Commit Graph

496 Commits

Author SHA1 Message Date
Sean Fertile 3c8c385a77 [PPC] cleanup of mayLoad/mayStore flags and memory operands.
1) Explicitly sets mayLoad/mayStore property in the tablegen files on load/store
   instructions.
2) Updated the flags on a number of intrinsics indicating that they write
    memory.
3) Added SDNPMemOperand flags for some target dependent SDNodes so that they
   propagate their memory operand

Review: https://reviews.llvm.org/D28818
llvm-svn: 293200
2017-01-26 18:59:15 +00:00
Tony Jiang 3a2f00b024 [PowerPC] Implement missing ISA 2.06 instructions.
Instructions: fctidu[.], fctiwu[.], ftdiv, ftsqrt are not implemented. Implement
them and add corresponding test cases in this patch.

llvm-svn: 291116
2017-01-05 15:00:45 +00:00
Nemanja Ivanovic 552c8e960e [Power9] Allow AnyExt immediates for XXSPLTIB
In some situations, the BUILD_VECTOR node that builds a v18i8 vector by
a splat of an i8 constant will end up with signed 8-bit values and other
situations, it'll end up with unsigned ones. Handle both situations.

Fixes PR31340.

llvm-svn: 289804
2016-12-15 11:16:20 +00:00
Nemanja Ivanovic df1cb520df [PowerPC] Improvements for BUILD_VECTOR Vol. 1
This patch corresponds to review:
https://reviews.llvm.org/D25912

This is the first patch in a series of 4 that improve the lowering and combining
for BUILD_VECTOR nodes on PowerPC.

llvm-svn: 288152
2016-11-29 16:11:34 +00:00
Ehsan Amiri c90b02cf50 [PPC] Generate positive FP zero using xor insn instead of loading from constant area
https://reviews.llvm.org/D23614

Currently we load +0.0 from constant area. That can change to be generated using
XOR instruction.

llvm-svn: 284995
2016-10-24 17:31:09 +00:00
Nemanja Ivanovic 11049f8f07 [Power9] Part-word VSX integer scalar loads/stores and sign extend instructions
This patch corresponds to review:
https://reviews.llvm.org/D23155

This patch removes the VSHRC register class (based on D20310) and adds
exploitation of the Power9 sub-word integer loads into VSX registers as well
as vector sign extensions.
The new instructions are useful for a few purposes:

    Int to Fp conversions of 1 or 2-byte values loaded from memory
    Building vectors of 1 or 2-byte integers with values loaded from memory
    Storing individual 1 or 2-byte elements from integer vectors

This patch implements all of those uses.

llvm-svn: 283190
2016-10-04 06:59:23 +00:00
Nemanja Ivanovic d2c3c51a70 [Power9] Exploit move and splat instructions for build_vector improvement
This patch corresponds to review:
https://reviews.llvm.org/D21135

This patch exploits the following instructions:
mtvsrws
lxvwsx
mtvsrdd
mfvsrld

In order to improve some build_vector and extractelement patterns.

llvm-svn: 282246
2016-09-23 13:25:31 +00:00
Hal Finkel 522e4d9d66 [PowerPC] Support asm parsing for bc[l][a][+-] mnemonics
PowerPC assembly code in the wild, so it seems, has things like this:

  bc+     12, 28, .L9

This is a bit odd because the '+' here becomes part of the BO field, and the BO
field is otherwise the first operand. Nevertheless, the ISA specification does
clearly say that the +- hint syntax applies to all conditional-branch mnemonics
(that test either CTR or a condition register, although not the forms which
check both), both basic and extended, so this is supposed to be valid.

This introduces some asm-parser-only definitions which take only the upper
three bits from the specified BO value, and the lower two bits are implied by
the +- suffix (via some associated aliases).

Fixes PR23646.

llvm-svn: 280571
2016-09-03 02:31:44 +00:00
Hal Finkel 28842b96f3 [PowerPC] Add asm parser/disassembler support for hrfid,nap,slbmfev
These few book-III instructions are used by the Linux kernel.

