since then the entire expression must equal zero (similarly for other operations
with an absorbing element). With this in place a bunch of reassociate code for
handling constants is dead since it is all taken care of when linearizing. No
intended functionality change.
llvm-svn: 158398
topologies, it is quite possible for a leaf node to have huge multiplicity, for
example: x0 = x*x, x1 = x0*x0, x2 = x1*x1, ... rapidly gives a value which is x
raised to a vast power (the multiplicity, or weight, of x). This patch fixes
the computation of weights by correctly computing them no matter how big they
are, rather than just overflowing and getting a wrong value. It turns out that
the weight for a value never needs more bits to represent than the value itself,
so it is enough to represent weights as APInts of the same bitwidth and do the
right overflow-avoiding dance steps when computing weights. As a side-effect it
reduces the number of multiplies needed in some cases of large powers. While
there, in view of external uses (eg by the vectorizer) I made LinearizeExprTree
static, pushing the rank computation out into users. This is progress towards
fixing PR13021.
llvm-svn: 158358
but with a critical fix to the SelectionDAG code that optimizes copies
from strings into immediate stores: the previous code was stopping reading
string data at the first nul. Address this by adding a new argument to
llvm::getConstantStringInfo, preserving the behavior before the patch.
llvm-svn: 149800
kicking in the big win of ConstantDataArray. As part of this, change
the implementation of GetConstantStringInfo in ValueTracking to work
with ConstantDataArray (and not ConstantArray) making it dramatically,
amazingly, more efficient in the process and renaming it to
getConstantStringInfo.
This keeps around a GetConstantStringInfo entrypoint that (grossly)
forwards to getConstantStringInfo and constructs the std::string
required, but existing clients should move over to
getConstantStringInfo instead.
llvm-svn: 149351
ConstantExpr::getWithOperandReplaced and ConstantExpr::replaceUsesOfWithOnConstant
in terms of ConstantExpr::getWithOperands. While we're at it,
make sure that ConstantExpr::getWithOperands covers all instructions: it was
missing insert/extractvalue.
llvm-svn: 149076
ConstantVector. Fix some outright bugs in the implementation of
ConstantArray and Constant struct, which would cause us to not make
one big UndefValue when asking for an array/struct with all undef
elements. Enhance Constant::isAllOnesValue to work with
ConstantDataVector.
llvm-svn: 149021
add a ConstantDataArray::getString method that corresponds to the (to be
removed) StringRef version of ConstantArray::get, but is dramatically more
efficient.
llvm-svn: 148804
and clean up some other misc stuff. Unlike ConstantArray, we will
prefer to emit .fill directives for "String" arrays that all have
the same value, since they are denser than emitting a .ascii
llvm-svn: 148793
same semantics as ConstantArray's but much more efficient because they
don't have to return std::string's. The ConstantArray methods will
eventually be removed.
llvm-svn: 148792
classes, per PR1324. Not all of their helper functions are implemented,
nothing creates them, and the rest of the compiler doesn't handle them yet.
llvm-svn: 148741
using OwningPtr. OwningPtr would barf when the densemap had to reallocate,
which doesn't appear to happen on the regression test suite, but obviously
happens in real life :)
llvm-svn: 148700
Micah Villmow