Commit Graph

5666 Commits

Author SHA1 Message Date
Benjamin Kramer
84dd75d8d2 Add a description to the test from r211433 explaining why it's written that way.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211465 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-22 12:22:04 +00:00
Arnold Schwaighofer
78f173a22d LoopVectorizer: Fix a dominance issue
The induction variables start value needs to be defined before we branch
(overflow check) to the scalar preheader where we used it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211460 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-22 03:38:59 +00:00
Benjamin Kramer
6b7ff6be9c LoopUnrollRuntime: Check for overflow in the trip count calculation.
Fixes PR19823.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211436 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-21 13:46:25 +00:00
Benjamin Kramer
b7f1fb47e6 SCEVExpander: Fold constant PHIs harder. The logic below only understands proper IVs.
PR20093.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211433 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-21 11:47:18 +00:00
Stepan Dyatkovskiy
81ed09a1d1 Commited patch from Björn Steinbrink:
Summary:
Different range metadata can lead to different optimizations in later
passes, possibly breaking the semantics of the merged function. So range
metadata must be taken into consideration when comparing Load
instructions.

Thanks!



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211391 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-20 19:11:56 +00:00
Karthik Bhat
d2ce9392dc Add Support to Recognize and Vectorize NON SIMD instructions in SLPVectorizer.
This patch adds support to recognize patterns such as fadd,fsub,fadd,fsub.../add,sub,add,sub... and
vectorizes them as vector shuffles if they are profitable.
These patterns of vector shuffle can later be converted to instructions such as addsubpd etc on X86.
Thanks to Arnold and Hal for the reviews. http://reviews.llvm.org/D4015 


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211339 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-20 04:32:48 +00:00
Hans Wennborg
160dcf5b61 Don't build switch lookup tables for dllimport or TLS variables
We would previously put dllimport variables in switch lookup tables, which
doesn't work because the address cannot be used in a constant initializer.
This is basically the same problem that we have in PR19955.

Putting TLS variables in switch tables also desn't work, because the
address of such a variable is not constant.

Differential Revision: http://reviews.llvm.org/D4220

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211331 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-20 00:38:12 +00:00
Jingyue Wu
e4d0a5ec18 [ValueTracking] Extend range metadata to call/invoke
Summary:
With this patch, range metadata can be added to call/invoke including
IntrinsicInst. Previously, it could only be added to load.

Rename computeKnownBitsLoad to computeKnownBitsFromRangeMetadata because
range metadata is not only used by load.

Update the language reference to reflect this change.

Test Plan:
Add several tests in range-2.ll to confirm the verifier is happy with
having range metadata on call/invoke.

Add two tests in AddOverFlow.ll to confirm annotating range metadata to
call/invoke can benefit InstCombine.

Reviewers: meheff, nlewycky, reames, hfinkel, eliben

Reviewed By: eliben

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D4187

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211281 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-19 16:50:16 +00:00
Dinesh Dwivedi
85386a3de9 Added instruction combine to transform few more negative values addition to subtraction (Part 1)
This patch enables transforms for following patterns.
  (x + (~(y & c) + 1)   -->   x - (y & c)
  (x + (~((y >> z) & c) + 1)   -->   x - ((y>>z) & c)

Differential Revision: http://reviews.llvm.org/D3733



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211266 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-19 10:36:52 +00:00
Dinesh Dwivedi
8317509052 Refactored and updated SimplifyUsingDistributiveLaws() to
* Find factorization opportunities using identity values.
 * Find factorization opportunities by treating shl(X, C) as mul (X, shl(C))
 * Keep NSW flag while simplifying instruction using factorization.

This fixes PR19263.

Differential Revision: http://reviews.llvm.org/D3799



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211261 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-19 08:29:18 +00:00
David Majnemer
6c2e8874b0 InstCombine: Stop two transforms dueling
InstCombineMulDivRem has:
// Canonicalize (X+C1)*CI -> X*CI+C1*CI.

InstCombineAddSub has:
// W*X + Y*Z --> W * (X+Z)  iff W == Y

These two transforms could fight with each other if C1*CI would not fold
away to something simpler than a ConstantExpr mul.

The InstCombineMulDivRem transform only acted on ConstantInts until
r199602 when it was changed to operate on all Constants in order to
let it fire on ConstantVectors.

