Commit Graph

2052 Commits

Author SHA1 Message Date
David Blaikie
198d8baafb [opaque pointer type] Add textual IR support for explicit type parameter to getelementptr instruction
One of several parallel first steps to remove the target type of pointers,
replacing them with a single opaque pointer type.

This adds an explicit type parameter to the gep instruction so that when the
first parameter becomes an opaque pointer type, the type to gep through is
still available to the instructions.

* This doesn't modify gep operators, only instructions (operators will be
  handled separately)

* Textual IR changes only. Bitcode (including upgrade) and changing the
  in-memory representation will be in separate changes.

* geps of vectors are transformed as:
    getelementptr <4 x float*> %x, ...
  ->getelementptr float, <4 x float*> %x, ...
  Then, once the opaque pointer type is introduced, this will ultimately look
  like:
    getelementptr float, <4 x ptr> %x
  with the unambiguous interpretation that it is a vector of pointers to float.

* address spaces remain on the pointer, not the type:
    getelementptr float addrspace(1)* %x
  ->getelementptr float, float addrspace(1)* %x
  Then, eventually:
    getelementptr float, ptr addrspace(1) %x

Importantly, the massive amount of test case churn has been automated by
same crappy python code. I had to manually update a few test cases that
wouldn't fit the script's model (r228970,r229196,r229197,r229198). The
python script just massages stdin and writes the result to stdout, I
then wrapped that in a shell script to handle replacing files, then
using the usual find+xargs to migrate all the files.

update.py:
import fileinput
import sys
import re

ibrep = re.compile(r"(^.*?[^%\w]getelementptr inbounds )(((?:<\d* x )?)(.*?)(| addrspace\(\d\)) *\*(|>)(?:$| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$))")
normrep = re.compile(       r"(^.*?[^%\w]getelementptr )(((?:<\d* x )?)(.*?)(| addrspace\(\d\)) *\*(|>)(?:$| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$))")

def conv(match, line):
  if not match:
    return line
  line = match.groups()[0]
  if len(match.groups()[5]) == 0:
    line += match.groups()[2]
  line += match.groups()[3]
  line += ", "
  line += match.groups()[1]
  line += "\n"
  return line

for line in sys.stdin:
  if line.find("getelementptr ") == line.find("getelementptr inbounds"):
    if line.find("getelementptr inbounds") != line.find("getelementptr inbounds ("):
      line = conv(re.match(ibrep, line), line)
  elif line.find("getelementptr ") != line.find("getelementptr ("):
    line = conv(re.match(normrep, line), line)
  sys.stdout.write(line)

apply.sh:
for name in "$@"
do
  python3 `dirname "$0"`/update.py < "$name" > "$name.tmp" && mv "$name.tmp" "$name"
  rm -f "$name.tmp"
done

The actual commands:
From llvm/src:
find test/ -name *.ll | xargs ./apply.sh
From llvm/src/tools/clang:
find test/ -name *.mm -o -name *.m -o -name *.cpp -o -name *.c | xargs -I '{}' ../../apply.sh "{}"
From llvm/src/tools/polly:
find test/ -name *.ll | xargs ./apply.sh

After that, check-all (with llvm, clang, clang-tools-extra, lld,
compiler-rt, and polly all checked out).

The extra 'rm' in the apply.sh script is due to a few files in clang's test
suite using interesting unicode stuff that my python script was throwing
exceptions on. None of those files needed to be migrated, so it seemed
sufficient to ignore those cases.

Reviewers: rafael, dexonsmith, grosser

Differential Revision: http://reviews.llvm.org/D7636

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230786 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-27 19:29:02 +00:00
Hal Finkel
532af6859f [InstCombine/PowerPC] Convert aligned QPX load/store intrinsics into loads/stores
InstCombine has long had logic to convert aligned Altivec load/store intrinsics
into regular loads and stores. This mirrors that functionality for QPX vector
load/store intrinsics.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230660 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-26 18:56:03 +00:00
Hal Finkel
9f9a6fd453 [InstCombine] Add a test for altivec load/store intrinsic simplification
InstCombine has logic to convert aligned Altivec load/store intrinsics into
regular loads and stores. Unfortunately, there seems to be no regression test
covering this behavior. Adding one...

