Commit Graph

6424 Commits

Author SHA1 Message Date
Reid Kleckner
ecc4595ce4 [Inliner] Don't inline functions with frameescape calls
Inlining such intrinsics is very difficult, since you need to
simultaneously transform many calls to llvm.framerecover and potentially
duplicate the functions containing them.  Normally this intrinsic isn't
added until EH preparation, which is part of the backend pass pipeline
after inlining.  However, if it were to get fed through the inliner,
this change will ensure that it doesn't break the code.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234937 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-14 20:38:14 +00:00
Jingyue Wu
9cecacd16a Simplify n-ary adds by reassociation
Summary:
This transformation reassociates a n-ary add so that the add can partially reuse
existing instructions. For example, this pass can simplify

  void foo(int a, int b) {
    bar(a + b);
    bar((a + 2) + b);
  }

to

  void foo(int a, int b) {
    int t = a + b;
    bar(t);
    bar(t + 2);
  }

saving one add instruction.

Fixes PR22357 (https://llvm.org/bugs/show_bug.cgi?id=22357).

Test Plan: nary-add.ll

Reviewers: broune, dberlin, hfinkel, meheff, sanjoy, atrick

Reviewed By: sanjoy, atrick

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D8950

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234855 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-14 04:59:22 +00:00
Sanjoy Das
888e8e3a66 [LoopUnrollRuntime] Avoid high-cost trip count computation.
Summary:
Runtime unrolling of loops needs to emit an expression to compute the
loop's runtime trip-count.  Avoid runtime unrolling if this computation
will be expensive.

Depends on D8993.

Reviewers: atrick

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D8994

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234846 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-14 03:20:38 +00:00
Sanjoy Das
17e08f50b9 [SCEV] Strengthen SCEVExpander::isHighCostExpansion.
Summary:

Teach `isHighCostExpansion` to consider divisions by power-of-two
constants as cheap and add a test case.  This change is needed for a new
user of `isHighCostExpansion` that will be added in a subsequent change.

Depends on D8995.

Reviewers: atrick

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D8993

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234845 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-14 03:20:32 +00:00
Nick Lewycky
d4b4e3e20f Subtraction is not commutative. Fixes PR23212!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234780 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-13 19:17:37 +00:00
Akira Hatanaka
a50a335767 [inliner] Don't inline a function if it doesn't have exactly the same
target-cpu and target-features attribute strings as the caller.

Differential Revision: http://reviews.llvm.org/D8984


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234773 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-13 18:43:38 +00:00
Sanjoy Das
e0f4a11a89 [LoopUnrollRuntime] Clean up a predicate.
Clean up a predicate I added in r229731, fix the relevant comment and
add a test case.  The earlier version is confusing to read and was also
buggy (probably not a coincidence) till Alexey fixed it in r233881.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234701 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-12 01:24:01 +00:00
Philip Reames
f894c7ecb2 [RewriteStatepointsForGC] test case missing from 234657
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234658 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-10 22:58:39 +00:00
Philip Reames
d92e9ef170 [RewriteStatepointsForGC] Use an actual liveness algorithm
When rewriting statepoints to make relocations explicit, we need to have a conservative but consistent notion of where a particular pointer is live at a particular site. The old code just used dominance, which is correct, but decidedly more conservative then it needed to be. This patch implements a simple dataflow algorithm that's run one per function (well, twice counting fixup after base pointer insertion). There's still lots of room to make this faster, but it's fast enough for all practical purposes today.

Differential Revision: http://reviews.llvm.org/D8674



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234657 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-10 22:53:14 +00:00
Philip Reames
82374f6b8a [RewriteStatepointsForGC] Preprocess the IR to remove unreachable blocks and single entry phis
Two related small changes:

    Various dominance based queries about liveness can get confused if we're talking about unreachable blocks. To avoid reasoning about such cases, just remove them before rewriting statepoints.
    Remove single entry phis (likely left behind by LCSSA) to reduce the number of live values.

