ScalarEvolution currently lowers a subtraction recurrence to an add
recurrence with the same no-wrap flags as the subtraction.  This is
incorrect because `sub nsw X, Y` is not the same as `add nsw X, -Y`
and `sub nuw X, Y` is not the same as `add nuw X, -Y`.  This patch
fixes the issue, and adds two test cases demonstrating the bug.

Differential Revision: http://reviews.llvm.org/D7081

llvm-svn: 226755

llvm-svn: 226750

llvm-svn: 226748

Addresses review comments for r226627.

llvm-svn: 226747

function. This is a bit tidier anyways and will make a subsquent patch
simpler as I want to add another case to this combine.

llvm-svn: 226746

Added most of the missing integer vector folding patterns for SSE (to SSE42) and AVX1.

The most useful of these are probably the i32/i64 extraction, i8/i16/i32/i64 insertions, zero/sign extension, unsigned saturation subtractions, i64 subtractions and the variable mask blends (pblendvb) - others include CLMUL, SSE42 string comparisons and bit tests.

Differential Revision: http://reviews.llvm.org/D7094

llvm-svn: 226745

It can help with argument juggling on some targets, and is generally a good
idea.

llvm-svn: 226740

When two calls from the same MDLocation are inlined they currently get
treated as one inlined function call (creating difficulty debugging,
duplicate variables, etc).

Clang worked around this by including column information on inline calls
which doesn't address LTO inlining or calls to the same function from
the same line and column (such as through a macro). It also didn't
address ctor and member function calls.

By making the inlinedAt locations distinct, every call site has an
explicitly distinct location that cannot be coalesced with any other
call.

This can produce linearly (2x in the worst case where every call is
inlined and the call instruction has a non-call instruction at the same
location) more debug locations. Any increase beyond that are in cases
where the Clang workaround was insufficient and the new scheme is
creating necessary distinct nodes that were being erroneously coalesced
previously.

After this change to LLVM the incomplete workarounds in Clang. That
should reduce the number of debug locations (in a build without column
info, the default on Darwin, not the default on Linux) by not creating
pseudo-distinct locations for every call to an inline function.

(oh, and I made the inlined-at chain rebuilding iterative instead of
recursive because I was having trouble wrapping my head around it the
way it was - open to discussion on the right design for that function
(including going back to a recursive solution))

llvm-svn: 226736

Make sure this uses the faster expansion using magic constants
to avoid the full division path.

llvm-svn: 226734

LiveIntervalAnalysis: Mark subregister defs as undef when we determined they are only reading a dead superregister value

This was not necessary before as this case can only be detected when the
liveness analysis is at subregister level.

llvm-svn: 226733

Summary: cl::getRegisteredOptions really exposes some of the innards of how command line parsing is implemented. Exposing new APIs that allow us to disentangle client code from implementation details will allow us to make more extensive changes to command line parsing.

Reviewers: chandlerc, dexonsmith, beanz

Reviewed By: dexonsmith

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D7100

llvm-svn: 226729

This patch adds shuffle matching for the SSE3 MOVDDUP, MOVSLDUP and MOVSHDUP instructions. The big use of these being that they avoid many single source shuffles from needing to use (pre-AVX) dual source instructions such as SHUFPD/SHUFPS: causing extra moves and preventing load folds.

Adding these instructions uncovered an issue in XFormVExtractWithShuffleIntoLoad which crashed on single operand shuffle instructions (now fixed). It also involved fixing getTargetShuffleMask to correctly identify theses instructions as unary shuffles.

Also adds a missing tablegen pattern for MOVDDUP.

Differential Revision: http://reviews.llvm.org/D7042

llvm-svn: 226716

llvm-svn: 226713

Thumbv4t does not have lo->lo copies other than MOVS,
and that can't be predicated. So emit MOVS when needed
and bail if there's a predicate.

http://reviews.llvm.org/D6592

llvm-svn: 226711

llvm-svn: 226710

The return type of a thunk is meaningless, we just want the arguments
and return value to be forwarded.

llvm-svn: 226708

Patch to provide shuffle decodes and asm comments for the SSE3/AVX1 movddup double duplication instructions.

llvm-svn: 226705

llvm-svn: 226701

llvm-svn: 226694

This cleans up code and is more in line with the general philosophy of
modifying LiveIntervals through LiveIntervalAnalysis instead of changing
them directly.

