Commit Graph

432 Commits

Author SHA1 Message Date
Pete Cooper 0deca6be79 Fix crash when when do lto on Bullet. Dynamic GEPs in SROA were incorrectly being applied to all accesses to an alloca, not just the ones which read from the GEP. Thanks to Evan for reducing the test. rdar://11861001
llvm-svn: 161654
2012-08-10 03:26:36 +00:00
Nadav Rotem 465834c85f Clean whitespaces.
llvm-svn: 160668
2012-07-24 10:51:42 +00:00
Chandler Carruth aafe0918bc Move llvm/Support/IRBuilder.h -> llvm/IRBuilder.h
This was always part of the VMCore library out of necessity -- it deals
entirely in the IR. The .cpp file in fact was already part of the VMCore
library. This is just a mechanical move.

I've tried to go through and re-apply the coding standard's preferred
header sort, but at 40-ish files, I may have gotten some wrong. Please
let me know if so.

I'll be committing the corresponding updates to Clang and Polly, and
Duncan has DragonEgg.

Thanks to Bill and Eric for giving the green light for this bit of cleanup.

llvm-svn: 159421
2012-06-29 12:38:19 +00:00
Bill Wendling f799efdedc The DIBuilder class is just a wrapper around debug info creation
(a.k.a. MDNodes). The module doesn't belong in Analysis. Move it to the VMCore
instead.

llvm-svn: 159414
2012-06-29 08:32:07 +00:00
Bill Wendling e38859dc8e Move lib/Analysis/DebugInfo.cpp to lib/VMCore/DebugInfo.cpp and
include/llvm/Analysis/DebugInfo.h to include/llvm/DebugInfo.h.

The reasoning is because the DebugInfo module is simply an interface to the
debug info MDNodes and has nothing to do with analysis.

llvm-svn: 159312
2012-06-28 00:05:13 +00:00
Nadav Rotem 4e9012c2b1 Add a number of threshold arguments to the SRA pass.
A patch by Tom Stellard with minor changes.

llvm-svn: 158918
2012-06-21 13:44:31 +00:00
Pete Cooper 33ee6c9bf1 Now that SROA can form alloca's for dynamic vector accesses, further improve it to be able to replace operations on these vector alloca's with insert/extract element insts
llvm-svn: 158623
2012-06-17 03:58:26 +00:00
Pete Cooper 818e9f4a26 Fix crash from r158529 on Bullet.
Dynamic GEPs created by SROA needed to insert extra "i32 0"
operands to index through structs and arrays to get to the
vector being indexed.

llvm-svn: 158590
2012-06-16 01:43:26 +00:00
Pete Cooper e24d6a19e3 Allow SROA to split up an array of vectors into multiple vectors, even when the vectors are dynamically indexed
llvm-svn: 158529
2012-06-15 18:07:29 +00:00
Pete Cooper 1d1fa72837 Recommit r158407: Allow SROA to look at a vector type and see if the offset is out of range to be replaced with a scalar access. Now with additional fix and test for indexing into a vector inside a struct
llvm-svn: 158479
2012-06-14 23:53:53 +00:00
Pete Cooper 5d19452f3f Revert r158454: Allow SROA to look at a vector type... Its breaking the vectorise buildbot
This reverts commit 12c1f86ffa731e2952c80d2cc577000c96b8962c.

llvm-svn: 158462
2012-06-14 18:32:52 +00:00
Pete Cooper a7e6d58a87 Recommit r158407: Allow SROA to look at a vector type and see if the offset is out of range to be replaced with a scalar access. Now with additional fix and test for indexing into a vector inside a struct
llvm-svn: 158454
2012-06-14 16:38:13 +00:00
Pete Cooper e2fe809772 Revert "Allow SROA to look at a vector type and see if the offset is out of range to be replaced with a scalar access"
This reverts commit 51786e0aaec76b973205066bd44f7f427b21969f.