Both of these are motivated by http://reviews.llvm.org/D8674 which will be submitted shortly.

Differential Revision: http://reviews.llvm.org/D8675



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234651 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-10 22:07:04 +00:00
Philip Reames
cb148c8541 [RewriteStatepointsForGC] Limited support for vectors of pointers
This patch adds limited support for inserting explicit relocations when there's a vector of pointers live over the statepoint. This doesn't handle the case where the vector contains a mix of base and non-base pointers; that's future work.

The current implementation just scalarizes the vector over the gc.statepoint before doing the explicit rewrite. An alternate approach would be to plumb the vector all the way though the backend lowering, but doing that appears challenging. In particular, the size of the indirect spill slot is currently assumed to be sizeof(pointer) throughout the backend.

In practice, this is enough to allow running the SLP and Loop vectorizers before RewriteStatepointsForGC.

Differential Revision: http://reviews.llvm.org/D8671



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234647 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-10 21:48:25 +00:00
Sanjoy Das
8aca90e5b6 [InstCombine][CodeGenPrep] Create llvm.uadd.with.overflow in CGP.
Summary:
This change moves creating calls to `llvm.uadd.with.overflow` from
InstCombine to CodeGenPrep.  Combining overflow check patterns into
calls to the said intrinsic in InstCombine inhibits optimization because
it introduces an intrinsic call that not all other transforms and
analyses understand.

Depends on D8888.

Reviewers: majnemer, atrick

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D8889

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234638 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-10 21:07:09 +00:00
Jingyue Wu
10483b93ea [SLSR] consider &B[S << i] as &B[(1 << i) * S]
Summary: This reduces handling &B[(1 << i) * s] to handling &B[i * S].

Test Plan: slsr-gep.ll

Reviewers: meheff

Subscribers: sanjoy, llvm-commits

Differential Revision: http://reviews.llvm.org/D8837

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234180 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-06 17:15:48 +00:00
David Majnemer
33b9ae320a Fix a typo
CHECK-LABEL had the wrong function name.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234051 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-03 20:56:24 +00:00
David Majnemer
701c2fca7e [InstCombine] Use DataLayout to determine vector element width
InstCombine didn't realize that it needs to use DataLayout to determine
how wide pointers are.  This lead to assertion failures.

This fixes PR23113.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234046 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-03 20:18:40 +00:00
Duncan P. N. Exon Smith
b0d0a65e1d Verifier: Check that inlined-at locations agree
Check that the `MDLocalVariable::getInlinedAt()` in a debug info
intrinsic's variable always matches the `MDLocation::getInlinedAt()` of
its `!dbg` attachment.

The goal here is to get rid of `MDLocalVariable::getInlinedAt()`
entirely (PR22778), since it's expensive and unnecessary, but I'll let
this verifier check bake for a while (a week maybe?) first.  I've
updated the testcases that had the wrong value for `inlinedAt:`.

This checks that things are sane in the IR, but currently things go out
of whack in a few places in the backend.  I'll follow shortly with
assertions in the backend (with code fixes).

If you have out-of-tree testcases that just started failing, here's how
I updated these ones:

 1. The verifier check gives you the basic block, function, instruction,
    and relevant metadata arguments (metadata numbering doesn't
    necessarily match the source file, unfortunately).
 2. Look at the `@llvm.dbg.*()` instruction, and compare the
    `inlinedAt:` fields of the variable argument (second `metadata`
    argument) and the `!dbg` attachment.
 3. Figure out based on the variable `scope:` chain and the functions in
    the file whether the variable has been inlined (and into what), so
    you can determine which `inlinedAt:` is actually correct.  In all of
    the in-tree testcases, the `!MDLocation()` was correct and the
    `!MDLocalVariable()` was wrong, but YMMV.
 4. Duplicate the metadata that you're going to change, and add/drop the
    `inlinedAt:` field from one of them.  Be careful that the other
    references to the same metadata node point at the correct one.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234021 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-03 16:54:30 +00:00
Jingyue Wu
6dedfc073a [SLSR] handles off bounds GEPs
Summary:
The old requirement on GEP candidates being in bounds is unnecessary.
For off-bound GEPs, we still have