Partially fixes PR24796.

llvm-svn: 280560
2016-09-02 23:42:01 +00:00
Hal Finkel 277736eee6 [PowerPC] Add support for the extended dcbf form and mnemonics
dcbf has an optional hint-like field, add support for the extended form and the
associated mnemonics (dcbfl and dcbflp).

Partially fixes PR24796.

llvm-svn: 280559
2016-09-02 23:41:54 +00:00
Hal Finkel a39fd4bc53 [PowerPC] Add a pattern for a runtime bit check
Following a suggestion by Sanjay, we should lower:

  %shl = shl i32 1, %y
  %and = and i32 %x, %shl
  %cmp = icmp eq i32 %and, %shl
  ret i1 %cmp

into:

  subfic r4, r4, 32
  rlwnm r3, r3, r4, 31, 31

Add this pattern and some associated patterns for the 64-bit case and the
not-equal case. Fixes PR27356.

llvm-svn: 280454
2016-09-02 02:34:44 +00:00
Hal Finkel 5728200f33 [PowerPC] Implement lowering for atomicrmw min/max/umin/umax
Implement lowering for atomicrmw min/max/umin/umax. Fixes PR28818.

llvm-svn: 279933
2016-08-28 16:17:58 +00:00
Michael Kuperstein 2bc3d4d46c [SelectionDAG] Rename fextend -> fpextend, fround -> fpround, frnd -> fround
The names of the tablegen defs now match the names of the ISD nodes.
This makes the world a slightly saner place, as previously "fround" matched
ISD::FP_ROUND and not ISD::FROUND.

Differential Revision: https://reviews.llvm.org/D23597

llvm-svn: 279129
2016-08-18 20:08:15 +00:00
Nemanja Ivanovic b43bb6141e [Power9] Add codegen for VSX word insert/extract instructions
This patch corresponds to review:
http://reviews.llvm.org/D20239

It adds exploitation of XXINSERTW and XXEXTRACTUW instructions that
are useful in some cases for inserting and extracting vector elements of
v4[if]32 vectors.

llvm-svn: 275215
2016-07-12 21:00:10 +00:00
David Majnemer e61e4bfd87 Replace silly uses of 'signed' with 'int'
llvm-svn: 273244
2016-06-21 05:10:24 +00:00
Eric Christopher 1dbb23e162 Add aliases for mfvrsave/mtvrsave.
Update a test as we're now going to emit it for easier reading of
generated assembly as well.

llvm-svn: 272339
2016-06-09 23:27:48 +00:00
Nemanja Ivanovic 1a2b2f03e7 [PowerPC] Generate VSX version of splat word
This patch corresponds to review:
http://reviews.llvm.org/D18592

It allows the PPC back end to generate the xxspltw instruction where we
previously only emitted vspltw.

llvm-svn: 268516
2016-05-04 16:04:02 +00:00
Marcin Koscielnicki 7b32957852 [PowerPC] Fix the EH_SjLj_Setup pseudo.
This instruction is just a control flow marker - it should not
actually exist in the object file.  Unfortunately, nothing catches
it before it gets to AsmPrinter.  If integrated assembler is used,
it's considered to be a normal 4-byte instruction, and emitted as
an all-0 word, crashing the program.  With external assembler,
a comment is emitted.

Fixed by setting Size to 0 and handling it in MCCodeEmitter - this
means the comment will still be emitted if integrated assembler
is not used.

This broke an ASan test, which has been disabled for a long time
as a result (see the discussion on D19657).  We can reenable it
once this lands.

llvm-svn: 267943
2016-04-28 21:24:37 +00:00
Kit Barton 7a1a9e01ad This reverts commit r265505.
Revert "[Power9] Implement add-pc, multiply-add, modulo, extend-sign-shift, random number, set bool, and dfp test significance".
This patch has caused a functional regression in SPEC2k6 namd, and a performance regression in mesa-pipe.

llvm-svn: 267927
2016-04-28 20:00:42 +00:00
Nemanja Ivanovic 87bcae366d [PowerPC] Basic support for P9 byte comparison and count trailing zero insns
This patch corresponds to review:
http://reviews.llvm.org/D17850

This patch implements the following instructions:
cmprb, cmpeqb, cnttzw, cnttzw., cnttzd, cnttzd.