llvm-svn: 158408
2012-06-13 17:55:22 +00:00
Pete Cooper e1d4e8b563 Allow SROA to look at a vector type and see if the offset is out of range to be replaced with a scalar access
llvm-svn: 158407
2012-06-13 17:30:34 +00:00
Peter Collingbourne 97b1076435 Do not eliminate allocas whose alignment exceeds that of the
copied-in constant, as a subsequent user may rely on over alignment.
Fixes PR12885.

llvm-svn: 157134
2012-05-19 22:52:10 +00:00
Chad Rosier cc899f3b6d Typo.
llvm-svn: 154522
2012-04-11 19:21:58 +00:00
Duncan Sands 8f897dc88b Indentation.
llvm-svn: 153322
2012-03-23 08:29:04 +00:00
Chris Lattner 7d7dba3c92 don't use "signed", just something I noticed in patches flying by.
llvm-svn: 153237
2012-03-22 03:46:58 +00:00
Aaron Ballman a733297fa6 Fixed a transform crash when setting a negative size value for memset. Fixes PR12202.
llvm-svn: 152756
2012-03-15 00:05:31 +00:00
Benjamin Kramer 077e55252a Reflow code, no functionality change.
llvm-svn: 151262
2012-02-23 17:42:19 +00:00
Chris Lattner 47a86bdbe2 use ConstantVector::getSplat in a few places.
llvm-svn: 148929
2012-01-25 06:02:56 +00:00
Rafael Espindola 2b14b80b60 Fix warning.
llvm-svn: 147284
2011-12-26 23:12:42 +00:00
Nadav Rotem 3924cb0267 Add support for vectors of pointers.
llvm-svn: 145801
2011-12-05 06:29:09 +00:00
Nick Lewycky 612d70b19d Refactor code to use new attribute getters on CallSite for NoCapture and ByVal.
Suggested in code review by Eli.

That code in InstCombine looks kinda suspicious.

llvm-svn: 145013
2011-11-20 19:09:04 +00:00
Eli Friedman ecb453805d Make sure scalarrepl picks the correct alloca when it rewrites a bitcast. Fixes PR11353.
llvm-svn: 144442
2011-11-12 02:07:50 +00:00
Cameron Zwarich 057fbb1a10 The element insertion code in scalar replacement doesn't handle incorrect
element types, even though the element extraction code does. It is surprising
that this bug has been here for so long. Fixes <rdar://problem/10318778>.

llvm-svn: 142740
2011-10-23 07:02:10 +00:00
Cameron Zwarich 1a761dcfbd Fix PR11106 by correcting a typo that has been in the code for over a year. This
would have never worked, since the element type of a vector type is never a
vector type. Also fix the conditional to be more direct in checking whether
EltTy is a vector type.

llvm-svn: 141713
2011-10-11 21:26:40 +00:00
Cameron Zwarich d7515ccc47 Remove a lot of the fancy scalar replacement code for dealing with llvm-gcc's
lowering of NEON code. It provides little-to-no benefit now and only introduces
additional complexity.

llvm-svn: 141646
2011-10-11 06:10:30 +00:00
Benjamin Kramer 547b6c5ecd Stop emitting instructions with the name "tmp" they eat up memory and have to be uniqued, without any benefit.
If someone prefers %tmp42 to %42, run instnamer.

llvm-svn: 140634
2011-09-27 20:39:19 +00:00
Eli Friedman f9b785f185 PR10987: add a missed safety check to isSafePHIToSpeculate in scalarrepl.
llvm-svn: 140327
2011-09-22 18:56:30 +00:00
Eli Friedman 7c5dc122a0 Change a bunch of isVolatile() checks to check for atomic load/store as well.
No tests; these changes aren't really interesting in the sense that the logic is the same for volatile and atomic.

I believe this completes all of the changes necessary for the optimizer to handle loads and stores correctly.  I'm going to try and come up with some additional testing, though.

llvm-svn: 139533
2011-09-12 20:23:13 +00:00
Nick Lewycky 15e2d90746 Finish adding support for lifetime intrinsics to SROA. Fixes PR10121!
llvm-svn: 136008
2011-07-25 23:14:22 +00:00
Jay Foad d1b7849d49 Convert GetElementPtrInst to use ArrayRef.
llvm-svn: 135904
2011-07-25 09:48:08 +00:00
Dan Gohman e106aee6f5 Fix MergeInVectorType to check for vector types with the same alloc
size but different element types, so that it filters out the cases
that CreateShuffleVectorCast doesn't handle. This fixes rdar://9786827.

llvm-svn: 135721
2011-07-21 23:30:09 +00:00
Jay Foad bf904773bb Convert TargetData::getIndexedOffset to use ArrayRef.
llvm-svn: 135478
2011-07-19 14:01:37 +00:00
Chris Lattner 229907cd11 land David Blaikie's patch to de-constify Type, with a few tweaks.
llvm-svn: 135375
2011-07-18 04:54:35 +00:00
Devang Patel 41e97da74f Use DBG_VALUE location while inserting DBG_VALUE during alloca promotion.
llvm-svn: 134568
2011-07-07 00:05:58 +00:00
Devang Patel c6ee9181d0 Handle cases where multiple dbg.declare and dbg.value intrinsics are tied to one alloca.
llvm-svn: 134549
2011-07-06 22:06:11 +00:00
Devang Patel a3cbf52a57 Simplify. Consolidate dbg.declare handling in AllocaPromoter.
llvm-svn: 134538
2011-07-06 21:09:55 +00:00
Nick Lewycky f64a39768d Fix likely typo, reduce number of instruction name collisions.
llvm-svn: 134235
2011-07-01 06:27:03 +00:00
Nick Lewycky a61df3f843 Teach one piece of scalarrepl to handle lifetime markers. When transforming an
alloca that only holds a copy of a global and we're going to replace the users
of the alloca with that global, just nuke the lifetime intrinsics. Part of
PR10121.

llvm-svn: 133905
2011-06-27 05:40:02 +00:00
Cameron Zwarich 9601ddb2f3 When scalar replacement returns a vector type, only accept it if the vector
type's bitwidth matches the (allocated) size of the alloca. This severely
pessimizes vector scalar replacement when the only vector type being used is
something like <3 x float> on x86 or ARM whose allocated size matches a
<4 x float>.

I hope to fix some of the flawed assumptions about allocated size throughout
scalar replacement and reenable this in most cases.

llvm-svn: 133338
2011-06-18 06:17:51 +00:00
Cameron Zwarich 2a26100c87 Fix an invalid bitcast crash that occurs when doing a partial memset of a vector
alloca. Fixes part of <rdar://problem/9580800>.

llvm-svn: 133336
2011-06-18 05:47:49 +00:00
Cameron Zwarich cd42038fdc Remove a pointless assignment. Nothing checks the value of VectorTy anymore now
unless ScalarKind is Vector.

llvm-svn: 133335
2011-06-18 05:47:45 +00:00
Cameron Zwarich b5f19d9f6f Be more obvious about what is being tested.
llvm-svn: 132982
2011-06-14 06:33:51 +00:00
Cameron Zwarich 922e4940bd Fix grammar.
llvm-svn: 132952
2011-06-13 23:39:23 +00:00
Cameron Zwarich 3ecbd59c27 Rename MergeInType to MergeInTypeForLoadOrStore.
llvm-svn: 132940
2011-06-13 21:44:43 +00:00
Cameron Zwarich 8cb90ac456 Remove the HadAVector instance variable and replace it with a use of ScalarKind.
llvm-svn: 132939
2011-06-13 21:44:40 +00:00
Cameron Zwarich 1bfab48edb Remove a vacuous check.
llvm-svn: 132938
2011-06-13 21:44:38 +00:00
Cameron Zwarich 5e9a0be4b3 Have SRoA explicitly track the kind of scalar it is promoting. This is pretty
spartan right now, but I plan to encode more information in this enum to improve
the correctness and reliability of SRoA. At least this first pass makes it
possible to make VectorTy an actual VectorType.