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230632 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-26 14:22:41 +00:00
JF Bastien
6fec24744f InstCombine: extract instead of shuffle when performing vector/array type punning
Summary: SROA generates code that isn't quite as easy to optimize and contains unusual-sized shuffles, but that code is generally correct. As discussed in D7487 the right place to clean things up is InstCombine, which will pick up the type-punning pattern and transform it into a more obvious bitcast+extractelement, while leaving the other patterns SROA encounters as-is.

Test Plan: make check

Reviewers: jvoung, chandlerc

Subscribers: llvm-commits

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230560 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-25 22:30:51 +00:00
Charles Davis
fba7e30f0f [IC] Turn non-null MD on pointer loads to range MD on integer loads.
Summary:
This change fixes the FIXME that you recently added when you committed
(a modified version of) my patch.  When `InstCombine` combines a load and
store of an pointer to those of an equivalently-sized integer, it currently
drops any `!nonnull` metadata that might be present.  This change replaces
`!nonnull` metadata with `!range !{ 1, -1 }` metadata instead.

Reviewers: chandlerc

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D7621

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230462 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-25 05:10:25 +00:00
Sanjoy Das
f922d9cfe4 New instcombine rule: max(~a,~b) -> ~min(a, b)
This case is interesting because ScalarEvolutionExpander lowers min(a,
b) as ~max(~a,~b).  I think the profitability heuristics can be made
more clever/aggressive, but this is a start.

Differential Revision: http://reviews.llvm.org/D7821



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230285 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-24 00:08:41 +00:00
Hal Finkel
5ecf528fc2 [InstCombine] Remove unnecessary variable indexing into single-element arrays
This change addresses a deficiency pointed out in PR22629. To copy from the bug
report:

[from the bug report]

Consider this code:

int f(int x) {
  int a[] = {12};
  return a[x];
}

GCC knows to optimize this to

movl     $12, %eax
ret

The code generated by recent Clang at -O3 is:

movslq   %edi, %rax
movl     .L_ZZ1fiE1a(,%rax,4), %eax
retq

.L_ZZ1fiE1a:
  .long    12                      # 0xc

[end from the bug report]

This definitely seems worth fixing. I've also seen this kind of code before (as
the base case of generic vector wrapper templates with one element).

The general idea is to look at the GEP feeding a load or a store, which has
some variable as its first non-zero index, and determine if that index must be
zero (or else an out-of-bounds access would occur). We can do this for allocas
and globals with constant initializers where we know the maximum size of the
underlying object. When we find such a GEP, we create a new one for the memory
access with that first variable index replaced with a constant zero.

Even if we can't eliminate the memory access (and sometimes we can't), it is
still useful because it removes unnecessary indexing calculations.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229959 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-20 03:05:53 +00:00
Akira Hatanaka
5506e22865 [InstCombine] Do not insert a GEP instruction before a landingpad instruction.
InstCombiner::visitGetElementPtrInst was using getFirstNonPHI to compute the
insertion point, which caused the verifier to complain when a GEP was inserted
before a landingpad instruction. This commit fixes it to use getFirstInsertionPt
instead.

rdar://problem/19394964


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229619 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-18 03:30:11 +00:00
Mehdi Amini
e97c675022 InstCombine: fold more cases of (fp_to_u/sint (u/sint_to_fp val))
Fixes radar 15486701.

From: Fiona Glaser <fglaser@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229437 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-16 21:47:54 +00:00
Mehdi Amini
be55a79941 Tests: reformat sitofp.ll and use FileCheck
From: Fiona Glaser <fglaser@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229436 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-16 21:47:50 +00:00
Ramkumar Ramachandra
0608cec657 InstCombine: propagate deref via new addDereferenceableAttr
The "dereferenceable" attribute cannot be added via .addAttribute(),
since it also expects a size in bytes. AttrBuilder#addAttribute or
AttributeSet#addAttribute is wrapped by classes Function, InvokeInst,
and CallInst. Add corresponding wrappers to
AttrBuilder#addDereferenceableAttr.

