Commit Graph

145 Commits

Author SHA1 Message Date
Chad Rosier
3ac68db42d [ValueTracking] Improve isImpliedCondition when the dominating cond is false.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@267430 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-25 17:23:36 +00:00
Chad Rosier
2974be9d8b [ValueTracking] Improve isImpliedCondition for conditions with matching operands.
This patch improves SimplifyCFG to catch cases like:

  if (a < b) {
    if (a > b) <- known to be false
      unreachable;
  }

Phabricator Revision: http://reviews.llvm.org/D18905

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@266767 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-19 17:19:14 +00:00
Haicheng Wu
691ed105b0 [JumpThreading] See through Cast Instructions
To capture more jump-thread opportunity.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@263618 91177308-0d34-0410-b5e6-96231b3b80d8
2016-03-16 04:52:52 +00:00
Haicheng Wu
35d3c7b00e Revert "[JumpThreading] Simplify Instructions first in ComputeValueKnownInPredecessors()"
Not sure it handles undef properly.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@263605 91177308-0d34-0410-b5e6-96231b3b80d8
2016-03-15 23:38:47 +00:00
Haicheng Wu
27a460f328 [JumpThreading] Simplify Instructions first in ComputeValueKnownInPredecessors()
This change tries to find more opportunities to thread over basic blocks.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@261981 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-26 06:06:04 +00:00
Philip Reames
bf09bb7151 [LVI] Introduce an intersect operation on lattice values
LVI has several separate sources of facts - edge local conditions, recursive queries, assumes, and control independent value facts - which all apply to the same value at the same location. The existing implementation was very conservative about exploiting all of these facts at once.

This change introduces an "intersect" function specifically to abstract the action of picking a good set of facts from all of the separate facts given. At the moment, this function is relatively simple (i.e. mostly just reuses the bits which were already there), but even the minor additions reveal the inherent power. For example, JumpThreading is now capable of doing an inductive proof that a particular value is always positive and removing a half range check.

I'm currently only using the new intersect function in one place. If folks are happy with the direction of the work, I plan on making a series of small changes without review to replace mergeIn with intersect at all the appropriate places.

Differential Revision: http://reviews.llvm.org/D14476




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259461 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-02 03:15:40 +00:00
Jun Bum Lim
da7cbcd8d5 Avoid inlining call sites in unreachable-terminated block
Summary:
If the normal destination of the invoke or the parent block of the call site is unreachable-terminated, there is little point in inlining the call site unless there is literally zero cost. Unlike my previous change (D15289), this change specifically handle the call sites followed by unreachable in the same basic block for call or in the normal destination for the invoke. This change could be a reasonable first step to conservatively inline call sites leading to an unreachable-terminated block while BFI / BPI is not yet available in inliner.

Reviewers: manmanren, majnemer, hfinkel, davidxl, mcrosier, dblaikie, eraman

Subscribers: dblaikie, davidxl, mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D16616

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259403 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-01 20:55:11 +00:00
David Majnemer
75771fdb0e Add test for r257279.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@257280 91177308-0d34-0410-b5e6-96231b3b80d8
2016-01-10 07:13:33 +00:00
Haicheng Wu
1d3fb4f736 [JumpThreading] Split select that has constant conditions coming from the PHI node
Look for PHI/Select in the same BB of the form

bb:
  %p = phi [false, %bb1], [true, %bb2], [false, %bb3], [true, %bb4], ...
  %s = select p, trueval, falseval

And expand the select into a branch structure. This later enables
jump-threading over bb in this pass.

Using the similar approach of SimplifyCFG::FoldCondBranchOnPHI(), unfold
select if the associated PHI has at least one constant.  If the unfolded
select is not jump-threaded, it will be folded again in the later
optimizations.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@257198 91177308-0d34-0410-b5e6-96231b3b80d8
2016-01-08 19:39:39 +00:00
Geoff Berry
7a39479674 [JumpThreading] Fix opcode bonus in getJumpThreadDuplicationCost()
The code that was meant to adjust the duplication cost based on the
terminator opcode was not being executed in cases where the initial
threshold was hit inside the loop.

Subscribers: mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D15536

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@256568 91177308-0d34-0410-b5e6-96231b3b80d8
2015-12-29 18:10:16 +00:00
Cong Hou
40288f7238 [BPI] Replace weights by probabilities in BPI.
This patch removes all weight-related interfaces from BPI and replace
them by probability versions. With this patch, we won't use edge weight
anymore in either IR or MC passes. Edge probabilitiy is a better
representation in terms of CFG update and validation.


