The C and C++ semantics for compare_exchange require it to return a bool
indicating success. This gets mapped to LLVM IR which follows each cmpxchg with
an icmp of the value loaded against the desired value.
When lowered to ldxr/stxr loops, this extra comparison is redundant: its
results are implicit in the control-flow of the function.
This commit makes two changes: it replaces that icmp with appropriate PHI
nodes, and then makes sure earlyCSE is called after expansion to actually make
use of the opportunities revealed.
I've also added -{arm,aarch64}-enable-atomic-tidy options, so that
existing fragile tests aren't perturbed too much by the change. Many
of them either rely on undef/unreachable too pervasively to be
restored to something well-defined (particularly while making sure
they test the same obscure assert from many years ago), or depend on a
particular CFG shape, which is disrupted by SimplifyCFG.
rdar://problem/16227836
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209883 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts r208640 (I've just XFAILed the test) because it broke ppc64/Linux
self-hosting. Because nearly every regression test triggers a segfault, I hope
this will be easy to fix.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209747 91177308-0d34-0410-b5e6-96231b3b80d8
Add regression tests for the following transformation:
str X, [x20]
...
add x20, x20, #32
->
str X, [x20], #32
with X being either w0, x0, s0, d0 or q0.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209715 91177308-0d34-0410-b5e6-96231b3b80d8
Add regression tests for the following transformation:
ldr X, [x20]
...
add x20, x20, #32
->
ldr X, [x20], #32
with X being either w0, x0, s0, d0 or q0.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209711 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is debatable. There are two possible approaches, neither
of which is really satisfactory:
1. Use "@foo(i1 zeroext)" to mean an extension to 32-bits on Darwin,
and 8 bits otherwise.
2. Redefine "@foo(i1)" to mean that the i1 is extended by the caller
to 8 bits. This goes against the spirit of "zeroext" I think, but
it's a bit of a vague construct anyway (by definition you're going
to extend to the amount required by the ABI, that's why it's the
ABI!).
This implements option 2. The DAG machinery really isn't setup for the
first (there's a fairly strong assumption that "zeroext" goes to at
least the smallest register size), and even if it was the resulting
DAG looks like it would be inferior in many cases.
Theoretically we could add AssertZext nodes in the consumers of
ABI-passed values too now, but this actually seems to make the code
worse in practice by making truncation proceed in two steps. The code
produced is equally valid if we continue to assume only the low bit is
defined.
Should fix PR19850
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209637 91177308-0d34-0410-b5e6-96231b3b80d8
We can eliminate the custom C++ code in favour of some TableGen to
check the same things. Functionality should be identical, except for a
buffer overrun that was present in the C++ code and meant webkit
failed if any small argument needed to be passed on the stack.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209636 91177308-0d34-0410-b5e6-96231b3b80d8
We have a couple of regression tests for load/store pairing, but (to my knowledge) there are no regression tests for the load/store + add/sub folding.
As a first step towards increased test coverage of this area, this commit adds a test for one instance of a load + add to pre-indexed load transformation.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209618 91177308-0d34-0410-b5e6-96231b3b80d8
This commit starts with a "git mv ARM64 AArch64" and continues out
from there, renaming the C++ classes, intrinsics, and other
target-local objects for consistency.
"ARM64" test directories are also moved, and tests that began their
life in ARM64 use an arm64 triple, those from AArch64 use an aarch64
triple. Both should be equivalent though.
This finishes the AArch64 merge, and everyone should feel free to
continue committing as normal now.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209577 91177308-0d34-0410-b5e6-96231b3b80d8
I'm doing this in two phases for a better "git blame" record. This
commit removes the previous AArch64 backend and redirects all
functionality to ARM64. It also deduplicates test-lines and removes
orphaned AArch64 tests.
The next step will be "git mv ARM64 AArch64" and rewire most of the
tests.
Hopefully LLVM is still functional, though it would be even better if
no-one ever had to care because the rename happens straight
afterwards.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209576 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts commit r208934.
The patch depends on aliases to GEPs with non zero offsets. That is not
supported and fairly broken.
The good news is that GlobalAlias is being redesigned and will have support
for offsets, so this patch should be a nice match for it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208978 91177308-0d34-0410-b5e6-96231b3b80d8
TableGen has a fairly dubious heuristic to decide whether an alias should be
printed: does the alias have lest operands than the real instruction. This is
bad enough (particularly with no way to override it), but it should at least be
calculated consistently for both strings.
This patch implements that logic: first get the *correct* string for the
variant, in the same way as the Matcher, without guessing; then count the
number of whitespace chars.