llvm-svn: 266228
2016-04-13 18:51:18 +00:00
Chuang-Yu Cheng 024a623c55 [Power9] Implement add-pc, multiply-add, modulo, extend-sign-shift, random number, set bool, and dfp test significance
This patch implement the following instructions:
- addpcis subpcis
- maddhd maddhdu maddld
- modsw moduw modsd modud
- darn
- extswsli extswsli.
- setb
- dtstsfi dtstsfiq

Total 15 instructions

Reviewers: nemanjai hfinkel tjablin amehsan kbarton

http://reviews.llvm.org/D17885

llvm-svn: 265505
2016-04-06 01:47:02 +00:00
Chuang-Yu Cheng eaf4b3d75c [Power9] Implement copy-paste, msgsync, slb, and stop instructions
This patch implements the following BookII and Book III instructions:
- copy copy_first cp_abort paste paste. paste_last
- msgsync
- slbieg slbsync
- stop

Total 10 instructions

Reviewers: nemanjai hfinkel tjablin amehsan kbarton
llvm-svn: 265504
2016-04-06 01:46:45 +00:00
Nemanja Ivanovic a621a7f9c3 [PowerPC] Basic support for P9 atomic loads and stores
This patch corresponds to review:
http://reviews.llvm.org/D18032

This patch provides asm implementation for the following instructions:
lwat, ldat, stwat, stdat, ldmx, mcrxrx

llvm-svn: 265022
2016-03-31 15:26:37 +00:00
Chuang-Yu Cheng 80722719eb [Power9] Implement new vsx instructions: insert, extract, test data class, min/max, reverse, permute, splat
This change implements the following vsx instructions:

- Scalar Insert/Extract
    xsiexpdp xsiexpqp xsxexpdp xsxsigdp xsxexpqp xsxsigqp

- Vector Insert/Extract
    xviexpdp xviexpsp xvxexpdp xvxexpsp xvxsigdp xvxsigsp
    xxextractuw xxinsertw

- Scalar/Vector Test Data Class
    xststdcdp xststdcsp xststdcqp
    xvtstdcdp xvtstdcsp

- Maximum/Minimum
    xsmaxcdp xsmaxjdp
    xsmincdp xsminjdp

- Vector Byte-Reverse/Permute/Splat
    xxbrd xxbrh xxbrq xxbrw
    xxperm xxpermr
    xxspltib

30 instructions

Thanks Nemanja for invaluable discussion! Thanks Kit's great help!
Reviewers: hal, nemanja, kbarton, tjablin, amehsan

http://reviews.llvm.org/D16842

llvm-svn: 264567
2016-03-28 08:34:28 +00:00
Kit Barton ba532dc816 [Power9] Implement new vsx instructions: load, store instructions for vector and scalar
We follow the comments mentioned in http://reviews.llvm.org/D16842#344378 to
implement this new patch.

This patch implements the following vsx instructions:

Vector load/store:
lxv lxvx lxvb16x lxvl lxvll lxvh8x lxvwsx
stxv stxvb16x stxvh8x stxvl stxvll stxvx
Scalar load/store:
lxsd lxssp lxsibzx lxsihzx
stxsd stxssp stxsibx stxsihx
21 instructions

Phabricator: http://reviews.llvm.org/D16919
llvm-svn: 262906
2016-03-08 03:49:13 +00:00
Nemanja Ivanovic 2314e83227 Prevent renaming of CR fields in AADB when a CR restore is present
This patch corresponds to review:
http://reviews.llvm.org/D15930

Moves to and from CR fields depend on shifts/masks that depend on the
target/source CR field. Thus, post-ra anti-dep breaking must not later
change that CR register assignment.

llvm-svn: 257168
2016-01-08 13:09:54 +00:00
Yury Gribov d7dbb66eb8 Introduce new @llvm.get.dynamic.area.offset.i{32, 64} intrinsics.
The @llvm.get.dynamic.area.offset.* intrinsic family is used to get the offset
from native stack pointer to the address of the most recent dynamic alloca on
the caller's stack. These intrinsics are intendend for use in combination with
@llvm.stacksave and @llvm.restore to get a pointer to the most recent dynamic
alloca. This is useful, for example, for AddressSanitizer's stack unpoisoning
routines.

Patch by Max Ostapenko.

