Previously this pass was using up to 5% compile time in some cases which
is a bit much for what it is doing. The pass featured a full blown
data-flow analysis which in the default configuration was restricted to a
single block.
This rewrites the pass under the assumption that we only ever work on a
single block. This is done in a single pass maintaining a state machine
per general purpose register to catch LOH patterns.
Differential Revision: https://reviews.llvm.org/D27329
llvm-svn: 288561
Summary: Implement custom lowering of SHL_PARTS to enable lowering of left shift with larger than 32-bit shifts.
Reviewers: eliben, majnemer
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D27232
llvm-svn: 288541
Add assembler support for instructions manipulating the FPC.
Also add codegen support via the GCC compatibility builtins:
__builtin_s390_sfpc
__builtin_s390_efpc
llvm-svn: 288525
Summary:
When X = 0 and Y = inf, the original code produces inf, but the transformed
code produces nan. So this transform (and its relatives) should only be
used when the no-infs-fp-math flag is explicitly enabled.
Also disable the transform using fmad (intermediate rounding) when unsafe-math
is not enabled, since it can reduce the precision of the result; consider this
example with binary floating point numbers with two bits of mantissa:
x = 1.01
y = 111
x * (y + 1) = 1.01 * 1000 = 1010 (this is the exact result; no rounding occurs at any step)
x * y + x = 1000.11 + 1.01 =r 1000 + 1.01 = 1001.01 =r 1000 (with rounding towards zero)
The example relies on rounding towards zero at least in the second step.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=98578
Reviewers: RKSimon, tstellarAMD, spatel, arsenm
Subscribers: wdng, llvm-commits
Differential Revision: https://reviews.llvm.org/D26602
llvm-svn: 288506
Since the spill is for the whole wave, these
don't have the swizzling problems that vector stores do
and a single 4-byte allocation is enough to spill a 64 element
register. This should reduce the number of spill instructions and
put all the spills for a register in the same cacheline.
This should save allocated private size, but for now it doesn't.
The extra slots are allocated for each component, but never used
because the frame layout is essentially finalized before frame
indices are replaced. For always using the scalar store path,
this should probably be moved into processFunctionBeforeFrameFinalized.
llvm-svn: 288445
This prevents erratic stepping behavior as well as incorrect source attribution
for sample profiling.
Reviewers: dblakie
Subscribers: llvm-commit
Differential Revision: https://reviews.llvm.org/D27290
llvm-svn: 288442
Summary:
Make AArch64InstrInfo::foldMemoryOperandImpl more general by folding all
full COPYs between register classes of the same size that are either
spilled or refilled.
Reviewers: MatzeB, qcolombet
Subscribers: aemerson, rengolin, mcrosier, llvm-commits
Differential Revision: https://reviews.llvm.org/D27271
llvm-svn: 288439
Summary:
This patch fixes comparison of 64-bit atomic with its expected value in CMP_SWAP_64 expansion.
Currently, the low words are compared with CMP, while the high words are compared with SBC. SBC expects the carry flag to be set if CMP detects a difference. CMP might leave the carry unset for unequal arguments though if the first one is >= than the second. This might cause the comparison logic to detect false equality.
Example of the broken C++ code:
```
std::atomic<long long> at(2);
long long ll = 1;
std::atomic_compare_exchange_strong(&at, &ll, 3);
```
Even though the atomic `at` and the expected value `ll` are not equal and `atomic_compare_exchange_strong` returns `false`, `at` is changed to 3.
The patch replaces SBC with CMPEQ.
Reviewers: t.p.northover
Subscribers: aemerson, rengolin, llvm-commits, asl
Differential Revision: https://reviews.llvm.org/D27315
llvm-svn: 288433
The coalescer eliminates copies from reserved registers of the form:
%vregX = COPY %rY
in the case where %rY is a reserved register. However this turns out to
be invalid if only some of the subregisters are reserved (see also
https://reviews.llvm.org/D26648).
Differential Revision: https://reviews.llvm.org/D26687
llvm-svn: 288428
This change fixes a regression in r279537 and
makes getRawSubclassData behave like r279536.
Without this change, the fp128-g.ll test case will have an
infinite loop involving SoftenFloatRes_LOAD.
Differential Revision: http://reviews.llvm.org/D26942
llvm-svn: 288420
This time the issue is fortunately just a simple mistake rather than a horrible
design spectre. I thought SUBS/SBCS provided sufficient NZCV flags for
comparing two 64-bit values, but they don't.
The fix is slightly clunkier in AArch64 because we can't use conditional
execution to emit a pair of CMPs. Traditionally an "icmp ne i128" would map to
an EOR/EOR/ORR/CBNZ, but that uses more registers so it's easier to go with a
CSET/CINC/CBNZ combination. Slightly less efficient, but this is -O0 anyway.
Thanks to Anton Korobeynikov for pointing out the issue.
llvm-svn: 288418
Support a new assembler directive, .import_global, to declare imported
global variables (i.e. those with external linkage and no
initializer). The linker turns these into wasm imports.
Patch by Jacob Gravelle
Differential Revision: https://reviews.llvm.org/D26875
llvm-svn: 288296
Choosing a "cfi" name makes the intend a bit clearer in an assembly dump
and more importantly the assembly dumps are slightly more stable as the
numbers don't move around anymore when unrelated code calls
createTempSymbol() more or less often.
As they are temp labels the name doesn't influence the generated object
code.
Differential Revision: https://reviews.llvm.org/D27244
llvm-svn: 288290
The LLDB tests are now ready for this patch.
DWARF specifies that "line 0" really means "no appropriate source
location" in the line table. Use this for branch targets and some
other cases that have no specified source location, to prevent
inheriting unfortunate line numbers from physically preceding
instructions (which might be from completely unrelated source).
Differential Revision: http://reviews.llvm.org/D24180
llvm-svn: 288283
Summary:
When computing useful bits for a BFM instruction, we need
to take into consideration the case where both operands
of the BFM are equal and provide data that we need to track.
Not doing this can cause us to miss useful bits.
Fixes PR31138 (https://llvm.org/bugs/show_bug.cgi?id=31138)
Reviewers: t.p.northover, jmolloy
Subscribers: evandro, gberry, srhines, pirama, mcrosier, aemerson, llvm-commits, rengolin
Differential Revision: https://reviews.llvm.org/D27130
llvm-svn: 288253
Initial support for target shuffle constant folding in cases where all shuffle inputs are constant. We may be able to relax this and merge shuffles with only some constant inputs in the future.
I've added the helper function getTargetConstantBitsFromNode (based off a similar function in X86ShuffleDecodeConstantPool.cpp) that could be reused for other cases requiring constant vector extraction.
Differential Revision: https://reviews.llvm.org/D27220
llvm-svn: 288250
Summary: Previously 0 and -1 was matched via tablegen rules. But this could cause problems where a physical register was being used where a virtual register was expected (seen in optimizeSelect and TwoAddressInstructionPass). Instead follow AArch64 and match in DAGToDAGISel.
Reviewers: eliben, majnemer
Subscribers: llvm-commits, aemerson
Differential Revision: https://reviews.llvm.org/D27171
llvm-svn: 288215
This commit caused some miscompiles that did not show up on any of the bots.
Reverting until we can investigate the cause of those failures.
llvm-svn: 288214
DWARF specifies that "line 0" really means "no appropriate source
location" in the line table. Use this for branch targets and some
other cases that have no specified source location, to prevent
inheriting unfortunate line numbers from physically preceding
instructions (which might be from completely unrelated source).
Differential Revision: http://reviews.llvm.org/D24180
llvm-svn: 288212