There are basically 4 changes this brings about after the previous
commits; all of these appear to be good, so I have changed the tests:
+ ARM64: we print "neg X, Y" instead of "sub X, xzr, Y".
+ ARM64: we skip implicit "uxtx" and "uxtw" modifiers.
+ Sparc: we print "mov A, B" instead of "or %g0, A, B".
+ Sparc: we print "fcmpX A, B" instead of "fcmpX %fcc0, A, B"
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208969 91177308-0d34-0410-b5e6-96231b3b80d8
This commit implements two command line switches -global-merge-on-external
and -global-merge-aligned, and both of them are false by default, so this
optimization is disabled by default for all targets.
For ARM64, some back-end behaviors need to be tuned to get this optimization
further enabled.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208934 91177308-0d34-0410-b5e6-96231b3b80d8
In all cases, if a "mov" alias exists, it is the canonical form of the
instruction. Now that TableGen can support aliases containing syntax variants,
we can enable them and improve the quality of the asm output.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208874 91177308-0d34-0410-b5e6-96231b3b80d8
To get at least one use of the change (and some actual tests) in with its
commit, I've enabled the AArch64 & ARM64 NEON mov aliases.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208867 91177308-0d34-0410-b5e6-96231b3b80d8
When performing a scalar comparison that feeds into a vector select,
it's actually better to do the comparison on the vector side: the
scalar route would be "CMP -> CSEL -> DUP", the vector is "CM -> DUP"
since the vector comparisons are all mask based.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208210 91177308-0d34-0410-b5e6-96231b3b80d8
This completes the port of r204814 (cpirker "AArch64_BE function argument
passing for ARM ABI") from AArch64 to ARM64, and fixes a bunch of issues
found during later development along the way. The biggest of these was
that the alignment fixup logic wasn't replicated into all the places it
should have been.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208192 91177308-0d34-0410-b5e6-96231b3b80d8
This patch implements the infrastructure to use named register constructs in
programs that need access to specific registers (bare metal, kernels, etc).
So far, only the stack pointer is supported as a technology preview, but as it
is, the intrinsic can already support all non-allocatable registers from any
architecture.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208104 91177308-0d34-0410-b5e6-96231b3b80d8
An alias has the address of what it points to, so it also has the same
alignment.
This allows a few optimizations to see past aliases for free.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208103 91177308-0d34-0410-b5e6-96231b3b80d8
The canonical form of the BFM instruction is always one of the more explicit
extract or insert operations, which makes reading output much easier.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207752 91177308-0d34-0410-b5e6-96231b3b80d8
On instructions using the NZCV register, a couple of conditions have dual
representations: HS/CS and LO/CC (meaning unsigned-higher-or-same/carry-set and
unsigned-lower/carry-clear). The first of these is more descriptive in most
circumstances, so we should print it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207644 91177308-0d34-0410-b5e6-96231b3b80d8
Since these are mostly used in "lsl #16", "lsl #32", "lsl #48" combinations to
piece together an immediate in 16-bit chunks, hex is probably the most
appropriate format.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207635 91177308-0d34-0410-b5e6-96231b3b80d8
Since these instructions only accept a 12-bit immediate, possibly shifted left
by 12, the canonical syntax used by the architecture reference manual is "#N {,
lsl #12 }". We should accept an immediate that has already been shifted, (e.g.
Also, print a comment giving the full addend since it can be helpful.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207633 91177308-0d34-0410-b5e6-96231b3b80d8
This is a partial port of r204816 (cpirker "Elf support for MC-JIT
runtime dynamic linker") from AArch64 to ARM64.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207625 91177308-0d34-0410-b5e6-96231b3b80d8
There are no patterns for this. This was already fixed for ARM64 but I forgot
to apply it to AArch64 too.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207515 91177308-0d34-0410-b5e6-96231b3b80d8
This patch is a supplement of implementing predicate of FP, enabling aarch64 backend
no-fp tests on arm64 target for verification. During this, one bug is exposed and
fixed by this patch.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207215 91177308-0d34-0410-b5e6-96231b3b80d8
This matches ARM64 behaviour, which I think is clearer. It also puts all the
churn from that difference into one easily ignored commit.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207116 91177308-0d34-0410-b5e6-96231b3b80d8
ARM64 was not producing pure BFI instructions for bitfield insertion
operations, unlike AArch64. The approach had to be a little different (in
ISelDAGToDAG rather than ISelLowering), and the outcomes aren't identical but
hopefully this gives it similar power.
This should address PR19424.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207102 91177308-0d34-0410-b5e6-96231b3b80d8