llvm-svn: 132937
2011-06-13 21:44:35 +00:00
Cameron Zwarich 8deb615d64 Remove an argument that is always true.
llvm-svn: 132936
2011-06-13 21:44:31 +00:00
Cameron Zwarich c62894d440 Remove a vacuous condition.
llvm-svn: 132767
2011-06-09 01:52:44 +00:00
Cameron Zwarich 77a699a829 Fix PR10104 by adding a bounds check on a vector element access check. It was
assuming that all offsets are legal vector accesses, and thus trying to access
the float member of { <2 x float>, float } as the 3rd element of the first
member.

llvm-svn: 132766
2011-06-09 01:45:33 +00:00
Cameron Zwarich c3b1cc9aca Fix an assymmetry between ConvertScalar_ExtractValue and ConvertScalar_InsertValue. The
former was using the size of the entire alloca, whereas the latter was correctly using
the allocated size of the immediate type being converted (which may differ from the size
of the alloca). This fixes PR10082.

llvm-svn: 132759
2011-06-08 22:08:31 +00:00
Devang Patel 84bb33add9 Use IRBuilder, preserve line numbers.
llvm-svn: 132578
2011-06-03 19:46:19 +00:00
Cameron Zwarich 46e1ebf367 Clean up the lazy initialization of DIBuilder a bit.
llvm-svn: 131956
2011-05-24 06:00:08 +00:00
Cameron Zwarich 843bc7d673 Make LoadAndStorePromoter preserve debug info and create llvm.dbg.values when
promoting allocas to SSA variables. Fixes <rdar://problem/9479036>.

llvm-svn: 131953
2011-05-24 03:10:43 +00:00
Duncan Sands a071c82900 Fix PR9820: a read-only call differs from a load in that a load doesn't
return the pointer being dereferenced, it returns the pointee, but a call
might return the pointer itself.

llvm-svn: 130979
2011-05-06 10:30:37 +00:00
Cameron Zwarich ca4c633489 Fix another case of <rdar://problem/9184212> that only occurs with code
generated by llvm-gcc, since llvm-gcc uses 2 i64s for passing a 4 x float
vector on ARM rather than an i64 array like Clang.

llvm-svn: 129878
2011-04-20 21:48:38 +00:00
Cameron Zwarich 76dfa226cf The bitcast case here is actually handled uniformly earlier in the function, so
delete it.

llvm-svn: 129877
2011-04-20 21:48:34 +00:00
Cameron Zwarich 4cd9a4a975 Cleanup some code to better use an early return style in preparation for adding
more cases.

llvm-svn: 129876
2011-04-20 21:48:16 +00:00
Mon P Wang 1cde91674a Cleanup r129509 based on comments by Chris
llvm-svn: 129532
2011-04-14 19:20:42 +00:00
Mon P Wang 0f6bad7b6e Cleanup r129472 by using a utility routine as suggested by Eli.
llvm-svn: 129509
2011-04-14 08:04:01 +00:00
Mon P Wang 2e5528f0b2 Vectors with different number of elements of the same element type can have
the same allocation size but different primitive sizes(e.g., <3xi32> and
<4xi32>).  When ScalarRepl promotes them, it can't use a bit cast but
should use a shuffle vector instead.

llvm-svn: 129472
2011-04-13 21:40:02 +00:00
Jay Foad 52131344a2 Remove PHINode::reserveOperandSpace(). Instead, add a parameter to
PHINode::Create() giving the (known or expected) number of operands.

llvm-svn: 128537
2011-03-30 11:28:46 +00:00
Jay Foad e0938d8a87 (Almost) always call reserveOperandSpace() on newly created PHINodes.
llvm-svn: 128535
2011-03-30 11:19:20 +00:00
Cameron Zwarich ff811cc475 Do some simple copy propagation through integer loads and stores when promoting
vector types. This helps a lot with inlined functions when using the ARM soft
float ABI. Fixes <rdar://problem/9184212>.

llvm-svn: 128453
2011-03-29 05:19:52 +00:00
Cameron Zwarich d4174ee43e Fix a typo and add a test.
llvm-svn: 128331
2011-03-26 04:58:50 +00:00
Cameron Zwarich 10ebc189ee Fix PR9464 by correcting some math that just happened to be right in most cases
that were hit in practice.

