Commit Graph

300 Commits

Author SHA1 Message Date
Dan Gohman
50f424c3d0 Fix Value::stripPointerCasts and BasicAA to avoid trouble on
code in unreachable blocks, which have have use-def cycles.
This fixes PR7514.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@107071 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-28 21:16:52 +00:00
Gabor Greif
71339c965c use ArgOperand accessors
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106697 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-23 23:38:07 +00:00
Eric Christopher
551754c495 Revert 101465, it broke internal OpenGL testing.
Probably the best way to know that all getOperand() calls have been handled
is to replace that API instead of updating.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101579 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-16 23:37:20 +00:00
Gabor Greif
4ec2258ffb reapply r101434
with a fix for self-hosting

rotate CallInst operands, i.e. move callee to the back
of the operand array

the motivation for this patch are laid out in my mail to llvm-commits:
more efficient access to operands and callee, faster callgraph-construction,
smaller compiler binary


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101465 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-16 15:33:14 +00:00
Gabor Greif
607a7ab3da back out r101423 and r101397, they break llvm-gcc self-host on darwin10
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101434 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-16 01:16:20 +00:00
Gabor Greif
2ff961f668 reapply r101364, which has been backed out in r101368
with a fix

rotate CallInst operands, i.e. move callee to the back
of the operand array

the motivation for this patch are laid out in my mail to llvm-commits:
more efficient access to operands and callee, faster callgraph-construction,
smaller compiler binary


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101397 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-15 20:51:13 +00:00
Gabor Greif
9ee1720811 back out r101364, as it trips the linux nightlybot on some clang C++ tests
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101368 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-15 12:46:56 +00:00
Gabor Greif
165dac08d1 rotate CallInst operands, i.e. move callee to the back
of the operand array

the motivation for this patch are laid out in my mail to llvm-commits:
more efficient access to operands and callee, faster callgraph-construction,
smaller compiler binary


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101364 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-15 10:49:53 +00:00
Dan Gohman
b57b6f1575 Pointers to zero-sized objects don't point to overlapping objects.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100789 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-08 18:11:50 +00:00
Duncan Sands
1df9859c40 There are two ways of checking for a given type, for example isa<PointerType>(T)
and T->isPointerTy().  Convert most instances of the first form to the second form.
Requested by Chris.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96344 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-16 11:11:14 +00:00
Chris Lattner
2033097b1f add some new methods to adjust this pointers. Not used yet.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94013 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-20 19:26:14 +00:00
Chris Lattner
e405c64f6b move DecomposeGEPExpression out into ValueTracking.cpp
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89956 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-26 17:12:50 +00:00
Chris Lattner
fa3966881f teach GetLinearExpression to be a bit more aggressive.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89955 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-26 17:00:01 +00:00
Chris Lattner
5369250b73 resolve a fixme. I haven't figured out how to write a testcase
to exercise this though.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89954 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-26 16:52:32 +00:00
Chris Lattner
5d5261c819 Teach basicaa that x|c == x+c when the c bits of x are clear. This
allows us to compile the example in readme.txt into:

LBB1_1:                                                     ## %bb
	movl	4(%rdx,%rax), %ecx
	movl	%ecx, %esi
	imull	(%rdx,%rax), %esi
	imull	%esi, %ecx
	movl	%esi, 8(%rdx,%rax)
	imull	%ecx, %esi
	movl	%ecx, 12(%rdx,%rax)
	movl	%esi, 16(%rdx,%rax)
	imull	%ecx, %esi
	movl	%esi, 20(%rdx,%rax)
	addq	$16, %rax
	cmpq	$4000, %rax
	jne	LBB1_1

instead of:

LBB1_1: 
	movl	(%rdx,%rax), %ecx
	imull	4(%rdx,%rax), %ecx
	movl	%ecx, 8(%rdx,%rax)
	imull	4(%rdx,%rax), %ecx
	movl	%ecx, 12(%rdx,%rax)
	imull	8(%rdx,%rax), %ecx
	movl	%ecx, 16(%rdx,%rax)
	imull	12(%rdx,%rax), %ecx
	movl	%ecx, 20(%rdx,%rax)
	addq	$16, %rax
	cmpq	$4000, %rax
	jne	LBB1_1

