Listing all of the attributes for the callee of a call/invoke instruction is way
too much and makes the IR unreadable. Use references to attributes instead.
llvm-svn: 175877
Analyse Phis under the starting assumption that they are NoAlias. Recursively
look at their inputs.
If they MayAlias/MustAlias there must be an input that makes them so.
Addresses bug 14351.
llvm-svn: 169788
This is a partial solution to PR14351. It removes some of the special
significance of the first incoming phi value in the phi aliasing checking logic
in BasicAA. In the context of a loop, the old logic assumes that the first
incoming value is the interesting one (meaning that it is the one that comes
from outside the loop), but this is often not the case. With this change, we
now test first the incoming value that comes from a block other than the parent
of the phi being tested.
llvm-svn: 168245
'nocapture' attribute.
The nocapture attribute only specifies that no copies are made that
outlive the function. This isn't the same as there being no copies at all.
This fixes PR14045.
llvm-svn: 167381
Enhances basic alias analysis to recognize phis whose first incoming values are
NoAlias and whose other incoming values are just the phi node itself through
some amount of recursion.
Example: With this change basicaa reports that ptr_phi and ptr_phi2 do not alias
each other.
bb:
ptr = ptr2 + 1
loop:
ptr_phi = phi [bb, ptr], [loop, ptr_plus_one]
ptr2_phi = phi [bb, ptr2], [loop, ptr2_plus_one]
...
ptr_plus_one = gep ptr_phi, 1
ptr2_plus_one = gep ptr2_phi, 1
This enables the elimination of one load in code like the following:
extern int foo;
int test_noalias(int *ptr, int num, int* coeff) {
int *ptr2 = ptr;
int result = (*ptr++) * (*coeff--);
while (num--) {
*ptr2++ = *ptr;
result += (*coeff--) * (*ptr++);
}
*ptr = foo;
return result;
}
Part 2/2 of fix for PR13564.
llvm-svn: 163319
If we can show that the base pointers of two GEPs don't alias each other using
precise analysis and the indices and base offset are equal then the two GEPs
also don't alias each other.
This is primarily needed for the follow up patch that analyses NoAlias'ing PHI
nodes.
Part 1/2 of fix for PR13564.
llvm-svn: 163317
versions of Bash. In addition, I can back out the change to the lit
built-in shell test runner to support this.
This should fix the majority of fallout on Darwin, but I suspect there
will be a few straggling issues.
llvm-svn: 159544
I followed three heuristics for deciding whether to set 'true' or
'false':
- Everything target independent got 'true' as that is the expected
common output of the GCC builtins.
- If the target arch only has one way of implementing this operation,
set the flag in the way that exercises the most of codegen. For most
architectures this is also the likely path from a GCC builtin, with
'true' being set. It will (eventually) require lowering away that
difference, and then lowering to the architecture's operation.
- Otherwise, set the flag differently dependending on which target
operation should be tested.
Let me know if anyone has any issue with this pattern or would like
specific tests of another form. This should allow the x86 codegen to
just iteratively improve as I teach the backend how to differentiate
between the two forms, and everything else should remain exactly the
same.
llvm-svn: 146370
for pre-2.9 bitcode files. We keep x86 unaligned loads, movnt, crc32, and the
target indep prefetch change.
As usual, updating the testsuite is a PITA.
llvm-svn: 133337
queries in the case of a DAG, where a query reaches a node
visited earlier, but it's not on a cycle. This avoids
MayAlias results in cases where BasicAA is expected to
return MustAlias or PartialAlias in order to protect TBAA.
llvm-svn: 132609
after checking for a GEP, so that it matches what GetUnderlyingObject
does. This fixes an obscure bug turned up by bugpoint in the testcase
for PR9931.
llvm-svn: 131971
Original log message:
When BasicAA can determine that two pointers have the same base but
differ by a dynamic offset, return PartialAlias instead of MayAlias.
See the comment in the code for details. This fixes PR9971.
llvm-svn: 131809
only check arguments with pointer types. Update the documentation
of IntrReadArgMem reflect this.
While here, add support for TBAA tags on intrinsic calls.
llvm-svn: 130317
is equivalent to any other relevant value; it isn't true in general.
If it is equivalent, the LoopPromoter will tell the AST the equivalence.
Also, delete the PreheaderLoad if it is unused.
Chris, since you were the last one to make major changes here, can you check
that this is sane?
llvm-svn: 129049
are pointing to the same object, one pointer is accessing the entire
object, and the other is access has a non-zero size. This prevents
TBAA from kicking in and saying NoAlias in such cases.
llvm-svn: 123775
does normal initialization and normal chaining. Change the default
AliasAnalysis implementation to NoAlias.
Update StandardCompileOpts.h and friends to explicitly request
BasicAliasAnalysis.
Update tests to explicitly request -basicaa.
llvm-svn: 116720
response from getModRefInfo is not useful here. Instead, check for identical
calls only in the NoModRef case.
Reapply r110270, and strengthen it to compensate for the memdep changes.
When both calls are readonly, there is no dependence between them.
llvm-svn: 110382
to return Ref if the left callsite only reads memory read or written
by the right callsite; fix BasicAliasAnalysis to implement this.
Add AliasAnalysisEvaluator support for testing the two-callsite
form of getModRefInfo.
llvm-svn: 110270
interface needs implementations to be consistent, so any code which
wants to support different semantics must use a different interface.
It's not currently worthwhile to add a new interface for this new
concept.
Document that AliasAnalysis doesn't support cross-function queries.
llvm-svn: 107776
Added support for address spaces and added a isVolatile field to memcpy, memmove, and memset,
e.g., llvm.memcpy.i32(i8*, i8*, i32, i32) -> llvm.memcpy.p0i8.p0i8.i32(i8*, i8*, i32, i32, i1)
llvm-svn: 100304
Added support for address spaces and added a isVolatile field to memcpy, memmove, and memset,
e.g., llvm.memcpy.i32(i8*, i8*, i32, i32) -> llvm.memcpy.p0i8.p0i8.i32(i8*, i8*, i32, i32, i1)
llvm-svn: 100191
e.g., llvm.memcpy.i32(i8*, i8*, i32, i32) -> llvm.memcpy.p0i8.p0i8.i32(i8*, i8*, i32, i32, i1)
A update of langref will occur in a subsequent checkin.
llvm-svn: 99928
first expression as P+4+4*i which we considered to possibly alias
P+4*j. Now we correctly analyze the former one as P+1+4*i.
@test10 is a sanity test that verfies that we know that P+4+4*i != P+4*i.
llvm-svn: 89960
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
input filename so that opt doesn't print the input filename in the
output so that grep lines in the tests don't unintentionally match
strings in the input filename.
llvm-svn: 81537