llvm-svn: 128146
2011-03-23 05:25:55 +00:00
Cameron Zwarich 7599b106b7 Fix a comment.
llvm-svn: 127728
2011-03-16 08:13:42 +00:00
Cameron Zwarich 0454253d7a Only convert allocas to scalars if it is profitable. The profitability metric I
chose is having a non-memcpy/memset use and being larger than any native integer
type. Originally I chose having an access of a size smaller than the total size
of the alloca, but this caused some minor issues on the spirit benchmark where
SRoA runs again after some inlining.

This fixes <rdar://problem/8613163>.

llvm-svn: 127718
2011-03-16 00:13:44 +00:00
Cameron Zwarich b51c830f7c Better use initializer lists.
llvm-svn: 127716
2011-03-16 00:13:37 +00:00
Cameron Zwarich 63062ccf85 Add a clarifying comment.
llvm-svn: 127715
2011-03-16 00:13:35 +00:00
Cameron Zwarich 19f2b3c652 Fix a crasher introduced by r127317 that is seen on the bots when using an
alloca as both integer and floating-point vectors of the same size. Bugpoint is
not cooperating with me, but I'll try to find a manual testcase tomorrow.

llvm-svn: 127320
2011-03-09 07:34:11 +00:00
Cameron Zwarich 3b649f4d01 Add support to scalar replacement for partial vector accesses of an alloca, e.g.
a union of a float, <2 x float>, and <4 x float>. This mostly comes up with the
use of vector intrinsics, especially in NEON when programmers know the layout of
the register file. This enables codegen to eliminate a lot of the subregister
traffic it would otherwise generate.

This commit only enables this for a small number of floating-point cases, but a
lot more integer cases. I assume this is okay for all ports, but I did not do
extensive testing of the quality of code involving i512 vectors and the like. If
there is a use case where this generates worse code than before, let me know and
we can scale it back.

This fixes <rdar://problem/9036264>.

llvm-svn: 127317
2011-03-09 05:43:05 +00:00
Cameron Zwarich 43a241fa06 Move vector type merging to a separate function in preparation for it getting
more complicated.

llvm-svn: 127316
2011-03-09 05:43:01 +00:00
Chris Lattner 69229316aa convert ConstantVector::get to use ArrayRef.
llvm-svn: 125537
2011-02-15 00:14:00 +00:00
Chris Lattner 34442e6ebf revert my ConstantVector patch, it seems to have made the llvm-gcc
builders unhappy.

llvm-svn: 125504
2011-02-14 18:15:46 +00:00
Chris Lattner d9f5b88548 Switch ConstantVector::get to use ArrayRef instead of a pointer+size
idiom.  Change various clients to simplify their code.

llvm-svn: 125487
2011-02-14 07:55:32 +00:00
Dan Gohman 0f124e1987 Give GetUnderlyingObject a TargetData, to keep it in sync
with BasicAA's DecomposeGEPExpression, which recently began
using a TargetData. This fixes PR8968, though the testcase
is awkward to reduce.

Also, update several off GetUnderlyingObject's users
which happen to have a TargetData handy to pass it in.

llvm-svn: 124134
2011-01-24 18:53:32 +00:00
Chris Lattner d83e7b0ff6 enhance SRoA to promote allocas that are used by PHI nodes. This often
occurs because instcombine sinks loads and inserts phis.  This kicks in 
on such apps as 175.vpr, eon, 403.gcc, xalancbmk and a bunch of times in
spec2006 in some app that uses std::deque.

