Reviewers: nicolasvasilache

Reviewed By: nicolasvasilache

Subscribers: mgester, lucyrfox, merge_guards_bot, AlexEichenberger, mravishankar, ftynse, mehdi_amini, rriddle, jpienaar, burmako, shauheen, antiagainst, nicolasvasilache, arpith-jacob, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D72094

When getting the file name form the line table prologue we assume that a
valid string form value can always be extracted as a string. If you look
at the implementation of DWARFormValue this is not necessarily true. I
hit this assertion from LLDB when I create a "dummy" DWARFContext that
was missing the string section.

Name: (X & (- Y)) - X  ->  - (X & (Y - 1))  (PR44448)
  %negy = sub i8 0, %y
  %unbiasedx = and i8 %negy, %x
  %r = sub i8 %unbiasedx, %x
=>
  %ymask = add i8 %y, -1
  %xmasked = and i8 %ymask, %x
  %r = sub i8 0, %xmasked

https://rise4fun.com/Alive/OIpla

This decreases use count of %x, may allow us to
later hoist said negation even further,
and results in marginally nicer X86 codegen.

See
  https://bugs.llvm.org/show_bug.cgi?id=44448
  https://reviews.llvm.org/D71499

As discussed in https://bugs.llvm.org/show_bug.cgi?id=44448,
we can hoist negation out of the pattern.

Reviewed By: dmgreen

Differential Revision: https://reviews.llvm.org/D72061

Summary:
While it's perfectly reasonable for non-named decls such as
static_assert to resolve to themselves:
 - nothing else ever resolves to them
 - features based on references (hover, highlight, find refs etc) tend
   to be uninteresting where only trivial references are possible
 - returning NamedDecl is a more convenient API (we cast to it in many places)
 - this aligns closer to findExplicitReferences/explicitReferenceTargets

This fixes a crash in explicitReferenceTargets: if the target is a
non-named decl then there's an invalid unchecked cast to NamedDecl.

In practice this means when hovering over e.g. a static_assert:
 - before ac3f9e48, we would show a (boring) hover card
 - after ac3f9e48, we would crash
 - after this patch, we will show nothing

Reviewers: kadircet, ilya-biryukov

Subscribers: MaskRay, jkorous, arphaman, usaxena95, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D72163

If the qualified reduction name is specified and not found, the compiler
may crash because of not specified parameter.

Before:
    class Foo {
      @CommandLineFlags
          .Add
          @Features.foo
          public void test() {}
    }

Now:
    class Foo {
        @Features.foo
        @CommandLineFlags.Add
        public void test() { }
    }

See also https://crbug.com/1034115

The OpenMP specification disallows having zero-length array
sections in the depend clause (OpenMP 5.0 2.17.11).

Differential Revision: https://reviews.llvm.org/D71969

If we replace a function with a new one because we rewrite the
signature, dead users may still refer to the old version. With this
patch we reuse the code that deals with dead functions, which the old
versions are, to avoid problems.

An integer isn't allowed in getAlignmentForValue so we need to stop at a
ptr2int instruction during exploration.

An inbounds GEP results in poison if the value is not "inbounds", not in
UB. We accidentally derived nonnull and dereferenceable from these
inbounds GEPs even in the absence of accesses that would make the poison
to UB.

Summary:
this allow much better support of codebases like the linux kernel that mix tabs and spaces.

-ftabstop=//Width// allow specifying how large tabs are considered to be.

Reviewers: xbolva00, aaron.ballman, rsmith

Reviewed By: aaron.ballman

Subscribers: mstorsjo, cfe-commits, jyknight, riccibruno, rsmith, nathanchance

Tags: #clang

Differential Revision: https://reviews.llvm.org/D71037

This should be looking at the RHS of the add for a constant.

The fold 'A - (A & (B - 1))' -> 'A & (0 - B)'
added in 8dab0a4a
is too specific. It should/can just be 'A - (A & B)' -> 'A & (~B)'

Even if we don't manage to fold `~` into B,
we have likely formed `ANDN` node.
Also, this way there's less similar-but-duplicate folds.

Name: X - (X & Y)  ->  X & (~Y)
%o = and i32 %X, %Y
%r = sub i32 %X, %o
  =>
%n = xor i32 %Y, -1
%r = and i32 %X, %n

https://rise4fun.com/Alive/kOUl

See
  https://bugs.llvm.org/show_bug.cgi?id=44448
  https://reviews.llvm.org/D71499

The fold 'A - (A & (B - 1))' -> 'A & (0 - B)'
added in 8dab0a4a
is too specific. It should just be 'A - (A & B)' -> 'A & (~B)'

Name: X - (X & Y)  ->  X & (~Y)
%o = and i32 %X, %Y
%r = sub i32 %X, %o
  =>
%n = xor i32 %Y, -1
%r = and i32 %X, %n

https://rise4fun.com/Alive/kOUl

See
  https://bugs.llvm.org/show_bug.cgi?id=44448
  https://reviews.llvm.org/D71499

The fold 'A - (A & (B - 1))' -> 'A & (0 - B)'
added in 8dab0a4a
is too specific. It should just be 'A - (A & B)' -> 'A & (~B)',
but we currently fail to sink that '~' into `(B - 1)`.

