Commit Graph

771 Commits

Author SHA1 Message Date
Simon Pilgrim 386b8ddd5f [MIPS][MSA] Convert vector integer min/max opcodes to use generic implementation
Found while investigating D43338

Simon^3 - the LLVM project needs more Simons.

Differential Revision: https://reviews.llvm.org/D43433

llvm-svn: 325447
2018-02-17 21:29:45 +00:00
Simon Atanasyan 0874cf5e62 [mips] Fix 'l' constraint handling for types smaller than 32 bits
In case of correct using of the 'l' constraint llvm now generates valid
code; otherwise it shows an error message. Initially these triggers an
assertion.

This commit is the same as r324869 with fixed the test's file name.

llvm-svn: 324885
2018-02-12 12:21:55 +00:00
Simon Atanasyan dc4ed35ea6 [mips] Revert rL324869
This commit adds inlineasm-cnstrnt-bad-l.ll which is clashing
with inlineasm-cnstrnt-bad-L.ll on case insensitive file systems.

llvm-svn: 324882
2018-02-12 11:15:37 +00:00
Simon Atanasyan e08f2a19d4 [mips] Fix 'l' constraint handling for types smaller than 32 bits
In case of correct using of the 'l' constraint llvm now generates valid
code; otherwise it shows an error message. Initially these triggers an
assertion.

llvm-svn: 324869
2018-02-12 07:51:21 +00:00
Stefan Maksimovic 8989940557 Revert accidental changes that snuck in r324584
llvm-svn: 324585
2018-02-08 09:31:48 +00:00
Stefan Maksimovic b3e7ed3b94 [mips] Define certain instructions in microMIPS32r3
Instructions affected:
mthc1, mfhc1, add.d, sub.d, mul.d, div.d,
mov.d, neg.d, cvt.w.d, cvt.d.s, cvt.d.w, cvt.s.d

These instructions are now defined for
microMIPS32r3 + microMIPS32r6 in MicroMipsInstrFPU.td
since they shared their encoding with those already defined
in microMIPS32r6InstrInfo.td and have been therefore
removed from the latter file.

Some instructions present in MicroMipsInstrFPU.td which
did not have both AFGR64 and FGR64 variants defined have
been altered to do so.

Differential revision: https://reviews.llvm.org/D42738

llvm-svn: 324584
2018-02-08 09:25:17 +00:00
Simon Dardis daaeaba665 [mips] Fix incorrect sign extension for fpowi libcall
PR36061 showed that during the expansion of ISD::FPOWI, that there
was an incorrect zero extension of the integer argument which for
MIPS64 would then give incorrect results. Address this with the
existing mechanism for correcting sign extensions.

This resolves PR36061.

Thanks to James Cowgill for reporting the issue!

Reviewers: atanasyan, hfinkel

Differential Revision: https://reviews.llvm.org/D42537

llvm-svn: 323781
2018-01-30 16:24:10 +00:00
Simon Atanasyan d41feef40f [mips] Provide correct descriptions of asm constraints in the comments. NFC
llvm-svn: 321566
2017-12-29 19:18:30 +00:00
Simon Atanasyan 970f686faa [mips] Replace assert by an error message
Initially, if the `c` constraint applied to the wrong data type that
causes LLVM to assert. This commit replaces the assert by an error
message.

llvm-svn: 321565
2017-12-29 19:18:24 +00:00
Matthias Braun f1caa2833f MachineFunction: Return reference from getFunction(); NFC
The Function can never be nullptr so we can return a reference.

llvm-svn: 320884
2017-12-15 22:22:58 +00:00
Aleksandar Beserminji d6dada17ff [mips] Removal of microMIPS64R6
All files and parts of files related to microMIPS4R6 are removed.
When target is microMIPS4R6, errors are printed.

This is LLVM part of patch.

Differential Revision: https://reviews.llvm.org/D35625

llvm-svn: 320350
2017-12-11 11:21:40 +00:00
Jonas Paulsson f0ff20f1f0 Use getStoreSize() in various places instead of 'BitSize >> 3'.
This is needed for cases when the memory access is not as big as the width of
the data type. For instance, storing i1 (1 bit) would be done in a byte (8
bits).

