When folding addo/subo with undef, the current
convention is to use { -1, false } for addo and
{ 0, false } for subo. This was fixed for InstSimplify in
https://reviews.llvm.org/rGf094d65beaa492e845b03561eddd75b5be653a01,
but not in ConstantFolding.

Reviewed By: nikic, lebedev.ri

Differential Revision: https://reviews.llvm.org/D99564

f18 was emitting a bogus error message about the lack of a TARGET
attribute when a pointer was initialized with a component of a
variable that was a legitimate TARGET.

Differential Revision: https://reviews.llvm.org/D99665

Use SetVector instead of SmallPtrSet to track values with uniform use. Doing this
can help avoid non-determinism caused by iterating over unordered containers.

This bug was found with reverse iteration turning on,
--extra-llvm-cmake-variables="-DLLVM_REVERSE_ITERATION=ON".
Failing LLVM test consecutive-ptr-uniforms.ll .

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D99549

Reviewed By: stellaraccident

Differential Revision: https://reviews.llvm.org/D99628

This helper method is useful even outside of Gnu toolchains, so move
it to ToolChain so it can be reused in other toolchains such as Fuchsia.

Differential Revision: https://reviews.llvm.org/D88452

Removes the prototype builtin and intrinsic for i64x2.eq and implements that
instruction as well as the other i64x2 comparison instructions in the final SIMD
spec. Unsigned comparisons were not included in the final spec, so they still
need to be scalarized via a custom lowering.

Differential Revision: https://reviews.llvm.org/D99623

This is a patch teaching ValueTracking that `s/u*.with.overflow` intrinsics do not
create undef/poison and they propagate poison.
I couldn't write a nice example like the one with ctpop; ValueTrackingTest.cpp were simply updated
to check these instead.
This patch helps reducing regression while fixing https://llvm.org/pr49688 .

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D99671

This fixes an issue introduced with my change d4648e, and reported in pr49768.

The root problem is that dominance collapses in unreachable code, and that LoopInfo explicitly only models reachable code.  Since the recurrence matcher doesn't filter by reachability (and can't easily because not all consumers have domtree), we need to bailout before assuming that finding a recurrence implies we found a loop.

The default expansion creates a MUL and either a MULHS/MULHU. Each
of those separately expand to sequences that use one or more
PMULLW instructions as well as additional instructions to
extend the types to vXi16. The MULHS/MULHU expansion computes the
whole 16-bit product, but only keeps the high part.

We can improve the lowering of SMULO/UMULO for some cases by using the MULHS/MULHU
expansion, but keep both the high and low parts. And we can use
those parts to calculate the overflow.

For AVX512 we might have vXi1 overflow outputs. We can improve those by using
vpcmpeqw to produce a k register if AVX512BW is enabled. This is a little better
than truncating the high result to use vpcmpeqb. If we don't have avx512bw we
can extend up to v16i32 to use vpcmpeqd to produce a k register.

Reviewed By: RKSimon

Differential Revision: https://reviews.llvm.org/D97624

On ppc64 linux , MachineLICM will hoist caller preserved registers, including TOC loads of the global variable address, out of loops. This is to enable this on AIX for both ppc64 and ppc32.

Differential Revision: https://reviews.llvm.org/D99076

We previously couldn't optimize out a TEST if the branch/setcc/cmov
used the overflow flag. This patches allows the TEST to be removed
if the flag producing instruction is known to clear the OF flag.
Thats what the TEST instruction would have done so that should be
equivalent.

Need to add test cases. I'll try to get back to this if I have bandwidth.

Fixes PR48768.

Reviewed By: RKSimon

Differential Revision: https://reviews.llvm.org/D94856

in this patch we add a new libLTO API to specify debug options independent of an lto_code_gen_t.
This allows clients to pass codegen flags (through libLTO) which otherwise today are ignored.

Reviewed By: steven_wu

Differential Revision: https://reviews.llvm.org/D92611

Our CLZW isel pattern is quite easily broken by surrounding code
preventing it from matching sometimes. This usually results in
failing to remove the and X, 0xffffffff inserted by type
legalization. The add with -32 that type legalization also inserts
will often gets combined into other add/sub nodes. That doesn't
usually result in extra code when we don't use clzw.

CTTZ seems to be less fragile, but I wanted to keep it consistent
with CTLZ.

Reviewed By: asb, HsiangKai

Differential Revision: https://reviews.llvm.org/D99317

[RISCV] Add isel patterns to select vsub_vx intrinsic to vadd.vi if it uses a small enough immediate

Also modify the simm5_plus1 check because Imm-1 is UB if Imm happens
to be INT64_MIN. I don't think the compiler would optimize based on that in this
usage, but it could fail UBSan or -ftrapv.