To fix this, make this transform more careful by checking to see if we
actually folded away C1*CI.

This fixes PR20079.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211258 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-19 07:14:33 +00:00
Nick Lewycky
fe3a219355 Move optimization of some cases of (A & C1)|(B & C2) from instcombine to instsimplify. Patch by Rahul Jain, plus some last minute changes by me -- you can blame me for any bugs.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211252 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-19 03:51:46 +00:00
Nick Lewycky
650b6ea893 Make instsimplify's analysis of icmp eq/ne use computeKnownBits to determine whether the icmp is always true or false. Patch by Suyog Sarda!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211251 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-19 03:35:49 +00:00
Matt Arsenault
d9b35435b8 R600/SI: Add intrinsics for various math instructions.
These will be used for custom lowering and for library
implementations of various math functions, so it's useful
to expose these as builtins.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211247 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-19 01:19:19 +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
Jingyue Wu
dcc9291851 [InstCombine] mark ADD with nuw if no unsigned overflow
Summary:
As a starting step, we only use one simple heuristic: if the sign bits
of both a and b are zero, we can prove "add a, b" do not unsigned
overflow, and thus convert it to "add nuw a, b".

Updated all affected tests and added two new tests (@zero_sign_bit and
@zero_sign_bit2) in AddOverflow.ll

Test Plan: make check-all

Reviewers: eliben, rafael, meheff, chandlerc

Reviewed By: chandlerc

Subscribers: chandlerc, llvm-commits

Differential Revision: http://reviews.llvm.org/D4144

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211084 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-17 00:42:07 +00:00
Duncan P. N. Exon Smith
0dee67560f SROA: Only split loads on byte boundaries
r199771 accidently broke the logic that makes sure that SROA only splits
load on byte boundaries.  If such a split happens, some bits get lost
when reassembling loads of wider types, causing data corruption.

Move the width check up to reject such splits early, avoiding the
corruption.  Fixes PR19250.

Patch by: Björn Steinbrink <bsteinbr@gmail.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211082 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-17 00:19:35 +00:00
Eli Bendersky
4046db0cdb Teach LoopUnrollPass to respect loop unrolling hints in metadata.
[This is resubmitting r210721, which was reverted due to suspected breakage
which turned out to be unrelated].

Some extra review comments were addressed. See D4090 and D4147 for more details.

The Clang change that produces this metadata was committed in r210667

Patch by Mark Heffernan.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211076 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-16 23:53:02 +00:00
Jim Grosbach
dc2dc390f6 LowerSwitch: track bounding range for the condition tree.
When LowerSwitch transforms a switch instruction into a tree of ifs it
is actually performing a binary search into the various case ranges, to
see if the current value falls into one cases range of values.

So, if we have a program with something like this:

switch (a) {
case 0:
  do0();
  break;
case 1:
  do1();
  break;
case 2:
  do2();
  break;
default:
  break;
}

the code produced is something like this:

  if (a < 1) {
    if (a == 0) {
      do0();
    }
  } else {
    if (a < 2) {
      if (a == 1) {
        do1();
      }
    } else {
      if (a == 2) {
        do2();
      }
    }
  }

This code is inefficient because the check (a == 1) to execute do1() is
not needed.

The reason is that because we already checked that (a >= 1) initially by
checking that also  (a < 2) we basically already inferred that (a == 1)
without the need of an extra basic block spawned to check if actually (a
== 1).

The patch addresses this problem by keeping track of already
checked bounds in the LowerSwitch algorithm, so that when the time
arrives to produce a Leaf Block that checks the equality with the case
value / range the algorithm can decide if that block is really needed
depending on the already checked bounds .

For example, the above with "a = 1" would work like this:

the bounds start as LB: NONE , UB: NONE
as (a < 1) is emitted the bounds for the else path become LB: 1 UB:
NONE. This happens because by failing the test (a < 1) we know that the
value "a" cannot be smaller than 1 if we enter the else branch.
After the emitting the check (a < 2) the bounds in the if branch become
LB: 1 UB: 1. This is because by checking that "a" is smaller than 2 then
the upper bound becomes 2 - 1 = 1.

When it is time to emit the leaf block for "case 1:" we notice that 1
can be squeezed exactly in between the LB and UB, which means that if we
arrived to that block there is no need to emit a block that checks if (a
== 1).