  &B[i * S] = B + (i * S) * e = B + (i * e) * S

Test Plan: slsr_offbound_gep in slsr-gep.ll

Reviewers: meheff

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D8809

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233949 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-02 21:18:32 +00:00
Ahmed Bougacha
252c120f4a [SimplifyLibCalls] Ignore nobuiltin/unavailable fortified libcalls.
We used to do this before refactorings around r225640.
Some clang users checked for _chk libcall availability using:
  __has_builtin(__builtin___memcpy_chk)
When compiling with -fno-builtin, this is always true.
When passing -ffreestanding/-mkernel, which both imply -fno-builtin, we
end up with fortified libcalls, which isn't acceptable in a freestanding
environment which only provides their non-fortified counterparts.

Until we change clang and/or teach external users to check for availability
differently, disregard the "nobuiltin" attribute and TLI::has.

Workaround for PR23093.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233776 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-01 00:45:09 +00:00
Hal Finkel
8360002904 [ConstantFold] Don't fold ppc_fp128 <-> int bitcasts
PPC_FP128 is really the sum of two consecutive doubles, where the first double
is always stored first in memory, regardless of the target endianness. The
memory layout of i128, however, depends on the target endianness, and so we
can't fold this without target endianness information. As a result, we must not
do this folding in lib/IR/ConstantFold.cpp (it could be done instead in
Analysis/ConstantFolding.cpp, but that's not done now).

Fixes PR23026.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233481 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-28 16:44:57 +00:00
Duncan P. N. Exon Smith
d397a52305 DebugInfo: Fix testcases with invalid MDSubprogram nodes
Fix testcases that don't pass the verifier after a WIP patch to check
`MDSubprogram` operands more effectively.  I found the following issues:

  - When `isDefinition: false`, the `variables:` field might point at
    `!{i32 786468}`, or at a tuple that pointed at an empty tuple with
    the comment "previously: invalid DW_TAG_base_type" (I vaguely recall
    adding those comments during an upgrade script).  In these cases, I
    just dropped the array.
  - The `variables:` field might point at something like `!{!{!8}}`,
    where `!8` was an `MDLocation`.  I removed the extra layer of
    indirection.
  - Invalid `type:` (not an `MDSubroutineType`).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233466 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-28 02:26:45 +00:00
Duncan P. N. Exon Smith
de89228dfb Verifier: Call verifyModule() from llc and opt
Change `llc` and `opt` to run `verifyModule()`.  This ensures that we
check the full module before `FunctionPass::doInitialization()` ever
gets called (I was getting crashes in `DwarfDebug` instead of verifier
failures when testing a WIP patch that checks operands of compile
units).  In `opt`, also move up debug-info-stripping so that it still
runs before verification.

There was a fair bit of broken code that was sitting in tree.
Interestingly, some were cases of a `select` that referred to itself in
`-instcombine` tests (apparently an intermediate result).  I split them
off to `*-noverify.ll` tests with RUN lines like this:

    opt < %s -S -disable-verify -instcombine | opt -S | FileCheck %s

This avoids verifying the input file (so we can get the broken code into
`-instcombine), but still verifies the output with a second call to
`opt` (to verify that `-instcombine` will clean it up like it should).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233432 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-27 22:04:28 +00:00
Duncan P. N. Exon Smith
77a0728d96 DebugInfo: Fix bad debug info for compile units and types
Fix debug info in these tests, which started failing with a WIP patch to
verify compile units and types.  The problems look like they were all
caused by bitrot.  They fell into these categories:

  - Using `!{i32 0}` instead of `!{}`.
  - Using `!{null}` instead of `!{}`.
  - Using `!MDExpression()` instead of `!{}`.
  - Using `!8` instead of `!{!8}`.
  - `file:` references that pointed at `MDCompileUnit`s instead of the
    same `MDFile` as the compile unit.
  - `file:` references that were numerically off-by-one or (off-by-ten).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233415 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-27 20:46:33 +00:00
Duncan P. N. Exon Smith
2ee615297c DebugInfo: Fix another bitrotted testcase
Fix another case of a missing `scope:` field on an `MDLocalVariable`.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233388 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-27 17:29:11 +00:00
James Molloy
fb45b9fafc Reapply r233175 and r233183: float2int.
This re-adds float2int to the tree, after fixing PR23038. It turns
out the argument to APSInt() is true-if-unsigned, rather than
true-if-signed :(. Added testcase and explanatory comment.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233370 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-27 10:36:57 +00:00
Philip Reames
76acab3fc7 Require a GC strategy be specified for functions which use gc.statepoint
This was discussed a while back and I left it optional for migration.  Since it's been far more than the 'week or two' that was discussed, time to actually make this manditory.  



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233357 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-27 05:09:33 +00:00
Nick Lewycky
b3ad90eacc Revert r233175 and r233183 with it. This pulls float2int back out of the tree, due to PR23038.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233350 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-27 02:00:11 +00:00
Duncan P. N. Exon Smith
97fcbf1874 DebugInfo: Update testcases with invalid variables
Fix testcases whose variables are invalid.  I'm working on a patch that
adds `Verifier` checks for `MDLocalVariable` (and `MDGlobalVariable`),
and these failed because:

  - `scope:` fields need to point at `MDLocalScope` and can't be null.
  - `file:` fields need to point at `MDFile`.
  - `inlinedAt:` fields need to point at `MDLocation`.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233349 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-27 01:58:34 +00:00
Benjamin Kramer
8f820e9495 InstCombine: fold (A << C) == (B << C) --> ((A^B) & (~0U >> C)) == 0
Anding and comparing with zero can be done in a single instruction on
most archs so this is a bit cheaper.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233291 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-26 17:12:06 +00:00
Jingyue Wu
439d17ca9f [SLSR] handle candidate form &B[i * S]
Summary:
This patch enhances SLSR to handle another candidate form &B[i * S]. If
we found two candidates

S1: X = &B[i * S]
S2: Y = &B[i' * S]

and S1 dominates S2, we can replace S2 with

Y = &X[(i' - i) * S]

Test Plan:
slsr-gep.ll
X86/no-slsr.ll: verify that we do not run SLSR on GEPs that already fit into
an addressing mode

Reviewers: eliben, atrick, meheff, hfinkel

Reviewed By: hfinkel

Subscribers: sanjoy, llvm-commits

Differential Revision: http://reviews.llvm.org/D7459

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233286 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-26 16:49:24 +00:00
Andrea Di Biagio
962dcdfdda [optnone] Skip pass Float2Int on optnone functions.
Added test Float2Int/float2int-optnone.ll to verify that pass Float2Int
is not run on optnone functions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233183 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-25 12:22:37 +00:00
James Molloy
09f1b672cb Reapply r233062: "float2int": Add a new pass to demote from float to int where possible.
Now with a fix for PR23008 and extra regression test.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233175 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-25 10:03:42 +00:00
Philip Reames
c50bf46a22 !invariant.load semantics with potentially clobbering calls
A load from an invariant location is assumed to not alias any otherwise potentially aliasing stores. Our implementation only applied this rule to store instructions themselves whereas they it should apply for any memory accessing instruction. This results in both FRE and PRE becoming more effective at eliminating invariant loads.

Note that as a follow on change I will likely move this into AliasAnalysis itself. That's where the TBAA constant flag is handled and the semantics are essentially the same. I'd like to separate the semantic change from the refactoring and thus have extended the hack that's already in MemoryDependenceAnalysis for this change.

