Commit Graph

485 Commits

Author SHA1 Message Date
Florian Hahn b6613ac665 Revert r337904: [IPSCCP] Use PredicateInfo to propagate facts from cmp instructions.
I suspect it is causing the clang-stage2-Rthinlto failures.

llvm-svn: 337956
2018-07-25 19:44:19 +00:00
Florian Hahn 6f5c6adbcd Recommit r333268: [IPSCCP] Use PredicateInfo to propagate facts from cmp instructions.
r337828 resolves a PredicateInfo issue with unnamed types.

Original message:
This patch updates IPSCCP to use PredicateInfo to propagate
facts to true branches predicated by EQ and to false branches
predicated by NE.

As a follow up, we should be able to extend it to also propagate additional
facts about nonnull.

Reviewers: davide, mssimpso, dberlin, efriedma

Reviewed By: davide, dberlin

llvm-svn: 337904
2018-07-25 11:13:40 +00:00
Florian Hahn ec3ca89a17 [IPSCCP] Fix for bot failure caused by r337548
llvm-svn: 337554
2018-07-20 14:37:10 +00:00
Florian Hahn 0a560d5d9c Recommit r328307: [IPSCCP] Use constant range information for comparisons of parameters.
This version contains a fix to add values for which the state in ParamState change
to the worklist if the state in ValueState did not change. To avoid adding the
same value multiple times, mergeInValue returns true, if it added the value to
the worklist. The value is added to the worklist depending on its state in
ValueState.

Original message:
For comparisons with parameters, we can use the ParamState lattice
elements which also provide constant range information. This improves
the code for PR33253 further and gets us closer to use
ValueLatticeElement for all values.

Also, as we are using the range information in the solver directly, we
do not need tryToReplaceWithConstantRange afterwards anymore.

Reviewers: dberlin, mssimpso, davide, efriedma

Reviewed By: mssimpso

Differential Revision: https://reviews.llvm.org/D43762

llvm-svn: 337548
2018-07-20 13:29:12 +00:00
Eli Friedman a3c78f5981 [SCCP] Don't use markForcedConstant on branch conditions.
It's more aggressive than we need to be, and leads to strange
workarounds in other places like call return value inference. Instead,
just directly mark an edge viable.

Tests by Florian Hahn.

Differential Revision: https://reviews.llvm.org/D49408

llvm-svn: 337507
2018-07-19 23:02:07 +00:00
Florian Hahn d95761d9d0 [IPSCCP] Run Solve each time we resolved an undef in a function.
Once we resolved an undef in a function we can run Solve, which could
lead to finding a constant return value for the function, which in turn
could turn undefs into constants in other functions that call it, before
resolving undefs there.

Computationally the amount of work we are doing stays the same, just the
order we process things is slightly different and potentially there are
a few less undefs to resolve.

We are still relying on the order of functions in the IR, which means
depending on the order, we are able to resolve the optimal undef first
or not. For example, if @test1 comes before @testf, we find the constant
return value of @testf too late and we cannot use it while solving
@test1.

This on its own does not lead to more constants removed in the
test-suite, probably because currently we have to be very lucky to visit
applicable functions in the right order.

Maybe we manage to come up with a better way of resolving undefs in more
'profitable' functions first.

Reviewers: efriedma, mssimpso, davide

Reviewed By: efriedma, davide

Differential Revision: https://reviews.llvm.org/D49385

llvm-svn: 337283
2018-07-17 14:04:59 +00:00
Eric Christopher 7289ac8a19 Temporarily revert "Recommit r328307: [IPSCCP] Use constant range information for comparisons of parameters." as it's causing miscompiles.
A testcase was provided in the original review thread.

This reverts commit r336098.

llvm-svn: 336877
2018-07-12 01:53:21 +00:00
Manoj Gupta 77eeac3d9e llvm: Add support for "-fno-delete-null-pointer-checks"
Summary:
Support for this option is needed for building Linux kernel.
This is a very frequently requested feature by kernel developers.

