Commit Graph

7580 Commits

Author SHA1 Message Date
Chris Lattner
28252b6f0a fix PR8932, a case where arg promotion could infinitely promote.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123574 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-16 08:09:24 +00:00
Chris Lattner
54cfe7e027 simplify a little
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123573 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-16 07:11:21 +00:00
Chris Lattner
7e9b427c87 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.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123571 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-16 06:18:28 +00:00
Chris Lattner
7072853279 Use an irbuilder to get some trivial constant folding when doing a store
of a constant.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123570 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-16 05:58:24 +00:00
Chris Lattner
6eb6116d52 remove a dead check, this was needed before we had an explicit veto on uses of phis.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123569 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-16 05:37:55 +00:00
Chris Lattner
192228edb1 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123568 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-16 05:28:59 +00:00
Chris Lattner
9922ccf4b4 remove the AllowAggressive argument to FoldOpIntoPhi. It is forced to false in the
first line of the function because it isn't a good idea, even for compares.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123566 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-16 05:14:26 +00:00
Chris Lattner
7dfe8fd96c more cleanups: use the IR builder.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123565 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-16 05:08:00 +00:00
Chris Lattner
5aac83288c tidy up code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123564 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-16 04:37:29 +00:00
Owen Anderson
66f708f7e5 Improve the safety of my globalopt enhancement by ensuring that the bitcast
of the stored value to the new store type is always.  Also, add a testcase.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123563 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-16 04:33:33 +00:00
Chris Lattner
d5f656f48b simplify this code, it is still broken but will follow up on llvm-commits.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123558 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-16 02:05:10 +00:00
Chris Lattner
0092b1142f remove the partial specialization pass. It is unmaintained and has bugs.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123554 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-16 00:27:10 +00:00
Nick Lewycky
cd7f0a1a7f Add missing whitespace.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123543 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-15 18:42:52 +00:00
Nick Lewycky
2820c25e84 Make constmerge a two-pass algorithm so that it won't miss merging
opporuntities. Fixes PR8978.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123541 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-15 18:14:21 +00:00
Benjamin Kramer
bfa3b90582 Try to unbreak selfhost.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123537 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-15 11:25:34 +00:00
Nick Lewycky
e8f8139429 Add a cache that protects mergefunc's internals from more surprises in DenseSet.
Also, replace tabs with spaces. Yes, it's 2011.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123535 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-15 10:16:23 +00:00
Chris Lattner
6ccb5ef1b5 temporarily revert r123526. While working on a follow-on patch I
realize that ConstantFoldTerminator doesn't preserve dominfo.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123527 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-15 07:51:19 +00:00
Chris Lattner
eeba3f5695 fix rdar://8785296 - -fcatch-undefined-behavior generates inefficient code
The basic issue is that isel (very reasonably!) expects conditional branches
to be folded, so CGP leaving around a bunch dead computation feeding
conditional branches isn't such a good idea.  Just fold branches on constants
into unconditional branches.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123526 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-15 07:36:13 +00:00
Chris Lattner
1a8943a1f8 simplify code, no functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123525 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-15 07:29:01 +00:00
Chris Lattner
94e8e0cfbe Now that instruction optzns can update the iterator as they go, we can
have objectsize folding recursively simplify away their result when it
folds.  It is important to catch this here, because otherwise we won't
eliminate the cross-block values at isel and other times.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123524 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-15 07:25:29 +00:00
Chris Lattner
7579609bfe make the current instruction iterator an ivar, allowing xforms that
potentially invalidate it (like inline asm lowering) to be sunk into
their proper place, cleaning up a ton of code.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123523 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-15 07:14:54 +00:00
Chris Lattner
62fe406dc2 implement an instcombine xform that canonicalizes casts outside of and-with-constant operations.
This fixes rdar://8808586 which observed that we used to compile:


union xy {
        struct x { _Bool b[15]; } x;
        __attribute__((packed))
        struct y {
                __attribute__((packed)) unsigned long b0to7;
                __attribute__((packed)) unsigned int b8to11;
                __attribute__((packed)) unsigned short b12to13;
                __attribute__((packed)) unsigned char b14;
        } y;
};

struct x
foo(union xy *xy)
{
        return xy->x;
}

into:

_foo:                                   ## @foo
	movq	(%rdi), %rax
	movabsq	$1095216660480, %rcx    ## imm = 0xFF00000000
	andq	%rax, %rcx
	movabsq	$-72057594037927936, %rdx ## imm = 0xFF00000000000000
	andq	%rax, %rdx
	movzbl	%al, %esi
	orq	%rdx, %rsi
	movq	%rax, %rdx
	andq	$65280, %rdx            ## imm = 0xFF00
	orq	%rsi, %rdx
	movq	%rax, %rsi
	andq	$16711680, %rsi         ## imm = 0xFF0000
	orq	%rdx, %rsi
	movl	%eax, %edx
	andl	$-16777216, %edx        ## imm = 0xFFFFFFFFFF000000
	orq	%rsi, %rdx
	orq	%rcx, %rdx
	movabsq	$280375465082880, %rcx  ## imm = 0xFF0000000000
	movq	%rax, %rsi
	andq	%rcx, %rsi
	orq	%rdx, %rsi
	movabsq	$71776119061217280, %r8 ## imm = 0xFF000000000000
	andq	%r8, %rax
	orq	%rsi, %rax
	movzwl	12(%rdi), %edx
	movzbl	14(%rdi), %esi
	shlq	$16, %rsi
	orl	%edx, %esi
	movq	%rsi, %r9
	shlq	$32, %r9
	movl	8(%rdi), %edx
	orq	%r9, %rdx
	andq	%rdx, %rcx
	movzbl	%sil, %esi
	shlq	$32, %rsi
	orq	%rcx, %rsi
	movl	%edx, %ecx
	andl	$-16777216, %ecx        ## imm = 0xFFFFFFFFFF000000
	orq	%rsi, %rcx
	movq	%rdx, %rsi
	andq	$16711680, %rsi         ## imm = 0xFF0000
	orq	%rcx, %rsi
	movq	%rdx, %rcx
	andq	$65280, %rcx            ## imm = 0xFF00
	orq	%rsi, %rcx
	movzbl	%dl, %esi
	orq	%rcx, %rsi
	andq	%r8, %rdx
	orq	%rsi, %rdx
	ret

We now compile this into:

_foo:                                   ## @foo
## BB#0:                                ## %entry
	movzwl	12(%rdi), %eax
	movzbl	14(%rdi), %ecx
	shlq	$16, %rcx
	orl	%eax, %ecx
	shlq	$32, %rcx
	movl	8(%rdi), %edx
	orq	%rcx, %rdx
	movq	(%rdi), %rax
	ret

A small improvement :-)



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123520 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-15 06:32:33 +00:00
Chris Lattner
67920320b2 one more instcombine variant that is needed to work with future changes,
no functionality change currently.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123517 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-15 05:50:18 +00:00
Chris Lattner
27a98482bd fix typo
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123516 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-15 05:42:47 +00:00
Chris Lattner
fdb5b01df4 Catch ~x < cst just like ~x < ~y, we currently handle this through
means that are about to disappear.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123515 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-15 05:41:33 +00:00
Chris Lattner
28621cb36f reduce indentation
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123514 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-15 05:40:29 +00:00
Chris Lattner
deaf55f698 Generalize LoadAndStorePromoter a bit and switch LICM
to use it.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123501 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-15 00:12:35 +00:00
Owen Anderson
e95a32ce40 Fix a false-positive warning.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123480 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-14 22:31:13 +00:00
Owen Anderson
cff6b3772b Enhance GlobalOpt to be able evaluate initializers that involve stores through
bitcasts, at least in simple cases.  This fixes clang's CodeGenCXX/virtual-base-dtor.cpp


