-fsyntax -c is supposed to lead to a -Wunused-command-line-argument
warning. There is currently no due to a gcov FIXME in
addPGOAndCoverageFlags.

This patch updates the transformations in InstCombineVectorOps to use the new
hufflevector semantics that say that undefined values in the mask yield poison.

To prevent miscompilations we have to match with m_Poison instead of m_Undef.
Otherwise, we might introduce poison where there was previously undef.

Differential Revision: https://reviews.llvm.org/D150039

Add the saturation arithmetic intrinsics to the LLVM dialect.

Reviewed By: Dinistro

Differential Revision: https://reviews.llvm.org/D150676

This change contains three util classes that were out from D145183 to make incremental progress
- automic_unique_lock
- intrusive_list
- intrusive_shared_ptr

Differential Revision: https://reviews.llvm.org/D150205

This addresses another buildbot breakage:
https://lab.llvm.org/buildbot/#/builders/37/builds/22166

My patch, https://reviews.llvm.org/D150708 introduced
stubs for common interceptor macros; these had unused
variables and functions. An earlier patch fixed the
unused variables; this patch suppresses unused-functions
warnings.

In file included from /data/llvm-project/compiler-rt/lib/hwasan/hwasan_interceptors.cpp:141:
/data/llvm-project/compiler-rt/lib/hwasan/../sanitizer_common/sanitizer_common_interceptors.inc:1044:13: error: unused function 'write_iovec' [-Werror,-Wunused-function]
static void write_iovec(void *ctx, struct __sanitizer_iovec *iovec,
            ^
/data/llvm-project/compiler-rt/lib/hwasan/../sanitizer_common/sanitizer_common_interceptors.inc:1053:13: error: unused function 'read_iovec' [-Werror,-Wunused-function]
static void read_iovec(void *ctx, struct __sanitizer_iovec *iovec,
            ^
/data/llvm-project/compiler-rt/lib/hwasan/../sanitizer_common/sanitizer_common_interceptors.inc:10363:13: error: unused function 'InitializeCommonInterceptors' [-Werror,-Wunused-function]
static void InitializeCommonInterceptors() {
            ^
3 errors generated.

The dwarf discriminator field for pseudo probes is not supposed to be used until the first FS discriminator pass. Unfortunately there are always corner cases that accidientally set this field. For example, the inliner could set this field for an inlined instruction if the instruction does not come with any debug information. While fixing all such spots is possible, but for future-proff I'd like to enforce a general cleanup before assigning probes any FS discriminator.

Reviewed By: wenlei

Differential Revision: https://reviews.llvm.org/D150741

Despite previous effort {D148569} to avoid screwing up existing disrminator field, I'm still seeing some call probes getting a non-zero discriminator eventually in non-FS mode. It could be related to callsite merge. While they are investigated I'm disabling discriminator emission for non-FS mode. This avoids breaking the compatiblity with older tools like llvm-profgen and bolt.

Reviewed By: wenlei

Differential Revision: https://reviews.llvm.org/D150625

After landing more precise trip multiples in
https://reviews.llvm.org/D149529, the SCEV multiple computation handles
constants, so there is no longer any need for special constant handling
in getSmallConstantTripMultiple.

This patch can improve the multiple of a non-constant SCEV that is huge
(>=2**32). This is very rare in practice.

Differential Revision: https://reviews.llvm.org/D150541

This (hopefully) fixes the buildbot breakage:
https://lab.llvm.org/buildbot/#/builders/77/builds/26793

My patch, https://reviews.llvm.org/D150708 introduced
stubs for common interceptor macros; these had unused
variables. This patch suppresses unused-variable
warnings.

Add expensive check that Uses, Defs are same for entries in memory folding table.
MemFolding could not change the Uses/Defs.

Reviewed By: skan

Differential Revision: https://reviews.llvm.org/D150633

When an instruction is determined to be divergent, not all its outputs are
divergent. The users of only divergent outputs should now be examined for
divergence.

Also, replaced a repeating pattern of "if new divergent instruction, then add to
worklist" by combining it into a single function. This does not cause any change
in functionality.

Reviewed By: foad, arsenm

Differential Revision: https://reviews.llvm.org/D150636

The corresponding function definition was removed by:

  commit e82a0084
  Author: Sam Parker <sam.parker@arm.com>
  Date:   Fri Sep 25 09:36:40 2020 +0100

Differential Revision: https://reviews.llvm.org/D150422

The last use was removed by:

  commit 9eb75c45
  Author: Krzysztof Parzyszek <kparzysz@codeaurora.org>
  Date:   Fri Jun 30 21:21:40 2017 +0000

The last uses were removed by:

  commit 8cda34f5
  Author: Tim Northover <tnorthover@apple.com>
  Date:   Wed Mar 11 18:54:22 2015 +0000

The unused declaration was introduced without a corresponding function
definition in:

  commit f5d07a05
  Author: Krzysztof Parzyszek <kparzysz@quicinc.com>
  Date:   Mon Sep 7 14:26:48 2020 -0500

This patch does the following things:

1, Add accurate Predicates in intrinsic-pseudo pattern class depending on the vector type.
2, Make vmulh, vmulhsu, vmulhu and vsmul intrinsic only able to select in v extension.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D150550

The corresponding function definition was removed by:

  commit b2680c71
  Author: Andrew Trick <atrick@apple.com>
  Date:   Tue Jun 5 03:44:43 2012 +0000

The corresponding function definition was removed by:

  commit e891654a
  Author: Evan Cheng <evan.cheng@apple.com>
  Date:   Tue Aug 30 01:34:54 2011 +0000

While we are at it, this patch removes ARMPCLabelIndex, for which the
host compiler issues an unused variable warning.

