Revert the rule that considers comparisons between two pointers in the
same object to be a non-capture; Duncan pointed out a way that such
a comparison could be a capture.

Make the rule that conside

Revert the rule that considers comparisons between two pointers in the
same object to be a non-capture; Duncan pointed out a way that such
a comparison could be a capture.

Make the rule that considers a comparison against null more specific,
and only consider noalias return values compared against null. This
still supports test/Transforms/GVN/nonescaping-malloc.ll, and is not
susceptible to the problem Duncan pointed out with noalias arguments.

llvm-svn: 89468

show more ...

Simplify this code; it's not necessary to check isIdentifiedObject here
because if the results from getUnderlyingObject match, the values must
be from the same underlying object, even if we don't kno

Simplify this code; it's not necessary to check isIdentifiedObject here
because if the results from getUnderlyingObject match, the values must
be from the same underlying object, even if we don't know what that
object is.

llvm-svn: 89434

show more ...

Refine the capture tracking rules for comparisons to be more
careful about crazy methods of capturing pointers using comparisons.
Comparisons of identified objects with null in the default address
sp

Refine the capture tracking rules for comparisons to be more
careful about crazy methods of capturing pointers using comparisons.
Comparisons of identified objects with null in the default address
space are not captures. And, comparisons of two pointers within the
same identified object are not captures.

llvm-svn: 89421

show more ...

Use isVoidTy().

llvm-svn: 89419

Refine this to only apply to null in the default address space.

llvm-svn: 89411

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

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

show more ...

Comparing a pointer with null is not a capture.

llvm-svn: 89389

remove a check of isFreeCall: the argument to free is already nocapture so the generic call code works fine.

llvm-svn: 85865

Rename MallocFreeHelper as MemoryBuiltins

llvm-svn: 85286

Rename MallocHelper as MallocFreeHelper, since it now also identifies calls to free()

llvm-svn: 85181

Remove FreeInst.
Remove LowerAllocations pass.
Update some more passes to treate free calls just like they were treating FreeInst.

llvm-svn: 85176

Push LLVMContexts through the IntegerType APIs.

llvm-svn: 78948

Revert r70876 and add a testcase (@c7) showing the problem:
bits captured, but the pointer marked nocapture. In fact
I now recall that this problem is why only readnone functions
returning void were

Revert r70876 and add a testcase (@c7) showing the problem:
bits captured, but the pointer marked nocapture. In fact
I now recall that this problem is why only readnone functions
returning void were considered before! However keep a small
fix that was also in r70876: a readnone function returning
void can result in bits being captured if it unwinds, so
test for this.

llvm-svn: 71168

show more ...

Teach capture tracking that readonly functions can
only capture their arguments by returning them or
throwing an exception or not based on the argument
value. Patch essentially by Frits van Bommel.

Teach capture tracking that readonly functions can
only capture their arguments by returning them or
throwing an exception or not based on the argument
value. Patch essentially by Frits van Bommel.

llvm-svn: 70876

show more ...

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 ver

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

llvm-svn: 62461

show more ...