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

This helps it avoid reusing an instruction that doesn't dominate all
of the users, in cases where the original instruction was inserted
before all of the users were known.  This may result in redundant
expansions of sub-expressions that depend on loop-unpredictable values
in some cases, however this isn't very common, and it primarily impacts
IndVarSimplify, so GVN can be expected to clean these up.

This eliminates the need for IndVarSimplify's FixUsesBeforeDefs,
which fixes several bugs.

llvm-svn: 74352

llvm-svn: 74330

llvm-svn: 74285

llvm-svn: 74243

llvm-svn: 74240

llvm-svn: 74146

terminator, instead of after the last phi. This fixes a bug
exposed by ScalarEvolution analyzing more kinds of loops.
This fixes PR4436.

llvm-svn: 74072

trip counts in more cases.

Generalize ScalarEvolution's isLoopGuardedByCond code to recognize
And and Or conditions, splitting the code out into an
isNecessaryCond helper function so that it can evaluate Ands and Ors
recursively, and make SCEVExpander be much more aggressive about
hoisting instructions out of loops.

test/CodeGen/X86/pr3495.ll has an additional instruction now, but
it appears to be due to an arbitrary register allocation difference.

llvm-svn: 74048

preheader is already an instruction.

llvm-svn: 74031

llvm-svn: 73910

llvm-svn: 73906

now, this hasn't mattered, because ScalarEvolution hasn't been able
to compute trip counts for loops with multiple exits. But it will
soon.

llvm-svn: 73864

terminology that LoopInfo uses.

llvm-svn: 73863

llvm-svn: 73796

hand-crafted testcase which demonstrates the bug that was exposed
in 254.gap.

llvm-svn: 73793

which it isn't prepared to handle.

llvm-svn: 73787

llvm-svn: 73783

as if they were multiple uses of the same instruction.  This interacts
well with the existing loadpre that j-t does to open up many new jump
threads earlier.

llvm-svn: 73768

llvm-svn: 73755

when it allows forming a tail call.  Patch by Frits van
Bommel.  This implements PR4323.

llvm-svn: 73752

strcmp -> memcmp when the lengths of the strings are unknown.

Patch by Nick Lewycky!

llvm-svn: 73751

as signed max tests. Along with r73717, this helps CodeGen avoid
emitting code for a maximum operation for this class of loop.

llvm-svn: 73718

llvm-svn: 73715

casted induction variables in cases where the cast
isn't foldable. It ended up being a pessimization in
many cases. This could be fixed, but it would require
a bunch of complicated code in IVUsers' clients. The
advantages of this approach aren't visible enough to
justify it at this time.

llvm-svn: 73706

C is not a low-bits mask, and add a similar instcombine for
zext((trunc(t) & C) ^ C).

llvm-svn: 73705

multiple users.

llvm-svn: 73656

move loads back past a check that the load address
is valid, see new testcase.  The test that went
in with 72661 has exactly this case, except that
the conditional it's moving past is checking
something else; I've settled for changing that
test to reference a global, not a pointer.  It
may be possible to scan all the tests you pass and
make sure none of them are checking any component
of the address, but it's not trivial and I'm not
trying to do that here.

llvm-svn: 73632

llvm-svn: 73625

llvm-svn: 73621

SRem.

llvm-svn: 73598

llvm-svn: 73541

to ignore readonly calls, and factor it out of instcombine so
that it can be used by other passes.  Patch by Frits van Bommel!

llvm-svn: 73506

llvm-svn: 73451

failures.

To support this, add some utility functions to Type to help support
vector/scalar-independent code. Change ConstantInt::get and
ConstantFP::get to support vector types, and add an overload to
ConstantInt::get that uses a static IntegerType type, for
convenience.

Introduce a new getConstant method for ScalarEvolution, to simplify
common use cases.

llvm-svn: 73431

llvm-svn: 73398

llvm-svn: 73362

SmallVector instead of std::vector.

llvm-svn: 73357

llvm-svn: 73355

induction variable when the addrec to be expanded does not require
a wider type. This eliminates the need for IndVarSimplify to
micro-manage SCEV expansions, because SCEVExpander now
automatically expands them in the form that IndVarSimplify considers
to be canonical. (LSR still micro-manages its SCEV expansions,
because it's optimizing for the target, rather than for
other optimizations.)

Also, this uses the new getAnyExtendExpr, which has more clever
expression simplification logic than the IndVarSimplify code it
replaces, and this cleans up some ugly expansions in code such as
the included masked-iv.ll testcase.

llvm-svn: 73294