Differential revision: http://reviews.llvm.org/D15519 




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@256263 91177308-0d34-0410-b5e6-96231b3b80d8
2015-12-22 18:56:14 +00:00
Sanjoy Das
ee37e50003 [JumpThreading] Use dominating conditions to prove implications
Summary:
If P branches to Q conditional on C and Q branches to R conditional on
C' and C => C' then the branch conditional on C' can be folded to an
unconditional branch.

Reviewers: reames

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D13972

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251557 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-28 21:27:08 +00:00
Manman Ren
0f34207b1d Recommit r250345, it was reverted in r250366 to investigate a bot failure.
Our internal bot is still red after r250366.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@250415 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-15 14:59:40 +00:00
Manman Ren
9b380854cd Temporarily revert r250345 to sort out bot failure.
With r250345 and r250343, we start to observe the following failure
when bootstrap clang with lto and pgo:
PHI node entries do not match predecessors!
  %.sroa.029.3.i = phi %"class.llvm::SDNode.13298"* [ null, %30953 ], [ null, %31017 ], [ null, %30998 ], [ null, %_ZN4llvm8dyn_castINS_14ConstantSDNodeENS_7SDValueEEENS_10cast_rettyIT_T0_E8ret_typeERS5_.exit.i.1804 ], [ null, %30975 ], [ null, %30991 ], [ null, %_ZNK4llvm3EVT13getScalarTypeEv.exit.i.1812 ], [ %..sroa.029.0.i, %_ZN4llvm11SmallVectorIiLj8EED1Ev.exit.i.1826 ], !dbg !451895
label %30998
label %_ZNK4llvm3EVTeqES0_.exit19.thread.i
LLVM ERROR: Broken function found, compilation aborted!

I will re-commit this if the bot does not recover.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@250366 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-15 04:58:24 +00:00
Cong Hou
a99158bbd8 Update the branch weight metadata in JumpThreading pass.
Currently in JumpThreading pass, the branch weight metadata is not updated after CFG modification. Consider the jump threading on PredBB, BB, and SuccBB. After jump threading, the weight on BB->SuccBB should be adjusted as some of it is contributed by the edge PredBB->BB, which doesn't exist anymore. This patch tries to update the edge weight in metadata on BB->SuccBB by scaling it by 1 - Freq(PredBB->BB) / Freq(BB->SuccBB).

This is the third attempt to submit this patch, while the first two led to failures in some FDO tests. After investigation, it is the edge weight normalization that caused those failures. In this patch the edge weight normalization is fixed so that there is no zero weight in the output and the sum of all weights can fit in 32-bit integer. Several unit tests are added.

Differential revision: http://reviews.llvm.org/D10979



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@250345 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-14 23:14:17 +00:00
Manman Ren
df57a6779d Revert r250204 and r250240 due to bot failure. We failed to build PGO-ed clang.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@250264 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-14 03:04:03 +00:00
Cong Hou
5fa57d9ce3 Update MachineBranchProbabilityInfo::normalizeEdgeWeights to make sure there is no zero weight in the output, and also add a missing test for JumpThreading.
The test is for the patch in http://reviews.llvm.org/D10979 but was missing when committing that patch.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@250240 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-13 22:27:41 +00:00
Manman Ren
a69c551eea Revert 250089 due to bot failure. It failed when building clang itself with PGO.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@250145 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-13 03:38:02 +00:00
Cong Hou
152b80c1ee Update the branch weight metadata in JumpThreading pass.
In JumpThreading pass, the branch weight metadata is not updated after CFG modification. Consider the jump threading on PredBB, BB, and SuccBB. After jump threading, the weight on BB->SuccBB should be adjusted as some of it is contributed by the edge PredBB->BB, which doesn't exist anymore. This patch tries to update the edge weight in metadata on BB->SuccBB by scaling it by 1 - Freq(PredBB->BB) / Freq(BB->SuccBB). 

Differential revision: http://reviews.llvm.org/D10979



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@250089 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-12 19:44:08 +00:00
Philip Reames
9c89f4441e [LazyValueInfo] Look through Phi nodes when trying to prove a predicate
If asked to prove a predicate about a value produced by a PHI node, LazyValueInfo was unable to do so even if the predicate was known to be true for each input to the PHI. This prevented JumpThreading from eliminating a provably redundant branch.