Patch by: Marcello Maggioni <hayarms@gmail.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211038 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-16 16:55:20 +00:00
Jingyue Wu
f6eb7e3175 Canonicalize addrspacecast ConstExpr between different pointer types
As a follow-up to r210375 which canonicalizes addrspacecast
instructions, this patch canonicalizes addrspacecast constant
expressions.

Given clang uses ConstantExpr::getAddrSpaceCast to emit addrspacecast
cosntant expressions, this patch is also a step towards having the
frontend emit canonicalized addrspacecasts.

Piggyback a minor refactor in InstCombineCasts.cpp

Update three affected tests in addrspacecast-alias.ll,
access-non-generic.ll and constant-fold-gep.ll and added one new test in
constant-fold-address-space-pointer.ll


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211004 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-15 21:40:57 +00:00
Jiangning Liu
c5bc067a0f Move GlobalMerge from Transform to CodeGen.
This patch is to move GlobalMerge pass from Transform/Scalar                                                           
to CodeGen, because GlobalMerge depends on TargetMachine.
In the mean time, the macro INITIALIZE_TM_PASS is also moved
to CodeGen/Passes.h. With this fix we can avoid making
libScalarOpts depend on libCodeGen.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210951 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-13 22:57:59 +00:00
Tim Northover
33fe993f2e Atomics: make use of the "cmpxchg weak" instruction.
This also simplifies the IR we create slightly: instead of working out
where success & failure should go manually, it turns out we can just
always jump to a success/failure block created for the purpose. Later
phases will sort out the mess without much difficulty.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210917 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-13 16:45:52 +00:00
Tim Northover
6b3ed2b821 Atomics: switch direction of cmpxchg comparison
This has two benefits: it makes the result more suitable for direct
insertaion into the struct to emulate the new cmpxchg, and it means
the name we give the instruction matches its actual effect better.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210916 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-13 16:45:36 +00:00
Tim Northover
e1a9d504a3 SCCP: update for cmpxchg returning { iN, i1 } now.
I accidentally missed this one since its use looked OK locally.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210909 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-13 14:54:09 +00:00
Tim Northover
8f2a85e099 IR: add "cmpxchg weak" variant to support permitted failure.
This commit adds a weak variant of the cmpxchg operation, as described
in C++11. A cmpxchg instruction with this modifier is permitted to
fail to store, even if the comparison indicated it should.

As a result, cmpxchg instructions must return a flag indicating
success in addition to their original iN value loaded. Thus, for
uniformity *all* cmpxchg instructions now return "{ iN, i1 }". The
second flag is 1 when the store succeeded.

At the DAG level, a new ATOMIC_CMP_SWAP_WITH_SUCCESS node has been
added as the natural representation for the new cmpxchg instructions.
It is a strong cmpxchg.

By default this gets Expanded to the existing ATOMIC_CMP_SWAP during
Legalization, so existing backends should see no change in behaviour.
If they wish to deal with the enhanced node instead, they can call
setOperationAction on it. Beware: as a node with 2 results, it cannot
be selected from TableGen.

Currently, no use is made of the extra information provided in this
patch. Test updates are almost entirely adapting the input IR to the
new scheme.

Summary for out of tree users:
------------------------------

+ Legacy Bitcode files are upgraded during read.
+ Legacy assembly IR files will be invalid.
+ Front-ends must adapt to different type for "cmpxchg".
+ Backends should be unaffected by default.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210903 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-13 14:24:07 +00:00
Duncan P. N. Exon Smith
3fdfffbfa3 GVN: Enable value forwarding for calloc
Enable value forwarding for loads from `calloc()` without an intervening
store.

This change extends GVN to handle the following case:

    %1 = tail call noalias i8* @calloc(i64 1, i64 4)
    %2 = bitcast i8* %1 to i32*
    ; This load is trivially constant zero
    %3 = load i32* %2, align 4

This is analogous to the handling for `malloc()` in the same places.
`malloc()` returns `undef`; `calloc()` returns a zero value.  Note that
it is correct to return zero even for out of bounds GEPs since the
result of such a GEP would be undefined.