Reviewed By: HsiangKai, frasercrmck

Differential Revision: https://reviews.llvm.org/D99637

Reviewed By: sgraenitz

Differential Revision: https://reviews.llvm.org/D99604

D99627 fixed a decoding bug, not an encoding bug. This renames the test
to correct it and fix comments.

Reviewed By: dschuff

Differential Revision: https://reviews.llvm.org/D99644

This is a missing optimization based on an example in:
https://llvm.org/PR49763

As noted there and the test here, we could add a more
general fold if that is shown useful.

https://alive2.llvm.org/ce/z/xEHdTv
https://alive2.llvm.org/ce/z/97dcY5

Differential Revision: https://reviews.llvm.org/D99265

... instantiations

They are currently not being diagnosed because ProhibitAttributes() does
not handle attribute lists with an invalid source range. But once it
does, we need to allow GNU attributes in this place.

Additionally, start optionally diagnosing empty attr lists in
ProhibitCXX11Attributes(), since ProhibitAttribute() does it.

Differential Revision: https://reviews.llvm.org/D97362

Because the constexpr-time codepath triggers a Clang bug. It seems
that Clang compiles it okay in release mode, but when Clang itself
is compiled in debug mode (with assertions turned on), this input
triggers an assertion failure in Clang itself. See comments on D96385
and Clang bug report https://bugs.llvm.org/show_bug.cgi?id=45879

This commit should get the debug-mode buildbots back to green.

See D80668, rG7b483264 and https://bugs.llvm.org/show_bug.cgi?id=46117
for details of the issue.

Differential Revision: https://reviews.llvm.org/D99108

This marks FSIN and other operations to EXPAND for scalable
vectors, so that they are not assumed to be legal by the cost-model.

Depends on D97470

Reviewed By: dmgreen, paulwalker-arm

Differential Revision: https://reviews.llvm.org/D97471

Let getIntrinsicInstrCost call getTypeBasedIntrinsicInstrCost for scalable vectors,
similar to how this is done for fixed-width vectors, instead of falling back
on BaseT::getIntrinsicInstrCost().

If the intrinsic cannot be costed (or is not overloaded by the target),
it will return InstructionCost::getInvalid() instead.

Depends on D97469

Reviewed By: david-arm

Differential Revision: https://reviews.llvm.org/D97470

This adds support for C++2b's z/uz suffixes for size_t literals (P0330).

The standard guarantees sleep durations of 2^63-1 nanoseconds to work.
Instead of depending on INT64_MAX or ULONGLONG_MAX to exist via the
header pollution, fold the constant directly. That has the additional
positive side effect that it avoids long double arithmetic bugs in GCC.

Differential Revision: https://reviews.llvm.org/D99516

This reverts commit 49c0ab6d.

Test failures showed up because non-deterministic output.

This patch migrates the TTI cost interfaces to return an InstructionCost.

See this patch for the introduction of the type: https://reviews.llvm.org/D91174
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2020-November/146408.html

Depends on D97468

Reviewed By: dmgreen

Differential Revision: https://reviews.llvm.org/D97469

This patch migrates the TTI cost interfaces to return an InstructionCost.

See this patch for the introduction of the type: https://reviews.llvm.org/D91174
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2020-November/146408.html

Depends on D97466

Reviewed By: dmgreen

Differential Revision: https://reviews.llvm.org/D97468

This reverts commit 1164b4e2.

Reason: LLDB AArch64 Linux buildbot failure

This reverts commit 9ab67718.

Reason: LLDB AArch64/Linux buildbot failure.

Attempts to compute savings more accurately cannot impact the set of critically important call sites.

Reviewed By: kazu

Differential Revision: https://reviews.llvm.org/D98577

This is an improvement over Zen 2, where only branch fusion is supported,
as per Agner, 21.4 Instruction fusion.
AMD SOG 17h has no mention of fusion.

AMD SOG 19h, 2.9.3 Branch Fusion
The following flag writing instructions support branch fusion
with their reg/reg, reg/imm and reg/mem forms
* CMP
* TEST
* SUB
* ADD
* INC (no fusion with branches dependent on CF)
* DEC (no fusion with branches dependent on CF)
* OR
* AND
* XOR

Agner, 22.4 Instruction fusion
<...> This applies to CMP, TEST, ADD, SUB, AND, OR, XOR, INC, DEC and
all conditional jumps, except if the arithmetic or logic instruction has a rip-relative address or
both an address displacement and an immediate operand.

D99576 introduced a duplicate symbol, now im removing it.

Differential Revision: https://reviews.llvm.org/D99576

This adds almost everything required for supporting the new stepvector
intrinsic on RVV. It is lowered to the existing VID_VL SDNode.

The only exception is a limitation that RV32 cannot yet lower the
intrinsic on i64 vectors. This is because the step operand is
(currently) required to be at least as large as the vector element type.
I will look into patching that out and loosening the requirement to only
an integer pointer type.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D99594

This reverts commit 73cf85e5.