Differential Revision: http://reviews.llvm.org/D14983

llvm-svn: 254404
2015-12-01 11:40:55 +00:00
Hal Finkel f4052340a4 [PowerPC] Replace cntlz[.] with cntlzw[.]
cntlz is the old POWER mnemonic. cntlzw is the PowerPC mnemonic.

This change fixes an issue when -no-integrated-as: The opcode cntlz is
unrecognized by gas

Alias the POWER mnemonic cntlz[.] to the PowerPC mnemonic cntlzw[.]
This is done for because the POWER cntlz mnemonic has be used by LLVM for
a very long time. We need to make sure that assembly programs
that are using the cntlz[.] do not break with this change.

Change PowerPC tests to reflect the insn change from cntlz to cntlzw.
Add assembly test to verify cntlz[.] is encoded correctly.

Patch by Tom Rix!

llvm-svn: 251489
2015-10-28 03:26:45 +00:00
Hal Finkel a2cdbce661 [PowerPC] Fixup SELECT_CC (and SETCC) patterns with i1 comparison operands
There were really two problems here. The first was that we had the truth tables
for signed i1 comparisons backward. I imagine these are not very common, but if
you have:
  setcc i1 x, y, LT
this has the '0 1' and the '1 0' results flipped compared to:
  setcc i1 x, y, ULT
because, in the signed case, '1 0' is really '-1 0', and the answer is not the
same as in the unsigned case.

The second problem was that we did not have patterns (at all) for the unsigned
comparisons select_cc nodes for i1 comparison operands. This was the specific
cause of PR24552. These had to be added (and a missing Altivec promotion added
as well) to make sure these function for all types. I've added a bunch more
test cases for these patterns, and there are a few FIXMEs in the test case
regarding code-quality.

Fixes PR24552.

llvm-svn: 246400
2015-08-30 22:12:50 +00:00
Kit Barton 4f79f96fd7 Properly handle the mftb instruction.
The mftb instruction was incorrectly marked as deprecated in the PPC
Backend. Instead, it should not be treated as deprecated, but rather be
implemented using the mfspr instruction. A similar patch was put into GCC last
year. Details can be found at:

https://sourceware.org/ml/binutils/2014-11/msg00383.html.
This change will replace instances of the mftb instruction with the mfspr
instruction for all CPUs except 601 and pwr3. This will also be the default
behaviour.

Additional details can be found in:

https://llvm.org/bugs/show_bug.cgi?id=23680

Phabricator review: http://reviews.llvm.org/D10419

llvm-svn: 239827
2015-06-16 16:01:15 +00:00
Bill Schmidt e26236eed9 [PPC64] Add support for clrbhrb, mfbhrbe, rfebb.
This patch adds support for the ISA 2.07 additions involving the
branch history rolling buffer and event-based branching.  These will
not be used by typical applications, so built-in support is not
required.  They will only be available via inline assembly.

Assembly/disassembly tests are included in the patch.

llvm-svn: 238032
2015-05-22 16:44:10 +00:00
Sergey Dmitrouk 842a51bad8 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 48e93f7181 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 adb4c69d5c [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
Hal Finkel d86e90abdd [PowerPC] Use sync inst alias when printing
So long as the choice between printing msync and sync is not ambiguous, we can
print 'sync 0' and just 'sync'.

llvm-svn: 235663
2015-04-23 23:05:08 +00:00
Hal Finkel fefcfffe68 [PowerPC] Add asm/disasm support for dcbt with hint
Add assembler/disassembler support for dcbt/dcbtst (and aliases) with the hint
field specified (non-zero). Unforunately, the syntax for this instruction is
special in that it differs for server vs. embedded cores:
   dcbt ra, rb, th [server]
   dcbt th, ra, rb [embedded]
where th can be omitted when it is 0. dcbtst is the same. Thus we need to play
games in the parser and the printer to flip the operands around on the embedded
cores. We'll use the server syntax as the default (binutils currently uses the
embedded form by default, but IBM is changing that).

We also stop marking dcbtst as having unmodeled side effects (this is not
necessary, it is just a hint like dcbt -- noticed by inspection, so no separate
test case).

llvm-svn: 235657
2015-04-23 22:47:57 +00:00
Nemanja Ivanovic c09047916a Add LLVM support for remaining integer divide and permute instructions from ISA 2.06
This is the patch corresponding to review:
http://reviews.llvm.org/D8406

It adds some missing instructions from ISA 2.06 to the PPC back end.

llvm-svn: 234546
2015-04-09 23:54:37 +00:00
Hal Finkel 6e9110abe9 [PowerPC] Add asm parser support for bitmask forms of rotate-and-mask instructions
The asm syntax for the 32-bit rotate-and-mask instructions can take a 32-bit
bitmask instead of an (mb, me) pair. This syntax is not specified in the Power
ISA manual, but is accepted by GNU as, and is documented in IBM's Assembler
Language Reference. The GNU Multiple Precision Arithmetic Library (gmp)
contains assembly that uses this syntax.

To implement this, I moved the isRunOfOnes utility function from
PPCISelDAGToDAG.cpp to PPCMCTargetDesc.h.

llvm-svn: 233483
2015-03-28 19:42:41 +00:00
Kit Barton 535e69de34 Add Hardware Transactional Memory (HTM) Support
This patch adds Hardware Transaction Memory (HTM) support supported by ISA 2.07
(POWER8). The intrinsic support is based on GCC one [1], but currently only the
'PowerPC HTM Low Level Built-in Function' are implemented.

The HTM instructions follows the RC ones and the transaction initiation result
is set on RC0 (with exception of tcheck). Currently approach is to create a
register copy from CR0 to GPR and comapring. Although this is suboptimal, since
the branch could be taken directly by comparing the CR0 value, it generates code
correctly on both test and branch and just return value. A possible future
optimization could be elimitate the MFCR instruction to branch directly.

The HTM usage requires a recently newer kernel with PPC HTM enabled. Tested on
powerpc64 and powerpc64le.

This is send along a clang patch to enabled the builtins and option switch.

[1] https://gcc.gnu.org/onlinedocs/gcc/PowerPC-Hardware-Transactional-Memory-Built-in-Functions.html

Phabricator Review: http://reviews.llvm.org/D8247

llvm-svn: 233204
2015-03-25 19:36:23 +00:00
Hal Finkel 6a778fb7c2 [PowerPC] Remove canFoldAsLoad from instruction definitions
The PowerPC backend had a number of loads that were marked as canFoldAsLoad
(and I'm partially at fault here for copying around the relevant line of
TableGen definitions without really looking at what it meant). This is not
right; PPC (non-memory) instructions don't support direct memory operands, and
so there is nothing a 'foldable' instruction could be folded into.

Noticed by inspection, no test case.

The one thing we might lose by doing this is ability to fold some loads into
stackmap/patchpoint pseudo-instructions. However, this was untested, and would
not obviously have worked for extending loads, and I'd rather re-add support
for that once it can be tested.

llvm-svn: 231982
2015-03-11 23:28:38 +00:00
Nemanja Ivanovic 0adf26b9b0 Add support for part-word atomics for PPC
http://reviews.llvm.org/D8090#inline-67337

llvm-svn: 231843
2015-03-10 20:51:07 +00:00
Nemanja Ivanovic e8effe1edb Add LLVM support for PPC cryptography builtins
Review: http://reviews.llvm.org/D7955

llvm-svn: 231285
2015-03-04 20:44:33 +00:00
Hal Finkel cf59921670 [PowerPC] Make LDtocL and friends invariant loads
LDtocL, and other loads that roughly correspond to the TOC_ENTRY SDAG node,
represent loads from the TOC, which is invariant. As a result, these loads can
be hoisted out of loops, etc. In order to do this, we need to generate
GOT-style MMOs for TOC_ENTRY, which requires treating it as a legitimate memory
intrinsic node type. Once this is done, the MMO transfer is automatically
handled for TableGen-driven instruction selection, and for nodes generated
directly in PPCISelDAGToDAG, we need to transfer the MMOs manually.

Also, we were not transferring MMOs associated with pre-increment loads, so do
that too.

Lastly, this fixes an exposed bug where R30 was not added as a defined operand of
UpdateGBR.