Using 'BitSize >> 3' (or '/ 8') would e.g. give the memory access of an i1 a
size of 0, which for instance makes alias analysis return NoAlias even when
it shouldn't.

There are no tests as this was done as a follow-up to the bugfix for the case
where this was discovered (r318824). This handles more similar cases.

Review: Björn Petterson
https://reviews.llvm.org/D40339

llvm-svn: 319173
2017-11-28 14:44:32 +00:00
David Blaikie b3bde2ea50 Fix a bunch more layering of CodeGen headers that are in Target
All these headers already depend on CodeGen headers so moving them into
CodeGen fixes the layering (since CodeGen depends on Target, not the
other way around).

llvm-svn: 318490
2017-11-17 01:07:10 +00:00
David Blaikie 3f833edc7c Target/TargetInstrInfo.h -> CodeGen/TargetInstrInfo.h to match layering
This header includes CodeGen headers, and is not, itself, included by
any Target headers, so move it into CodeGen to match the layering of its
implementation.

llvm-svn: 317647
2017-11-08 01:01:31 +00:00
David Blaikie 1be62f0327 Move TargetFrameLowering.h to CodeGen where it's implemented
This header already includes a CodeGen header and is implemented in
lib/CodeGen, so move the header there to match.

This fixes a link error with modular codegeneration builds - where a
header and its implementation are circularly dependent and so need to be
in the same library, not split between two like this.

llvm-svn: 317379
2017-11-03 22:32:11 +00:00
Aleksandar Beserminji 143572984d Revert "[mips] Reordering callseq* nodes to be linear"
This reverts commit r314507, because the original patch is causing test
failures.

llvm-svn: 316215
2017-10-20 14:35:41 +00:00
Vitaly Buka 7450398e01 Remove unused variables
llvm-svn: 315847
2017-10-15 05:35:02 +00:00
Aleksandar Beserminji 29341b88ac [mips] Reordering callseq* nodes to be linear
Fix nested callseq* nodes by moving callseq_start after the
arguments calculation to temporary registers, so that callseq* nodes
in resulting DAG are linear.

Recommitting r314497. This version does not contain test which fails
when compiler is not build in debug mode.

Differential Revision: https://reviews.llvm.org/D37328

llvm-svn: 314507
2017-09-29 11:05:02 +00:00
Aleksandar Beserminji a0a01e7172 Revert "[mips] Reordering callseq* nodes to be linear"
Added test relies on the compiler being built in debug mode,
which may not be the case.

This reverts commit r314497.

llvm-svn: 314506
2017-09-29 10:52:03 +00:00
Aleksandar Beserminji 502dcb035a [mips] Reordering callseq* nodes to be linear
Fix nested callseq* nodes by moving callseq_start after the
arguments calculation to temporary registers, so that callseq* nodes
in resulting DAG are linear.

Differential Revision: https://reviews.llvm.org/D37328

llvm-svn: 314497
2017-09-29 09:32:14 +00:00
Sanjay Patel f31b1a00ea [DAGCombiner] fold assertzexts separated by trunc
If we have an AssertZext of a truncated value that has already been AssertZext'ed, 
we can assert on the wider source op to improve the zext-y knowledge:
 assert (trunc (assert X, i8) to iN), i1 --> trunc (assert X, i1) to iN

This moves a fold from being Mips-specific to general combining, and x86 shows
improvements.

Differential Revision: https://reviews.llvm.org/D37017

llvm-svn: 313577
2017-09-18 22:05:35 +00:00
Simon Dardis ae5b53e7cd [mips] Lift the assertion on the types that can be used with MipsGPRel
Post commit review of rL308619 highlighted the need for handling N64
with -fno-pic. Testing reveale a stale assert when generating a GP
relative addressing mode.

This patch removes that assert and adds the necessary patterns for
MIPS64 to perform gp relative addressing with -fno-pic
(and the implicit -mno-abicalls + -mgpopt).

