use and only call IsProfitableToFold/IsLegalToFold on the load
being folded, like the old dagiselemitter does. This
substantially simplifies the code and improves opportunities for
sharing.
llvm-svn: 96368
IsLegalToFold and IsProfitableToFold. The generic version of the later simply checks whether the folding candidate has a single use.
This allows the target isel routines more flexibility in deciding whether folding makes sense. The specific case we are interested in is folding constant pool loads with multiple uses.
llvm-svn: 96255
produce a table based matcher instead of gobs of C++ Code.
Though it's not done yet, the shrinkage seems promising,
the table for the X86 ISel is 75K and still has a lot of
optimization to come (compare to the ~1.5M of .o generated
the old way, much of which will go away).
The code is currently disabled by default (the #if 0 in
DAGISelEmitter.cpp). When enabled it generates a dead
SelectCode2 function in the DAGISel Header which will
eventually replace SelectCode.
There is still a lot of stuff left to do, which are
documented with a trail of FIXMEs.
llvm-svn: 96215
insert location has become an "inserted" instruction since the time
it was saved. If so, advance to the first non-"inserted" instruction.
llvm-svn: 96203
current insertion point, advance the current insertion point.
This avoids a use-before-def situation in a testcase extracted
from clang which is difficult to reduce to a reasonable-sized
regression test.
llvm-svn: 96151
created. This ensures it's updated at all time. It means targets which perform
dynamic stack alignment would know whether it is required and whether frame
pointer register cannot be made available register allocation.
This is a fix for rdar://7625239. Sorry, I can't create a reasonably sized test
case.
llvm-svn: 96069
bug fixes, and with improved heuristics for analyzing foreign-loop
addrecs.
This change also flattens IVUsers, eliminating the stride-oriented
groupings, which makes it easier to work with.
llvm-svn: 95975
reduce down to a single value. InstCombine already does this transformation
but DAG legalization may introduce new opportunities. This has turned out to
be important for ARM where 64-bit values are split up during type legalization:
InstCombine is not able to remove the PHI cycles on the 64-bit values but
the separate 32-bit values can be optimized. I measured the compile time
impact of this (running llc on 176.gcc) and it was not significant.
llvm-svn: 95951
lowering and requires that certain types exist in ValueTypes.h. Modified widening to
check if an op can trap and if so, the widening algorithm will apply only the op on
the defined elements. It is safer to do this in widening because the optimizer can't
guarantee removing unused ops in some cases.
llvm-svn: 95823