The problematic test case looks something like this:
ListNode *p = ...;
while (p != null) {
  if (!p) return;
  x = g->x; // unrelated
  p = p->next
}

The null check at the top of the loop is redundant since the value of 'p' is null checked on entry to the loop and before executing the backedge. This resulted in us a) executing an extra null check per iteration and b) not being able to LICM unrelated loads after the check since we couldn't prove they would execute or that their dereferenceability wasn't effected by the null check on the first iteration.

Differential Revision: http://reviews.llvm.org/D12383



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246465 91177308-0d34-0410-b5e6-96231b3b80d8
2015-08-31 18:31:48 +00:00
Jingyue Wu
0a613536b1 [JumpThreading] make jump threading respect convergent annotation.
Summary:
JumpThreading shouldn't duplicate a convergent call, because that would move a convergent call into a control-inequivalent location. For example,
  if (cond) {
    ...
  } else {
    ...
  }
  convergent_call();
  if (cond) {
    ...
  } else {
    ...
  }
should not be optimized to
  if (cond) {
    ...
    convergent_call();
    ...
  } else {
    ...
    convergent_call();
    ...
  }

Test Plan: test/Transforms/JumpThreading/basic.ll

Patch by Xuetian Weng. 

Reviewers: resistor, arsenm, jingyue

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D12484

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246415 91177308-0d34-0410-b5e6-96231b3b80d8
2015-08-31 06:10:27 +00:00
David Majnemer
cc714e2142 Move the personality function from LandingPadInst to Function
The personality routine currently lives in the LandingPadInst.

This isn't desirable because:
- All LandingPadInsts in the same function must have the same
  personality routine.  This means that each LandingPadInst beyond the
  first has an operand which produces no additional information.

- There is ongoing work to introduce EH IR constructs other than
  LandingPadInst.  Moving the personality routine off of any one
  particular Instruction and onto the parent function seems a lot better
  than have N different places a personality function can sneak onto an
  exceptional function.

Differential Revision: http://reviews.llvm.org/D10429

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239940 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-17 20:52:32 +00:00
Philip Reames
16e7e690b7 [JumpThreading] Simplify comparisons when simplifying branches
If we have recognized that a conditional is constant at a particular location in the code (while trying to decide if we can simplify a conditional branch), we can eagerly replace that condition with a constant if it's definition is post dominated by the branch in question.

In practice, this ends up being a compile time savings at most. JumpThreading would have visited each using branch anyways. CVP would have visited the cmp itself again. Unless LVI gives up early, we shouldn't gain any addition power by doing this transformation early. What we do gain is simplicity and compile time.

Differential Revision: http://reviews.llvm.org/D9312



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236684 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-07 00:19:14 +00:00
David Blaikie
32b845d223 [opaque pointer type] Add textual IR support for explicit type parameter to the call instruction
See r230786 and r230794 for similar changes to gep and load
respectively.

Call is a bit different because it often doesn't have a single explicit
type - usually the type is deduced from the arguments, and just the
return type is explicit. In those cases there's no need to change the
IR.

When that's not the case, the IR usually contains the pointer type of
the first operand - but since typed pointers are going away, that
representation is insufficient so I'm just stripping the "pointerness"
of the explicit type away.

This does make the IR a bit weird - it /sort of/ reads like the type of
the first operand: "call void () %x(" but %x is actually of type "void
()*" and will eventually be just of type "ptr". But this seems not too
bad and I don't think it would benefit from repeating the type
("void (), void () * %x(" and then eventually "void (), ptr %x(") as has
been done with gep and load.

This also has a side benefit: since the explicit type is no longer a
pointer, there's no ambiguity between an explicit type and a function
that returns a function pointer. Previously this case needed an explicit
type (eg: a function returning a void() function was written as
"call void () () * @x(" rather than "call void () * @x(" because of the
ambiguity between a function returning a pointer to a void() function
and a function returning void).

No ambiguity means even function pointer return types can just be
written alone, without writing the whole function's type.

This leaves /only/ the varargs case where the explicit type is required.

Given the special type syntax in call instructions, the regex-fu used
for migration was a bit more involved in its own unique way (as every
one of these is) so here it is. Use it in conjunction with the apply.sh
script and associated find/xargs commands I've provided in rr230786 to
migrate your out of tree tests. Do let me know if any of this doesn't
cover your cases & we can iterate on a more general script/regexes to
help others with out of tree tests.