This also fixes a case where SplitEditor::removeBackCopies() would miss
the subregister ranges.

llvm-svn: 226690

llvm-svn: 226689

This cleans up code and is more in line with the general philosophy of
modifying LiveIntervals through LiveIntervalAnalysis instead of changing
them directly.

llvm-svn: 226687

llvm-svn: 226686

verification. Tested via a unit test.

Follow-up to r226616.

llvm-svn: 226684

This fixes it for SI. It also removes the pattern
used previously for Evergreen for f32. I'm not sure
if the the new R600 output is better or not, but it uses
1 fewer instructions if BFI is available.

llvm-svn: 226682

llvm-svn: 226681

Now that we can fully specify extload legality, we can declare them
legal for the PMOVSX/PMOVZX instructions.  This for instance enables
a DAGCombine to fire on code such as
  (and (<zextload-equivalent> ...), <redundant mask>)
to turn it into:
  (zextload ...)
as seen in the testcase changes.

There is one regression, in widen_load-2.ll: we're no longer able
to do store-to-load forwarding with illegal extload memory types.
This will be addressed separately.

Differential Revision: http://reviews.llvm.org/D6533

llvm-svn: 226676

llvm-svn: 226672

llvm-svn: 226671

llvm-svn: 226669

It hadn't gone through review yet, but was still on my local copy.

This reverts commit r226663

llvm-svn: 226665

AAPCS64 says that it's up to the platform to specify whether x18 is
reserved, and a first step on that way is to add a flag controlling
it.

From: Andrew Turner <andrew@fubar.geek.nz>
llvm-svn: 226664

llvm-svn: 226663

llvm-svn: 226661

When opt is compiled with AddressSanitizer it takes more than 30 seconds
to unroll the loop in unroll_1M().

llvm-svn: 226660

Previously we always stored 4 bytes of origin at the destination address
even for 8-byte (and longer) stores.

This should fix rare missing, or incorrect, origin stacks in MSan reports.

llvm-svn: 226658

Implement microMIPS 16-bit unconditional branch instruction B.

Implemented 16-bit microMIPS unconditional instruction has real name B16, and
B is an alias which expands to either B16 or BEQ according to the rules:
b 256 --> b16 256 # R_MICROMIPS_PC10_S1
b 12256 --> beq $zero, $zero, 12256 # R_MICROMIPS_PC16_S1
b label --> beq $zero, $zero, label # R_MICROMIPS_PC16_S1

Differential Revision: http://reviews.llvm.org/D3514

llvm-svn: 226657

Differential Revision: http://reviews.llvm.org/D6582

llvm-svn: 226656

Because in its primary function pass the combiner is run repeatedly over
the same function until doing so produces no changes, it is essentially
to not re-allocate the worklist. However, as a utility, the more common
pattern would be to put a limited set of instructions in the worklist
rather than the entire function body. That is also the more likely
pattern when used by the new pass manager.

The result is a very light weight combiner that does the visiting with
a separable worklist. This can then be wrapped up in a helper function
for users that want a combiner utility, or as I have here it can be
wrapped up in a pass which manages the iterations used when combining an
entire function's instructions.

Hopefully this removes some of the worst of the interface warts that
became apparant with the last patch here. However, there is clearly more
work. I've again left some FIXMEs for the most egregious. The ones that
stick out to me are the exposure of the worklist and IR builder as
public members, and the use of pointers rather than references. However,
fixing these is likely to be much more mechanical and less interesting
so I didn't want to touch them in this patch.

llvm-svn: 226655

SimplifyLibCalls utility by sinking it into the specific call part of
the combiner.

This will avoid us needing to do any contortions to build this object in
a subsequent refactoring I'm doing and seems generally better factored.
We don't need this utility everywhere and it carries no interesting
state so we might as well build it on demand.

llvm-svn: 226654