Having done this, propagate the dereferenceable attribute via
gc.relocate, adding a test to exercise it. Note that -datalayout is
required during execution over and above -instcombine, because
InstCombine only optionally requires DataLayoutPass.

Differential Revision: http://reviews.llvm.org/D7510

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229265 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-14 19:37:54 +00:00
Philip Reames
d777c2c0c0 [InstCombine] When canonicalizing gep indices, prefer zext when possible
If we know that the sign bit of a value being sign extended is zero, we can use a zero extension instead.  This is motivated by the fact that zero extensions are generally cheaper on x86 (and most other architectures?).  We already apply a similar transform in DAGCombine, this just extends that to the IR level.

This comes up when we eagerly canonicalize gep indices to the width of a machine register (i64 on x86_64). To do so, we insert sign extensions (sext) to promote smaller types. 

Differential Revision: http://reviews.llvm.org/D7255



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229189 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-14 00:05:36 +00:00
Andrea Di Biagio
d25126faae [InstCombine] Fix regression introduced at r227197.
This patch fixes a problem I accidentally introduced in an instruction combine
on select instructions added at r227197. That revision taught the instruction
combiner how to fold a cttz/ctlz followed by a icmp plus select into a single
cttz/ctlz with flag 'is_zero_undef' cleared.

However, the new rule added at r227197 would have produced wrong results in the
case where a cttz/ctlz with flag 'is_zero_undef' cleared was follwed by a
zero-extend or truncate. In that case, the folded instruction would have
been inserted in a wrong location thus leaving the CFG in an inconsistent
state.

This patch fixes the problem and add two reproducible test cases to
existing test 'InstCombine/select-cmp-cttz-ctlz.ll'.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229124 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-13 16:33:34 +00:00
Michael Liao
4235574ce3 [InstCombine] Fix a bug when combining icmp from ptrtoint
- First, there's a crash when we try to combine that pointers into `icmp`
  directly by creating a `bitcast`, which is invalid if that two pointers are
  from different address spaces.

- It's not always appropriate to cast one pointer to another if they are from
  different address spaces as that is not no-op cast. Instead, we only combine
  `icmp` from `ptrtoint` if that two pointers are of the same address space.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229063 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-13 04:51:26 +00:00
Chandler Carruth
a768c4a096 [IC] Fix a bug with the instcombine canonicalizing of loads and
propagating of metadata.

We were propagating !nonnull metadata even when the newly formed load is
no longer of a pointer type. This is clearly broken and results in LLVM
failing the verifier and aborting. This patch just restricts the
propagation of !nonnull metadata to when we actually have a pointer
type.

This bug report and the initial version of this patch was provided by
Charles Davis! Many thanks for finding this!

We still need to add logic to round-trip the metadata correctly if we
combine from pointer types to integer types and then back by using range
metadata for the integer type loads. But this is the minimal and safe
version of the patch, which is important so we can backport it into 3.6.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229029 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-13 02:30:01 +00:00
Benjamin Kramer
d038a7fe67 InstCombine: Allow folding of xor into icmp by changing the predicate for vectors
The loop vectorizer can create this pattern.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228954 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-12 20:26:46 +00:00
Chandler Carruth
3e77df419d Revert r228556: InstCombine: propagate nonNull through assume
This commit isn't using the correct context, and is transfoming calls
that are operands to loads rather than calls that are operands to an
icmp feeding into an assume. I've replied on the original review thread
with a very reduced test case and some thoughts on how to rework this.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228677 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-10 08:07:32 +00:00
Ramkumar Ramachandra
5439a80dca InstCombine: propagate nonNull through assume
Make assume (load (call|invoke) != null) set nonNull return attribute
for the call and invoke. Also include tests.

