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Commit Graph

112 Commits

Author SHA1 Message Date
Geoff Berry
5377924081 [AArch64] Generate csinv instruction more often
Reviewers: t.p.northover, jmolloy

Subscribers: aemerson, rengolin, mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D17546

llvm-svn: 261675
2016-02-23 19:34:13 +00:00
Tim Northover
1dabed8e29 AArch64: match correct order in subtraction pattern.
The accumulator in multiply-and-subtract instructions is actually subtracted
*from* so these patterns were computing the wrong value.

llvm-svn: 260131
2016-02-08 19:33:18 +00:00
Silviu Baranga
22ab3adc5c [AArch64] Multiply extended 32-bit ints with `[U|S]MADDL'
During instruction selection, the AArch64 backend can recognise the
following pattern and generate an [U|S]MADDL instruction, i.e. a
multiply of two 32-bit operands with a 64-bit result:

(mul (sext i32), (sext i32))
However, when one of the operands is constant, the sign extension
gets folded into the constant in SelectionDAG::getNode(). This means
that the instruction selection sees this:

(mul (sext i32), i64)
...which doesn't match the pattern. Sign-extension and 64-bit
multiply instructions are generated, which are slower than one 32-bit
multiply.

Add a pattern to match this and generate the correct instruction, for
both signed and unsigned multiplies.

Patch by Chris Diamand!

llvm-svn: 259800
2016-02-04 16:47:09 +00:00
Ahmed Bougacha
94c2d7d066 [AArch64] Fix i64 nontemporal high-half extraction.
Since we only have pair - not single - nontemporal store instructions,
we have to extract the high part into a separate register to be able
to use them.

When the initial nontemporal codegen support was added, I wrote the
extract using the nonsensical UBFX [0,32[.
Use the correct LSR form instead.

llvm-svn: 259134
2016-01-29 01:08:41 +00:00
Matthew Simpson
f8053302ae [AArch64] Add additional extract-extend patterns for smov
This patch adds to the target description two additional patterns for matching
extract-extend operations to SMOV. The patterns catch the v16i8-to-i64 and
v8i16-to-i64 cases. The existing patterns miss these cases because the
extracted elements must first be legalized to i32, resulting in any_extend
nodes.

This was originally implemented as a DAG combine (r255895), but was reverted
due to failing out-of-tree tests.

llvm-svn: 256176
2015-12-21 18:31:25 +00:00
Hal Finkel
e58db13c29 Revert r248483, r242546, r242545, and r242409 - absdiff intrinsics
After much discussion, ending here:

  http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20151123/315620.html

it has been decided that, instead of having the vectorizer directly generate
special absdiff and horizontal-add intrinsics, we'll recognize the relevant
reduction patterns during CodeGen. Accordingly, these intrinsics are not needed
(the operations they represent can be pattern matched, as is already done in
some backends). Thus, we're backing these out in favor of the current
development work.

r248483 - Codegen: Fix llvm.*absdiff semantic.
r242546 - [ARM] Use [SU]ABSDIFF nodes instead of intrinsics for VABD/VABA
r242545 - [AArch64] Use [SU]ABSDIFF nodes instead of intrinsics for ABD/ABA
r242409 - [Codegen] Add intrinsics 'absdiff' and corresponding SDNodes for absolute difference operation

llvm-svn: 255387
2015-12-11 23:11:52 +00:00
Matt Arsenault
fad94dae85 Start replacing vector_extract/vector_insert with extractelt/insertelt
These are redundant pairs of nodes defined for
INSERT_VECTOR_ELEMENT/EXTRACT_VECTOR_ELEMENT.
insertelement/extractelement are slightly closer to the corresponding
C++ node name, and has stricter type checking so prefer it.

Update targets to only use these nodes where it is trivial to do so.
AArch64, ARM, and Mips all have various type errors on simple replacement,
so they will need work to fix.

Example from AArch64:

def : Pat<(sext_inreg (vector_extract (v16i8 V128:$Rn), VectorIndexB:$idx), i8),
          (i32 (SMOVvi8to32 V128:$Rn, VectorIndexB:$idx))>;

Which is trying to do sext_inreg i8, i8.

llvm-svn: 255359
2015-12-11 19:20:16 +00:00
Pirama Arumuga Nainar
43afcbe1a1 Define selection for v4f16, v8f16 scalar_to_vector
Summary:
This fixes failure when trying to select
    insertelement <4 x half> undef, half %a, i64 0
which gets transformed to a scalar_to_vector node.

The accompanying v4 and v8 tests fail instruction selection without this
patch.

Reviewers: ab, jmolloy

Subscribers: srhines, llvm-commits

Differential Revision: http://reviews.llvm.org/D15322

llvm-svn: 255072
2015-12-08 23:07:06 +00:00
Oliver Stannard
421ddae8b6 [AArch64] Add ARMv8.2-A FP16 vector instructions
ARMv8.2-A adds 16-bit floating point versions of all existing SIMD
floating-point instructions. This is an optional extension, so all of
these instructions require the FeatureFullFP16 subtarget feature.

Note that VFP without SIMD is not a valid combination for any version of
ARMv8-A, but I have ensured that these instructions all depend on both
FeatureNEON and FeatureFullFP16 for consistency.

The ".2h" vector type specifier is now legal (for the scalar pairwise
reduction instructions), so some unrelated tests have been modified as
different error messages are emitted. This is not a problem as the
invalid operands are still caught.

llvm-svn: 255010
2015-12-08 12:16:10 +00:00
Oliver Stannard
03049a3fcc [AArch64] Add ARMv8.2-A Statistical Profiling Extension
The Statistical Profiling Extension is an optional extension to
ARMv8.2-A. Since it is an optional extension, I have added the
FeatureSPE subtarget feature to control it. The assembler-visible parts
of this extension are the new "psb csync" instruction, which is
equivalent to "hint #17", and a number of system registers.

Differential Revision: http://reviews.llvm.org/D15021

llvm-svn: 254401
2015-12-01 10:48:51 +00:00
Oliver Stannard
55e6d9804d [AArch64] Add subtarget features for ARMv8.2-A
This adds subtarget features for ARMv8.2-A, which builds on (and
requires the features from) ARMv8.1-A. Most assembler-visible features
of ARMv8.2-A are system instructions, and are all required parts of the
architecture, so just depend on the HasV8_2aOps subtarget feature. There
is also one large, optional feature, which adds 16-bit floating point
versions of all existing floating-point instructions (VFP and SIMD),
this is represented by the FeatureFullFP16 subtarget feature.

Differential Revision: http://reviews.llvm.org/D15013

llvm-svn: 254154
2015-11-26 15:23:32 +00:00
Charlie Turner
4ca51cd513 [AArch64] Add UABDL patterns for log2 shuffle.
Summary:
This matches the sum-of-absdiff patterns emitted by the vectoriser using log2 shuffles.

Relies on D14207 to be able to match the `extract_subvector(..., 0)`

Reviewers: t.p.northover, jmolloy

Subscribers: aemerson, llvm-commits, rengolin

Differential Revision: http://reviews.llvm.org/D14208

llvm-svn: 252465
2015-11-09 13:10:52 +00:00
Charlie Turner
fc688fc567 [AArch64] Handle extract_subvector(..., 0) in ISel.
Summary:
Lowering this pattern early to an `EXTRACT_SUBREG` was making it impossible to match larger patterns in tblgen that use `extract_subvector(..., 0)` as part of the their input pattern.

It seems like there will exist somewhere a better way of specifying this pattern over all relevant register value types, but I didn't manage to find it.

Reviewers: t.p.northover, jmolloy

Subscribers: aemerson, llvm-commits, rengolin

Differential Revision: http://reviews.llvm.org/D14207

llvm-svn: 252464
2015-11-09 12:45:11 +00:00
Alexandros Lamprineas
7f36d7f86a [MC layer][AArch64] llvm-mc accepts 4-bit immediate values for
"msr pan, #imm", while only 1-bit immediate values should be valid.
Changed encoding and decoding for msr pstate instructions.

Differential Revision: http://reviews.llvm.org/D13011

llvm-svn: 249313
2015-10-05 13:42:31 +00:00
Stephen Canon
7777a204e2 Don't raise inexact when lowering ceil, floor, round, trunc.
The C standard has historically not specified whether or not these functions should raise the inexact flag. Traditionally on Darwin, these functions *did* raise inexact, and the llvm lowerings followed that conventions. n1778 (C bindings for IEEE-754 (2008)) clarifies that these functions should not set inexact. This patch brings the lowerings for arm64 and x86 in line with the newly specified behavior.  This also lets us fold some logic into TD patterns, which is nice.

Differential Revision: http://reviews.llvm.org/D12969

llvm-svn: 248266
2015-09-22 11:43:17 +00:00
Ahmed Bougacha
5f7023b12c [AArch64] Support selecting STNP.
We could go through the load/store optimizer and match STNP where
we would have matched a nontemporal-annotated STP, but that's not
reliable enough, as an opportunistic optimization.
Insetad, we can guarantee emitting STNP, by matching them at ISel.
Since there are no single-input nontemporal stores, we have to
resort to some high-bits-extracting trickery to generate an STNP
from a plain store.

Also, we need to support another, LDP/STP-specific addressing mode,
base + signed scaled 7-bit immediate offset.
For now, only match the base. Let's make it smart separately.

Part of PR24086.

llvm-svn: 247231
2015-09-10 01:42:28 +00:00
Ahmed Bougacha
b87a61b44f [AArch64] Lower READCYCLECOUNTER using MRS PMCCTNR_EL0.
This matches the ARM behavior. In both cases, the register is part
of the optional Performance Monitors extension, so, add the feature,
and enable it for the A-class processors we support.

Differential Revision: http://reviews.llvm.org/D12425

llvm-svn: 246555
2015-09-01 16:23:45 +00:00
Silviu Baranga
313f33a95b [AArch64] Unify the integer min/max vector selection patterns with the intrinsic ones
Summary:
This change lowers the aarch64 integer vector min/max intrinsic nodes to
generic min/max nodes and replaces the intrinsic selection patterns with
the generic ones.

There should already be testing in place for this, so no further tests
were added.

Reviewers: jmolloy

Subscribers: aemerson, llvm-commits, rengolin

Differential Revision: http://reviews.llvm.org/D12276

llvm-svn: 246030
2015-08-26 11:11:14 +00:00
Ahmed Bougacha
693e93889e [AArch64] Fix FMLS scalar-indexed-from-2s-after-neg patterns.
We canonicalize V64 vectors to V128 through insert_subvector: the other
FMLA/FMLS/FMUL/FMULX patterns match that already, but this one doesn't,
so we'd fail to match fmls and generate fneg+fmla instead.
The vector equivalents are already tested and functional.

llvm-svn: 245107
2015-08-14 22:06:05 +00:00
James Molloy
e0929cde28 [AArch64] Match fminnum/fmaxnum for vector fminnm/fmaxnm instead of an intrinsic.
Lower Intrinsic::aarch64_neon_fmin/fmax to fminnum/fmannum and match that instead. Minimal functional change:

  - Extra tests added because coverage of scalar fminnm/fmaxnm instructions was nonexistant.
  - f16 test updated because now we actually generate scalar fminnm/fmaxnm we no longer need to bail out to a libcall!

llvm-svn: 244595
2015-08-11 12:06:37 +00:00
James Molloy
655902e549 [AArch64] Replace the custom AArch64ISD::FMIN/MAX nodes with ISD::FMINNAN/MAXNAN
NFCI. This just removes custom ISDNodes that are no longer needed.

llvm-svn: 244594
2015-08-11 12:06:33 +00:00
Ahmed Bougacha
24c0f16401 [AArch64] Rename FP formats to be more consistent. NFC.
Some are named "FP", others "SD", others still "FP*SD".
Rename all this to just use "FP", which, except for conversions
(which don't use this format naming scheme), implies "SD" anyway.

llvm-svn: 243936
2015-08-04 01:38:08 +00:00
Geoff Berry
6d2bb54f01 [AArch64] Favor extended reg patterns for sub
Summary:
Favor the extended reg patterns over the shifted reg patterns that match
only the operand shift and not the full sign/zero extend and shift.

Reviewers: jmolloy, t.p.northover

Subscribers: mcrosier, aemerson, llvm-commits, rengolin

Differential Revision: http://reviews.llvm.org/D11569

llvm-svn: 243753
2015-07-31 15:55:54 +00:00
Tim Northover
ab2c0f5890 AArch64: use 32-bit MOV rather than UBFX to truncate registers.
It's potentially more efficient on Cyclone, and from the optimization guides &
schedulers looks like it has no effect on Cortex-A53 or A57. In general you'd
expect a MOV to be about the most efficient instruction with its semantics,
even though the official "UXTW" alias is really a UBFX.

llvm-svn: 243576
2015-07-29 21:34:32 +00:00
Chad Rosier
69ba87e018 [AArch64] Change EON pattern to match more often.
Phabricator: http://reviews.llvm.org/D11359
Patch by Geoff Berry <gberry@codeaurora.org>

llvm-svn: 242694
2015-07-20 18:42:27 +00:00
James Molloy
c5d3ffedd0 [AArch64] Use [SU]ABSDIFF nodes instead of intrinsics for ABD/ABA
No functional change, but it preps codegen for the future when SABSDIFF
will start getting generated in anger.

llvm-svn: 242545
2015-07-17 17:10:45 +00:00
Matthias Braun
0a9f87ba79 AArch64: Implement conditional compare sequence matching.
This is a new iteration of the reverted r238793 /
http://reviews.llvm.org/D8232 which wrongly assumed that any and/or
trees can be represented by conditional compare sequences, however there
are some restrictions to that. This version fixes this and adds comments
that explain exactly what types of and/or trees can actually be
implemented as conditional compare sequences.

Related to http://llvm.org/PR20927, rdar://18326194

Differential Revision: http://reviews.llvm.org/D10579

llvm-svn: 242436
2015-07-16 20:02:37 +00:00
Tim Northover
9509e14e0a AArch64: add rev64 alias for 64-bit rev instruction.
It could be useful to assembly programmers and makes the permitted variants a
little more uniform.

llvm-svn: 242164
2015-07-14 17:07:29 +00:00
Arnold Schwaighofer
6d6b413fa3 Add more nvcasts
Tim Northover has told me that they can occur when the compiler cleverly
constructs constants - as demonstrated in the test case.

rdar://21703486

llvm-svn: 241641
2015-07-07 23:13:18 +00:00
Arnold Schwaighofer
a112326960 Add a pattern for a nvcast from v2f64 -> v4f32
Since the NvCast is generated by the selection process the concerns about
endianess and bit reversal don't apply.

rdar://21703486

llvm-svn: 241611
2015-07-07 18:31:55 +00:00
Arnaud A. de Grandmaison
9f66584696 [AArch64] Implement add/adds/sub/subs/cmp/cmn with negative immediate aliases
This patch teaches the AsmParser to accept add/adds/sub/subs/cmp/cmn
with a negative immediate operand and convert them as shown:

  add  Rd, Rn, -imm -> sub  Rd, Rn, imm
  sub  Rd, Rn, -imm -> add  Rd, Rn, imm
  adds Rd, Rn, -imm -> subs Rd, Rn, imm
  subs Rd, Rn, -imm -> adds Rd, Rn, imm
  cmp  Rn, -imm     -> cmn  Rn, imm
  cmn  Rn, -imm     -> cmp  Rn, imm

Those instructions are an alternate syntax available to assembly coders,
and are needed in order to support code already compiling with some other
assemblers (gas). They are documented in the "ARMv8 Instruction Set
Overview", in the "Arithmetic (immediate)" section. This makes llvm-mc
a programmer-friendly assembler !

This also fixes PR20978: "Assembly handling of adding negative numbers
not as smart as gas".

llvm-svn: 241166
2015-07-01 15:05:58 +00:00
Matthias Braun
53746a75e4 Revert "AArch64: Use CMP;CCMP sequences for and/or/setcc trees."
The patch triggers a miscompile on SPEC 2006 403.gcc with the (ref)
200.i and scilab.i inputs. I opened PR23866 to track analysis of this.

This reverts commit r238793.

llvm-svn: 239880
2015-06-17 04:02:32 +00:00
Tim Northover
0f51120873 AArch64: fix typo in SMIN far atomics and add tests
llvm-svn: 238858
2015-06-02 18:37:20 +00:00
Vladimir Sukharev
42d76a2a46 [AArch64] Add v8.1a atomic instructions
Patch by: Tom Coxon

Reviewers: t.p.northover

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D8501

llvm-svn: 238818
2015-06-02 10:58:41 +00:00
Matthias Braun
0c511ee9db AArch64: Use CMP;CCMP sequences for and/or/setcc trees.
Previously CCMP/FCCMP instructions were only used by the
AArch64ConditionalCompares pass for control flow. This patch uses them
for SELECT like instructions as well by matching patterns in ISelLowering.

PR20927, rdar://18326194

Differential Revision: http://reviews.llvm.org/D8232

llvm-svn: 238793
2015-06-01 22:31:17 +00:00
James Molloy
a6f56a768b Mark SMIN/SMAX/UMIN/UMAX nodes as legal and add patterns for them.
The new [SU]{MIN,MAX} SDNodes can be lowered directly to instructions for
most NEON datatypes - the big exclusion being v2i64.

llvm-svn: 237455
2015-05-15 16:15:57 +00:00
Sergey Dmitrouk
7bfbc12128 Reapply r235977 "[DebugInfo] Add debug locations to constant SD nodes"
[DebugInfo] Add debug locations to constant SD nodes

This adds debug location to constant nodes of Selection DAG and updates
all places that create constants to pass debug locations
(see PR13269).

