This commit adds tail call support to the MachineOutliner pass. This allows
the outliner to insert jumps rather than calls in areas where tail calling is
possible. Outlined tail calls include the return or terminator of the basic
block being outlined from.
Tail call support allows the outliner to take returns and terminators into
consideration while finding candidates to outline. It also allows the outliner
to save more instructions. For example, in the X86-64 outliner, a tail called
outlined function saves one instruction since no return has to be inserted.
llvm-svn: 297653
Fixed the asan bot failure which led to the last commit of the outliner being reverted.
The change is in lib/CodeGen/MachineOutliner.cpp in the SuffixTree's constructor. LeafVector
is no longer initialized using reserve but just a standard constructor.
llvm-svn: 297081
This is a patch for the outliner described in the RFC at:
http://lists.llvm.org/pipermail/llvm-dev/2016-August/104170.html
The outliner is a code-size reduction pass which works by finding
repeated sequences of instructions in a program, and replacing them with
calls to functions. This is useful to people working in low-memory
environments, where sacrificing performance for space is acceptable.
This adds an interprocedural outliner directly before printing assembly.
For reference on how this would work, this patch also includes X86
target hooks and an X86 test.
The outliner is run like so:
clang -mno-red-zone -mllvm -enable-machine-outliner file.c
Patch by Jessica Paquette<jpaquette@apple.com>!
rdar://29166825
Differential Revision: https://reviews.llvm.org/D26872
llvm-svn: 296418
Jessica Paquette