to more accurately describe what it does. Expand its doxygen comment
to describe what the backedge-taken count is and how it differs
from the actual iteration count of the loop. Adjust names and
comments in associated code accordingly.

llvm-svn: 65382

ashr instcombine to help expose this code. And apply the fix to
SelectionDAG's copy of this code too.

llvm-svn: 65364

handling non-constant strides. No functionality change.

llvm-svn: 65363

llvm-svn: 65359

trip counts that use signed comparisons. It's not obviously the best
approach for preserving trip count information, and at any rate there
isn't anything in the tree right now that makes use of that, so for
now always using zero-extensions is preferable.

llvm-svn: 65347

so that ScalarEvolution doesn't hang onto a dangling Loop*, which
could be a problem if another Loop happens to get allocated at the
same address.

llvm-svn: 65323

-std-compile-opts sequence, this avoids the need for ScalarEvolution to
be rerun before LoopDeletion.

llvm-svn: 65318

llvm-svn: 65314

llvm-svn: 65306

memcpy to match the alignment of the destination. It isn't necessary
for making loads and stores handled like the SSE loadu/storeu
intrinsics, and it was causing a performance regression in
MultiSource/Applications/JM/lencod.

The problem appears to have been a memcpy that copies from some
highly aligned array into an alloca; the alloca was then being
assigned a large alignment, which required codegen to perform
dynamic stack-pointer re-alignment, which forced the enclosing
function to have a frame pointer, which led to increased spilling.

llvm-svn: 65289

-full-lsr code, as well as a GCC warning.

llvm-svn: 65288

Only try to sink immediate when TLI is not null. It needs to check if immediate would fit in target addressing field.

llvm-svn: 65268

load(bitcast(char[4] to i32*)) evaluation.

llvm-svn: 65246

Teach LSR sink to sink the immediate portion of the common expression back into uses if they fit in address modes of all the uses.

llvm-svn: 65215

as legality.  Make load sinking and gep sinking more careful: we only
do it when it won't pessimize loads from the stack.  This has the added
benefit of not producing code that is unanalyzable to SROA.

llvm-svn: 65209

addresses, part 1. This fixes an obvious logic bug. Previously if the only
in-loop use is a PHI, it would return AllUsesAreAddresses as true.

llvm-svn: 65178

llvm-svn: 65167

llvm-svn: 65159

llvm-svn: 65157

llvm-svn: 65147

Factor address mode matcher out of codegen prepare to make it available to other passes, e.g. loop strength reduction.

llvm-svn: 65134

reduction of address calculations down to basic pointer arithmetic.
This is currently off by default, as it needs a few other features
before it becomes generally useful. And even when enabled, full
strength reduction is only performed when it doesn't increase
register pressure, and when several other conditions are true.

This also factors out a bunch of exisiting LSR code out of
StrengthReduceStridedIVUsers into separate functions, and tidies
up IV insertion. This actually decreases register pressure even
in non-superhero mode. The change in iv-users-in-other-loops.ll
is an example of this; there are two more adds because there are
two fewer leas, and there is less spilling.

llvm-svn: 65108

since the latter just passes a null reference when
debugging is not enabled.

llvm-svn: 65060

llvm-svn: 65057

trip count value when the original loop iteration condition is
signed and the canonical induction variable won't undergo signed
overflow. This isn't required for correctness; it just preserves
more information about original loop iteration values.

Add a getTruncateOrSignExtend method to ScalarEvolution,
following getTruncateOrZeroExtend.

llvm-svn: 64918

llvm-svn: 64917

llvm-svn: 64888

are multiple IV's in a loop, some of them may under go signed
or unsigned wrapping even if the IV that's used in the loop
exit condition doesn't. Restrict sign-extension-elimination
and zero-extension-elimination to only those that operate on
the original loop-controlling IV.

llvm-svn: 64866

llvm-svn: 64859

llvm-svn: 64811

modified in a way that may effect the trip count calculation. Change
IndVars to use this method when it rewrites pointer or floating-point
induction variables instead of using a doInitialization method to
sneak these changes in before ScalarEvolution has a chance to see
the loop. This eliminates the need for LoopPass to depend on
ScalarEvolution.

llvm-svn: 64810

eliminate all the extensions and all but the one required truncate
from the testcase, but the or/and/shift stuff still isn't zapped.

llvm-svn: 64809

llvm-svn: 64784

llvm-svn: 64766

llvm-svn: 64703

llvm-svn: 64702

of an alloca or global variable.

llvm-svn: 64693

been written for is no longer relevant with the elimination of
signed and unsigned types.

llvm-svn: 64625

Enhance instcombine to use the preferred field of
GetOrEnforceKnownAlignment in more cases, so that regular IR operations are
optimized in the same way that the intrinsics currently are.

llvm-svn: 64623

when I was looking at functions used by python.

Highlights include, better largefile support (64-bit file sizes on 32-bit
systems), fputs string is nocapture, popen/pclose added (popen being noalias
return), modf and frexp and friends. Also added some missing 'break' statements
and combined identical sections.

llvm-svn: 64615