Differential Revision: http://reviews.llvm.org/D7107

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228556 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-09 01:13:13 +00:00
Matthias Braun
2f2dec87fb InstCombine: Combine select sequences into a single select
Normalize
select(C0, select(C1, a, b), b) -> select((C0 & C1), a, b)
select(C0, a, select(C1, a, b)) -> select((C0 | C1), a, b)

This normal form may enable further combines on the And/Or and shortens
paths for the values. Many targets prefer the other but can go back
easily in CodeGen.

Differential Revision: http://reviews.llvm.org/D7399

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228409 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-06 17:49:36 +00:00
Reid Kleckner
0935e7a79b Move EH personality type classification to Analysis/LibCallSemantics.h
Summary:
Also add enum types for __C_specific_handler and _CxxFrameHandler3 for
which we know a few things.

Reviewers: majnemer

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D7214

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@227284 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-28 01:17:38 +00:00
Ahmed Bougacha
37be0d7c43 [SimplifyLibCalls] Don't confuse strcpy_chk for stpcpy_chk.
This was introduced in a faulty refactoring (r225640, mea culpa):
the tests weren't testing the return values, so, for both
__strcpy_chk and __stpcpy_chk, we would return the end of the
buffer (matching stpcpy) instead of the beginning (for strcpy).

The root cause was the prefix "__" being ignored when comparing,
which made us always pick LibFunc::stpcpy_chk.
Pass the LibFunc::Func directly to avoid this kind of error.
Also, make the testcases as explicit as possible to prevent this.

The now-useful testcases expose another, entangled, stpcpy problem,
with the further simplification.  This was introduced in a
refactoring (r225640) to match the original behavior.

However, this leads to problems when successive simplifications
generate several similar instructions, none of which are removed
by the custom replaceAllUsesWith.

For instance, InstCombine (the main user) doesn't erase the
instruction in its custom RAUW.  When trying to simplify say
__stpcpy_chk:
- first, an stpcpy is created (fortified simplifier),
- second, a memcpy is created (normal simplifier), but the
  stpcpy call isn't removed.
- third, InstCombine later revisits the instructions,
  and simplifies the first stpcpy to a memcpy.  We now have
  two memcpys.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@227250 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-27 21:52:16 +00:00
Andrea Di Biagio
944d86558e [InstCombine] Teach how to fold a select into a cttz/ctlz with the 'is_zero_undef' flag.
This patch teaches the Instruction Combiner how to fold a cttz/ctlz followed by
a icmp plus select into a single cttz/ctlz with flag 'is_zero_undef' cleared.

Added test InstCombine/select-cmp-cttz-ctlz.ll.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@227197 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-27 15:58:14 +00:00
Chandler Carruth
7a98df7f74 [PM] Port instcombine to the new pass manager!
This is exciting as this is a much more involved port. This is
a complex, existing transformation pass. All of the core logic is shared
between both old and new pass managers. Only the access to the analyses
is separate because the actual techniques are separate. This also uses
a bunch of different and interesting analyses and is the first time
where we need to use an analysis across an IR layer.

This also paves the way to expose instcombine utility functions. I've
got a static function that implements the core pass logic over
a function which might be mildly interesting, but more interesting is
likely exposing a routine which just uses instructions *already in* the
worklist and combines until empty.

I've switched one of my favorite instcombine tests to run with both as
well to make sure this keeps working.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226987 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-24 04:19:17 +00:00
Chandler Carruth
b778cbc0c8 [canonicalize] Teach InstCombine to canonicalize loads which are only
ever stored to always use a legal integer type if one is available.

Regardless of whether this particular type is good or bad, it ensures we
don't get weird differences in generated code (and resulting
performance) from "equivalent" patterns that happen to end up using
a slightly different type.

After some discussion on llvmdev it seems everyone generally likes this
canonicalization. However, there may be some parts of LLVM that handle
it poorly and need to be fixed. I have at least verified that this
doesn't impede GVN and instcombine's store-to-load forwarding powers in
any obvious cases. Subtle cases are exactly what we need te flush out if
they remain.