Differential Revision: http://reviews.llvm.org/D8591



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233140 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-24 23:54:54 +00:00
Justin Bogner
fa71fb34ad Update a test I missed in r233132
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233134 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-24 23:44:03 +00:00
Sanjay Patel
14c1d068a3 optimize the AVX2 (integer) version of vperm2 into a shuffle
...because this is what happens when an instruction
set puts its underwear on after its pants.

This is an extension of r232852, r233100, and 233110:
http://llvm.org/viewvc/llvm-project?view=revision&revision=232852
http://llvm.org/viewvc/llvm-project?view=revision&revision=233100
http://llvm.org/viewvc/llvm-project?view=revision&revision=233110



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233127 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-24 22:39:29 +00:00
Philip Reames
6bde9f6994 Merge empty landing pads in SimplifyCFG
This patch tries to merge duplicate landing pads when they branch to a common shared target.

Given IR that looks like this:
lpad1:
  %exn = landingpad {i8*, i32} personality i32 (...)* @__gxx_personality_v0
         cleanup
  br label %shared_resume
lpad2:
  %exn2 = landingpad {i8*, i32} personality i32 (...)* @__gxx_personality_v0
          cleanup
  br label %shared_resume
shared_resume:
  call void @fn()
  ret void
}

We can rewrite the users of both landing pad blocks to use one of them. This will generally allow the shared_resume block to be merged with the common landing pad as well.

Without this change, tail duplication would likely kick in - creating N (2 in this case) copies of the shared_resume basic block.

Differential Revision: http://reviews.llvm.org/D8297



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233125 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-24 22:28:45 +00:00
David Blaikie
ef9962d9bb Revert "Remove an InstCombine that seems to have become redundant."
Assertion fires in compiler-rt. Guess it does fire..

This reverts commit r233116.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233121 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-24 21:50:35 +00:00
David Blaikie
80da8623a4 Remove an InstCombine that seems to have become redundant.
Assert that this doesn't fire - I'll remove all of this later, but just
leaving it in for a while in case this is firing & we just don't have
test coverage.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233116 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-24 21:31:31 +00:00
Sanjay Patel
5e0ce9d13a [X86, AVX] instcombine vperm2 intrinsics with zero inputs into shuffles
This is the IR optimizer follow-on patch for D8563: the x86 backend patch
that converts this kind of shuffle back into a vperm2.

This is also a continuation of the transform that started in D8486. 
In that patch, Andrea suggested that we could convert vperm2 intrinsics that
use zero masks into a single shuffle. 

This is an implementation of that suggestion.

Differential Revision: http://reviews.llvm.org/D8567



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233110 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-24 20:36:42 +00:00
Hans Wennborg
f61cd8b368 Revert r233062 ""float2int": Add a new pass to demote from float to int where possible."
This caused PR23008, compiles failing with: "Use still stuck around after Def is
destroyed: %.sroa.speculated"

Also reverting follow-up r233064.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233105 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-24 20:07:08 +00:00
Sanjoy Das
33a864aae2 [IRCE] Fix a regression introduced in r232444.
IRCE should not try to eliminate range checks that check an induction
variable against a loop-varying length.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233101 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-24 19:29:18 +00:00
James Molloy
a54c5b4489 "float2int": Add a new pass to demote from float to int where possible.
It is possible to have code that converts from integer to float, performs operations then converts back, and the result is provably the same as if integers were used.

This can come from different sources, but the most obvious is a helper function that uses floats but the arguments given at an inlined callsites are integers.

This pass considers all integers requiring a bitwidth less than or equal to the bitwidth of the mantissa of a floating point type (23 for floats, 52 for doubles) as exactly representable in floating point.