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123477 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-14 22:19:20 +00:00
Chris Lattner
d0f56132cf switch SRoA to use LoadAndStorePromoter instead of its own copy of the code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123457 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-14 19:50:47 +00:00
Chris Lattner
a2d845a3ff Add a new LoadAndStorePromoter class, which implements the general
"promote a bunch of load and stores" logic, allowing the code to
be shared and reused.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123456 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-14 19:36:13 +00:00
Chris Lattner
b352d6eb49 split SROA into two passes: one that uses DomFrontiers (-scalarrepl)
and one that uses SSAUpdater (-scalarrepl-ssa)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123436 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-14 08:13:00 +00:00
Chris Lattner
e0a1a5ba91 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123434 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-14 07:50:47 +00:00
Chris Lattner
70e5e222db indentation
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123426 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-14 04:23:53 +00:00
Duncan Sands
c43cee3fbb Move some shift transforms out of instcombine and into InstructionSimplify.
While there, I noticed that the transform "undef >>a X -> undef" was wrong.
For example if X is 2 then the top two bits must be equal, so the result can
not be anything.  I fixed this in the constant folder as well.  Also, I made
the transform for "X << undef" stronger: it now folds to undef always, even
though X might be zero.  This is in accordance with the LangRef, but I must
admit that it is fairly aggressive.  Also, I added "i32 X << 32 -> undef"
following the LangRef and the constant folder, likewise fairly aggressive.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123417 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-14 00:37:45 +00:00
Bob Wilson
6974302e3f Fix whitespace.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123396 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-13 20:59:44 +00:00
Bob Wilson
f0908aeade Check for empty structs, and for consistency, zero-element arrays.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123383 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-13 18:26:59 +00:00
Bob Wilson
704d1347c5 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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123381 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-13 17:45:11 +00:00
Bob Wilson
694a10e7d8 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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123380 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-13 17:45:08 +00:00
Devang Patel
85bbd576ea Use SmallVector instead of SmallPtrSet and avoid non-deterministic behavior.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123318 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-12 19:12:45 +00:00
Chris Lattner
d318fc2ceb revert 123144, reenabling the rest of memset formation.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123302 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-12 03:25:15 +00:00
Chris Lattner
d2e905027b revert r123146 which disabled code that wasn't the root cause
of the bootstrap miscompare issue.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123299 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-12 01:52:23 +00:00
Chris Lattner
2d5c0cd197 revert r123149, reenabling an improvement to memcpyopt that wasn't
the source of the bootstrap problem.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123298 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-12 01:43:46 +00:00
Jakob Stoklund Olesen
89f1582616 Remove the PR8954 workaround.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123288 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-11 22:56:41 +00:00
Jakob Stoklund Olesen
fbbd4abfe5 Fix a non-deterministic loop in llvm::MergeBlockIntoPredecessor.
DT->changeImmediateDominator() trivially ignores identity updates, so there is
really no need for the uniqueing provided by SmallPtrSet.

I expect this to fix PR8954.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123286 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-11 22:54:38 +00:00
Cameron Zwarich
d8c120bbd3 Dial back the speculative fix for PR8954 a bit, so that we only recompute dominators
once at the beginning of GVN instead of once per iteration.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123278 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-11 22:14:42 +00:00
Cameron Zwarich
e641863cd2 Attempt to fix the bootstrap buildbot. Rafael says this works for him on x86-64 Linux.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123270 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-11 20:23:34 +00:00
Owen Anderson
a33b6254bb Remove dead variable, const-ref-ize an APInt.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123248 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-11 18:26:37 +00:00
Chris Lattner
f73b99ab43 this pass claims to preserve scev, make sure to tell it about deletions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123247 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-11 18:14:50 +00:00
Frits van Bommel
65fdded319 Factor the actual simplification out of SimplifyIndirectBrOnSelect and into a new helper function so it can be reused in e.g. an upcoming SimplifySwitchOnSelect.
No functional change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123234 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-11 12:52:11 +00:00