Commit Graph

318 Commits

Author SHA1 Message Date
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
Bob Wilson 08713d3c5f Extend SROA to handle arrays accessed as homogeneous structs and vice versa.
This is a minor extension of SROA to handle a special case that is
important for some ARM NEON operations.  Some of the NEON intrinsics
return multiple values, which are handled as struct types containing
multiple elements of the same vector type.  The corresponding return
types declared in the arm_neon.h header have equivalent arrays.  We
need SROA to recognize that it can split up those arrays and structs
into separate vectors, even though they are not always accessed with
the same type.  SROA already handles loads and stores of an entire
alloca by using insertvalue/extractvalue to access the individual
pieces, and that code works the same regardless of whether the type
is a struct or an array.  So, all that needs to be done is to check
for compatible arrays and homogeneous structs.

llvm-svn: 123381
2011-01-13 17:45:11 +00:00
Bob Wilson 12eec40c83 Make SROA more aggressive with allocas containing padding.
SROA only split up structs and arrays one level at a time, so padding can
only cause trouble if it is located in between the struct or array elements.

llvm-svn: 123380
2011-01-13 17:45:08 +00:00
Chris Lattner bf0aa927cc split dom frontier handling stuff out to its own DominanceFrontier header,
so that Dominators.h is *just* domtree.  Also prune #includes a bit.

llvm-svn: 122714
2011-01-02 22:09:33 +00:00
Chris Lattner 6cf8d6cc6e start using irbuilder to make mem intrinsics in a few passes.
llvm-svn: 122572
2010-12-26 22:57:41 +00:00
Mon P Wang 18b762a946 Preserve the address space when generating bitcasts for MemTransferInst in ConvertToScalarInfo
llvm-svn: 122462
2010-12-23 01:41:32 +00:00
Dan Gohman a4fcd2418d Move Value::getUnderlyingObject to be a standalone
function so that it can live in Analysis instead of
VMCore.

llvm-svn: 121885
2010-12-15 20:02:24 +00:00
Nick Lewycky b8de00ee07 Treat a call of function pointer like a load of the pointer when considering
whether the pointer can be replaced with the global variable it is a copy of.
Fixes PR8680.

llvm-svn: 120126
2010-11-24 22:04:20 +00:00
Benjamin Kramer ddd1b7b801 Simplify code. No change in functionality.
llvm-svn: 119908
2010-11-20 18:43:35 +00:00
Chris Lattner 1e37bbafbb finish a thought.
llvm-svn: 119690
2010-11-18 07:32:33 +00:00
Chris Lattner ac5701319b allow eliminating an alloca that is just copied from an constant global
if it is passed as a byval argument.  The byval argument will just be a
read, so it is safe to read from the original global instead.  This allows
us to promote away the %agg.tmp alloca in PR8582

llvm-svn: 119686
2010-11-18 06:41:51 +00:00
Chris Lattner f183d5c4be enhance the "alloca is just a memcpy from constant global"
to ignore calls that obviously can't modify the alloca
because they are readonly/readnone.

llvm-svn: 119683
2010-11-18 06:26:49 +00:00
Chris Lattner 7aeae25c78 fix a small oversight in the "eliminate memcpy from constant global"
optimization.  If the alloca that is "memcpy'd from constant" also has
a memcpy from *it*, ignore it: it is a load.  We now optimize the testcase to:

define void @test2() {
  %B = alloca %T
  %a = bitcast %T* @G to i8*
  %b = bitcast %T* %B to i8*
  call void @llvm.memcpy.p0i8.p0i8.i64(i8* %b, i8* %a, i64 124, i32 4, i1 false)
  call void @bar(i8* %b)
  ret void
}

previously we would generate:

define void @test() {
  %B = alloca %T
  %b = bitcast %T* %B to i8*
  %G.0 = getelementptr inbounds %T* @G, i32 0, i32 0
  %tmp3 = load i8* %G.0, align 4
  %G.1 = getelementptr inbounds %T* @G, i32 0, i32 1
  %G.15 = bitcast [123 x i8]* %G.1 to i8*
  %1 = bitcast [123 x i8]* %G.1 to i984*
  %srcval = load i984* %1, align 1
  %B.0 = getelementptr inbounds %T* %B, i32 0, i32 0
  store i8 %tmp3, i8* %B.0, align 4
  %B.1 = getelementptr inbounds %T* %B, i32 0, i32 1
  %B.12 = bitcast [123 x i8]* %B.1 to i8*
  %2 = bitcast [123 x i8]* %B.1 to i984*
  store i984 %srcval, i984* %2, align 1
  call void @bar(i8* %b)
  ret void
}

llvm-svn: 119682
2010-11-18 06:20:47 +00:00
Owen Anderson 6c18d1aac0 Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which
must be called in the pass's constructor.  This function uses static dependency declarations to recursively initialize
the pass's dependencies.

Clients that only create passes through the createFooPass() APIs will require no changes.  Clients that want to use the
CommandLine options for passes will need to manually call the appropriate initialization functions in PassInitialization.h
before parsing commandline arguments.

I have tested this with all standard configurations of clang and llvm-gcc on Darwin.  It is possible that there are problems
with the static dependencies that will only be visible with non-standard options.  If you encounter any crash in pass
registration/creation, please send the testcase to me directly.

llvm-svn: 116820
2010-10-19 17:21:58 +00:00
Benjamin Kramer 1dc34b48dd Eliminate some calls to Value::getNameStr.
llvm-svn: 116670
2010-10-16 11:28:23 +00:00