About 9 test cases couldn't be automatically migrated - half of those
were functions returning function pointers, where I just had to manually
delete the function argument types now that we didn't need an explicit
function type there. The other half were typedefs of function types used
in calls - just had to manually drop the * from those.

import fileinput
import sys
import re

pat = re.compile(r'((?:=|:|^|\s)call\s(?:[^@]*?))(\s*$|\s*(?:(?:\[\[[a-zA-Z0-9_]+\]\]|[@%](?:(")?[\\\?@a-zA-Z0-9_.]*?(?(3)"|)|{{.*}}))(?:\(|$)|undef|inttoptr|bitcast|null|asm).*$)')
addrspace_end = re.compile(r"addrspace\(\d+\)\s*\*$")
func_end = re.compile("(?:void.*|\)\s*)\*$")

def conv(match, line):
  if not match or re.search(addrspace_end, match.group(1)) or not re.search(func_end, match.group(1)):
    return line
  return line[:match.start()] + match.group(1)[:match.group(1).rfind('*')].rstrip() + match.group(2) + line[match.end():]

for line in sys.stdin:
  sys.stdout.write(conv(re.search(pat, line), line))

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235145 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-16 23:24:18 +00:00
David Blaikie
5a70dd1d82 [opaque pointer type] Add textual IR support for explicit type parameter to gep operator
Similar to gep (r230786) and load (r230794) changes.

Similar migration script can be used to update test cases, which
successfully migrated all of LLVM and Polly, but about 4 test cases
needed manually changes in Clang.

(this script will read the contents of stdin and massage it into stdout
- wrap it in the 'apply.sh' script shown in previous commits + xargs to
apply it over a large set of test cases)

import fileinput
import sys
import re

rep = re.compile(r"(getelementptr(?:\s+inbounds)?\s*\()((<\d*\s+x\s+)?([^@]*?)(|\s*addrspace\(\d+\))\s*\*(?(3)>)\s*)(?=$|%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|zeroinitializer|<|\[\[[a-zA-Z]|\{\{)", re.MULTILINE | re.DOTALL)

def conv(match):
  line = match.group(1)
  line += match.group(4)
  line += ", "
  line += match.group(2)
  return line

line = sys.stdin.read()
off = 0
for match in re.finditer(rep, line):
  sys.stdout.write(line[off:match.start()])
  sys.stdout.write(conv(match))
  off = match.end()
sys.stdout.write(line[off:])

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232184 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-13 18:20:45 +00:00
David Blaikie
7c9c6ed761 [opaque pointer type] Add textual IR support for explicit type parameter to load instruction
Essentially the same as the GEP change in r230786.

A similar migration script can be used to update test cases, though a few more
test case improvements/changes were required this time around: (r229269-r229278)

import fileinput
import sys
import re

pat = re.compile(r"((?:=|:|^)\s*load (?:atomic )?(?:volatile )?(.*?))(| addrspace\(\d+\) *)\*($| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$)")

for line in sys.stdin:
  sys.stdout.write(re.sub(pat, r"\1, \2\3*\4", line))

Reviewers: rafael, dexonsmith, grosser

Differential Revision: http://reviews.llvm.org/D7649

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230794 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-27 21:17:42 +00:00
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
David Blaikie
51e38bc096 Update a test to make it easier to migrate to untyped pointers
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229277 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-15 04:13:58 +00:00
David Majnemer
77e22b7836 ValueTracking: ComputeNumSignBits should tolerate misshapen phi nodes
PHI nodes can have zero operands in the middle of a transform.  It is
expected that utilities in Analysis don't freak out when this happens.

Note that it is considered invalid to allow these misshapen phi nodes to
make it to another pass.

This fixes PR22086.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225126 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-04 07:06:53 +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
Hans Wennborg
4d48c3f1aa LazyValueInfo: Actually re-visit partially solved block-values in solveBlockValue()
If solveBlockValue() needs results from predecessors that are not already
computed, it returns false with the intention of resuming when the dependencies
have been resolved. However, the computation would never be resumed since an
'overdefined' result had been placed in the cache, preventing any further
computation.

The point of placing the 'overdefined' result in the cache seems to have been
to break cycles, but we can check for that when inserting work items in the
BlockValue stack instead. This makes the "stop and resume" mechanism of
solveBlockValue() work as intended, unlocking more analysis.

Using this patch shaves 120 KB off a 64-bit Chromium build on Linux.

