case where the operands of a computation fit into 32 -bit and to only fall back to large arbitrary precision integers for the -remaining cases. This optimization has greatly improved the compile-time -performance of Polly, both due to faster native operations also due to a -reduction in malloc traffic and pointer indirections. As a result, computations -that use arbitrary precision integers heavily have been speed up by almost 6x. -As a result, the compile-time of Polly on the Polybench test kernels in the LNT -suite has been reduced by 20% on average with compile time reductions between -9-43%. + The MIT licensed imath backend using in `isl <http://repo.or.cz/w/isl.git>`_ for + arbitrary width integer computations has been optimized to use native integer + operations for the common case where the operands of a computation fit into 32 + bit and to only fall back to large arbitrary precision integers for the + remaining cases. This optimization has greatly improved the compile-time + performance of Polly, both due to faster native operations also due to a + reduction in malloc traffic and pointer indirections. As a result, computations + that use arbitrary precision integers heavily have been speed up by almost 6x. + As a result, the compile-time of Polly on the Polybench test kernels in the LNT + suite has been reduced by 20% on average with compile time reductions between + 9-43%. * Schedule Trees -Polly now uses internally so-called > Schedule Trees < to model the loop -structure it optimizes. Schedule trees are an easy to understand tree structure -that describes a loop nest using integer constraint sets to keep track of -execution constraints. It allows the developer to use per-tree-node operations -to modify the loop tree. Programatic analysis that work on the schedule tree -(e.g., as dependence analysis) also show a visible speedup as they can exploit -the tree structure of the schedule and need to fall back to ILP based -optimization problems less often. Section 6 of `Polyhedral AST generation is -more than scanning polyhedra -<http://www.grosser.es/#pub-polyhedral-AST-generation>`_ gives a detailed -explanation of this schedule trees. + Polly now uses internally so-called > Schedule Trees < to model the loop + structure it optimizes. Schedule trees are an easy to understand tree structure + that describes a loop nest using integer constraint sets to keep track of + execution constraints. It allows the developer to use per-tree-node operations + to modify the loop tree. Programatic analysis that work on the schedule tree + (e.g., as dependence analysis) also show a visible speedup as they can exploit + the tree structure of the schedule and need to fall back to ILP based + optimization problems less often. Section 6 of `Polyhedral AST generation is + more than scanning polyhedra + <http://www.grosser.es/#pub-polyhedral-AST-generation>`_ gives a detailed + explanation of this schedule trees. * Scalar and PHI node modeling - Polly as an analysis -Polly now requires almost no preprocessing to analyse LLVM-IR, which makes it -easier to use Polly as a pure analysis pass e.g. to provide more precise -dependence information to non-polyhedral transformation passes. Originally, -Polly required the input LLVM-IR to be preprocessed such that all scalar and -PHI-node dependences are translated to in-memory operations. Since this release, -Polly has full support for scalar and PHI node dependences and requires no -scalar-to-memory translation for such kind of dependences. + Polly now requires almost no preprocessing to analyse LLVM-IR, which makes it + easier to use Polly as a pure analysis pass e.g. to provide more precise + dependence information to non-polyhedral transformation passes. Originally, + Polly required the input LLVM-IR to be preprocessed such that all scalar and + PHI-node dependences are translated to in-memory operations. Since this release, + Polly has full support for scalar and PHI node dependences and requires no + scalar-to-memory translation for such kind of dependences. * Modeling of modulo and non-affine conditions -Polly can now supports modulo operations such as A[t%2][i][j] as they appear -often in stencil computations and also allows data-dependent conditional -branches as they result e.g. from ternary conditions ala A[i] > 255 ? 255 : -A[i]. + Polly can now supports modulo operations such as A[t%2][i][j] as they appear + often in stencil computations and also allows data-dependent conditional + branches as they result e.g. from ternary conditions ala A[i] > 255 ? 255 : + A[i]. * Delinearization -Polly now support the analysis of manually linearized multi-dimensional arrays -as they result form macros such as -"#define 2DARRAY(A,i,j) (A.data[(i) * A.size + (j)]". Similar constructs appear -in old C code written before C99, C++ code such as boost::ublas, LLVM exported -from Julia, Matlab generated code and many others. Our work titled -`Optimistic Delinearization of Parametrically Sized Arrays -<http://www.grosser.es/#pub-optimistic-delinerization>`_ gives details. + Polly now support the analysis of manually linearized multi-dimensional arrays + as they result form macros such as + "#define 2DARRAY(A,i,j) (A.data[(i) * A.size + (j)]". Similar constructs appear + in old C code written before C99, C++ code such as boost::ublas, LLVM exported + from Julia, Matlab generated code and many others. Our work titled + `Optimistic Delinearization of Parametrically Sized Arrays + <http://www.grosser.es/#pub-optimistic-delinerization>`_ gives details. * Compile time improvements -Pratik Bahtu worked on compile-time performance tuning of Polly. His work -together with the support for schedule trees and the small integer optimization -in isl notably reduced the compile time. + Pratik Bahtu worked on compile-time performance tuning of Polly. His work + together with the support for schedule trees and the small integer optimization + in isl notably reduced the compile time. * Increased compute timeouts -As Polly's compile time has been notabily improved, we were able to increase -the compile time saveguards in Polly. As a result, the default configuration -of Polly can now analyze larger loop nests without running into compile time -restrictions. + As Polly's compile time has been notabily improved, we were able to increase + the compile time saveguards in Polly. As a result, the default configuration + of Polly can now analyze larger loop nests without running into compile time + restrictions. * Export Debug Locations via JSCoP file -Polly's JSCoP import/export format gained support for debug locations that show -to the user the source code location of detected scops. + Polly's JSCoP import/export format gained support for debug locations that show + to the user the source code location of detected scops. * Improved windows support -The compilation of Polly on windows using cmake has been improved and several -visual studio build issues have been addressed. + The compilation of Polly on windows using cmake has been improved and several + visual studio build issues have been addressed. * Many bug fixes |