This resolves the last of rdar://7339113.

llvm-svn: 124090
2011-01-24 01:07:11 +00:00
Chris Lattner a960725d18 Enhance SRoA to promote allocas that are used by selects in some
common cases.  This triggers a surprising number of times in SPEC2K6
because min/max idioms end up doing this.  For example, code from the
STL ends up looking like this to SRoA:

  %202 = load i64* %__old_size, align 8, !tbaa !3
  %203 = load i64* %__old_size, align 8, !tbaa !3
  %204 = load i64* %__n, align 8, !tbaa !3
  %205 = icmp ult i64 %203, %204
  %storemerge.i = select i1 %205, i64* %__n, i64* %__old_size
  %206 = load i64* %storemerge.i, align 8, !tbaa !3

We can now promote both the __n and the __old_size allocas.

This addresses another chunk of rdar://7339113, poor codegen on
stringswitch.

llvm-svn: 124088
2011-01-23 22:04:55 +00:00
Chris Lattner 9491dee24e Enhance SRoA to be more aggressive about scalarization of aggregate allocas
that have PHI or select uses of their element pointers.  This can often happen
when instcombine sinks two loads into a successor, inserting a phi or select.

With this patch, we can scalarize the alloca, but the pinned elements are not
yet promoted.  This is still a win for large aggregates where only one element
is used.  This fixes rdar://8904039 and part of rdar://7339113 (poor codegen
on stringswitch).

llvm-svn: 124070
2011-01-23 08:27:54 +00:00
Chris Lattner 8acbb79506 have AllocaInfo store the alloca being inspected, simplifying callers.
No functionality change.

llvm-svn: 124067
2011-01-23 07:29:29 +00:00
Chris Lattner 3e56c29068 Rearrange some code a bit. Change MarkUnsafe to
handle the "Transformation preventing inst" printing, 
so that -scalarrepl -debug will always print the rejected
instruction.  No functionality change.

llvm-svn: 124066
2011-01-23 07:05:44 +00:00
Chris Lattner a587ab7b94 remove an old hack that avoided creating MMX datatypes. The
X86 backend has been fixed.

llvm-svn: 124064
2011-01-23 06:40:33 +00:00
Cameron Zwarich 4694e69540 Remove outdated references to dominance frontiers.
llvm-svn: 123724
2011-01-18 03:53:26 +00:00
Cameron Zwarich b410858a5f Roll r123609 back in with two changes that fix test failures with expensive
checks enabled:

1) Use '<' to compare integers in a comparison function rather than '<='.

2) Use the uniqued set DefBlocks rather than Info.DefiningBlocks to initialize
the priority queue.

The speedup of scalarrepl on test-suite + SPEC2000 + SPEC2006 is a bit less, at
just under 16% rather than 17%.

llvm-svn: 123662
2011-01-17 17:38:41 +00:00
Cameron Zwarich 67431d7943 Roll out r123609 due to failures on the llvm-x86_64-linux-checks bot.
llvm-svn: 123618
2011-01-17 07:26:51 +00:00
Cameron Zwarich 814cd9233e Eliminate the use of dominance frontiers in PromoteMemToReg. In addition to
eliminating a potentially quadratic data structure, this also gives a 17%
speedup when running -scalarrepl on test-suite + SPEC2000 + SPEC2006. My initial
experiment gave a greater speedup around 25%, but I moved the dominator tree
level computation from dominator tree construction to PromoteMemToReg.

Since this approach to computing IDFs has a much lower overhead than the old
code using precomputed DFs, it is worth looking at using this new code for the
second scalarrepl pass as well.

llvm-svn: 123609
2011-01-17 01:08:59 +00:00
Chris Lattner 7c9f4c9c2b tidy up a comment, as suggested by duncan
llvm-svn: 123590
2011-01-16 17:46:19 +00:00
Chris Lattner 6fab2e9418 if an alloca is only ever accessed as a unit, and is accessed with load/store instructions,
then don't try to decimate it into its individual pieces.  This will just make a mess of the
IR and is pointless if none of the elements are individually accessed.  This was generating
really terrible code for std::bitset (PR8980) because it happens to be lowered by clang
as an {[8 x i8]} structure instead of {i64}.