More details : https://lkml.org/lkml/2018/4/4/601

GCC option description for -fdelete-null-pointer-checks:
This Assume that programs cannot safely dereference null pointers,
and that no code or data element resides at address zero.

-fno-delete-null-pointer-checks is the inverse of this implying that
null pointer dereferencing is not undefined.

This feature is implemented in LLVM IR in this CL as the function attribute
"null-pointer-is-valid"="true" in IR (Under review at D47894).
The CL updates several passes that assumed null pointer dereferencing is
undefined to not optimize when the "null-pointer-is-valid"="true"
attribute is present.

Reviewers: t.p.northover, efriedma, jyknight, chandlerc, rnk, srhines, void, george.burgess.iv

Reviewed By: efriedma, george.burgess.iv

Subscribers: eraman, haicheng, george.burgess.iv, drinkcat, theraven, reames, sanjoy, xbolva00, llvm-commits

Differential Revision: https://reviews.llvm.org/D47895

llvm-svn: 336613
2018-07-09 22:27:23 +00:00
Florian Hahn 4ebba909a2 Recommit r328307: [IPSCCP] Use constant range information for comparisons of parameters.
This version contains a fix to add values for which the state in ParamState change
to the worklist if the state in ValueState did not change. To avoid adding the
same value multiple times, mergeInValue returns true, if it added the value to
the worklist. The value is added to the worklist depending on its state in
ValueState.

Original message:
For comparisons with parameters, we can use the ParamState lattice
elements which also provide constant range information. This improves
the code for PR33253 further and gets us closer to use
ValueLatticeElement for all values.

Also, as we are using the range information in the solver directly, we
do not need tryToReplaceWithConstantRange afterwards anymore.

Reviewers: dberlin, mssimpso, davide, efriedma

Reviewed By: mssimpso

Differential Revision: https://reviews.llvm.org/D43762

llvm-svn: 336098
2018-07-02 12:44:04 +00:00
Florian Hahn 388af14f85 [SCCP] Mark CFG as preserved.
SCCP does not change the CFG, so we can mark it as preserved.

Reviewers: dberlin, efriedma, davide

Reviewed By: davide

Differential Revision: https://reviews.llvm.org/D47149

llvm-svn: 335820
2018-06-28 09:53:38 +00:00
Florian Hahn 4a69b0bb36 [IPSCCP] Change dead blocks to unreachable after visiting all executable blocks.
changeToUnreachable may remove PHI nodes from executable blocks we found values
for and we would fail to replace them. By changing dead blocks to unreachable after
we replaced constants in all executable blocks, we ensure such PHI nodes are replaced
by their known value before.

Fixes PR37780.

Reviewers: efriedma, davide

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D48421

llvm-svn: 335588
2018-06-26 10:15:02 +00:00
Francis Visoiu Mistrih ac599b6951 Revert r335206 "Recommit r333268: [IPSCCP] Use PredicateInfo to propagate facts from cmp instructions."
This reverts commit r335206.

As discussed here: https://reviews.llvm.org/rL333740, a fix will come
tomorrow. In the meanwhile, revert this to fix some bots.

llvm-svn: 335272
2018-06-21 19:18:36 +00:00
Florian Hahn d36aa1f763 Recommit r333268: [IPSCCP] Use PredicateInfo to propagate facts from cmp instructions.
r335150 should resolve the issues with the clang-with-thin-lto-ubuntu
and clang-with-lto-ubuntu builders.

Original message:
This patch updates IPSCCP to use PredicateInfo to propagate
facts to true branches predicated by EQ and to false branches
predicated by NE.

As a follow up, we should be able to extend it to also propagate additional
facts about nonnull.

Reviewers: davide, mssimpso, dberlin, efriedma

Reviewed By: davide, dberlin

llvm-svn: 335206
2018-06-21 07:15:08 +00:00
David Blaikie 31b98d2e99 Move Analysis/Utils/Local.h back to Transforms
Review feedback from r328165. Split out just the one function from the
file that's used by Analysis. (As chandlerc pointed out, the original
change only moved the header and not the implementation anyway - which
was fine for the one function that was used (since it's a
template/inlined in the header) but not in general)

llvm-svn: 333954
2018-06-04 21:23:21 +00:00
Florian Hahn 8a17f1f43e Revert r333740: IPSCCP] Use PredicateInfo to propagate facts from cmp.
This is breaking the clang-with-thin-lto-ubuntu bot.

llvm-svn: 333745
2018-06-01 12:58:43 +00:00
Florian Hahn f4df554f32 Recommit r333268: [IPSCCP] Use PredicateInfo to propagate facts from cmp instructions.
This patch updates IPSCCP to use PredicateInfo to propagate
facts to true branches predicated by EQ and to false branches
predicated by NE.

As a follow up, we should be able to extend it to also propagate additional
facts about nonnull.

Reviewers: davide, mssimpso, dberlin, efriedma

Reviewed By: davide, dberlin

Differential Revision: https://reviews.llvm.org/D45330

llvm-svn: 333740
2018-06-01 10:48:54 +00:00
Florian Hahn 718af2f817 Revert r333268: [IPSCCP] Use PredicateInfo to propagate facts from...
Reverting this to see if this is causing the failures of the
clang-with-thin-lto-ubuntu bot.

[IPSCCP] Use PredicateInfo to propagate facts from cmp instructions.

This patch updates IPSCCP to use PredicateInfo to propagate
facts to true branches predicated by EQ and to false branches
predicated by NE.

As a follow up, we should be able to extend it to also propagate additional
facts about nonnull.

Reviewers: davide, mssimpso, dberlin, efriedma

Reviewed By: davide, dberlin

Differential Revision: https://reviews.llvm.org/D45330

llvm-svn: 333323
2018-05-25 23:32:02 +00:00
Florian Hahn b4a70b9f47 [IPSCCP] Use PredicateInfo to propagate facts from cmp instructions.
This patch updates IPSCCP to use PredicateInfo to propagate
facts to true branches predicated by EQ and to false branches
predicated by NE.

As a follow up, we should be able to extend it to also propagate additional
facts about nonnull.

Reviewers: davide, mssimpso, dberlin, efriedma

Reviewed By: davide, dberlin

Differential Revision: https://reviews.llvm.org/D45330

llvm-svn: 333268
2018-05-25 11:12:33 +00:00
Nicola Zaghen d34e60ca85 Rename DEBUG macro to LLVM_DEBUG.
The DEBUG() macro is very generic so it might clash with other projects.
The renaming was done as follows:
- git grep -l 'DEBUG' | xargs sed -i 's/\bDEBUG\s\?(/LLVM_DEBUG(/g'
- git diff -U0 master | ../clang/tools/clang-format/clang-format-diff.py -i -p1 -style LLVM
- Manual change to APInt
- Manually chage DOCS as regex doesn't match it.

In the transition period the DEBUG() macro is still present and aliased
to the LLVM_DEBUG() one.

Differential Revision: https://reviews.llvm.org/D43624

llvm-svn: 332240
2018-05-14 12:53:11 +00:00
Florian Hahn f73c3ece7f Revert r328307: [IPSCCP] Use constant range information for comparisons of parameters.
Reverted for now, due to it causing verifier failures.

llvm-svn: 328312
2018-03-23 12:49:39 +00:00
Florian Hahn b1feec087e [IPSCCP] Use constant range information for comparisons of parameters.
For comparisons with parameters, we can use the ParamState lattice
elements which also provide constant range information. This improves
the code for PR33253 further and gets us closer to use
ValueLatticeElement for all values.

Also, as we are using the range information in the solver directly, we
do not need tryToReplaceWithConstantRange afterwards anymore.

Reviewers: dberlin, mssimpso, davide, efriedma

Reviewed By: mssimpso

Differential Revision: https://reviews.llvm.org/D43762

llvm-svn: 328307
2018-03-23 11:56:00 +00:00
David Blaikie 3bbf5af0ac Fix layering between SCCP and IPO SCCP
Transforms/Scalar/SCCP.cpp implemented both the Scalar and IPO SCCP, but
this meant Transforms/Scalar including Transfroms/IPO headers, creating
a circular dependency. (IPO depends on Scalar already) - so move the IPO
SCCP shims out into IPO and the basic library implementation accessible
from Scalar/SCCP.h to be used from the IPO/SCCP.cpp implementation.

llvm-svn: 328250
2018-03-22 21:41:29 +00:00
David Blaikie 2be3922807 Fix a couple of layering violations in Transforms
Remove #include of Transforms/Scalar.h from Transform/Utils to fix layering.

Transforms depends on Transforms/Utils, not the other way around. So
remove the header and the "createStripGCRelocatesPass" function
declaration (& definition) that is unused and motivated this dependency.

Move Transforms/Utils/Local.h into Analysis because it's used by
Analysis/MemoryBuiltins.cpp.

llvm-svn: 328165
2018-03-21 22:34:23 +00:00
Florian Hahn 0b7c6422fb [IPSCCP] Add getCompare which returns either true, false, undef or null.
getCompare returns true, false or undef constants if the comparison can
be evaluated, or nullptr if it cannot. This is in line with what
ConstantExpr::getCompare returns. It also allows us to use
ConstantExpr::getCompare for comparing constants.

Reviewers: davide, mssimpso, dberlin, anna

Reviewed By: davide

Differential Revision: https://reviews.llvm.org/D43761

llvm-svn: 326720
2018-03-05 17:33:50 +00:00
Benjamin Kramer d1cf7ff5ab [SCCP] Fix unused variable warning in release builds.
llvm-svn: 326429
2018-03-01 11:31:44 +00:00
Reid Kleckner 3762a089d7 [IPSCCP] do not break musttail invariant (PR36485)
Do not replace results of `musttail` calls with a constant if the
call itself can't be removed.

Do not zap returns of `musttail` callees, if the call site can't be
removed and replaced with a constant.

Do not zap returns of `musttail`-calling blocks, this breaks
invariant too.

Patch by Fedor Indutny

Differential Revision: https://reviews.llvm.org/D43695

llvm-svn: 326404
2018-03-01 01:19:18 +00:00
Chris Bieneman abdea268c1 [IPSCCP] Remove calls without side effects
Summary:
When performing constant propagation for call instructions we have historically replaced all uses of the return from a call, but not removed the call itself. This is required for correctness if the calls have side effects, however the compiler should be able to safely remove calls that don't have side effects.

This allows the compiler to completely fold away calls to functions that have no side effects if the inputs are constant and the output can be determined at compile time.

Reviewers: davide, sanjoy, bruno, dberlin

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D38856

llvm-svn: 322125
2018-01-09 21:58:46 +00:00
Davide Italiano e15bffe9ea Revert "[SCCP] Manually fold branches on undef."
I thought this was responsible for PR35723, but I was
wrong, the issue lies elsewhere. Revert while I debug.

llvm-svn: 321975
2018-01-07 22:09:44 +00:00
Benjamin Kramer c7fc81e659 Use phi ranges to simplify code. No functionality change intended.
llvm-svn: 321585
2017-12-30 15:27:33 +00:00
Davide Italiano 55b663431e [SCCP] Manually fold branches on undef.
This code was originally removed and replace with an assertion
because believed unnecessary. It turns out there was simply
no test coverage for this case, and the constant folder doesn't
yet know about patterns like `br undef %label1, %label2`.
Presumably at some point the constant folder might learn about
these patterns, but it's a broader change.
A testcase will be added to make sure this doesn't regress again
in the future.