GCC (4.2) doesn't seem to be able to eliminate the loads in this 
testcase either, it generates:

L2:
	movl	(%rdx), %eax
	imull	4(%rdx), %eax
	movl	%eax, 8(%rdx)
	imull	4(%rdx), %eax
	movl	%eax, 12(%rdx)
	imull	8(%rdx), %eax
	movl	%eax, 16(%rdx)
	imull	12(%rdx), %eax
	movl	%eax, 20(%rdx)
	addl	$4, %ecx
	addq	$16, %rdx
	cmpl	$1002, %ecx
	jne	L2




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89952 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-26 16:26:43 +00:00
Chris Lattner
f6ac4d9dad teach basicaa that A[i] != A[i+1].
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89951 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-26 16:18:10 +00:00
Chris Lattner
d84eb911a9 Change the other half of aliasGEP (which handles GEP differencing) to use DecomposeGEPExpression. This dramatically simplifies and shrinks the code by eliminating the horrible CheckGEPInstructions method, fixes a miscompilation (@test3) and makes the code more aggressive. In particular, we now handle the @test4 case, which is reduced from the SmallPtrSet constructor. Missing this caused us to emit a variable length memset instead of a fixed size one.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89922 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-26 02:17:34 +00:00
Chris Lattner
23e2a5b2ff Generalize DecomposeGEPExpression to exactly handle what Value::getUnderlyingObject does (when TD is around). This allows us to avoid calling DecomposeGEPExpression unless the ultimate alias check we care about passes, speedup up BasicAA a bit.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89920 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-26 02:14:59 +00:00
Chris Lattner
4e91ee7a2a Implement a new DecomposeGEPExpression method, which decomposes a GEP into a list of scaled offsets. Use this to eliminate some previous ad-hoc code which was subtly broken (it assumed all Constant*'s were non-zero, but strange constant express could be zero).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89915 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-26 02:13:03 +00:00
Chris Lattner
539c9b99c2 Use GEPOperator more pervasively to simplify code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89914 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-26 02:11:08 +00:00
Chris Lattner
b27db37ed0 fix comment, thanks all :)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89666 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-23 17:07:35 +00:00
Chris Lattner
403ac2ece3 use the new isNoAlias method to simplify some code, only do an escaping check if
we have a non-constant pointer.  Constant pointers can't be local.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89665 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-23 16:46:41 +00:00
Chris Lattner
5d56b2d47d whitespace cleanup, tidying
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89664 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-23 16:45:27 +00:00
Chris Lattner
b34b82e9d1 speed up BasicAA a bit by implementing a long-standing TODO.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89663 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-23 16:44:43 +00:00
Chris Lattner
6c7276f17e add fixme for dubious code. Duncan, what do you think?
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89602 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-22 16:16:48 +00:00
Chris Lattner
4723303c97 remove a silly condition that doesn't make a lot of sense anymore.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89601 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-22 16:15:59 +00:00
Chris Lattner
92e803c2a4 reduce indentation, no functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89600 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-22 16:05:05 +00:00
Chris Lattner
66e08cf79a Remove the AliasAnalysis::getMustAliases method, which is dead.
The hasNoModRefInfoForCalls isn't worth it as a filter because 
basicaa provides m/r info and everything chains to it, so remove
it.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89599 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-22 16:01:44 +00:00
Dan Gohman
f94b5edc45 Extend CaptureTracking to indicate when a value is never stored, even
if it is not ultimately captured. Teach BasicAliasAnalysis that a 
local object address which does not escape and is never stored does
not alias with a value resulting from a load.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89398 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-19 21:57:48 +00:00
Nick Lewycky
20162ac566 Teach BasicAA that a constant expression can't alias memory provably not
allocated until runtime (such as an alloca). Patch by Hans Wennborg!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@88760 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-14 06:15:14 +00:00
Dan Gohman
f75ef668a7 Default-addressspace null pointers don't alias anything. This allows
GVN to be more aggressive. Patch by Hans Wennborg! (with a comment added by me)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86582 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-09 19:29:11 +00:00
Chris Lattner
7b550ccfc5 remove a bunch of extraneous LLVMContext arguments
from various APIs, addressing PR5325.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86231 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-06 04:27:31 +00:00
Victor Hernandez
f006b183e2 Rename MallocFreeHelper as MemoryBuiltins
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85286 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-27 20:05:49 +00:00
Victor Hernandez
f2becca90b Rename MallocHelper as MallocFreeHelper, since it now also identifies calls to free()
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85181 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-26 23:58:56 +00:00
Dan Gohman