Also note that this IR pattern should already be hitting LLVM from Clang
at least because it is exactly the IR which would be produced if you
used memcpy to copy a pointer or floating point between memory instead
of a variable.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226781 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-22 05:08:12 +00:00
David Majnemer
c070e4e528 InstCombine: Don't strip bitcasts off of callsites marked 'thunk'
The return type of a thunk is meaningless, we just want the arguments
and return value to be forwarded.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226708 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-21 22:32:04 +00:00
Richard Smith
ef7d38d35a For PR21145: recognise a builtin call to a known deallocation function even if
it's defined in the current module. Clang generates this situation for the
C++14 sized deallocation functions, because it generates a weak definition in
case one isn't provided by the C++ runtime library.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226069 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-15 01:00:33 +00:00
Duncan P. N. Exon Smith
37ac8d3622 IR: Move MDLocation into place
This commit moves `MDLocation`, finishing off PR21433.  There's an
accompanying clang commit for frontend testcases.  I'll attach the
testcase upgrade script I used to PR21433 to help out-of-tree
frontends/backends.

This changes the schema for `DebugLoc` and `DILocation` from:

    !{i32 3, i32 7, !7, !8}

to:

    !MDLocation(line: 3, column: 7, scope: !7, inlinedAt: !8)

Note that empty fields (line/column: 0 and inlinedAt: null) don't get
printed by the assembly writer.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226048 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-14 22:27:36 +00:00
David Majnemer
5e8cd99f55 InstCombine: Don't take A-B<0 into A<B if A-B has other uses
This fixes PR22226.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226023 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-14 19:26:56 +00:00
Ahmed Bougacha
61d6dc41fa [SimplifyLibCalls] Don't try to simplify indirect calls.
It turns out, all callsites of the simplifier are guarded by a check for
CallInst::getCalledFunction (i.e., to make sure the callee is direct).

This check wasn't done when trying to further optimize a simplified fortified
libcall, introduced by a refactoring in r225640.

Fix that, add a testcase, and document the requirement.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225895 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-14 00:55:05 +00:00
Matt Arsenault
3b1f741856 Fix fcmp + fabs instcombines when using the intrinsic
This was only handling the libcall. This is another example
of why only the intrinsic should ever be used when it exists.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225465 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-08 20:09:34 +00:00
Matt Arsenault
374b57cec9 Fix using wrong intrinsic in test
This is a leftover from renaming the intrinsic.
It's surprising the unknown llvm. intrinsic wasn't rejected.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225304 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-06 23:00:33 +00:00
Matt Arsenault
d883ca0ca7 Convert fcmp with 0.0 from casted integers to icmp
This is already handled in general when it is known the
conversion can't lose bits with smaller integer types
casted into wider floating point types.

This pattern happens somewhat often in GPU programs that cast
workitem intrinsics to float, which are often compared with 0.

Specifically handle the special case of compares with zero which
should also be known to not lose information. I had a more general
version of this which allows equality compares if the casted float is
exactly representable in the integer, but I'm not 100% confident that
is always correct.

Also fold cases that aren't integers to true / false.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225265 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-06 15:50:59 +00:00
David Majnemer
51e4a66417 InstCombine: Bitcast call arguments from/to pointer/integer type
Try harder to get rid of bitcast'd calls by ptrtoint/inttoptr'ing
arguments and return values when DataLayout says it is safe to do so.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225254 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-06 08:41:31 +00:00
David Majnemer
07d7dbae9e InstCombine: match can find ConstantExprs, don't assume we have a Value
We assumed the output of a match was a Value, this would cause us to
assert because we would fail a cast<>.  Instead, use a helper in the
Operator family to hide the distinction between Value and Constant.