This problem was highlighted by an example (used to generate the test case)
posted to llvmdev by Francois Pichet.

llvm-svn: 230553
2015-02-25 21:36:59 +00:00
Hal Finkel 0746211811 [PowerPC] Cleanup unused target-specific SDAG nodes
We had somehow accumulated a few target-specific SDAG nodes dealing with PPC64
TOC access that were referenced only in TableGen patterns. The associated
(pseudo-)instructions are used, but are being generated directly. NFC.

llvm-svn: 230518
2015-02-25 18:06:45 +00:00
Hal Finkel c93a9a2cb4 [PowerPC] Add support for the QPX vector instruction set
This adds support for the QPX vector instruction set, which is used by the
enhanced A2 cores on the IBM BG/Q supercomputers. QPX vectors are 256 bytes
wide, holding 4 double-precision floating-point values. Boolean values, modeled
here as <4 x i1> are actually also represented as floating-point values
(essentially  { -1, 1 } for { false, true }). QPX shares many features with
Altivec and VSX, but is distinct from both of them. One major difference is
that, instead of adding completely-separate vector registers, QPX vector
registers are extensions of the scalar floating-point registers (lane 0 is the
corresponding scalar floating-point value). The operations supported on QPX
vectors mirrors that supported on the scalar floating-point values (with some
additional ones for permutations and logical/comparison operations).

I've been maintaining this support out-of-tree, as part of the bgclang project,
for several years. This is not the entire bgclang patch set, but is most of the
subset that can be cleanly integrated into LLVM proper at this time. Adding
this to the LLVM backend is part of my efforts to rebase bgclang to the current
LLVM trunk, but is independently useful (especially for codes that use LLVM as
a JIT in library form).

The assembler/disassembler test coverage is complete. The CodeGen test coverage
is not, but I've included some tests, and more will be added as follow-up work.

llvm-svn: 230413
2015-02-25 01:06:45 +00:00
Bill Schmidt 82f1c775a0 [PowerPC] Fix reverted patch r227976 to avoid register assignment issues
See full discussion in http://reviews.llvm.org/D7491.

We now hide the add-immediate and call instructions together in a
separate pseudo-op, which is tagged to define GPR3 and clobber the
call-killed registers.  The PPCTLSDynamicCall pass prior to RA now
expands this op into the two separate addi and call ops, with explicit
definitions of GPR3 on both instructions, and explicit clobbers on the
call instruction.  The pass is now marked as requiring and preserving
the LiveIntervals and SlotIndexes analyses, and fixes these up after
the replacement sequences are introduced.

Self-hosting has been verified on LE P8 and BE P7 with various
optimization levels, etc.  It has also been verified with the
--no-tls-optimize flag workaround removed.

llvm-svn: 228725
2015-02-10 19:09:05 +00:00
Hal Finkel 57c6ac5e41 [PowerPC] Support the (old) cntlz instruction alias
Some old assembly code uses the cntlz alias for cntlzw, binutils supports this,
and we should too. Fixes PR22519.

llvm-svn: 228719
2015-02-10 18:45:02 +00:00
Hal Finkel 0d2a1515d5 Revert "r227976 - [PowerPC] Yet another approach to __tls_get_addr" and related fixups
Unfortunately, even with the workaround of disabling the linker TLS
optimizations in Clang restored (which has already been done), this still
breaks self-hosting on my P7 machine (-O3 -DNDEBUG -mcpu=native).

Bill is currently working on an alternate implementation to address the TLS
issue in a way that also fully elides the linker bug (which, unfortunately,
this approach did not fully), so I'm reverting this now.

llvm-svn: 228460
2015-02-06 23:07:40 +00:00
Sylvestre Ledru 9be0b77f3f Fix an incorrect identifier
Summary:
EIEIO is not a correct declaration and breaks the build under Debian HURD.
Instead, E_IEIO is used.