To reduce the risk of harming efficient code, the pass only attempts to perform complete removal of inttofp/fptoint operations, not just move them around.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233062 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-24 11:15:23 +00:00
Duncan P. N. Exon Smith
7ad96398c6 DebugInfo: Overload get() in DIDescriptor subclasses
Continue to simplify the `DIDescriptor` subclasses, so that they behave
more like raw pointers.  Remove `getRaw()`, replace it with an
overloaded `get()`, and overload the arrow and cast operators.  Two
testcases started to crash on the arrow operators with this change
because of `scope:` references that weren't real scopes.  I fixed them.
Soon I'll add verifier checks for them too.

This also adds explicit dereference operators.  Previously, the builtin
dereference against `operator MDNode *()` would have worked, but now the
builtins are ambiguous.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233030 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-23 21:54:07 +00:00
Benjamin Kramer
42a84b54bf [SimplifyLibCalls] Fix negative shifts being produced by the memchr -> bitfield transform.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232903 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-21 22:04:26 +00:00
Benjamin Kramer
fd48a80e14 [SimplifyLibCalls] Turn memchr(const, C, const) into a bitfield check.
strchr("123!", C) != nullptr is a common pattern to check if C is one
of 1, 2, 3 or !. If the largest element of the string is smaller than
the target's register size we can easily create a bitfield and just
do a simple test for set membership.

int foo(char C) { return strchr("123!", C) != nullptr; } now becomes

	cmpl	$64, %edi ## range check
	sbbb	%al, %al
	movabsq	$0xE000200000001, %rcx
	btq	%rdi, %rcx ## bit test
	sbbb	%cl, %cl
	andb	%al, %cl ## and the two conditions
	andb	$1, %cl
	movzbl	%cl, %eax ## returning an int
	ret

(imho the backend should expand this into a series of branches, but
that's a different story)

The code is currently limited to bit fields that fit in a register, so
usually 64 or 32 bits. Sadly, this misses anything using alpha chars
or {}. This could be fixed by just emitting a i128 bit field, but that
can generate really ugly code so we have to find a better way. To some
degree this is also recreating switch lowering logic, but we can't
simply emit a switch instruction and thus change the CFG within
instcombine.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232902 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-21 21:09:33 +00:00
Benjamin Kramer
4b74df7229 SimplifyLibCalls: Add basic optimization of memchr calls.
This is just memchr(x, y, 0) -> nullptr and constant folding.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232896 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-21 15:36:21 +00:00
David Majnemer
ac5b42cad8 MemoryDependenceAnalysis: Don't miscompile atomics
r216771 introduced a change to MemoryDependenceAnalysis that allowed it
to reason about acquire/release operations.  However, this change does
not ensure that the acquire/release operations pair.  Unfortunately,
this leads to miscompiles as we won't see an acquire load as properly
memory effecting.  This largely reverts r216771.

This fixes PR22708.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232889 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-21 06:19:17 +00:00
Sanjay Patel
be9ee96926 [X86, AVX] instcombine common cases of vperm2* intrinsics into shuffles
vperm2* intrinsics are just shuffles. 
In a few special cases, they're not even shuffles.

Optimizing intrinsics in InstCombine is better than
handling this in the front-end for at least two reasons:

1. Optimizing custom-written SSE intrinsic code at -O0 makes vector coders
   really angry (and so I have regrets about some patches from last week).

2. Doing mask conversion logic in header files is hard to write and 
   subsequently read.

There are a couple of TODOs in this patch to complete this optimization.

Differential Revision: http://reviews.llvm.org/D8486



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232852 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-20 21:47:56 +00:00
Wei Mi
8979e3f69b Correctly estimate SROA savings for store operands in inline cost analysis.
When estimating SROA savings, we want to see if an address is derived
off an alloca in the caller. For store instructions, operand 1 is the
address operand, but the current code uses operand 0.  Use
getPointerOperand for loads and stores to fix this.