This fixes PR22087.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225127 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-04 07:36:02 +00:00
David Majnemer
5e9c6212a8 InstCombine: Detect when llvm.umul.with.overflow always overflows
We know overflow always occurs if both ~LHSKnownZero * ~RHSKnownZero
and LHSKnownOne * RHSKnownOne overflow.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225077 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-02 07:29:47 +00:00
Sanjay Patel
28650b8ec2 InstCombine: fsub nsz 0, X ==> fsub nsz -0.0, X
Some day the backend may handle instruction-level fast math flags and make
this transform unnecessary, but it's still better practice to use the canonical
representation of fneg when possible (use a -0.0).

This is a partial fix for PR20870 ( http://llvm.org/bugs/show_bug.cgi?id=20870 ).
See also http://reviews.llvm.org/D6723.

Differential Revision: http://reviews.llvm.org/D6731



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225050 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-31 22:14:05 +00:00
David Majnemer
0f77ccd6bb InstCombine: try to transform A-B < 0 into A < B
We are allowed to move the 'B' to the right hand side if we an prove
there is no signed overflow and if the comparison itself is signed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225034 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-31 04:21:41 +00:00
Philip Reames
91a083c57f Carry facts about nullness and undef across GC relocation
This change implements four basic optimizations:

    If a relocated value isn't used, it doesn't need to be relocated.
    If the value being relocated is null, relocation doesn't change that. (Technically, this might be collector specific. I don't know of one which it doesn't work for though.)
    If the value being relocated is undef, the relocation is meaningless.
    If the value being relocated was known nonnull, the relocated pointer also isn't null. (Since it points to the same source language object.)

I outlined other planned work in comments.

Differential Revision: http://reviews.llvm.org/D6600



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224968 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-29 23:27:30 +00:00
Philip Reames
456b7b602c Loading from null is valid outside of addrspace 0
This patches fixes a miscompile where we were assuming that loading from null is undefined and thus we could assume it doesn't happen.  This transform is perfectly legal in address space 0, but is not neccessarily legal in other address spaces.

We really should introduce a hook to control this property on a per target per address space basis.  We may be loosing valuable optimizations in some address spaces by being too conservative.

Original patch by Thomas P Raoux (submitted to llvm-commits), tests and formatting fixes by me.




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224961 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-29 22:46:21 +00:00
David Majnemer
7627d9c229 InstCombine: Infer nuw for multiplies
A multiply cannot unsigned wrap if there are bitwidth, or more, leading
zero bits between the two operands.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224849 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-26 09:50:35 +00:00
David Majnemer
998ae69abe InstCombe: Infer nsw for multiplies
We already utilize this logic for reducing overflow intrinsics, it makes
sense to reuse it for normal multiplies as well.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224847 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-26 09:10:14 +00:00
Michael Kuperstein
a098c770e1 [ValueTracking] Move GlobalAlias handling to be after the max depth check in computeKnownBits()
GlobalAlias handling used to be after GlobalValue handling, which meant it was, in practice, dead code. r220165 moved GlobalAlias handling to be before GlobalValue handling, but also moved it to be before the max depth check, causing an assert due to a recursion depth limit violation. 

This moves GlobalAlias handling forward to where it's safe, and changes the GlobalValue handling to only look at GlobalObjects.

Differential Revision: http://reviews.llvm.org/D6758

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224765 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-23 11:33:41 +00:00
David Majnemer
6df827240e This should have been part of r224676.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224677 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-20 04:48:34 +00:00
David Majnemer
854a37649a InstCombine: Squash an icmp+select into bitwise arithmetic
(X & INT_MIN) == 0 ? X ^ INT_MIN : X  into  X | INT_MIN
(X & INT_MIN) != 0 ? X ^ INT_MIN : X  into  X & INT_MAX

This fixes PR21993.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224676 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-20 04:45:35 +00:00
Bruno Cardoso Lopes
06833ca7c1 Reapply: [InstCombine] Fix visitSwitchInst to use right operand types for sub cstexpr
The visitSwitchInst generates SUB constant expressions to recompute the
switch condition. When truncating the condition to a smaller type, SUB
expressions should use the previous type (before trunc) for both
operands. Also, fix code to also return the modified switch when only
the truncation is performed.