I benchmarked compiling bzip2.c at -O2 but couldn't measure any difference in
compile time.

Tests by Jiangning Liu from r215343 / PR21238, Pete Cooper, and me.

Differential Revision: http://reviews.llvm.org/D6397

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222768 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-25 17:23:05 +00:00
Chandler Carruth
080dfb5bda Fix a somewhat subtle pair of issues with JumpThreading I introduced in
r220178. First, the creation routine doesn't insert prior to the
terminator of the basic block provided, but really at the end of the
basic block. Instead, get the terminator and insert before that. The
next issue was that we need to ensure multiple PHI node entries for
a single predecessor re-use the same cast instruction rather than
creating new ones.

All of the logic here was without tests previously. I've reduced and
added a test case from the test suite that crashed without both of these
fixes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220186 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-20 05:34:36 +00:00
Hal Finkel
2993617e41 [LVI] Check for @llvm.assume dominating the edge branch
When LazyValueInfo uses @llvm.assume intrinsics to provide edge-value
constraints, we should check for intrinsics that dominate the edge's branch,
not just any potential context instructions. An assumption that dominates the
edge's branch represents a truth on that edge. This is specifically useful, for
example, if multiple predecessors assume a pointer to be nonnull, allowing us
to simplify a later null comparison.

The test case, and an initial patch, were provided by Philip Reames. Thanks!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219688 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-14 16:04:49 +00:00
James Molloy
c75d43e0c0 Revert r215343.
This was contentious and needs invesigation.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218971 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-03 09:29:24 +00:00
Hal Finkel
3ef1aae2b5 Make use of @llvm.assume from LazyValueInfo
This change teaches LazyValueInfo to use the @llvm.assume intrinsic. Like with
the known-bits change (r217342), this requires feeding a "context" instruction
pointer through many functions. Aside from a little refactoring to reuse the
logic that turns predicates into constant ranges in LVI, the only new code is
that which can 'merge' the range from an assumption into that otherwise
computed. There is also a small addition to JumpThreading so that it can have
LVI use assumptions in the same block as the comparison feeding a conditional
branch.

With this patch, we can now simplify this as expected:
int foo(int a) {
  __builtin_assume(a > 5);
  if (a > 3) {
    bar();
    return 1;
  }
  return 0;
}

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217345 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-07 20:29:59 +00:00
Jiangning Liu
1505fa4376 In LVI(Lazy Value Info), originally value on a BB can only be caculated once,
and the lattice will be updated to be a state other than "undefined". This
limiation could miss some opportunities of lowering "overdefined" to be an
even accurate value. So this patch ask the algorithm to try to lower the
lattice value again even if the value has been lowered to be "overdefined".



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215343 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-11 05:02:04 +00:00
Dinesh Dwivedi
199da600f3 Fixed jump threading going to infinite loop.
This patch add code to remove unreachable blocks from function
as they may cause jump threading to stuck in infinite loop.

Differential Revision: http://reviews.llvm.org/D3991



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211103 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-17 14:34:19 +00:00
Arnaud A. de Grandmaison
08f32401a9 No need for those tests to go thru llvm-as and/or llvm-dis.
opt can handle them by itself.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209689 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-27 22:03:28 +00:00
Bill Wendling
3e033f2923 Don't eliminate a partially redundant load if it's in a landing pad.
A landing pad can be jumped to only by the unwind edge of an invoke
instruction. If we eliminate a partially redundant load in a landing pad, it
will create a basic block that violates this constraint. It then leads to other
problems down the line if it tries to merge that basic block with the landing
pad. Avoid this by not eliminating the load in a landing pad.

PR17621


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193064 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-21 04:09:17 +00:00
Bill Wendling
d5b7f2b62c Perform an intelligent splice of the predecessor with the single successor.
If the predecessor's being spliced into a landing pad, then we need the PHIs to
come first and the rest of the predecessor's code to come *after* the landing
pad instruction.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193035 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-19 11:27:12 +00:00
Manman Ren
9e81c3bdb2 TBAA: handle scalar TBAA format and struct-path aware TBAA format.
Remove the command line argument "struct-path-tbaa" since we should not depend
on command line argument to decide which format the IR file is using. Instead,
we check the first operand of the tbaa tag node, if it is a MDNode, we treat
it as struct-path aware TBAA format, otherwise, we treat it as scalar TBAA
format.

When clang starts to use struct-path aware TBAA format no matter whether
struct-path-tbaa is no, and we can auto-upgrade existing bc files, the support
for scalar TBAA format can be dropped.