Instead of doing the local filesystem scan for kexts and kernels
when the PlatformDarwinKernel is constructed, delay doing it until
the scan is needed.

Differential Revision: https://reviews.llvm.org/D150621
rdar://109186357

This patch implements the enhancement proposed by
https://github.com/llvm/llvm-project/issues/59312.

Suppose we have following code

     v0 = load %addr
     br %LoadBB

  LoadBB:
     v1 = load %addr
     ...

  PredBB:
     ...
     br %cond, label %LoadBB, label %SuccBB

  SuccBB:
     v2 = load %addr
     ...

Instruction v1 in LoadBB is partially redundant, edge (PredBB, LoadBB) is a
critical edge. SuccBB is another successor of PredBB, it contains another load
v2 which is identical to v1. Current GVN splits the critical edge
(PredBB, LoadBB) and inserts a new load in it. A better method is move the load
of v2 into PredBB, then v1 can be changed to a PHI instruction.

If there are two or more similar predecessors, like the test case in the bug
entry, current GVN simply gives up because otherwise it needs to split multiple
critical edges. But we can move all loads in successor blocks into predecessors.

Differential Revision: https://reviews.llvm.org/D141712

Reviewed By: koakuma

Differential Revision: https://reviews.llvm.org/D150512

Reviewed By: RKSimon

Differential Revision: https://reviews.llvm.org/D150099

Add `exact` flag handling for `udiv` and add entire `sdiv` case.

Differential Revision: https://reviews.llvm.org/D150098

Differential Revision: https://reviews.llvm.org/D150097

We now of an implementation of `KnownBits::sdiv` so we can implement
this case.

Differential Revision: https://reviews.llvm.org/D150096

This information was previously missing but we can use it for
determining the low-bits.

Differential Revision: https://reviews.llvm.org/D150095

We can more precisely determine the upper bits doing `MaxNum /
MinDenum` as opposed to only using the MSB.

As well, if the `exact` flag is set, we can sometimes determine some
of the low-bits.

Differential Revision: https://reviews.llvm.org/D150094

Can figure out some of the upper bits (similiar to `udiv`) if we know
the sign of the inputs.

As well, if we have the `exact` flag we can sometimes determine some
low-bits.

Differential Revision: https://reviews.llvm.org/D150093

Differential Revision: https://reviews.llvm.org/D150092

For `X * Y`, if there exists a subset of `X` and subset of `Y` s.t `sX * sY != 0`,
then `X * Y != 0`.
    - See first proof: https://alive2.llvm.org/ce/z/28C9CG
    - NB: This is why the previous Odd case works.

In knownbits we could exhaustively hunt for such a subset, but
`LSB(X)` and `LSB(Y)` actually works. If `LSB(X) * LSB(Y) != 0`, then
`X * Y != 0`
    - See proof: https://alive2.llvm.org/ce/z/p5wWid

In `isKnownNonZero` we can use this as if the `LowestKnownOne(X) *
LowestKnownOne(Y) != 0`, then `X * Y != 0`, and we don't need to try
and other subsets.

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D150425

Differential Revision: https://reviews.llvm.org/D150424

Issue was an assertion failure due to an unchecked `cast`. Fix is to
check the operator is `BinaryOperator` before cast so that we won't
match `ConstExpr`

Reviewed By: goldstein.w.n, RKSimon

Differential Revision: https://reviews.llvm.org/D149699

This is the implementation of D149782

The patch implements a helper function that matches and fold the following cases in the DAGCombiner:

1. `bswap(logic_op(x, bswap(y))) -> logic_op(bswap(x), y)`
2. `bswap(logic_op(bswap(x), y)) -> logic_op(x, bswap(y))`
3. `bswap(logic_op(bswap(x), bswap(y))) -> logic_op(x, y)` in multiuse case, which still reduces the number of instructions.

The helper function accepts SDValue with BSWAP and BITREVERSE opcode. This patch folds the BSWAP cases and remain the BITREVERSE optimization in the future

Reviewed By: RKSimon, goldstein.w.n

Differential Revision: https://reviews.llvm.org/D149783

Fold the following case on SelectionDAG combiner
This patch includes the regression test cases

```
bswap(logic_op(x, bswap(y))) -> logic_op(bswap(x), y)
bswap(logic_op(bswap(x), y)) -> logic_op(x, bswap(y))
bswap(logic_op(bswap(x), bswap(y))) -> logic_op(x, y) (with multiuse)
```

Reviewed By: goldstein.w.n

Differential Revision: https://reviews.llvm.org/D149782

We want to reference both byte-sized globals (@A and @C) to prevent them from
being dead-stripped.