Reviewers: atanasyan, nitesh.jain

Differential Revision: https://reviews.llvm.org/D36472

llvm-svn: 310713
2017-08-11 14:36:05 +00:00
Eugene Zelenko 79220eaeec [Mips] Fix some Clang-tidy modernize-use-using and Include What You Use warnings; other minor fixes (NFC).
llvm-svn: 309993
2017-08-03 22:12:30 +00:00
Peter Collingbourne 081ffe2ff2 Change CallLoweringInfo::CS to be an ImmutableCallSite instead of a pointer. NFCI.
This was a use-after-free waiting to happen.

llvm-svn: 309159
2017-07-26 19:15:29 +00:00
Jonas Paulsson 024e319489 [SystemZ, LoopStrengthReduce]
This patch makes LSR generate better code for SystemZ in the cases of memory
intrinsics, Load->Store pairs or comparison of immediate with memory.

In order to achieve this, the following common code changes were made:

 * New TTI hook: LSRWithInstrQueries(), which defaults to false. Controls if
 LSR should do instruction-based addressing evaluations by calling
 isLegalAddressingMode() with the Instruction pointers.
 * In LoopStrengthReduce: handle address operands of memset, memmove and memcpy
 as address uses, and call isFoldableMemAccessOffset() for any LSRUse::Address,
 not just loads or stores.

SystemZ changes:

 * isLSRCostLess() implemented with Insns first, and without ImmCost.
 * New function supportedAddressingMode() that is a helper for TTI methods
 looking at Instructions passed via pointers.

Review: Ulrich Weigand, Quentin Colombet
https://reviews.llvm.org/D35262
https://reviews.llvm.org/D35049

llvm-svn: 308729
2017-07-21 11:59:37 +00:00
Stefan Maksimovic be0bc71e02 Reland r308585
Builder clang-x86_64-linux-abi-test apparently failed due
to a spurious error unrelated to the changes r308585
introduced.

llvm-svn: 308612
2017-07-20 13:08:18 +00:00
Simon Atanasyan fb953926b1 [mips] Support `long_call/far/near` attributes passed by front-end
This patch adds handling of the `long_call`, `far`, and `near`
attributes passed by front-end. The patch depends on D35479.

Differential revision: https://reviews.llvm.org/D35480.

llvm-svn: 308606
2017-07-20 12:19:26 +00:00
Stefan Maksimovic 3793a82b28 Revert r308585
Builder clang-x86_64-linux-abi-test seems to fail after this change

llvm-svn: 308597
2017-07-20 09:57:14 +00:00
Stefan Maksimovic 8539f77bc3 [mips] Fix fp select machine verifier errors
Introduced FSELECT node necesary when lowering ISD::SELECT
which has i32, f64, f64 as its operands.
SEL_D instruction required that its output and first operand
of a SELECT node, which it used, have matching types.
MTC1_D64 node introduced to aid FSELECT lowering.

This fixes machine verifier errors on following tests:
CodeGen/Mips/llvm-ir/select-dbl.ll
CodeGen/Mips/llvm-ir/select-flt.ll
CodeGen/Mips/select.ll

Differential Revision: https://reviews.llvm.org/D35408

llvm-svn: 308595
2017-07-20 09:21:10 +00:00
Simon Atanasyan f217c7b7e2 [mips] Handle the `long-calls` feature flags in the MIPS backend
If the `long-calls` feature flags is enabled, disable use of the `jal`
instruction. Instead of that call a function by by first loading its
address into a register, and then using the contents of that register.

Differential revision: https://reviews.llvm.org/D35168

llvm-svn: 308087
2017-07-15 07:14:25 +00:00
Simon Dardis 250256f9c9 Reland "[mips] Fix multiprecision arithmetic."
For multiprecision arithmetic on MIPS, rather than using ISD::ADDE / ISD::ADDC,
get SelectionDAG to break down the operation into ISD::ADDs and ISD::SETCCs.

For MIPS, only the DSP ASE has a carry flag, so in the general case it is not
useful to directly support ISD::{ADDE, ADDC, SUBE, SUBC} nodes.

