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| author | Eli Friedman <efriedma@quicinc.com> | 2020-05-16 17:55:18 -0700 |
|---|---|---|
| committer | Eli Friedman <efriedma@quicinc.com> | 2020-05-20 16:37:20 -0700 |
| commit | f26bdb539e8acef23e2a0370408521a6458001ee (patch) | |
| tree | 858d012071872321fd2f4417bd10e90b6c414a33 /llvm/lib/Analysis/ValueTracking.cpp | |
| parent | 770ba4f0516e9af7279767ae90e283c3755c0c97 (diff) | |
| download | llvm-f26bdb539e8acef23e2a0370408521a6458001ee.zip llvm-f26bdb539e8acef23e2a0370408521a6458001ee.tar.gz llvm-f26bdb539e8acef23e2a0370408521a6458001ee.tar.bz2 | |
Make Value::getPointerAlignment() return an Align, not a MaybeAlign.
If we don't know anything about the alignment of a pointer, Align(1) is
still correct: all pointers are at least 1-byte aligned.
Included in this patch is a bugfix for an issue discovered during this
cleanup: pointers with "dereferenceable" attributes/metadata were
assumed to be aligned according to the type of the pointer. This
wasn't intentional, as far as I can tell, so Loads.cpp was fixed to
stop making this assumption. Frontends may need to be updated. I
updated clang's handling of C++ references, and added a release note for
this.
Differential Revision: https://reviews.llvm.org/D80072
Diffstat (limited to 'llvm/lib/Analysis/ValueTracking.cpp')
| -rw-r--r-- | llvm/lib/Analysis/ValueTracking.cpp | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp index 8d69df3..a5fb6fb 100644 --- a/llvm/lib/Analysis/ValueTracking.cpp +++ b/llvm/lib/Analysis/ValueTracking.cpp @@ -2008,9 +2008,8 @@ void computeKnownBits(const Value *V, const APInt &DemandedElts, // Aligned pointers have trailing zeros - refine Known.Zero set if (isa<PointerType>(V->getType())) { - const MaybeAlign Align = V->getPointerAlignment(Q.DL); - if (Align) - Known.Zero.setLowBits(countTrailingZeros(Align->value())); + Align Alignment = V->getPointerAlignment(Q.DL); + Known.Zero.setLowBits(countTrailingZeros(Alignment.value())); } // computeKnownBitsFromAssume strictly refines Known. |