[llvm] r236666 - Add remove method to operate on AttrBuilder instead of AttributeSet.

[Justin Bogner]

Pete Cooper <peter_cooper at apple.com> writes:
> Author: pete
> Date: Wed May  6 18:19:43 2015
> New Revision: 236666
>
> URL: http://llvm.org/viewvc/llvm-project?rev=236666&view=rev
> Log:
> Add remove method to operate on AttrBuilder instead of AttributeSet.
>
> Prior to this change we would have to construct a temporary
> AttributeSet (which isn't temporary at all given that its allocated on
> the context), just to contain the attributes in the builder, then call
> remove on that.
>
> Now we can just remove any attributes from the (lightweight and really
> temporary) builder itself.
>
> Will be used in a future commit to remove some temporary attributes sets.

An MSAN bot was sad after this change:

    http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-fast/builds/3678

Looks like the AttrBuilder constructors forgot to initialize a field, so
I made an attempt to fix it in r236686.

> Modified:
>     llvm/trunk/include/llvm/IR/Attributes.h
>     llvm/trunk/lib/IR/Attributes.cpp
>
> Modified: llvm/trunk/include/llvm/IR/Attributes.h
> URL:
> http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/IR/Attributes.h?rev=236666&r1=236665&r2=236666&view=diff
> ==============================================================================
> --- llvm/trunk/include/llvm/IR/Attributes.h (original)
> +++ llvm/trunk/include/llvm/IR/Attributes.h Wed May  6 18:19:43 2015
> @@ -289,6 +289,12 @@ public:
>    AttributeSet removeAttributes(LLVMContext &C, unsigned Index, 
>                                  AttributeSet Attrs) const;
>  
> +  /// \brief Remove the specified attributes at the specified index from this
> +  /// attribute list. Because attribute lists are immutable, this returns the
> +  /// new list.
> +  AttributeSet removeAttributes(LLVMContext &C, unsigned Index,
> +                                const AttrBuilder &Attrs) const;
> +
>    /// \brief Add the dereferenceable attribute to the attribute set at the given
>    /// index. Since attribute sets are immutable, this returns a new set.
>    AttributeSet addDereferenceableAttr(LLVMContext &C, unsigned Index,
> @@ -464,6 +470,13 @@ public:
>    /// \brief Add the attributes from the builder.
>    AttrBuilder &merge(const AttrBuilder &B);
>  
> +  /// \brief Remove the attributes from the builder.
> +  AttrBuilder &remove(const AttrBuilder &B);
> +
> +  /// \brief \brief Return true if the builder has any attribute that's in the
> +  /// specified builder.
> +  bool overlaps(const AttrBuilder &B) const;
> +
>    /// \brief Return true if the builder has the specified attribute.
>    bool contains(Attribute::AttrKind A) const {
>      assert((unsigned)A < Attribute::EndAttrKinds && "Attribute out of range!");
>
> Modified: llvm/trunk/lib/IR/Attributes.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/IR/Attributes.cpp?rev=236666&r1=236665&r2=236666&view=diff
> ==============================================================================
> --- llvm/trunk/lib/IR/Attributes.cpp (original)
> +++ llvm/trunk/lib/IR/Attributes.cpp Wed May  6 18:19:43 2015
> @@ -857,6 +857,42 @@ AttributeSet AttributeSet::removeAttribu
>    return get(C, AttrSet);
>  }
>  
> +AttributeSet AttributeSet::removeAttributes(LLVMContext &C, unsigned Index,
> +                                            const AttrBuilder &Attrs) const {
> +  if (!pImpl) return AttributeSet();
> +
> +  // FIXME it is not obvious how this should work for alignment.
> +  // For now, say we can't pass in alignment, which no current use does.
> +  assert(!Attrs.hasAlignmentAttr() && "Attempt to change alignment!");
> +
> +  // Add the attribute slots before the one we're trying to add.
> +  SmallVector<AttributeSet, 4> AttrSet;
> +  uint64_t NumAttrs = pImpl->getNumAttributes();
> +  AttributeSet AS;
> +  uint64_t LastIndex = 0;
> +  for (unsigned I = 0, E = NumAttrs; I != E; ++I) {
> +    if (getSlotIndex(I) >= Index) {
> +      if (getSlotIndex(I) == Index) AS = getSlotAttributes(LastIndex++);
> +      break;
> +    }
> +    LastIndex = I + 1;
> +    AttrSet.push_back(getSlotAttributes(I));
> +  }
> +
> +  // Now remove the attribute from the correct slot. There may already be an
> +  // AttributeSet there.
> +  AttrBuilder B(AS, Index);
> +  B.remove(Attrs);
> +
> +  AttrSet.push_back(AttributeSet::get(C, Index, B));
> +
> +  // Add the remaining attribute slots.
> +  for (unsigned I = LastIndex, E = NumAttrs; I < E; ++I)
> +    AttrSet.push_back(getSlotAttributes(I));
> +
> +  return get(C, AttrSet);
> +}
> +
>  AttributeSet AttributeSet::addDereferenceableAttr(LLVMContext &C, unsigned Index,
>                                                    uint64_t Bytes) const {
>    llvm::AttrBuilder B;
> @@ -1211,15 +1247,52 @@ AttrBuilder &AttrBuilder::merge(const At
>    if (!DerefBytes)
>      DerefBytes = B.DerefBytes;
>  
> +  if (!DerefOrNullBytes)
> +    DerefOrNullBytes = B.DerefOrNullBytes;
> +
>    Attrs |= B.Attrs;
>  
> -  for (td_const_iterator I = B.TargetDepAttrs.begin(),
> -         E = B.TargetDepAttrs.end(); I != E; ++I)
> -    TargetDepAttrs[I->first] = I->second;
> +  for (auto I : B.td_attrs())
> +    TargetDepAttrs[I.first] = I.second;
> +
> +  return *this;
> +}
> +
> +AttrBuilder &AttrBuilder::remove(const AttrBuilder &B) {
> +  // FIXME: What if both have alignments, but they don't match?!
> +  if (B.Alignment)
> +    Alignment = 0;
> +
> +  if (B.StackAlignment)
> +    StackAlignment = 0;
> +
> +  if (B.DerefBytes)
> +    DerefBytes = 0;
> +
> +  if (B.DerefOrNullBytes)
> +    DerefOrNullBytes = 0;
> +
> +  Attrs &= ~B.Attrs;
> +
> +  for (auto I : B.td_attrs())
> +    TargetDepAttrs.erase(I.first);
>  
>    return *this;
>  }
>  
> +bool AttrBuilder::overlaps(const AttrBuilder &B) const {
> +  // First check if any of the target independent attributes overlap.
> +  if ((Attrs & B.Attrs).any())
> +    return true;
> +
> +  // Then check if any target dependent ones do.
> +  for (auto I : td_attrs())
> +    if (B.contains(I.first))
> +      return true;
> +
> +  return false;
> +}
> +
>  bool AttrBuilder::contains(StringRef A) const {
>    return TargetDepAttrs.find(A) != TargetDepAttrs.end();
>  }
>
>
> _______________________________________________
> llvm-commits mailing list
> llvm-commits at cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits