so that the SCEVExpander doesn't retain a dangling pointer as its
insert position. The dangling pointer in this case wasn't ever used
to insert new instructions, but it was causing trouble with
SCEVExpander's code for automatically advancing its insert position
past debug intrinsics.

This fixes use-after-free errors that valgrind noticed in
test/Transforms/IndVarSimplify/2007-06-06-DeleteDanglesPtr.ll and
test/Transforms/IndVarSimplify/exit_value_tests.ll.

llvm-svn: 99036

llvm-svn: 98584

compute a set of reachable blocks for itself each time it is called, which
is fairly frequently.

llvm-svn: 98179

llvm-svn: 97453

which branch on undef to branch on a boolean constant for the edge
exiting the loop. This helps ScalarEvolution compute trip counts for
loops.

Teach ScalarEvolution to recognize single-value PHIs, when safe, and
ForgetSymbolicName to forget such single-value PHI nodes as apprpriate
in ForgetSymbolicName.

llvm-svn: 97126

llvm-svn: 96780

llvm-svn: 96771

to be spurious

llvm-svn: 96662

llvm-svn: 96653

a loop exit value, so that if a loop gets deleted, ScalarEvolution
isn't stick holding on to dangling SCEVAddRecExprs for that loop. This
fixes PR6339.

llvm-svn: 96626

llvm-svn: 96614

and T->isPointerTy().  Convert most instances of the first form to the second form.
Requested by Chris.

llvm-svn: 96344

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

llvm-svn: 95781

This new version is much more aggressive about doing "full" reduction in
cases where it reduces register pressure, and also more aggressive about
rewriting induction variables to count down (or up) to zero when doing so
reduces register pressure.

It currently uses fairly simplistic algorithms for finding reuse
opportunities, but it introduces a new framework allows it to combine
multiple strategies at once to form hybrid solutions, instead of doing
all full-reduction or all base+index.

llvm-svn: 94061

llvm-svn: 92735

llvm-svn: 92609

contains another loop, or an instruction. The loop form is
substantially more efficient on large loops than the typical
code it replaces.

llvm-svn: 91654

LoopSimplify form may not be available.

llvm-svn: 86175

clears out more information than just the stored backedge taken count.

llvm-svn: 85664

llvm-svn: 85327

update all the callers.

llvm-svn: 82889

llvm-svn: 80766

sinking code, since they are special. If the loop preheader happens
to be the entry block of a function, don't sink static allocas
out of it. This fixes PR4775.

llvm-svn: 80010

This required converting a bunch of stuff off DOUT and other cleanups.

llvm-svn: 79819

that Value's operator<< doesn't include one.

llvm-svn: 79240

llvm-svn: 78948

llvm-svn: 77635

llvm-svn: 77152

Revert the ConstantInt constructors back to their 2.5 forms where possible, thanks to contexts-on-types.  More to come.

llvm-svn: 77011

llvm-svn: 76702

using it.

llvm-svn: 75852

llvm-svn: 75723

This results in the pass manager running IVUsers only once for
indvars, instead of twice.

llvm-svn: 75633

block has a single unique exiting block.

llvm-svn: 75579

This started as a small change, I swear.  Unfortunately, lots of things call the [I|F]CmpInst constructors.  Who knew!?

llvm-svn: 75200

llvm-svn: 74918

llvm-svn: 74748

PassManager was scheduling LCSSA before LoopSimplify, which does not
preserve LCSSA.

llvm-svn: 74661

inserted to replace that value must dominate all of of the basic
blocks associated with the uses of the value in the PHI, not just
one of them.

llvm-svn: 74376