We were already doing this for integer constants. This patch implements
the same thing for floating point constants.
Differential Revision: https://reviews.llvm.org/D88570
In the motivating case from https://llvm.org/PR47517
we create a node that does not get constant folded
before getNegatedExpression is attempted from some
other node, and we crash.
By moving the fold into SelectionDAG::simplifyFPBinop(),
we get the constant fold sooner and avoid the problem.
Marks constants of an ICmp instruction as free if it's only user is a select
instruction that is part of a min(max()) pattern. Ensures that in loops, in
particular when loop unrolling is turned on, SSAT will still be correctly generated.
Differential Revision: https://reviews.llvm.org/D88662
Added patterns to generate an SSAT or USAT with shift for
SSAT/USAT instructions that are matched from IR patterns.
Differential Revision: https://reviews.llvm.org/D88145
Previously, if a floating-point type was legal, but FNEG wasn't legal,
we would use FSUB. Instead, we should use integer ops, to preserve the
semantics. (Alternatively, there's a compiler-rt call we could use, but
there isn't much reason to use that.)
It turns out we actually are still using this obscure codepath in a few
cases: on some targets, we have "legal" floating-point types that don't
actually support any floating-point operations. In particular, ARM and
AArch64 are using this path.
The implementation for SelectionDAG is pretty simple because we can
reuse the infrastructure from FCOPYSIGN.
See also 9a3dc3e, the corresponding change to type legalization.
Also includes a "bonus" change to STRICT_FSUB legalization, so we can
lower a STRICT_FSUB to a float libcall.
Includes the changes to both LegalizeDAG and GlobalISel so we don't have
inconsistent results in the future.
Fixes https://bugs.llvm.org/show_bug.cgi?id=46792 .
Differential Revision: https://reviews.llvm.org/D84287
security boundary
It was never supported and that part was accidentally omitted when
upstreaming D76518.
Differential Revision: https://reviews.llvm.org/D86478
Change-Id: If6ba9506eb0431c87a1d42a38aa60e47ce263039
This adds lowering for f32 values using the vmov.f16, which zeroes the
top bits whilst setting the lower bits to a pattern. This range of
values does not often come up, except where a f16 constant value has
been converted to a f32.
Differential Revision: https://reviews.llvm.org/D87790
SelectionDAGBuilder was inconsistently mangling values based on ABI
Calling Conventions when getting them through copyFromRegs in
SelectionDAGBuilder, causing duplicate value type convertions for
function arguments. The checking for the mangling requirement was based
on the value's originating instruction and was performed outside of, and
inspite of, the regular Calling Convention Lowering.
The issue could be observed in a scenario such as:
```
%arg1 = load half, half* %const, align 2
%arg2 = call fastcc half @someFunc()
call fastcc void @otherFunc(half %arg1, half %arg2)
; Here, %arg2 was incorrectly mangled twice, as the CallConv data from
; the call to @someFunc() was taken into consideration for the check
; when getting the value for processing the call to @otherFunc(...),
; after the proper convertion had taken place when lowering the return
; value of the first call.
```
This patch fixes the issue by disregarding the Calling Convention
information for such copyFromRegs, making sure the ABI mangling is
properly contanined in the Calling Convention Lowering.
This fixes Bugzilla #47454.
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D87844
This adds simple constant folding for VMOVrh, to constant fold fp16
constants to integer values. It can help especially with soft calling
conventions, but some of the results are not optimal as we end up
loading using a vldr. This will be improved in a follow up patch.
Differential Revision: https://reviews.llvm.org/D87789
This changes the order of output sections and the output assembly, but
is otherwise NFC.
It simplifies the TLOF interface by removing two COFF-only methods.
This rewrites big parts of the fast register allocator. The basic
strategy of doing block-local allocation hasn't changed but I tweaked
several details:
Track register state on register units instead of physical
registers. This simplifies and speeds up handling of register aliases.
Process basic blocks in reverse order: Definitions are known to end
register livetimes when walking backwards (contrary when walking
forward then uses may or may not be a kill so we need heuristics).
Check register mask operands (calls) instead of conservatively
assuming everything is clobbered. Enhance heuristics to detect
killing uses: In case of a small number of defs/uses check if they are
all in the same basic block and if so the last one is a killing use.
Enhance heuristic for copy-coalescing through hinting: We check the
first k defs of a register for COPYs rather than relying on there just
being a single definition. When testing this on the full llvm
test-suite including SPEC externals I measured:
average 5.1% reduction in code size for X86, 4.9% reduction in code on
aarch64. (ranging between 0% and 20% depending on the test) 0.5%
faster compiletime (some analysis suggests the pass is slightly slower
than before, but we more than make up for it because later passes are
faster with the reduced instruction count)
Also adds a few testcases that were broken without this patch, in
particular bug 47278.
Patch mostly by Matthias Braun
The regressions this caused should be fixed when
https://reviews.llvm.org/D52010 is applied.
This reverts commit a21387c65470417c58021f8d3194a4510bb64f46.
This seems to have caused incorrect register allocation in some cases,
breaking tests in the Zig standard library (PR47278).
As discussed on the bug, revert back to green for now.
> Record internal state based on register units. This is often more
> efficient as there are typically fewer register units to update
> compared to iterating over all the aliases of a register.
>
> Original patch by Matthias Braun, but I've been rebasing and fixing it
> for almost 2 years and fixed a few bugs causing intermediate failures
> to make this patch independent of the changes in
> https://reviews.llvm.org/D52010.
This reverts commit 66251f7e1de79a7c1620659b7f58352b8c8e892e, and
follow-ups 931a68f26b9a3de853807ffad7b2cd0a2dd30922
and 0671a4c5087d40450603d9d26cf239f1a8b1367e. It also adjust some
test expectations.