6665b0ea68 Teach BasicAA how to analyze Select instructions, and make it more
aggressive on PHI instructions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85158 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-26 21:55:43 +00:00
Nick Lewycky
f5a86f45e7 Remove includes of Support/Compiler.h that are no longer needed after the
VISIBILITY_HIDDEN removal.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85043 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-25 06:57:41 +00:00
Nick Lewycky
6726b6d75a Remove VISIBILITY_HIDDEN from class/struct found inside anonymous namespaces.
Chris claims we should never have visibility_hidden inside any .cpp file but
that's still not true even after this commit.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85042 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-25 06:33:48 +00:00
Victor Hernandez
7b929dad59 Remove AllocationInst. Since MallocInst went away, AllocaInst is the only subclass of AllocationInst, so it no longer is necessary.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@84969 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-23 21:09:37 +00:00
Chris Lattner
391d23b6c2 inline isGEP away.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@84373 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-17 23:48:54 +00:00
Evan Cheng
a846a8a1dc When checking aliases between phi sources and V2, we know the sources are not themselves phi nodes. However, V2 may be. Call aliasCheck with V2 first to potentially eliminate a std::swap call.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@84226 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-16 00:33:09 +00:00
Nick Lewycky
20312d0bb8 Add missing break statements! Thanks to Duncan Sands for pointing this out!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@84191 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-15 18:48:58 +00:00
Nick Lewycky
6e9e010752 Teach basicaa about memcpy/memmove/memset. The length argument can be used to
improve alias results if constant, and the source pointer can't be modified.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@84175 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-15 07:11:24 +00:00
Nick Lewycky
2d3820c29c Teach BasicAA to use the size parameter of the memory use marker intrinsics.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@84174 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-15 06:12:11 +00:00
Nick Lewycky
22c031296c Take advantage of TargetData when available; we know that the atomic intrinsics
only dereference the element they point to directly with no pointer arithmetic.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@84159 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-15 00:36:35 +00:00
Evan Cheng
f0429fd1ca Clear VisitedPHIs after use.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@84080 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-14 06:46:26 +00:00
Evan Cheng
681a33e26d Another BasicAA fix. If a value does not alias a GEP's base pointer, then it
cannot alias the GEP. GEP pointer alias rule states this clearly:
A pointer value formed from a getelementptr instruction is associated with the
addresses associated with the first operand of the getelementptr.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@84079 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-14 06:41:49 +00:00
Evan Cheng
d83c2ca336 More code clean up based on patch feedback.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@84074 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-14 05:22:03 +00:00
Evan Cheng
3dbe43b1b5 Change VisitedPHIs into an instance variable that's freed by each alias() call.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@84072 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-14 05:05:02 +00:00
Evan Cheng
50a5914e12 Teach basic AA about PHI nodes. If all operands of a phi NoAlias another value than it's safe to declare the PHI NoAlias the value. Ditto for MustAlias.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@84038 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-13 22:02:20 +00:00
Evan Cheng
094f04b429 Refactor some code. No functionality changes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@84000 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-13 18:42:04 +00:00
Nick Lewycky
5c9be67cff Teach BasicAA a little something about the atomic intrinsics: they can only
modify through the pointer they're given.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@83959 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-13 07:48:38 +00:00
Victor Hernandez
46e8312fb7 Enhance analysis passes so that they apply the same analysis to malloc calls as to MallocInst.
Reviewed by Eli Friedman.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82281 91177308-0d34-0410-b5e6-96231b3b80d8
2009-09-18 21:34:51 +00:00
Dan Gohman
aae87cde50 Use stripPointerCasts instead of doing the same manually.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@80267 91177308-0d34-0410-b5e6-96231b3b80d8
2009-08-27 18:02:03 +00:00
Owen Anderson
1d0be15f89 Push LLVMContexts through the IntegerType APIs.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78948 91177308-0d34-0410-b5e6-96231b3b80d8
2009-08-13 21:58:54 +00:00
Owen Anderson
a7235ea724 Move a few more APIs back to 2.5 forms. The only remaining ones left to change back are
metadata related, which I'm waiting on to avoid conflicting with Devang.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77721 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-31 20:28:14 +00:00
Owen Anderson
baf3c40440 Move ConstantExpr to 2.5 API.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77494 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-29 18:55:55 +00:00
Dan Gohman
fc2a3ed0c9 Make AliasAnalysis and related classes use
getAnalysisIfAvailable<TargetData>().