Existing testing cases are updated to use the struct-path aware TBAA format.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191538 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-27 18:34:27 +00:00
Daniel Dunbar
24ec2e5a72 [tests] Cleanup initialization of test suffixes.
- Instead of setting the suffixes in a bunch of places, just set one master
   list in the top-level config. We now only modify the suffix list in a few
   suites that have one particular unique suffix (.ml, .mc, .yaml, .td, .py).

 - Aside from removing the need for a bunch of lit.local.cfg files, this enables
   4 tests that were inadvertently being skipped (one in
   Transforms/BranchFolding, a .s file each in DebugInfo/AArch64 and
   CodeGen/PowerPC, and one in CodeGen/SI which is now failing and has been
   XFAILED).

 - This commit also fixes a bunch of config files to use config.root instead of
   older copy-pasted code.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188513 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-16 00:37:11 +00:00
Benjamin Kramer
c11b107f21 JumpThreading: Turn a select instruction into branching if it allows to thread one half of the select.
This is a common pattern coming out of simplifycfg generating gross code.

a:                                       ; preds = %entry
  %sel = select i1 %cmp1, double %add, double 0.000000e+00
  br label %b

b:
  %cond5 = phi double [ %sel, %a ], [ %sub, %entry ]
  %cmp6 = fcmp oeq double %cond5, 0.000000e+00
  br i1 %cmp6, label %if.then, label %if.end

becomes

a:
  br i1 %cmp1, label %b, label %if.then

b:
  %cond5 = phi double [ %sub, %entry ], [ %add, %a ]
  %cmp6 = fcmp oeq double %cond5, 0.000000e+00
  br i1 %cmp6, label %if.then, label %if.end

Skipping block b completely if possible.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187880 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-07 10:29:38 +00:00
Stephen Lin
39f4e8d9cc Update Transforms tests to use CHECK-LABEL for easier debugging. No functionality change.
This update was done with the following bash script:

  find test/Transforms -name "*.ll" | \
  while read NAME; do
    echo "$NAME"
    if ! grep -q "^; *RUN: *llc" $NAME; then
      TEMP=`mktemp -t temp`
      cp $NAME $TEMP
      sed -n "s/^define [^@]*@\([A-Za-z0-9_]*\)(.*$/\1/p" < $NAME | \
      while read FUNC; do
        sed -i '' "s/;\(.*\)\([A-Za-z0-9_]*\):\( *\)@$FUNC\([( ]*\)\$/;\1\2-LABEL:\3@$FUNC(/g" $TEMP
      done
      mv $TEMP $NAME
    fi
  done


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186268 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-14 01:42:54 +00:00
Manman Ren
2dc50d3067 TBAA: remove !tbaa from testing cases if not used.
This will make it easier to turn on struct-path aware TBAA since the metadata
format will change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180796 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-30 17:52:57 +00:00
Bill Wendling
351b7a10e2 Use references to attribute groups on the call/invoke instructions.
Listing all of the attributes for the callee of a call/invoke instruction is way
too much and makes the IR unreadable. Use references to attributes instead.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@175877 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-22 09:09:42 +00:00
Dmitri Gribenko
fbfb1b286f Tests: rewrite 'opt ... %s' to 'opt ... < %s' so that opt does not emit a ModuleID
This is done to avoid odd test failures, like the one fixed in r171243.

My previous regex was not good enough to find these.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171343 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-01 13:57:25 +00:00
Dmitri Gribenko
a6542923b8 Tests: rewrite 'opt ... %s' to 'opt ... < %s' so that opt does not emit a ModuleID
This is done to avoid odd test failures, like the one fixed in r171243.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171250 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-30 02:33:22 +00:00
Dmitri Gribenko
b4912b9dcc Tests: rewrite 'opt ... %s' to 'opt ... < %s' so that opt does not emit a ModuleID
This is done to avoid odd test failures, like the one fixed in r171243.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171246 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-30 01:28:40 +00:00
James Molloy
67ae135759 Add a new attribute, 'noduplicate'. If a function contains a noduplicate call, the call cannot be duplicated - Jump threading, loop unrolling, loop unswitching, and loop rotation are inhibited if they would duplicate the call.
Similarly inlining of the function is inhibited, if that would duplicate the call (in particular inlining is still allowed when there is only one callsite and the function has internal linkage).



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170704 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-20 16:04:27 +00:00