Add some shortcuts in LazyValueInfo to reduce compile time of
Correlated Value Propagation.
The patch is to partially fix PR10584. Correlated Value Propagation
queries LVI to check non-null for pointer params of each callsite. If
we know the def of param is an alloca instruction, we know it is
non-null and can return early from LVI. Similarly, CVP queries LVI to
check whether pointer for each mem access is constant. If the def of
the pointer is an alloca instruction, we know it is not a constant
pointer. These shortcuts can reduce the cost of CVP significantly.
Differential Revision: https://reviews.llvm.org/D18066
This significantly reduces memory usage and compilation time when
compiling a particular C++ source file of the graphics/colmap port.
PR: 215136
MFC after: 3 days
all of the features in the current working draft of the upcoming C++
standard, provisionally named C++1y.
The code generator's performance is greatly increased, and the loop
auto-vectorizer is now enabled at -Os and -O2 in addition to -O3. The
PowerPC backend has made several major improvements to code generation
quality and compile time, and the X86, SPARC, ARM32, Aarch64 and SystemZ
backends have all seen major feature work.
Release notes for llvm and clang can be found here:
<http://llvm.org/releases/3.4/docs/ReleaseNotes.html>
<http://llvm.org/releases/3.4/tools/clang/docs/ReleaseNotes.html>
MFC after: 1 month
upcoming 3.3 release (branching and freezing expected in a few weeks).
Preliminary release notes can be found at the usual location:
<http://llvm.org/docs/ReleaseNotes.html>
An MFC is planned once the actual 3.3 release is finished.
