240 Commits

Author SHA1 Message Date
Chris Lattner
af362f014d add some new methods to adjust this pointers. Not used yet.
llvm-svn: 94013
2010-01-20 19:26:14 +00:00
Chris Lattner
29f82a1465 move DecomposeGEPExpression out into ValueTracking.cpp
llvm-svn: 89956
2009-11-26 17:12:50 +00:00
Chris Lattner
631c5b2cb9 teach GetLinearExpression to be a bit more aggressive.
llvm-svn: 89955
2009-11-26 17:00:01 +00:00
Chris Lattner
5c1cfc252c resolve a fixme. I haven't figured out how to write a testcase
to exercise this though.

llvm-svn: 89954
2009-11-26 16:52:32 +00:00
Chris Lattner
29bc8a91d3 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

llvm-svn: 89952
2009-11-26 16:26:43 +00:00
Chris Lattner
12dacdd359 teach basicaa that A[i] != A[i+1].
llvm-svn: 89951
2009-11-26 16:18:10 +00:00
Chris Lattner
7a5b56aca9 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.
llvm-svn: 89922
2009-11-26 02:17:34 +00:00
Chris Lattner
5341c9679d 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.
llvm-svn: 89920
2009-11-26 02:14:59 +00:00
Chris Lattner
8928899413 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).
llvm-svn: 89915
2009-11-26 02:13:03 +00:00
Chris Lattner
a99edbedd1 Use GEPOperator more pervasively to simplify code.
llvm-svn: 89914
2009-11-26 02:11:08 +00:00
Chris Lattner
214ef9a4ef fix comment, thanks all :)
llvm-svn: 89666
2009-11-23 17:07:35 +00:00
Chris Lattner
1e7b37ebba 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.

llvm-svn: 89665
2009-11-23 16:46:41 +00:00
Chris Lattner
98e25326a0 whitespace cleanup, tidying
llvm-svn: 89664
2009-11-23 16:45:27 +00:00
Chris Lattner
84ed59abcf speed up BasicAA a bit by implementing a long-standing TODO.
llvm-svn: 89663
2009-11-23 16:44:43 +00:00
Chris Lattner
a13c9d1a5e add fixme for dubious code. Duncan, what do you think?
llvm-svn: 89602
2009-11-22 16:16:48 +00:00
Chris Lattner
db1e9f1290 remove a silly condition that doesn't make a lot of sense anymore.
llvm-svn: 89601
2009-11-22 16:15:59 +00:00
Chris Lattner
d6a49ad25a reduce indentation, no functionality change.
llvm-svn: 89600
2009-11-22 16:05:05 +00:00
Chris Lattner
88874ec60a 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.

llvm-svn: 89599
2009-11-22 16:01:44 +00:00
Dan Gohman
94e617627d 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.

llvm-svn: 89398
2009-11-19 21:57:48 +00:00
Nick Lewycky
c53e2ecf02 Teach BasicAA that a constant expression can't alias memory provably not
allocated until runtime (such as an alloca). Patch by Hans Wennborg!

llvm-svn: 88760
2009-11-14 06:15:14 +00:00
Dan Gohman
ccb4584edd 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)

llvm-svn: 86582
2009-11-09 19:29:11 +00:00
Chris Lattner
46b5c642b9 remove a bunch of extraneous LLVMContext arguments
from various APIs, addressing PR5325.

llvm-svn: 86231
2009-11-06 04:27:31 +00:00
Victor Hernandez
f390e04a47 Rename MallocFreeHelper as MemoryBuiltins
llvm-svn: 85286
2009-10-27 20:05:49 +00:00
Victor Hernandez
762195bd01 Rename MallocHelper as MallocFreeHelper, since it now also identifies calls to free()
llvm-svn: 85181
2009-10-26 23:58:56 +00:00
Dan Gohman
3b7ba5f35b Teach BasicAA how to analyze Select instructions, and make it more
aggressive on PHI instructions.

llvm-svn: 85158
2009-10-26 21:55:43 +00:00
Nick Lewycky
974e12b2d3 Remove includes of Support/Compiler.h that are no longer needed after the
VISIBILITY_HIDDEN removal.

