We could truncate the condition and then try to fold the add into the
original condition value causing wrong case constants to be used.
Move the offset transform ahead of the truncate transform and return
after each transform, so there's no chance of getting confused values.
Fix for:
https://llvm.org/bugs/show_bug.cgi?id=31260
llvm-svn: 289442
Summary:
This change adds some verification in the IR verifier around struct path
TBAA metadata.
Other than some basic sanity checks (e.g. we get constant integers where
we expect constant integers), this checks:
- That by the time an struct access tuple `(base-type, offset)` is
"reduced" to a scalar base type, the offset is `0`. For instance, in
C++ you can't start from, say `("struct-a", 16)`, and end up with
`("int", 4)` -- by the time the base type is `"int"`, the offset
better be zero. In particular, a variant of this invariant is needed
for `llvm::getMostGenericTBAA` to be correct.
- That there are no cycles in a struct path.
- That struct type nodes have their offsets listed in an ascending
order.
- That when generating the struct access path, you eventually reach the
access type listed in the tbaa tag node.
Reviewers: dexonsmith, chandlerc, reames, mehdi_amini, manmanren
Subscribers: mcrosier, llvm-commits
Differential Revision: https://reviews.llvm.org/D26438
llvm-svn: 289402
This teaches SimplifyDemandedElts that the FMA can be removed if the lower element isn't used. It also teaches it that if upper elements of the first operand aren't used then we can simplify them.
llvm-svn: 289377
The tests that already work are folded in InstSimplify, so those
tests should be redundant and we can remove them if they don't
seem worthwhile for completeness.
llvm-svn: 288957
This solves a secondary problem seen in PR6137:
https://llvm.org/bugs/show_bug.cgi?id=6137#c6
This is similar to the bitwise logic op fold added with:
https://reviews.llvm.org/rL287707
And like that patch, I'm artificially restricting the
transform from vector <-> scalar types until we're sure
that the backend can handle that.
llvm-svn: 288584
The instcombine code which folds loads and stores into their use types can trip up if the use is a bitcast to a type which we can't directly load or store in the IR. In principle, such types shouldn't exist, but in practice they do today. This is a workaround to avoid a bug while we work towards the long term goal.
Differential Revision: https://reviews.llvm.org/D24365
llvm-svn: 288415
In PR27925:
https://llvm.org/bugs/show_bug.cgi?id=27925
...we proposed adding this fold to eliminate a bitcast. In D20774, there was
some concern about changing the type of a bitwise op as well as creating
bitcasts that might not be free for a target. However, if we're strictly
eliminating an instruction (by limiting this to one-use ops), then we should
be able to do this in InstCombine.
But we're cautiously restricting the transform for now to vector types to
avoid possible backend problems. A transform to make sure the logic op is
legal for the target should be added to reverse this transform and improve
codegen.
Differential Revision: https://reviews.llvm.org/D26641
llvm-svn: 287707
This is a first step towards canonicalization and improved folding/codegen
for integer min/max as discussed here:
http://lists.llvm.org/pipermail/llvm-dev/2016-November/106868.html
Here, we're just matching the simplest min/max patterns and adjusting the
icmp predicate while swapping the select operands.
I've included FIXME tests in test/Transforms/InstCombine/select_meta.ll
so it's easier to see how this might be extended (corresponds to the TODO
comment in the code). That's also why I'm using matchSelectPattern()
rather than a simpler check; once the backend is patched, we can just
remove some of the restrictions to allow the obfuscated min/max patterns
in the FIXME tests to be matched.
Differential Revision: https://reviews.llvm.org/D26525
llvm-svn: 287585
Currently LLVM assumes that a pointer addrspacecasted to a different addr space is equivalent to trunc or zext bitwise, which is not true. For example, in amdgcn target, when a null pointer is addrspacecasted from addr space 4 to 0, its value is changed from i64 0 to i32 -1.
This patch teaches LLVM not to assume known bits of addrspacecast instruction to its operand.
Differential Revision: https://reviews.llvm.org/D26803
llvm-svn: 287545
This is a prerequisite patch for D26556:
https://reviews.llvm.org/D26556
...because there was no direct coverage for these folds (which in some cases are adding instructions).
llvm-svn: 287400
This is a straightforward extension of the existing support for 32/64-bit element types. Just needed to add the additional instrinsics to the switches.
llvm-svn: 287316
Summary: These intrinsics have been unused for clang for a while. This patch removes them. We auto upgrade them to extractelements, a scalar operation and then an insertelement. This matches the sequence used by clangs intrinsic file.
Reviewers: zvi, delena, RKSimon
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D26660
llvm-svn: 287083
Note that the existing metadata checking was re-added by hand because the
script doesn't currently know how to generate checks for lines outside of
functions.
llvm-svn: 286460
Removing the limitation in visitInsertElementInst() causes several regressions
because we're not prepared to fold sequences of shuffles or inserts and extracts
separated by shuffles. Fixing that appears to be a difficult mission because we
are purposely trying to avoid creating shuffles with arbitrary shuffle masks
because some targets may choke on those.
https://llvm.org/bugs/show_bug.cgi?id=30923
llvm-svn: 286423
As the test change shows, we can increase the critical path by adding
a 'not' instruction, so make sure that we're actually removing an
instruction if we do this transform.
This transform could also cause us to miss folds of min/max pairs.
llvm-svn: 286315
For example, it invalidates the domtree, causing assertions
in later passes which need dominator infos. Make it preserve
GlobalsAA, as suggested by Eli.
Differential Revision: https://reviews.llvm.org/D26381
llvm-svn: 286271
This was reverted at r285866 because there was a crash handling a scalar
select of vectors. I added a check for that pattern and a test case based
on the example provided in the post-commit thread for r285732.
llvm-svn: 286113
This reverts commit r285732.
This change introduced a new assertion failure in the following
testcase at -O2:
typedef short __v8hi __attribute__((__vector_size__(16)));
__v8hi foo(__v8hi &V1, __v8hi &V2, unsigned mask) {
__v8hi Result = V1;
if (mask & 0x80)
Result[0] = V2[0];
return Result;
}
llvm-svn: 285866
I think the former 'test50' had a typo making it functionally equivalent
to the former 'test49'; changed the predicate to provide more coverage.
llvm-svn: 285706
Sanjay Patel