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77028 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-25 00:48:42 +00:00
Owen Anderson
eed707b1e6 Revert the ConstantInt constructors back to their 2.5 forms where possible, thanks to contexts-on-types. More to come.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77011 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-24 23:12:02 +00:00
Owen Anderson
e922c02019 Get rid of the Pass+Context magic.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@76702 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-22 00:24:57 +00:00
Dan Gohman
f241174421 Revert the addition of hasNoPointerOverflow to GEPOperator.
Getelementptrs that are defined to wrap are virtually useless to
optimization, and getelementptrs that are undefined on any kind
of overflow are too restrictive -- it's difficult to ensure that
all intermediate addresses are within bounds. I'm going to take
a different approach.

Remove a few optimizations that depended on this flag.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@76437 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-20 17:43:30 +00:00
Dan Gohman
3a7a68c108 Make BasicAliasAnalysis and Value::getUnderlyingObject use
GEPOperator's hasNoPointer0verflow(), and make a few places in instcombine
that create GEPs that may overflow clear the NoOverflow value. Among
other things, this partially addresses PR2831.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@76252 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-17 22:25:10 +00:00
Owen Anderson
001dbfebcb Move the ConstantInt uniquing table into LLVMContextImpl. This exposed a number of issues in
our current context-passing stuff, which is also fixed here


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@76089 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-16 18:04:31 +00:00
Torok Edwin
c23197a26f llvm_unreachable->llvm_unreachable(0), LLVM_UNREACHABLE->llvm_unreachable.
This adds location info for all llvm_unreachable calls (which is a macro now) in
!NDEBUG builds.
In NDEBUG builds location info and the message is off (it only prints
"UREACHABLE executed").


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75640 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-14 16:55:14 +00:00
Torok Edwin
c25e7581b9 assert(0) -> LLVM_UNREACHABLE.
Make llvm_unreachable take an optional string, thus moving the cerr<< out of
line.
LLVM_UNREACHABLE is now a simple wrapper that makes the message go away for
NDEBUG builds.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75379 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-11 20:10:48 +00:00
Owen Anderson
07cf79ef53 "LLVMContext* " --> "LLVMContext *"
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74878 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-06 23:00:19 +00:00
Owen Anderson
508955156a Thread LLVMContext through the constant folding APIs, which touches a lot of files.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74844 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-06 18:42:36 +00:00
Owen Anderson
e7b6118a51 Remove unneeded #include.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73911 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-22 22:09:07 +00:00
Dan Gohman
72776d2190 Teach BasicAliasAnalysis to understand constant gep indices that fall
beyond their associated static array type.

I believe that this fixes a legitimate bug, because BasicAliasAnalysis
already has code to check for this condition that works for non-constant
indices, however it was missing the case of constant indices. With this
change, it checks for both.