Patch by Philip Reames!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210828 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-12 21:16:19 +00:00
Eli Bendersky
26278061ee Revert r210721 as it causes breakage in internal builds (and possibly GDB).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210807 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-12 18:05:39 +00:00
Dinesh Dwivedi
7edfaf7148 This removes TODO added in http://reviews.llvm.org/D3658
The patch transforms

ABS(NABS(X)) -> ABS(X)
NABS(ABS(X)) -> NABS(X)

Differential Revision: http://reviews.llvm.org/D4040



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210782 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-12 14:06:00 +00:00
Eli Bendersky
87fcb536ab Teach LoopUnrollPass to respect loop unrolling hints in metadata.
See http://reviews.llvm.org/D4090 for more details.

The Clang change that produces this metadata was committed in r210667

Patch by Mark Heffernan.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210721 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-11 23:15:35 +00:00
Chad Rosier
9ce94d7df4 [Reassociate] FileCheckize and cleanup a few testcases. No functional change
intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210685 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-11 18:28:45 +00:00
Jiangning Liu
f847ccb87a Global merge for global symbols.
This commit is to improve global merge pass and support global symbol merge.
The global symbol merge is not enabled by default. For aarch64, we need some
more back-end fix to make it really benifit ADRP CSE.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210640 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-11 06:44:53 +00:00
Jiangning Liu
4c3b0b7594 Rename global-merge to enable-global-merge.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210639 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-11 06:35:26 +00:00
Juergen Ributzka
8b9e31c6e2 [ConstantHoisting][X86] Improve the cost model for small constants with large types (i64 and above).
This improves the X86 cost model for small constants with large types. Before
this commit we would even hoist trivial constants such as i96 2.

This is related to <rdar://problem/17070936>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210504 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-10 00:32:29 +00:00
Alp Toker
8aeca44558 Reduce verbiage of lit.local.cfg files
We can just split targets_to_build in one place and make it immutable.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210496 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-09 22:42:55 +00:00
Matt Arsenault
8a0c2d17f5 Look through addrspacecasts when turning ptr comparisons into
index comparisons.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210488 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-09 19:20:29 +00:00
Stepan Dyatkovskiy
77b0b852fa Added functions cross-reference test.
Originally this similar was initiated by Björn Steinbrink here:
http://reviews.llvm.org/D3437

Bug itself has been fixed by principal changes in MergeFunctions. Though
special checks for functions merging are still actual. And the test has
been accepted with slight modifications.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210486 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-09 19:03:02 +00:00
Jingyue Wu
09d6a9040c [SeparateConstOffsetFromGEP] inbounds zext => sext for better splitting
For each array index that is in the form of zext(a), convert it to sext(a)
if we can prove zext(a) <= max signed value of typeof(a). The conversion
helps to split zext(x + y) into sext(x) + sext(y).

Reviewed in http://reviews.llvm.org/D4060



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210444 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-08 23:49:34 +00:00
Jingyue Wu
724d2a8f1a [SeparateConstOffsetFromGEP] make two tests more strict
inbounds are not necessary in these two tests. zext(a +nuw b) = zext(a) +
zext(b) should hold with or without inbounds.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210437 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-08 20:01:42 +00:00
Rafael Espindola
68caf1727f Revert 209903 and 210040.
The messages were

 "PR19753: Optimize comparisons with "ashr exact" of a constanst."
 "Added support to optimize comparisons with "lshr exact" of a constant."

They were not correctly handling signed/unsigned operation differences,
causing pr19958.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210393 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-07 04:12:35 +00:00
Jingyue Wu
c77dec905a InstCombine: Canonicalize addrspacecast between different element types
addrspacecast X addrspace(M)* to Y addrspace(N)*

-->

bitcast X addrspace(M)* to Y addrspace(M)*
addrspacecast Y addrspace(M)* to Y addrspace(N)*

Updat all affected tests and add several new tests in addrspacecast.ll.

This patch is based on http://reviews.llvm.org/D2186 (authored by Matt
Arsenault) with fixes and more tests.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210375 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-06 21:52:55 +00:00
Michael Zolotukhin
f4f9c6bfc1 Fix typo in a test from r210342.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210343 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-06 15:49:47 +00:00
Michael Zolotukhin
afbe82d590 [SLP] Enable vectorization of GEP expressions.
The use cases look like the following:
    x->a = y->a + 10
    x->b = y->b + 12

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210342 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-06 15:34:24 +00:00
Dinesh Dwivedi
2c3e3b491e Added select flavour for ABS and NEG(ABS)
This patch can identify 
  ABS(X) ==> (X >s 0) ? X : -X and (X >s -1) ? X : -X
  ABS(X) ==> (X <s 0) ? -X : X and (X <s 1) ? -X : X
  NABS(X) ==> (X >s 0) ? -X : X and (X >s -1) ? -X : X
  NABS(X) ==> (X <s 0) ? X : -X and (X <s 1) ? X : -X
  
and can transform
  ABS(ABS(X)) -> ABS(X)
  NABS(NABS(X)) -> NABS(X)
  
Differential Revision: http://reviews.llvm.org/D3658



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210312 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-06 06:54:45 +00:00
Karthik Bhat
b73a9b384e Fix PR19657 (scalar loads not combined into vector load)
If we have common uses on separate paths in the tree; process the one with greater common depth first.
This makes sure that we do not assume we need to extract a load when it is actually going to be part of a vectorized tree.

Review: http://reviews.llvm.org/D3800


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210310 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-06 06:20:08 +00:00
Rafael Espindola
6fd1b8ee48 Allow aliases to be unnamed_addr.
Alias with unnamed_addr were in a strange state. It is stored in GlobalValue,
the language reference talks about "unnamed_addr aliases" but the verifier
was rejecting them.

It seems natural to allow unnamed_addr in aliases:

* It is a property of how it is accessed, not of the data itself.
* It is perfectly possible to write code that depends on the address
of an alias.

This patch then makes unname_addr legal for aliases. One side effect is that
the syntax changes for a corner case: In globals, unnamed_addr is now printed
before the address space.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210302 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-06 01:20:28 +00:00
Jingyue Wu
6156e562ef Fixed several correctness issues in SeparateConstOffsetFromGEP
Most issues are on mishandling s/zext.

Fixes:

1. When rebuilding new indices, s/zext should be distributed to
sub-expressions. e.g., sext(a +nsw (b +nsw 5)) = sext(a) + sext(b) + 5 but not
sext(a + b) + 5. This also affects the logic of recursively looking for a
constant offset, we need to include s/zext into the context of the searching.

2. Function find should return the bitwidth of the constant offset instead of
always sign-extending it to i64.

3. Stop shortcutting zext'ed GEP indices. LLVM conceptually sign-extends GEP
indices to pointer-size before computing the address. Therefore, gep base,
zext(a + b) != gep base, a + b

Improvements:

1. Add an optimization for splitting sext(a + b): if a + b is proven
non-negative (e.g., used as an index of an inbound GEP) and one of a, b is
non-negative, sext(a + b) = sext(a) + sext(b)

2. Function Distributable checks whether both sext and zext can be distributed
to operands of a binary operator. This helps us split zext(sext(a + b)) to
zext(sext(a) + zext(sext(b)) when a + b does not signed or unsigned overflow.

Refactoring:

Merge some common logic of handling add/sub/or in find.

Testing:

Add many tests in split-gep.ll and split-gep-and-gvn.ll to verify the changes
we made.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210291 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-05 22:07:33 +00:00
Rafael Espindola
64bcc6d81e Add a testcase where there is an overflow when combining two constants.
I noticed that a proposed optimization would have prevented this.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210287 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-05 21:29:49 +00:00
Nick Lewycky
59aecc1cf0 Fix coverage for files with global constructors again. Adds a testcase to the commit from r206671, as requested by David Blaikie.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210239 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-05 04:31:43 +00:00
Alexey Samsonov
a66075fdd1 Use AArch64 instead of now removed ARM64 in test configs
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210229 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-05 00:25:30 +00:00
Rafael Espindola
82db274d15 InstCombine: Improvement to check if signed addition overflows.
This patch implements two things:

1. If we know one number is positive and another is negative, we return true as
    signed addition of two opposite signed numbers will never overflow.

2. Implemented TODO : If one of the operands only has one non-zero bit, and if
    the other operand has a known-zero bit in a more significant place than it
    (not including the sign bit) the ripple may go up to and fill the zero, but
    won't change the sign. e.x -  (x & ~4) + 1

We make sure that we are ignoring 0 at MSB.

Patch by Suyog Sarda.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210186 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-04 15:39:14 +00:00