The testcase now is optimized to:

define i64 @test2(i64 %X) {
  br label %L2

L2:                                               ; preds = %0
  ret i64 %X
}

before we generated:

define i64 @test2(i64 %X) {
  %sroa.store.elt = lshr i64 %X, 56
  %1 = trunc i64 %sroa.store.elt to i8
  %sroa.store.elt8 = lshr i64 %X, 48
  %2 = trunc i64 %sroa.store.elt8 to i8
  %sroa.store.elt9 = lshr i64 %X, 40
  %3 = trunc i64 %sroa.store.elt9 to i8
  %sroa.store.elt10 = lshr i64 %X, 32
  %4 = trunc i64 %sroa.store.elt10 to i8
  %sroa.store.elt11 = lshr i64 %X, 24
  %5 = trunc i64 %sroa.store.elt11 to i8
  %sroa.store.elt12 = lshr i64 %X, 16
  %6 = trunc i64 %sroa.store.elt12 to i8
  %sroa.store.elt13 = lshr i64 %X, 8
  %7 = trunc i64 %sroa.store.elt13 to i8
  %8 = trunc i64 %X to i8
  br label %L2

L2:                                               ; preds = %0
  %9 = zext i8 %1 to i64
  %10 = shl i64 %9, 56
  %11 = zext i8 %2 to i64
  %12 = shl i64 %11, 48
  %13 = or i64 %12, %10
  %14 = zext i8 %3 to i64
  %15 = shl i64 %14, 40
  %16 = or i64 %15, %13
  %17 = zext i8 %4 to i64
  %18 = shl i64 %17, 32
  %19 = or i64 %18, %16
  %20 = zext i8 %5 to i64
  %21 = shl i64 %20, 24
  %22 = or i64 %21, %19
  %23 = zext i8 %6 to i64
  %24 = shl i64 %23, 16
  %25 = or i64 %24, %22
  %26 = zext i8 %7 to i64
  %27 = shl i64 %26, 8
  %28 = or i64 %27, %25
  %29 = zext i8 %8 to i64
  %30 = or i64 %29, %28
  ret i64 %30
}

In this case, instcombine was able to eliminate the nonsense, but in PR8980 enough
PHIs are in play that instcombine backs off.  It's better to not generate this stuff
in the first place.

llvm-svn: 123571
2011-01-16 06:18:28 +00:00
Chris Lattner 7cd8cf7d24 Use an irbuilder to get some trivial constant folding when doing a store
of a constant.

llvm-svn: 123570
2011-01-16 05:58:24 +00:00
Chris Lattner d55581ded8 enhance FoldOpIntoPhi in instcombine to try harder when a phi has
multiple uses.  In some cases, all the uses are the same operation,
so instcombine can go ahead and promote the phi.  In the testcase
this pushes an add out of the loop.

llvm-svn: 123568
2011-01-16 05:28:59 +00:00
Chris Lattner b68ec5c339 Generalize LoadAndStorePromoter a bit and switch LICM
to use it.

llvm-svn: 123501
2011-01-15 00:12:35 +00:00
Chris Lattner b498f9aff3 switch SRoA to use LoadAndStorePromoter instead of its own copy of the code.
llvm-svn: 123457
2011-01-14 19:50:47 +00:00
Chris Lattner 9987a6f49b split SROA into two passes: one that uses DomFrontiers (-scalarrepl)
and one that uses SSAUpdater (-scalarrepl-ssa)

llvm-svn: 123436
2011-01-14 08:13:00 +00:00
Chris Lattner 543384efb4 Implement full support for promoting allocas to registers using SSAUpdater
instead of DomTree/DomFrontier.  This may be interesting for reducing compile 
time.  This is currently disabled, but seems to work just fine.

When this is enabled, we eliminate two runs of dominator frontier, one in the
"early per-function" optimizations and one in the "interlaced with inliner"
function passes.

llvm-svn: 123434
2011-01-14 07:50:47 +00:00
Bob Wilson 328e91bbe1 Fix whitespace.
llvm-svn: 123396
2011-01-13 20:59:44 +00:00
Bob Wilson c8056a952e Check for empty structs, and for consistency, zero-element arrays.
llvm-svn: 123383
2011-01-13 18:26:59 +00:00