Patch by Easwaran Raman.
http://reviews.llvm.org/D8425


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232827 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-20 18:33:12 +00:00
Peter Collingbourne
58e8e3505d LowerBitSets: Avoid reusing byte set addresses.
Each use of the byte array uses a different alias. This makes the
backend less likely to reuse previously computed byte array addresses,
improving the security of the CFI mechanism based on this pass.

Differential Revision: http://reviews.llvm.org/D8455

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232770 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-19 22:02:10 +00:00
Daniel Jasper
3baea2951d [InstCombine] Don't fold a GEP into itself through a PHI node
This can only occur (I think) through the back-edge of the loop.

However, folding a GEP into itself means that the value of the previous
iteration needs to be stored in the meantime, thus requiring an
additional register variable to be live, but not actually achieving
anything (the gep still needs to be executed once per loop iteration).

The attached test case is derived from:
  typedef unsigned uint32;
  typedef unsigned char uint8;
  inline uint8 *f(uint32 value, uint8 *target) {
    while (value >= 0x80) {
      value >>= 7;
      ++target;
    }
    ++target;
    return target;
  }
  uint8 *g(uint32 b, uint8 *target) {
    target = f(b, f(42, target));
    return target;
  }

What happens is that the GEP stored in incptr2 is folded into itself
through the loop's back-edge and the phi-node stored in loopptr,
effectively incrementing the ptr by "2" in each iteration instead of "1".

In this case, it is actually increasing the number of GEPs required as
the GEP before the loop can't be folded away anymore. For comparison:

With this patch:
  define i8* @test4(i32 %value, i8* %buffer) {
  entry:
    %cmp = icmp ugt i32 %value, 127
    br i1 %cmp, label %loop.header, label %exit

  loop.header:                                      ; preds = %entry
    br label %loop.body

  loop.body:                                        ; preds = %loop.body, %loop.header
    %buffer.pn = phi i8* [ %buffer, %loop.header ], [ %loopptr, %loop.body ]
    %newval = phi i32 [ %value, %loop.header ], [ %shr, %loop.body ]
    %loopptr = getelementptr inbounds i8, i8* %buffer.pn, i64 1
    %shr = lshr i32 %newval, 7
    %cmp2 = icmp ugt i32 %newval, 16383
    br i1 %cmp2, label %loop.body, label %loop.exit

  loop.exit:                                        ; preds = %loop.body
    br label %exit

  exit:                                             ; preds = %loop.exit, %entry
    %0 = phi i8* [ %loopptr, %loop.exit ], [ %buffer, %entry ]
    %incptr3 = getelementptr inbounds i8, i8* %0, i64 2
    ret i8* %incptr3
  }

Without this patch:
  define i8* @test4(i32 %value, i8* %buffer) {
  entry:
    %incptr = getelementptr inbounds i8, i8* %buffer, i64 1
    %cmp = icmp ugt i32 %value, 127
    br i1 %cmp, label %loop.header, label %exit

  loop.header:                                      ; preds = %entry
    br label %loop.body

  loop.body:                                        ; preds = %loop.body, %loop.header
    %0 = phi i8* [ %buffer, %loop.header ], [ %loopptr, %loop.body ]
    %loopptr = phi i8* [ %incptr, %loop.header ], [ %incptr2, %loop.body ]
    %newval = phi i32 [ %value, %loop.header ], [ %shr, %loop.body ]
    %shr = lshr i32 %newval, 7
    %incptr2 = getelementptr inbounds i8, i8* %0, i64 2
    %cmp2 = icmp ugt i32 %newval, 16383
    br i1 %cmp2, label %loop.body, label %loop.exit

  loop.exit:                                        ; preds = %loop.body
    br label %exit

  exit:                                             ; preds = %loop.exit, %entry
    %ptr2 = phi i8* [ %incptr2, %loop.exit ], [ %incptr, %entry ]
    %incptr3 = getelementptr inbounds i8, i8* %ptr2, i64 1
    ret i8* %incptr3
  }

Review: http://reviews.llvm.org/D8245

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232718 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-19 11:05:08 +00:00