Name: ~(X - 1)  ->  (0 - X)
%o = add i32 %X, -1
%r = xor i32 %o, -1
  =>
%r = sub i32 0, %X

https://rise4fun.com/Alive/rjU

The fold 'A - (A & (B - 1))' -> 'A & (0 - B)'
added in 8dab0a4a
is too specific. It should just be 'A - (A & B)' -> 'A & (~B)',
but we currently fail to sink that '~' into `(B - 1)`.

Name: ~(X - 1)  ->  (0 - X)
%o = add i32 %X, -1
%r = xor i32 %o, -1
  =>
%r = sub i32 0, %X

https://rise4fun.com/Alive/rjU

While we do manage to fold integer-typed IR in middle-end,
we can't do that for the main motivational case of pointers.

There is @llvm.ptrmask() intrinsic which may or may not be helpful,
but i'm not sure it is fully considered canonical yet,
not everything is fully aware of it likely.

Name: PR44448  ptr - (ptr & C) -> ptr & (~C)
%bias = and i32 %ptr, C
%r = sub i32 %ptr, %bias
  =>
%r = and i32 %ptr, ~C

See
  https://bugs.llvm.org/show_bug.cgi?id=44448
  https://reviews.llvm.org/D71499

Name: PR44448  ptr - (ptr & C) -> ptr & (~C)
%bias = and i32 %ptr, C
%r = sub i32 %ptr, %bias
  =>
%r = and i32 %ptr, ~C

The main motivational pattern involes pointer-typed values,
so this transform can't really be done in middle-end.

See
  https://bugs.llvm.org/show_bug.cgi?id=44448
  https://reviews.llvm.org/D71499

Differential Revision: https://reviews.llvm.org/D72130

Correctly declare example dependency. Pipe stderr through FileCheck.

Differential Revision: https://reviews.llvm.org/D72130

s/CHECK-/CHECK

Differential Revision: https://reviews.llvm.org/D72130

The patch makes sure that the LastThrowing pointer does not point to any instruction deleted by call to DeleteDeadInstruction.

While iterating through the instructions the pass maintains a pointer to the lastThrowing Instruction. A call to deleteDeadInstruction deletes a dead store and other instructions feeding the original dead instruction which also become dead. The instruction pointed by the lastThrowing pointer could also be deleted by the call to DeleteDeadInstruction and thus it becomes a dangling pointer. Because of this, we see an error in the next iteration.

In the patch, we maintain a list of throwing instructions encountered previously and use the last non deleted throwing instruction from the container.

Reviewers: fhahn, bcahoon, efriedma

Reviewed By: fhahn

Differential Revision: https://reviews.llvm.org/D65326

As shown in P44383:
https://bugs.llvm.org/show_bug.cgi?id=44383
...we can't safely propagate a vector constant through this icmp fold
if that vector constant contains undefined elements.

We know that each defined element of the constant is safe though, so
find the first of those and replicate it into the formerly undef lanes.

Differential Revision: https://reviews.llvm.org/D72101

These have been obsolete since about r221926, when
TargetLoweringObjectFile was completely moved from TargetLowering to
TargetMachine.

This commit fixes shader ABI attributes to use `spv.` as the prefix
so that they match the dialect's namespace. This enables us to add
verification hooks in the SPIR-V dialect to verify them.

Reviewed By: mravishankar

Differential Revision: https://reviews.llvm.org/D72062

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D72092

The V5 directory and filename tables had checks in to make sure we
hadn't read past the end of the line table prologue. Since previous
changes to the data extractor class ensure we never read past the end,
these checks are now redundant, so this patch removes them.

There is still a check to show that the whole prologue remains within
the prologue length.

Reviewed By: JDevlieghere

Differential Revision: https://reviews.llvm.org/D71768

Remove description of language mode from the language
extensions and add a link to pdf document.

Tags: #clang

Differential Revision: https://reviews.llvm.org/D72076

When they are free-standing, e.g. `struct X;` or `struct X {};`.
Although this complicates the common case (of free-standing class
declarations), this ensures the less common case (e.g. `struct X {} a;`)
are handled uniformly and produce similar syntax trees.