This fixes an assertion crash.

Differential Revision: http://reviews.llvm.org/D6644

rdar://problem/19191835

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224588 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-19 17:12:35 +00:00
Sanjay Patel
7c5fa50875 use -0.0 when creating an fneg instruction
Backends recognize (-0.0 - X) as the canonical form for fneg
and produce better code. Eg, ppc64 with 0.0:

   lis r2, ha16(LCPI0_0)
   lfs f0, lo16(LCPI0_0)(r2)
   fsubs f1, f0, f1
   blr

vs. -0.0:

   fneg f1, f1
   blr

Differential Revision: http://reviews.llvm.org/D6723



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224583 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-19 16:44:08 +00:00
Bruno Cardoso Lopes
01b07d541b Revert "[InstCombine] Fix visitSwitchInst to use right operand types for sub cstexpr"
Reverts commit r224574 to appease buildbots:

The visitSwitchInst generates SUB constant expressions to recompute the
switch condition. When truncating the condition to a smaller type, SUB
expressions should use the previous type (before trunc) for both
operands. This fixes an assertion crash.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224576 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-19 14:36:24 +00:00
Bruno Cardoso Lopes
cba407d019 [InstCombine] Fix visitSwitchInst to use right operand types for sub cstexpr
The visitSwitchInst generates SUB constant expressions to recompute the
switch condition. When truncating the condition to a smaller type, SUB
expressions should use the previous type (before trunc) for both
operands. This fixes an assertion crash.

Differential Revision: http://reviews.llvm.org/D6644

rdar://problem/19191835

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224574 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-19 14:23:15 +00:00
Erik Eckstein
96bd465d6c Strength reduce intrinsics with overflow into regular arithmetic operations if possible.
Some intrinsics, like s/uadd.with.overflow and umul.with.overflow, are already strength reduced.
This change adds other arithmetic intrinsics: s/usub.with.overflow, smul.with.overflow.
It completes the work on PR20194.




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224417 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-17 07:29:19 +00:00
Duncan P. N. Exon Smith
1ef70ff39b IR: Make metadata typeless in assembly
Now that `Metadata` is typeless, reflect that in the assembly.  These
are the matching assembly changes for the metadata/value split in
r223802.

  - Only use the `metadata` type when referencing metadata from a call
    intrinsic -- i.e., only when it's used as a `Value`.

  - Stop pretending that `ValueAsMetadata` is wrapped in an `MDNode`
    when referencing it from call intrinsics.

So, assembly like this:

    define @foo(i32 %v) {
      call void @llvm.foo(metadata !{i32 %v}, metadata !0)
      call void @llvm.foo(metadata !{i32 7}, metadata !0)
      call void @llvm.foo(metadata !1, metadata !0)
      call void @llvm.foo(metadata !3, metadata !0)
      call void @llvm.foo(metadata !{metadata !3}, metadata !0)
      ret void, !bar !2
    }
    !0 = metadata !{metadata !2}
    !1 = metadata !{i32* @global}
    !2 = metadata !{metadata !3}
    !3 = metadata !{}

turns into this:

    define @foo(i32 %v) {
      call void @llvm.foo(metadata i32 %v, metadata !0)
      call void @llvm.foo(metadata i32 7, metadata !0)
      call void @llvm.foo(metadata i32* @global, metadata !0)
      call void @llvm.foo(metadata !3, metadata !0)
      call void @llvm.foo(metadata !{!3}, metadata !0)
      ret void, !bar !2
    }
    !0 = !{!2}
    !1 = !{i32* @global}
    !2 = !{!3}
    !3 = !{}

I wrote an upgrade script that handled almost all of the tests in llvm
and many of the tests in cfe (even handling many `CHECK` lines).  I've
attached it (or will attach it in a moment if you're speedy) to PR21532
to help everyone update their out-of-tree testcases.

This is part of PR21532.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224257 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-15 19:07:53 +00:00