Fixes PR35723.

llvm-svn: 321402
2017-12-23 15:06:30 +00:00
Davide Italiano b480b5c2ee [SCCP] Pick the right lattice value for constants.
After the dataflow algorithm proves that an argument is constant,
it replaces it value with the integer constant and drops the lattice
value associated to the DEF.

e.g. in the example we have @f() that's called twice:
call @f(undef, ...)
call @f(2, ...)

`undef` MEET 2 = 2 so we replace the argument and all its uses with
the constant 2.

Shortly after, tryToReplaceWithConstantRange() tries to get the lattice
value for the argument we just replaced, causing an assertion.
This function is a little peculiar as it runs when we're doing replacement
and not as part of the solver but still queries the solver.

The fix is that of checking whether we replaced the value already and
get a temporary lattice value for the constant.

Thanks to Zhendong Su for the report!

Fixes PR35357.

llvm-svn: 318817
2017-11-22 03:04:55 +00:00
Davide Italiano 5df8080011 [SCCP] If we replace with a constant, we can't replace with a range.
This microoptimization is NFC.

llvm-svn: 318711
2017-11-21 00:21:52 +00:00
Florian Hahn d0208b4b1c Recommit r315288: [SCCP] Propagate integer range info for parameters in IPSCCP.
This version of the patch includes a fix addressing a stage2 LTO buildbot
failure and addressed some additional nits.

Original commit message:
This updates the SCCP solver to use of the ValueElement lattice for
parameters, which provides integer range information. The range
information is used to remove unneeded icmp instructions.

For the following function, f() can be optimized to ret i32 2 with
this change

    source_filename = "sccp.c"
    target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
    target triple = "x86_64-unknown-linux-gnu"

    ; Function Attrs: norecurse nounwind readnone uwtable
    define i32 @main() local_unnamed_addr #0 {
    entry:
      %call = tail call fastcc i32 @f(i32 1)
      %call1 = tail call fastcc i32 @f(i32 47)
      %add3 = add nsw i32 %call, %call1
      ret i32 %add3
    }

    ; Function Attrs: noinline norecurse nounwind readnone uwtable
    define internal fastcc i32 @f(i32 %x) unnamed_addr #1 {
    entry:
      %c1 = icmp sle i32 %x, 100

      %cmp = icmp sgt i32 %x, 300
      %. = select i1 %cmp, i32 1, i32 2
      ret i32 %.
    }

    attributes #1 = { noinline }

Reviewers: davide, sanjoy, efriedma, dberlin

Reviewed By: davide, dberlin

Subscribers: mcrosier, gberry, mssimpso, dberlin, llvm-commits

Differential Revision: https://reviews.llvm.org/D36656

llvm-svn: 316891
2017-10-30 10:07:42 +00:00
Florian Hahn d18443edad Revert r316887 to fix buildbot failures.
llvm-svn: 316888
2017-10-30 09:21:50 +00:00
Florian Hahn 925d3e4a98 Recommit r315288: [SCCP] Propagate integer range info for parameters in IPSCCP.
This version of the patch includes a fix addressing a stage2 LTO buildbot
failure and addressed some additional nits.

Original commit message:
This updates the SCCP solver to use of the ValueElement lattice for
parameters, which provides integer range information. The range
information is used to remove unneeded icmp instructions.