//
http://www.gnu.org/software/libc/manual/html_node/Reserved-Names.html
Some additional classes of identifier names are reserved for future
extensions to the C language or the POSIX.1 environment. While using
these names for your own purposes right now might not cause a problem,
they do raise the possibility of conflict with future versions of the C
or POSIX standards, so you should avoid these names.
...
Names beginning with a capital ‘E’ followed a digit or uppercase letter
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Reported here:
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=776965
And patch wrote by Svante Signell 
With this patch, LLVM, Clang & LLDB build under Debian HURD:
https://buildd.debian.org/status/fetch.php?pkg=llvm-toolchain-3.6&arch=hurd-i386&ver=1%3A3.6~%2Brc2-2&stamp=1423040039

Reviewers: hfinkel

Reviewed By: hfinkel

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D7437

llvm-svn: 228331
2015-02-05 18:57:02 +00:00
Bill Schmidt 685aa8b0c5 [PowerPC] Yet another approach to __tls_get_addr
This patch is a third attempt to properly handle the local-dynamic and
global-dynamic TLS models.

In my original implementation, calls to __tls_get_addr were hidden
from view until the asm-printer phase, at which point the underlying
branch-and-link instruction was created with proper relocations.  This
mostly worked well, but I used some repellent techniques to ensure
that the TLS_GET_ADDR nodes at the SD and MI levels correctly received
input from GPR3 and produced output into GPR3.  This proved to work
badly in the presence of multiple TLS variable accesses, with the
copies to and from GPR3 being scheduled incorrectly and generally
creating havoc.

In r221703, I addressed that problem by representing the calls to
__tls_get_addr as true calls during instruction lowering.  This had
the advantage of removing all of the bad hacks and relying on the
existing call machinery to properly glue the copies in place. It
looked like this was going to be the right way to go.

However, as a side effect of the recent discovery of problems with
linker optimizations for TLS, we discovered cases of suboptimal code
generation with this strategy.  The problem comes when tls_get_addr is
called for the same address, and there is a resulting CSE
opportunity.  It turns out that in such cases MachineCSE will common
the addis/addi instructions that set up the input value to
tls_get_addr, but will not common the calls themselves.  MachineCSE
does not have any machinery to common idempotent calls.  This is
perfectly sensible, since presumably this would be done at the IR
level, and introducing calls in the back end isn't commonplace.  In
any case, we end up with two calls to __tls_get_addr when one would
suffice, and that isn't good.

I presumed that the original design would have allowed commoning of
the machine-specific nodes that hid the __tls_get_addr calls, so as
suggested by Ulrich Weigand, I went back to that design and cleaned it
up so that the copies were properly held together by glue
nodes.  However, it turned out that this didn't work either...the
presence of copies to physical registers kept the machine-specific
nodes from being commoned also.

All of which leads to the design presented here.  This is a return to
the original design, except that no attempt is made to introduce
copies to and from GPR3 during instruction lowering.  Virtual registers
are used until prior to register allocation.  At that point, a special
pass is run that identifies the machine-specific nodes that hide the
tls_get_addr calls and introduces the copies to and from GPR3 around
them.  The register allocator then coalesces these copies away.  With
this design, MachineCSE succeeds in commoning tls_get_addr calls where
possible, and we get nice optimal code generation (better than GCC at
the moment, which does not common these calls).

One additional problem must be dealt with:  After introducing the
mentions of the physical register GPR3, the aggressive anti-dependence
breaker sees opportunities to improve scheduling by selecting a
different register instead.  Flags must be used on the instruction
descriptions to tell the anti-dependence breaker to keep its hands in
its pockets.

One thing missing from the original design was recording a definition
of the link register on the GET_TLS_ADDR nodes.  Doing this was found
to be insufficient to force a stack frame to be created, which led to
looping behavior because two different LR values were stored at the
same address.  This appears to have been an oversight in
PPCFrameLowering::determineFrameLayout(), which is repaired here.

Because MustSaveLR() returns true for calls to builtin_return_address,
this changed the expected behavior of
test/CodeGen/PowerPC/retaddr2.ll, which now stacks a frame but
formerly did not.  I've fixed the test case to reflect this.

There are existing TLS tests to catch regressions; the checks in
test/CodeGen/PowerPC/tls-store2.ll proved to be too restrictive in the
face of instruction scheduling with these changes, so I fixed that
up.

I've added a new test case based on the PrettyStackTrace module that
demonstrated the original problem. This checks that we get correct
code generation and that CSE of the calls to __get_tls_addr has taken
place.

llvm-svn: 227976
2015-02-03 16:16:01 +00:00