Because we've canonicalised on using LD1/ST1, every time we do a bitcast
between vector types we must do an equivalent lane reversal.
Consider a simple memory load followed by a bitconvert then a store.
v0 = load v2i32
v1 = BITCAST v2i32 v0 to v4i16
store v4i16 v2
In big endian mode every memory access has an implicit byte swap. LDR and
STR do a 64-bit byte swap, whereas LD1/ST1 do a byte swap per lane - that
is, they treat the vector as a sequence of elements to be byte-swapped.
The two pairs of instructions are fundamentally incompatible. We've decided
to use LD1/ST1 only to simplify compiler implementation.
LD1/ST1 perform the equivalent of a sequence of LDR/STR + REV. This makes
the original code sequence: v0 = load v2i32
v1 = REV v2i32 (implicit)
v2 = BITCAST v2i32 v1 to v4i16
v3 = REV v4i16 v2 (implicit)
store v4i16 v3
But this is now broken - the value stored is different to the value loaded
due to lane reordering. To fix this, on every BITCAST we must perform two
other REVs:
v0 = load v2i32
v1 = REV v2i32 (implicit)
v2 = REV v2i32
v3 = BITCAST v2i32 v2 to v4i16
v4 = REV v4i16
v5 = REV v4i16 v4 (implicit)
store v4i16 v5
This means an extra two instructions, but actually in most cases the two REV
instructions can be combined into one. For example:
(REV64_2s (REV64_4h X)) === (REV32_4h X)
There is also no 128-bit REV instruction. This must be synthesized with an
EXT instruction.
Most bitconverts require some sort of conversion. The only exceptions are:
a) Identity conversions - vNfX <-> vNiX
b) Single-lane-to-scalar - v1fX <-> fX or v1iX <-> iX
Even though there are hundreds of changed lines, I have a fairly high confidence
that they are somewhat correct. The changes to add two REV instructions per
bitcast were pretty mechanical, and once I'd done that I threw the resulting
.td at a script I wrote which combined the two REVs together (and added
an EXT instruction, for f128) based on an instruction description I gave it.
This was much less prone to error than doing it all manually, plus my brain
would not just have melted but would have vapourised.
llvm-svn: 208194
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.
llvm-svn: 208192
This is a third patch of patch series that improves MergeFunctions
performance time from O(N*N) to O(N*log(N)).
This patch description:
Being comparing functions we need to compare values we meet at left and
right sides.
Its easy to sort things out for external values. It just should be
the same value at left and right.
But for local values (those were introduced inside function body)
we have to ensure they were introduced at exactly the same place,
and plays the same role.
In short, patch introduces values serial numbering and comparison routine.
The last one compares two values by their serial numbers.
llvm-svn: 208189
In cases where a struct must, according to the AAPCS, not be split between
general purpose and floating point registers, we use
ABIArgInfo::getExpandWithPadding to add the padding arguments. However,
ExpandWithPadding does not work if the struct contains bitfields, so we
instead must use ABIArgInfo::getDirect.
llvm-svn: 208185
Summary:
The overall idea is to chop the Predicates list into subsets that are
usually overridden independently. This allows subclasses to partially
override the predicates of their superclasses without having to re-add all
the existing predicates.
This patch starts the process by moving HasStdEnc into a new
EncodingPredicates list and almost everything else into
AdditionalPredicates.
It has revealed a couple likely bugs where 'let Predicates' has removed
the HasStdEnc predicate.
No functional change (confirmed by diffing tablegen-erated files).
Depends on D3549, D3506
Reviewers: vmedic
Differential Revision: http://reviews.llvm.org/D3550
llvm-svn: 208184
Summary:
It concatenates two or more lists. In addition to the !strconcat semantics
the lists must have the same element type.
My overall aim is to make it easy to append to Instruction.Predicates
rather than override it. This can be done by concatenating lists passed as
arguments, or by concatenating lists passed in additional fields.
Reviewers: dsanders
Reviewed By: dsanders
Subscribers: hfinkel, llvm-commits
Differential Revision: http://reviews.llvm.org/D3506
llvm-svn: 208183
Summary:
This will make it easier to prove that a more complicated change in the
following commit is non-functional.
No functional change.
Depends on D3506
Reviewers: vmedic
Reviewed By: vmedic
Differential Revision: http://reviews.llvm.org/D3549
llvm-svn: 208179
1) Fix for printing debug locations for absolute paths.
2) Location printing is moved into public method DebugLoc::print() to avoid re-inventing the wheel.
Differential Revision: http://reviews.llvm.org/D3513
llvm-svn: 208177
So that JS functions can also be merged into a single line.
Before:
var func = function() {
return 1;
};
After:
var func = function() { return 1; };
llvm-svn: 208176
Summary:
Also displays a hint to use -header-filter='.*' in case any warnings
are in non-user code. This will help discoverability of this option.
Reviewers: klimek
Reviewed By: klimek
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D3621
llvm-svn: 208174
O(N*log(N)). The idea is to introduce total ordering among functions set.
It allows to build binary tree and perform function look-up procedure in O(log(N)) time.
This patch description:
Introduced total ordering among constants implemented in cmpConstants method.
Method performs lexicographical comparison between constants represented as
hypothetical numbers of next format:
<bitcastability-trait><raw-bit-contents>
Please, read cmpConstants declaration comments for more details.
llvm-svn: 208173
Don't bother with keeping the old support for x86_64 in 6.99.23+, just
use a single range. Update test cases for the always-on --eh-frame-hdr.
llvm-svn: 208170
This field is used for a list of variables to ensure they are not lost
during optimization (they're only included when optimizations are
enabled).
llvm-svn: 208159
interface methods isCOFF().
The '-coff' command line option has been removed. It was not used in any
test cases.
The patch reviewed by Michael Spencer.
llvm-svn: 208157
This applies to __attribute__((pure)) as well, but 'const' is more interesting
because many of our builtins are marked 'const'.
PR19661
llvm-svn: 208154
Mark up additional instructions which are part of the function prologue as
MachineFrameSetup. These instructions are part of the function prologue,
emitted by the PEI pass to setup the stack for use in the activating frame.
llvm-svn: 208153
The ARM::BLX instruction is an ARM mode instruction. The Windows on ARM target
is limited to Thumb instructions. Correctly use the thumb mode tBLXr
instruction. This would manifest as an errant write into the object file as the
instruction is 4-bytes in length rather than 2. The result would be a corrupted
object file that would eventually result in an executable that would crash at
runtime.
llvm-svn: 208152
whether the definition of the template is visible rather than checking whether
the instantiated definition happens to be in an imported module.
llvm-svn: 208150
If the source files referenced by a gcno file are missing, gcov
outputs a coverage file where every line is simply /*EOF*/. This also
occurs for lines in the coverage that are past the end of a file that
is found.
This change mimics gcov.
llvm-svn: 208149
In gcov, there's a -n/--no-output option, which disables the writing
of any .gcov files, so that it emits only the summary info on stdout.
This implements the same behaviour in llvm-cov.
llvm-svn: 208148
Evgeniy Stepanov