For the following function, f() can be optimized to ret i32 2 with
this change

    source_filename = "sccp.c"
    target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
    target triple = "x86_64-unknown-linux-gnu"

    ; Function Attrs: norecurse nounwind readnone uwtable
    define i32 @main() local_unnamed_addr #0 {
    entry:
      %call = tail call fastcc i32 @f(i32 1)
      %call1 = tail call fastcc i32 @f(i32 47)
      %add3 = add nsw i32 %call, %call1
      ret i32 %add3
    }

    ; Function Attrs: noinline norecurse nounwind readnone uwtable
    define internal fastcc i32 @f(i32 %x) unnamed_addr #1 {
    entry:
      %c1 = icmp sle i32 %x, 100

      %cmp = icmp sgt i32 %x, 300
      %. = select i1 %cmp, i32 1, i32 2
      ret i32 %.
    }

    attributes #1 = { noinline }

Reviewers: davide, sanjoy, efriedma, dberlin

Reviewed By: davide, dberlin

Subscribers: mcrosier, gberry, mssimpso, dberlin, llvm-commits

Differential Revision: https://reviews.llvm.org/D36656

llvm-svn: 316887
2017-10-30 09:04:18 +00:00
Eugene Zelenko 99241d75c1 [Transforms] Fix some Clang-tidy modernize and Include What You Use warnings; other minor fixes (NFC).
llvm-svn: 316241
2017-10-20 21:47:29 +00:00
Matthew Simpson 2284937bbc [IPSCCP] Move common functions to ValueLatticeUtils (NFC)
This patch moves some common utility functions out of IPSCCP and makes them
available globally. The functions determine if interprocedural data-flow
analyses can propagate information through function returns, arguments, and
global variables.

Differential Revision: https://reviews.llvm.org/D37638

llvm-svn: 315719
2017-10-13 17:53:44 +00:00
Bruno Cardoso Lopes 993d2e67d8 Revert "Reintroduce "[SCCP] Propagate integer range info for parameters in IPSCCP.""
This reverts commit r315593: still affect two bots:

http://lab.llvm.org:8011/builders/clang-with-lto-ubuntu/builds/5308
http://green.lab.llvm.org/green/job/clang-stage2-configure-Rlto/21751/

llvm-svn: 315618
2017-10-12 20:52:34 +00:00
Bruno Cardoso Lopes 326fdcbff8 Reintroduce "[SCCP] Propagate integer range info for parameters in IPSCCP."
This is r315288 & r315294, which were reverted due to stage2 bot
failures.

Summary:
This updates the SCCP solver to use of the ValueElement lattice for
parameters, which provides integer range information. The range
information is used to remove unneeded icmp instructions.

For the following function, f() can be optimized to `ret i32 2` with
this change

  source_filename = "sccp.c"
  target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
  target triple = "x86_64-unknown-linux-gnu"

  ; Function Attrs: norecurse nounwind readnone uwtable
  define i32 @main() local_unnamed_addr #0 {
  entry:
    %call = tail call fastcc i32 @f(i32 1)
    %call1 = tail call fastcc i32 @f(i32 47)
    %add3 = add nsw i32 %call, %call1
    ret i32 %add3
  }

  ; Function Attrs: noinline norecurse nounwind readnone uwtable
  define internal fastcc i32 @f(i32 %x) unnamed_addr #1 {
  entry:
    %c1 = icmp sle i32 %x, 100

    %cmp = icmp sgt i32 %x, 300
    %. = select i1 %cmp, i32 1, i32 2
    ret i32 %.
  }

  attributes #1 = { noinline }

Reviewers: davide, sanjoy, efriedma, dberlin

Reviewed By: davide, dberlin

Subscribers: mcrosier, gberry, mssimpso, dberlin, llvm-commits

Differential Revision: https://reviews.llvm.org/D36656

llvm-svn: 315593
2017-10-12 16:54:11 +00:00
Bruno Cardoso Lopes 57304923ca Revert "[SCCP] Propagate integer range info for parameters in IPSCCP."
This reverts commit r315288. This is part of fixing segfault introduced
in:

http://green.lab.llvm.org/green/job/clang-stage2-configure-Rlto/21675/

llvm-svn: 315329
2017-10-10 16:37:57 +00:00
Bruno Cardoso Lopes 122c4b3c8c Revert "[SCCP] Fix mem-sanitizer failure introduced by r315288."
This reverts commit r315294. Part of fixing seg fault introduced in:
http://green.lab.llvm.org/green/job/clang-stage2-configure-Rlto/21675/