llvm-svn: 85043
2009-10-25 06:57:41 +00:00
Nick Lewycky
02d5f77d26 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.

llvm-svn: 85042
2009-10-25 06:33:48 +00:00
Victor Hernandez
8acf2956b8 Remove AllocationInst. Since MallocInst went away, AllocaInst is the only subclass of AllocationInst, so it no longer is necessary.
llvm-svn: 84969
2009-10-23 21:09:37 +00:00
Chris Lattner
b2647b9e67 inline isGEP away.
llvm-svn: 84373
2009-10-17 23:48:54 +00:00
Evan Cheng
8ec25937f1 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.
llvm-svn: 84226
2009-10-16 00:33:09 +00:00
Nick Lewycky
d708a4908c Add missing break statements! Thanks to Duncan Sands for pointing this out!
llvm-svn: 84191
2009-10-15 18:48:58 +00:00
Nick Lewycky
9cec2380f2 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.

llvm-svn: 84175
2009-10-15 07:11:24 +00:00
Nick Lewycky
d7216cf74c Teach BasicAA to use the size parameter of the memory use marker intrinsics.
llvm-svn: 84174
2009-10-15 06:12:11 +00:00
Nick Lewycky
fcb27ad54c Take advantage of TargetData when available; we know that the atomic intrinsics
only dereference the element they point to directly with no pointer arithmetic.

llvm-svn: 84159
2009-10-15 00:36:35 +00:00
Evan Cheng
b3ccb6498c Clear VisitedPHIs after use.
llvm-svn: 84080
2009-10-14 06:46:26 +00:00
Evan Cheng
c1eed9d120 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.

llvm-svn: 84079
2009-10-14 06:41:49 +00:00
Evan Cheng
f92f5557ee More code clean up based on patch feedback.
llvm-svn: 84074
2009-10-14 05:22:03 +00:00
Evan Cheng
31565b3e9f Change VisitedPHIs into an instance variable that's freed by each alias() call.
llvm-svn: 84072
2009-10-14 05:05:02 +00:00
Evan Cheng
c10e88db22 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.
llvm-svn: 84038
2009-10-13 22:02:20 +00:00
Evan Cheng
f1f3dd3c3c Refactor some code. No functionality changes.
llvm-svn: 84000
2009-10-13 18:42:04 +00:00
Nick Lewycky
e2782c7614 Teach BasicAA a little something about the atomic intrinsics: they can only
modify through the pointer they're given.

llvm-svn: 83959
2009-10-13 07:48:38 +00:00
Victor Hernandez
537d8d99be Enhance analysis passes so that they apply the same analysis to malloc calls as to MallocInst.
Reviewed by Eli Friedman.

llvm-svn: 82281
2009-09-18 21:34:51 +00:00
Dan Gohman
bc1d841a63 Use stripPointerCasts instead of doing the same manually.
llvm-svn: 80267
2009-08-27 18:02:03 +00:00
Owen Anderson
55f1c09e31 Push LLVMContexts through the IntegerType APIs.
llvm-svn: 78948
2009-08-13 21:58:54 +00:00
Owen Anderson
5a1acd9912 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.

llvm-svn: 77721
2009-07-31 20:28:14 +00:00
Owen Anderson
487375e9a2 Move ConstantExpr to 2.5 API.
llvm-svn: 77494
2009-07-29 18:55:55 +00:00
Dan Gohman
43d19d61d4 Make AliasAnalysis and related classes use
getAnalysisIfAvailable<TargetData>().

llvm-svn: 77028
2009-07-25 00:48:42 +00:00
Owen Anderson
edb4a70325 Revert the ConstantInt constructors back to their 2.5 forms where possible, thanks to contexts-on-types. More to come.
llvm-svn: 77011
2009-07-24 23:12:02 +00:00
Owen Anderson
47db941fd3 Get rid of the Pass+Context magic.
llvm-svn: 76702
2009-07-22 00:24:57 +00:00
Dan Gohman
33a3fd0b9c 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.

llvm-svn: 76437
2009-07-20 17:43:30 +00:00