Get rid of an optimization in SCCP which appears to have many issues.  Specifically, it doesn't handle many cases involving undef correctly, and it is missing other checks which
lead to it trying to re-mark a value marked as a constant with a different value.  It also appears to trigger very rarely.

Fixes PR11357.

llvm-svn: 144352

Size of data being pointed to wasn't always being checked so some small writes were killing big writes

Fixes <rdar://problem/10426753>

llvm-svn: 144312

Currently checks alignment and killing stores on a power of 2 boundary as this is likely
to trim the size of the earlier store without breaking large vector stores into scalar ones.

Fixes <rdar://problem/10140300>

llvm-svn: 144239

LICM pass now understands invariant load metadata.  Nothing generates this yet so it will currently never get used in real tests

llvm-svn: 144107

Fixes r8429

llvm-svn: 144036

<rdar://problem/10405911>

llvm-svn: 144000

llvm-svn: 143808

the end of it is dead.", which appears to break bootstrapping LLVM.

llvm-svn: 143668

llvm-svn: 143634

Only currently done if the later store is writing to a power of 2 address or 
has the same alignment as the earlier store as then its likely to not break up
large stores into smaller ones

Fixes <rdar://problem/10140300>

llvm-svn: 143630

We've been hitting asserts in this code due to the many supported
combintions of modes (iv-rewrite/no-iv-rewrite) and IV types. This
second rewrite of the code attempts to deal with these cases systematically.

llvm-svn: 143546

silence -Wparentheses.

llvm-svn: 143534

Narrowest possible fix for PR11279.

llvm-svn: 143522

Make sure we use the right insertion point when instcombine replaces a PHI with another instruction.  (Specifically, don't insert an arbitrary instruction before a PHI.)  Fixes PR11275.

llvm-svn: 143437

Patch by Kostya Serebryany.

llvm-svn: 143405

SimplifyLibCalls: Use IRBuilder.CreateGlobalString when creating a string for printf->puts, which correctly sets the unnamed_addr bit on the resulting GlobalVariable.

Fixes PR11264.

llvm-svn: 143289

Fixes rdar://10359193 Indvar LinearFunctionTestReplace assertion

llvm-svn: 143183

It is not safe to sink an alloca into a stacksave/stackrestore pair, so don't do that. <rdar://problem/10352360>

llvm-svn: 143093

instructions.

This doesn't introduce any optimizations we weren't doing before (except
potentially due to pass ordering issues), now passes will eliminate them sooner
as part of their own cleanups.

llvm-svn: 142787

element types, even though the element extraction code does. It is surprising
that this bug has been here for so long. Fixes <rdar://problem/10318778>.

llvm-svn: 142740

elimination on them too.

llvm-svn: 142735

llvm-svn: 142684

llvm-svn: 142672

Extend instcombine's shufflevector simplification to handle more cases where the input and output vectors have different sizes.  Patch by Xiaoyi Guo.

llvm-svn: 142671

Refactor code from inlining and globalopt that checks whether a function definition is unused, and enhance it so it can tell that functions which are only used by a blockaddress are in fact dead.  This probably doesn't happen much on most code, but the Linux kernel's _THIS_IP_ can trigger this issue with blockaddress.  (GlobalDCE can also handle the given tescase, but we only run that at -O3.)  Found while looking at PR11180.

llvm-svn: 142572

Patch by Pranav Bhandarkar!

llvm-svn: 142556

tag on objc_retainBlock calls, which indicates that they may be
optimized away. rdar://10211286.

llvm-svn: 142298

combining of the landingpad instruction. The ObjC personality function acts
almost identically to the C++ personality function. In particular, it uses
"null" as a "catch-all" value.

llvm-svn: 142256

possibility that it will span multiple CFG diamonds/triangles which
could have different controlling predicates.  rdar://10282956

llvm-svn: 142222

Some code want to check that *any* call within a function has the 'returns
twice' attribute, not just that the current function has one.

llvm-svn: 142221

obsolete. Check the attribute instead.
<rdar://problem/8031714>

llvm-svn: 142212

llvm-svn: 142204

There is no reason to have simple IR level pass in lib/Target.

llvm-svn: 142200

profile metadata at the same time. Use it to preserve metadata attached
to a branch when re-writing it in InstCombine.

Add metadata to the canonicalize_branch InstCombine test, and check that
it is tranformed correctly.

Reviewed by Nick Lewycky!

llvm-svn: 142168

llvm-svn: 142162

on the memcpy call will pull up other unrelated stuff. Fixes PR11142.

llvm-svn: 142150

use can't be dominated, saving one domtree lookup.

llvm-svn: 142066

I rewrote the algorithm a while back so it doesn't require map lookup,
but neglected to change the data structure. This was caught by
llvm-gcc self host, not because there's anything special about
llvm-gcc, but because it is the only test for nondeterminism we
currently have. Unit tests don't work well for everything; we should
always try to have a nondeterminism stress test running.

Fixes PR11133: llvm-gcc self host .o mismatch after enable-iv-rewrite=false

llvm-svn: 142036

Someone more familiar with LSR should double-check that the extra cast is actually doing the right thing in the overflow cases; I'm not completely confident that's that case. 

llvm-svn: 141916

Enhance the memdep interface so that users can tell the difference between a dependency which cannot be calculated and a path reaching the entry point of the function. This patch introduces isNonFuncLocal, which replaces isUnknown in some cases.

Patch by Xiaoyi Guo.

llvm-svn: 141896