llvm-svn: 315328
2017-10-10 16:37:51 +00:00
Florian Hahn 7d2375df30 [SCCP] Fix mem-sanitizer failure introduced by r315288.
llvm-svn: 315294
2017-10-10 10:33:45 +00:00
Florian Hahn 22a44bca40 [SCCP] Propagate integer range info for parameters in IPSCCP.
Summary:
This updates the SCCP solver to use of the ValueElement lattice for 
parameters, which provides integer range information. The range
information is used to remove unneeded icmp instructions.

For the following function, f() can be optimized to `ret i32 2` with
this change

  source_filename = "sccp.c"
  target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
  target triple = "x86_64-unknown-linux-gnu"
  
  ; Function Attrs: norecurse nounwind readnone uwtable
  define i32 @main() local_unnamed_addr #0 {
  entry:
    %call = tail call fastcc i32 @f(i32 1)
    %call1 = tail call fastcc i32 @f(i32 47)
    %add3 = add nsw i32 %call, %call1
    ret i32 %add3
  }
  
  ; Function Attrs: noinline norecurse nounwind readnone uwtable
  define internal fastcc i32 @f(i32 %x) unnamed_addr #1 {
  entry:
    %c1 = icmp sle i32 %x, 100
  
    %cmp = icmp sgt i32 %x, 300
    %. = select i1 %cmp, i32 1, i32 2
    ret i32 %.
  }
  
  attributes #1 = { noinline }



Reviewers: davide, sanjoy, efriedma, dberlin

Reviewed By: davide, dberlin

Subscribers: mcrosier, gberry, mssimpso, dberlin, llvm-commits

Differential Revision: https://reviews.llvm.org/D36656

llvm-svn: 315288
2017-10-10 09:32:38 +00:00
David Majnemer 91c6330c96 [IPSCCP] Guard a user of getInitializer with hasDefinitiveInitializer
We are not allowed to reason about an initializer value without first
consulting hasDefinitiveInitializer.

llvm-svn: 309594
2017-07-31 17:47:07 +00:00
Craig Topper 79ab643da8 [Constants] If we already have a ConstantInt*, prefer to use isZero/isOne/isMinusOne instead of isNullValue/isOneValue/isAllOnesValue inherited from Constant. NFCI
Going through the Constant methods requires redetermining that the Constant is a ConstantInt and then calling isZero/isOne/isMinusOne.

llvm-svn: 307292
2017-07-06 18:39:47 +00:00
Davide Italiano ec5b0257bf [SCCP] Simplify the code a bit. NFCI.
llvm-svn: 305583
2017-06-16 20:50:31 +00:00
Davide Italiano 0b1190aa8d [SCCP] Clarify a comment about unhandled instructions.
llvm-svn: 305579
2017-06-16 20:27:17 +00:00
Davide Italiano d95d871af0 [SCCP] Remove redundant instruction visitors.
Whenever we don't know what to do with an instruction, we send
it to overdefined anyway.

llvm-svn: 305575
2017-06-16 19:43:57 +00:00
Andrew Kaylor 647025f9e1 [InstSimplify] Don't constant fold or DCE calls that are marked nobuiltin
Differential Revision: https://reviews.llvm.org/D33737

llvm-svn: 305132
2017-06-09 23:18:11 +00:00
Davide Italiano c4861adad9 [SCCP] Use the `hasAddressTaken()` version defined in `Function`.
Instead of using the SCCP homegrown one. We should eventually
make the private SCCP version disappear, but that wont' be today.
PR33143 tracks this issue.

Add braces for consistency while here. No functional change intended.

llvm-svn: 303706
2017-05-23 23:59:23 +00:00