Can't guarantee that all locations are correct, but in a lot of cases choice
is obvious, so most of them should be. At least all tests pass.

Tests for these changes do not cover everything, instead just check it for
SDNodes, ARM and AArch64 where it's easy to get incorrect locations on
constants.

This is not complete fix as FastISel contains workaround for wrong debug
locations, which drops locations from instructions on processing constants,
but there isn't currently a way to use debug locations from constants there
as llvm::Constant doesn't cache it (yet). Although this is a bit different
issue, not directly related to these changes.

Differential Revision: http://reviews.llvm.org/D9084

llvm-svn: 235989
2015-04-28 14:05:47 +00:00
Daniel Jasper
39180626db Revert "[DebugInfo] Add debug locations to constant SD nodes"
This breaks a test:
http://bb.pgr.jp/builders/cmake-llvm-x86_64-linux/builds/23870

llvm-svn: 235987
2015-04-28 13:38:35 +00:00
Sergey Dmitrouk
01a4dcd3bb [DebugInfo] Add debug locations to constant SD nodes
This adds debug location to constant nodes of Selection DAG and updates
all places that create constants to pass debug locations
(see PR13269).

Can't guarantee that all locations are correct, but in a lot of cases choice
is obvious, so most of them should be. At least all tests pass.

Tests for these changes do not cover everything, instead just check it for
SDNodes, ARM and AArch64 where it's easy to get incorrect locations on
constants.

This is not complete fix as FastISel contains workaround for wrong debug
locations, which drops locations from instructions on processing constants,
but there isn't currently a way to use debug locations from constants there
as llvm::Constant doesn't cache it (yet). Although this is a bit different
issue, not directly related to these changes.

Differential Revision: http://reviews.llvm.org/D9084

llvm-svn: 235977
2015-04-28 11:56:37 +00:00
Pirama Arumuga Nainar
17c8db4460 [AArch64] Add nvcast patterns for v4f16 and v8f16
Summary:
Constant stores of f16 vectors can create NvCast nodes from various
operand types to v4f16 or v8f16 depending on patterns in the stored
constants.  This patch adds nvcast rules with v4f16 and v8f16 values.

AArchISelLowering::LowerBUILD_VECTOR has the details on which constant
patterns generate the nvcast nodes.

Reviewers: jmolloy, srhines, ab

Subscribers: rengolin, aemerson, llvm-commits

Differential Revision: http://reviews.llvm.org/D9201

llvm-svn: 235610
2015-04-23 17:32:25 +00:00
Vladimir Sukharev
143cc59aa9 [AArch64] Add v8.1a "Limited Ordering Regions" extension
Reviewers: 	t.p.northover

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D8499

Patch by: Tom Coxon

llvm-svn: 235105
2015-04-16 15:30:43 +00:00
Bradley Smith
2d2de3c295 [AArch64] Allow non-standard INS/DUP encodings
The ARMv8 ARMARM states that for these instructions in A64 state:

  "Unspecified bits in "imm5" are ignored but should be set to zero by an assembler.", (imm4 for INS).

Make the disassembler accept any encoding with these ignored bits set to 1.

llvm-svn: 234896
2015-04-14 15:07:26 +00:00
Vladimir Sukharev
520cdd942a [AArch64] Rename v8.1a from "extension" to "architecture"
v8.1a is renamed to architecture, accordingly to approaches in ARM backend.

Excess generic cpu is removed. Intended use: "generic" cpu with "v8.1a" subtarget feature

Reviewers: jmolloy

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D8766

llvm-svn: 233810
2015-04-01 14:49:29 +00:00
Vladimir Sukharev
22589e7b79 [AArch64] Add v8.1a "Rounding Double Multiply Add/Subtract" extension
Reviewers: t.p.northover, jmolloy

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D8502

llvm-svn: 233693
2015-03-31 13:15:48 +00:00
Vladimir Sukharev
790efe2f48 [AArch64, ARM] Add v8.1a architecture and generic cpu
New architecture and cpu added, following http://community.arm.com/groups/processors/blog/2014/12/02/the-armv8-a-architecture-and-its-ongoing-development