This fixes PR4267, and miscompiles of SPEC 188.ammp and 464.h264.href.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72451 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-27 01:48:27 +00:00
Duncan Sands
777d2306b3 Rename PaddedSize to AllocSize, in the hope that this
will make it more obvious what it represents, and stop
it being confused with the StoreSize.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71349 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-09 07:06:46 +00:00
Duncan Sands
d869b3847f Generalize some alias analysis logic from atomic
intrinsics to any IntrWriteArgMem intrinsics.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@64551 91177308-0d34-0410-b5e6-96231b3b80d8
2009-02-14 10:56:35 +00:00
Nick Lewycky
826f7cebfd BasicAA was making the assumption that a local allocation which hadn't escaped
couldn't ever be the return of call instruction. However, it's quite possible
that said local allocation is itself the return of a function call. That's
what malloc and calloc are for, actually.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@64442 91177308-0d34-0410-b5e6-96231b3b80d8
2009-02-13 07:06:27 +00:00
Owen Anderson
e79422096e Refactor my previous change to maintain the distinction between AliasAnalysis and BasicAliasAnalysis. This involves some wider changes because it
folds away some never-used methods.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@63900 91177308-0d34-0410-b5e6-96231b3b80d8
2009-02-05 23:36:27 +00:00
Owen Anderson
fe9388ccb4 Finish making AliasAnalysis aware of the fact that most atomic intrinsics only dereference their arguments, and enhance
BasicAA to make use of this fact when computing ModRef info.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@63718 91177308-0d34-0410-b5e6-96231b3b80d8
2009-02-04 05:16:46 +00:00
Dan Gohman
a5f81bba4a Move isIdentifiedObject and isNoAliasCall into AliasAnalysis.cpp since
they are useful to analyses other than BasicAliasAnalysis.cpp. Include
the full comment for isIdentifiedObject in the header file. Thanks to
Chris for suggeseting this.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@63589 91177308-0d34-0410-b5e6-96231b3b80d8
2009-02-03 01:28:32 +00:00
Dan Gohman
3311a1f8f0 Fix a post-RA scheduling dependency bug.
If a MachineInstr doesn't have a memoperand but has an opcode that
is known to load or store, assume its memory reference may alias
*anything*, including stack slots which the compiler completely
controls.

To partially compensate for this, teach the ScheduleDAG building
code to do basic getUnderlyingValue analysis. This greatly
reduces the number of instructions that require restrictive
dependencies. This code will need to be revisited when we start
doing real alias analysis, but it should suffice for now.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@63370 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-30 02:49:14 +00:00
Duncan Sands
8556d2a7f1 BasicAliasAnalysis and FunctionAttrs were both
doing very similar pointer capture analysis.
Factor out the common logic.  The new version
is from FunctionAttrs since it does a better
job than the version in BasicAliasAnalysis


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62461 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-18 12:19:30 +00:00
Gabor Greif
7f85bb6f83 add a comment
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62436 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-18 00:27:21 +00:00
Duncan Sands
ceb4d1aecb Rename getABITypeSize to getTypePaddedSize, as
suggested by Chris.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62099 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-12 20:38:59 +00:00
Chris Lattner
d4a2700fdc make tblgen autogenerate the nocapture intrinsics for
llvm.memcpy/memset/memmove.  This allows removal of some 
hackish code from basicaa.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62071 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-12 02:41:37 +00:00
Duncan Sands
91c9c31033 When checking if an Argument escapes, check if
the argument is marked nocapture - no need to
analyze the argument if the answer is already
known!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61753 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-05 21:19:53 +00:00
Nick Lewycky
f23d0d392a Resubmit support for the 'nocapture' attribute.
The problematic part of this patch is that we were out of attribute bits,
requiring some fancy bit hacking to make it fit (by shrinking alignment)
without breaking existing users or the file format.

This change will require users to rebuild llvm-gcc to match llvm.


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2008-12-19 06:39:12 +00:00
Bill Wendling
6fa311c233 Temporarily revert r61019, r61030, and r61040. These were breaking LLVM Release
builds.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61094 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-16 19:06:48 +00:00
Chris Lattner
1314f20283 Teach basicaa to use the nocapture attribute when possible. When the
intrinsics are properly marked nocapture, the fixme should be addressed.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61040 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-15 18:59:22 +00:00
Chris Lattner
b957bda0bc Allow basicaa to walk through geps with identical indices in
parallel, allowing it to decide that P/Q must alias if A/B
must alias in things like:
 P = gep A, 0, i, 1
 Q = gep B, 0, i, 1

This allows GVN to delete 62 more instructions out of 403.gcc.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60820 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-10 01:04:47 +00:00
Chris Lattner
20d6f0982a Teach BasicAA::getModRefInfo(CallSite, CallSite) some
tricks based on readnone/readonly functions.