This adds SoftenFloatRes, PromoteFloatRes and SoftPromoteHalfRes
legalizations for VECREDUCE, to fill the remaining hole in the SDAG
legalization. These legalizations simply expand the reduction and
let it be recursively legalized. For the PromoteFloatRes case at
least it is possible to do better than that, but it's pretty tricky
(because we need to consider the interaction of three different
vector legalizations and the type promotion) and probably not
really worthwhile.
I haven't added ExpandFloatRes support, as I am not familiar with
ppc_fp128.
Differential Revision: https://reviews.llvm.org/D87569
Similar to D87415, this folds the various float min/max opcodes
with a constant INF or -INF operand, or FLT_MAX / -FLT_MAX operand
if the ninf flag is set. Some of the folds are only possible under
nnan.
The fminnum(X, INF) with nnan and fmaxnum(X, -INF) with nnan cases
are needed to improve the VECREDUCE_FMIN/FMAX lowerings on X86,
the rest is here for the sake of completeness.
Differential Revision: https://reviews.llvm.org/D87571
LLVM will canonicalize conditional selectors to a different pattern than the old code that was used.
This is updating the function to match the new expected patterns and select SSAT or USAT when successful.
Tests have also been updated to use the new patterns.
Differential Review: https://reviews.llvm.org/D87379
Treating an SoImm offset as a multiple of 4 between -1020 and 1020
mis-handles the second of a pair of 16-bit constants where the offset is a multiple of 2 but not a multiple of 4,
leading to an LLVM ERROR: out of range pc-relative fixup value
For 32-bit and larger (64-bit) constants, continue to treat an SoImm offset as a multiple of 4 between -1020 and 1020.
For smaller (16-bit) constants, treat an SoImm offset as a multiple of 1 between -255 and 255.
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D86949
Clang emits (and (ctpop X), 1) for __builtin_parity. If ctpop
isn't natively supported by the target, this leads to poor codegen
due to the expansion of ctpop being more complex than what is needed
for parity.
This adds a DAG combine to convert the pattern to ISD::PARITY
before operation legalization. Type legalization is updated
to handled Expanding and Promoting this operation. If after type
legalization, CTPOP is supported for this type, LegalizeDAG will
turn it back into CTPOP+AND. Otherwise LegalizeDAG will emit a
series of shifts and xors followed by an AND with 1.
I've avoided vectors in this patch to avoid more legalization
complexity for this patch.
X86 previously had a custom DAG combiner for this. This is now
moved to Custom lowering for the new opcode. There is a minor
regression in vector-reduce-xor-bool.ll, but a follow up patch
can easily fix that.
Fixes PR47433
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D87209
fminnum(X, NaN) is X, fminimum(X, NaN) is NaN. This mirrors the
behavior of existing InstSimplify folds.
This is expected to improve the reduction lowerings in D87391,
which use NaN as a neutral element.
Differential Revision: https://reviews.llvm.org/D87415
In getMemcpyLoadsAndStores(), a memcpy where the source is a zero constant is expanded to a MemOp::Set instead of a MemOp::Copy, even when the memcpy is volatile.
This is incorrect.
The fix is to add a check for volatile, and expand to MemOp::Copy in the volatile case.
Reviewed By: chill
Differential Revision: https://reviews.llvm.org/D87134
This patch implements the foldMemoryOperand hook in Thumb1InstrInfo,
allowing tBLXr and a spilled function address to be combined back into a
tBL. This can help with codesize at Oz, especailly in the tinycrypt
library.
Differential Revision: https://reviews.llvm.org/D79785
Skip this for now, to avoid a backend crash in:
UNREACHABLE executed at llvm/lib/Target/ARM/ARMISelLowering.cpp:13412
This should fix PR45824.
Differential Revision: https://reviews.llvm.org/D86784
The global-isel feature has been required for a long time and was
removed in c9455d3c579292e7ae5b7559ad0302d459e69a95, so this was
causing all tests to be skipped.
This patch adjusts the following ARM/AArch64 LLVM IR intrinsics:
- neon_bfmmla
- neon_bfmlalb
- neon_bfmlalt
so that they take and return bf16 and float types. Previously these
intrinsics used <8 x i8> and <4 x i8> vectors (a rudiment from
implementation lacking bf16 IR type).
The neon_vbfdot[q] intrinsics are adjusted similarly. This change
required some additional selection patterns for vbfdot itself and
also for vector shuffles (in a previous patch) because of SelectionDAG
transformations kicking in and mangling the original code.
This patch makes the generated IR cleaner (less useless bitcasts are
produced), but it does not affect the final assembly.
Reviewed By: dmgreen
Differential Revision: https://reviews.llvm.org/D86146
When joining the legal parts of vector arguments into its original value
during the lower of Formal Arguments in SelectionDAGBuilder, the Calling
Convention information was not being propagated for the handling of each
individual parts. The same did not happen when lowering calls, causing a
mismatch.
This patch fixes the issue by properly propagating the Calling
Convention details.
This fixes Bugzilla #47001.
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D86715
Enable default outlining when the function has the minsize attribute
and we're targeting an m-class core.
Differential Revision: https://reviews.llvm.org/D82951
Fix the ARM backend's analyzeBranch so it doesn't ignore predicated
return instructions, and make the MachineVerifier rule more strict.
Differential Revision: https://reviews.llvm.org/D40061
Use the stack to save and restore the link register when there is no
available register to do it.
Differential Revision: https://reviews.llvm.org/D76069
The ARM backend breaks some specific immediates to two parts
in binary operations. And this patch adds more tests
for that.
Reviewed By: samparker
Differential Revision: https://reviews.llvm.org/D84100