Reviewers: t.p.northover

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D8505

llvm-svn: 233290
2015-03-26 17:05:54 +00:00
Chad Rosier
c67eff5c3b [AArch64] Enable rematerialization of float 0 values.
Patch by Geoff Berry<gberry@codeaurora.org>.

llvm-svn: 232967
2015-03-23 17:19:34 +00:00
Ahmed Bougacha
faad462651 [AArch64] Avoid going through GPRs for across-vector instructions.
This adds new node types for each intrinsic.
For instance, for addv, we have AArch64ISD::UADDV, such that:
  (v4i32 (uaddv ...))
is the same as
  (v4i32 (scalar_to_vector (i32 (int_aarch64_neon_uaddv ...))))
that is,
  (v4i32 (INSERT_SUBREG (v4i32 (IMPLICIT_DEF)),
           (i32 (int_aarch64_neon_uaddv ...)), ssub)

In a combine, we transform all such across-vector-lanes intrinsics to:

  (i32 (extract_vector_elt (uaddv ...), 0))

This has one big advantage: by making the extract_element explicit, we
enable the existing patterns for lane-aware instructions to fire.
This lets us avoid needlessly going through the GPRs.  Consider:

    uint32x4_t test_mul(uint32x4_t a, uint32x4_t b) {
        return vmulq_n_u32(a, vaddvq_u32(b));
    }

We now generate:
    addv.4s  s1, v1
    mul.4s   v0, v0, v1[0]
instead of the previous:
    addv.4s  s1, v1
    fmov     w8, s1
    dup.4s   v1, w8
    mul.4s   v0, v1, v0

rdar://20044838

llvm-svn: 231840
2015-03-10 20:45:38 +00:00
Ahmed Bougacha
b20ce2fe64 [AArch64] Remove integer INSvi*lane patterns. NFCI.
Most are redundant, and they never seem to fire.

The V128 integer patterns already exist in the INS multiclass.
The duplicates only fire when the vector index type isn't i64,
because they accept "imm" instead of an explicit "i64", as the
instruction definition patterns do.

TLI::getVectorIdxTy is i64 on AArch64, so this should never happen.
Also, one of them had a typo: for i64, INSvi32lane was used.
I noticed because I mistakenly used an explicit i32 as the idx type,
and got ins.s for an i64 vector_insert.

The V64 patterns also don't seem to ever fire, as V64 vector
extract/insert are legalized to V128.

The equivalent float patterns are unique and useful, so keep them.

No functional change intended;  none exhibited on the LIT and LNT tests.

llvm-svn: 231838
2015-03-10 20:37:19 +00:00
Kristof Beyls
4e1076f140 Fix PR22408 - LLVM producing AArch64 TLS relocations that GNU linkers cannot handle yet.
As is described at http://llvm.org/bugs/show_bug.cgi?id=22408, the GNU linkers
ld.bfd and ld.gold currently only support a subset of the whole range of AArch64
ELF TLS relocations. Furthermore, they assume that some of the code sequences to
access thread-local variables are produced in a very specific sequence.
When the sequence is not as the linker expects, it can silently mis-relaxe/mis-optimize
the instructions.
Even if that wouldn't be the case, it's good to produce the exact sequence,
as that ensures that linkers can perform optimizing relaxations.

This patch:

* implements support for 16MiB TLS area size instead of 4GiB TLS area size. Ideally clang
  would grow an -mtls-size option to allow support for both, but that's not part of this patch.
* by default doesn't produce local dynamic access patterns, as even modern ld.bfd and ld.gold
  linkers do not support the associated relocations. An option (-aarch64-elf-ldtls-generation)
  is added to enable generation of local dynamic code sequence, but is off by default.
* makes sure that the exact expected code sequence for local dynamic and general dynamic
  accesses is produced, by making use of a new pseudo instruction. The patch also removes
  two (AArch64ISD::TLSDESC_BLR, AArch64ISD::TLSDESC_CALL) pre-existing AArch64-specific pseudo
  SDNode instructions that are superseded by the new one (TLSDESC_CALLSEQ).

llvm-svn: 231227
2015-03-04 09:12:08 +00:00
Ahmed Bougacha
53ed9373bc [AArch64] Prefer DUP/MOV ("CPY") to INS for vector_extract.
This avoids a partial false dependency on the previous content of
the upper lanes of the destination vector register.

Differential Revision: http://reviews.llvm.org/D7307

llvm-svn: 227820
2015-02-02 17:55:57 +00:00