Teach memdep to look past readonly calls when analyzing
deps for a readonly call.  This allows elimination of a
few more calls from 403.gcc:

before:
     63 gvn    - Number of instructions PRE'd
 153986 gvn    - Number of instructions deleted
  50069 gvn    - Number of loads deleted

after:
     63 gvn    - Number of instructions PRE'd
 153991 gvn    - Number of instructions deleted
  50069 gvn    - Number of loads deleted

5 calls isn't much, but this adds plumbing for the next change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60794 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-09 21:19:42 +00:00
Duncan Sands
1832705b06 Fix comment typo.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60697 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-08 14:01:59 +00:00
Chris Lattner
295d4e953a Some minor optimizations for isObjectSmallerThan.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60687 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-08 06:28:54 +00:00
Nick Lewycky
b2b32fd3fe Seriously strengthen the guarantee offered by noalias on a function's return
value. It must now be as if the pointer were allocated and has not escaped to
the caller. Thanks to Dan Gohman for pointing out the error in the original
and helping devise this definition.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@59940 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-24 05:00:44 +00:00
Nick Lewycky
02ff308aa1 Extend the 'noalias' attribute to function return values. This is intended to
indicate functions that allocate, such as operator new, or list::insert. The
actual definition is slightly less strict (for now).

No changes to the bitcode reader/writer, asm printer or verifier were needed.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@59934 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-24 03:41:24 +00:00
Duncan Sands
5d0392c6b3 Factorize code: remove variants of "strip off
pointer bitcasts and GEP's", and centralize the
logic in Value::getUnderlyingObject.  The
difference with stripPointerCasts is that
stripPointerCasts only strips GEPs if all
indices are zero, while getUnderlyingObject
strips GEPs no matter what the indices are.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56922 91177308-0d34-0410-b5e6-96231b3b80d8
2008-10-01 15:25:41 +00:00
Devang Patel
eaf42abab6 s/ParameterAttributes/Attributes/g
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56513 91177308-0d34-0410-b5e6-96231b3b80d8
2008-09-23 23:03:40 +00:00
Dan Gohman
ae73dc1448 Tidy up several unbeseeming casts from pointer to intptr_t.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55779 91177308-0d34-0410-b5e6-96231b3b80d8
2008-09-04 17:05:41 +00:00
Chris Lattner
25df20f169 simplify some code by using a helper function. This really really
wants a 'nocapture' predicate.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52304 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-16 06:38:26 +00:00
Chris Lattner
defa1c8034 move a bunch of predicates up into their own section
in this file, no other changes.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52303 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-16 06:30:22 +00:00
Chris Lattner
e7275794d3 Other parts of this code treat noalias arguments as objects for
the purposes of escape analysis.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52302 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-16 06:28:01 +00:00
Chris Lattner
845f0d2f0f If we are checking to see if the result of a call aliases a
pointer derived from a local allocation, if the local allocation
never escapes, the pointers can't alias.  This implements PR2436


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52301 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-16 06:19:11 +00:00
Chris Lattner
a413960a48 Refactor basicaa's main alias function somethin' fierce.
This fixes several minor bugs (such as returning noalias
for comparisons between external weak functions an null) but
is mostly a cleanup.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52299 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-16 06:10:11 +00:00
Wojciech Matyjewicz
98e3a6829a Fixes PR2395. Looking for a constant in a GEP tail (when the first GEP
is longer than the second one) should stop after finding one. Added break 
instruction guarantees it. It also changes difference between offsets to 
absolute value of this difference in the condition.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51875 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-02 17:26:12 +00:00
Dan Gohman
844731a7f1 Clean up the use of static and anonymous namespaces. This turned up
several things that were neither in an anonymous namespace nor static
but not intended to be global.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51017 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-13 00:00:25 +00:00
Duncan Sands
e47d98200e Fix a "large integer implicitly truncated to unsigned type"
warning.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50033 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-21 07:35:28 +00:00