Also improve the generation code in such cases for targets with
TargetLoweringBase::ZeroOrOneBooleanContent by directly using the result of the
comparison node rather than using it in selects. Similarly for ISD::SUBE /
ISD::SUBC.

Address optimization breakage by moving the generation of MIPS specific integer
multiply-accumulate nodes to before legalization.

This revolves PR32713 and PR33424.

Thanks to Simonas Kazlauskas and Pirama Arumuga Nainar for reporting the issue!

Reviewers: slthakur

Differential Revision: https://reviews.llvm.org/D33494

The previous version of this patch was too aggressive in producing fused
integer multiple-addition instructions.

llvm-svn: 307906
2017-07-13 11:28:05 +00:00
Simon Dardis dede76f428 Revert "[mips] Fix multiprecision arithmetic."
This reverts commit r305389. This broke chromium builds, so reverting
while I investigate further.

llvm-svn: 306741
2017-06-29 20:59:47 +00:00
Strahinja Petrovic d280ea4f76 [MIPS] Fix for selecting of DINS/INS instruction
This patch adds one more condition in selection DINS/INS
instruction, which fixes MultiSource/Applications/JM/ldecod/
for mips32r2 (and mips64r2 n32 abi).

Differential Revision: https://reviews.llvm.org/D33725

llvm-svn: 305888
2017-06-21 09:25:51 +00:00
Simon Dardis 9790e39f45 [mips] Fix multiprecision arithmetic.
For multiprecision arithmetic on MIPS, rather than using ISD::ADDE / ISD::ADDC,
get SelectionDAG to break down the operation into ISD::ADDs and ISD::SETCCs.

For MIPS, only the DSP ASE has a carry flag, so in the general case it is not
useful to directly support ISD::{ADDE, ADDC, SUBE, SUBC} nodes.

Also improve the generation code in such cases for targets with
TargetLoweringBase::ZeroOrOneBooleanContent by directly using the result of the
comparison node rather than using it in selects. Similarly for ISD::SUBE /
ISD::SUBC.

Address optimization breakage by moving the generation of MIPS specific integer
multiply-accumulate nodes to before legalization.

This revolves PR32713 and PR33424.

Thanks to Simonas Kazlauskas and Pirama Arumuga Nainar for reporting the issue!

Reviewers: slthakur

Differential Revision: https://reviews.llvm.org/D33494

llvm-svn: 305389
2017-06-14 14:46:30 +00:00
Simon Dardis 212cccb2f4 Reland "[SelectionDAG] Enable target specific vector scalarization of calls and returns"
By target hookifying getRegisterType, getNumRegisters, getVectorBreakdown,
backends can request that LLVM to scalarize vector types for calls
and returns.

The MIPS vector ABI requires that vector arguments and returns are passed in
integer registers. With SelectionDAG's new hooks, the MIPS backend can now
handle LLVM-IR with vector types in calls and returns. E.g.
'call @foo(<4 x i32> %4)'.

Previously these cases would be scalarized for the MIPS O32/N32/N64 ABI for
calls and returns if vector types were not legal. If vector types were legal,
a single 128bit vector argument would be assigned to a single 32 bit / 64 bit
integer register.

By teaching the MIPS backend to inspect the original types, it can now
implement the MIPS vector ABI which requires a particular method of
scalarizing vectors.

Previously, the MIPS backend relied on clang to scalarize types such as "call
@foo(<4 x float> %a) into "call @foo(i32 inreg %1, i32 inreg %2, i32 inreg %3,
i32 inreg %4)".

This patch enables the MIPS backend to take either form for vector types.

The previous version of this patch had a "conditional move or jump depends on
uninitialized value".

Reviewers: zoran.jovanovic, jaydeep, vkalintiris, slthakur

Differential Revision: https://reviews.llvm.org/D27845

llvm-svn: 305083
2017-06-09 14:37:08 +00:00
Petar Jovanovic 3c039d968e [mips] do not use FastISel when -mxgot is present
The clang compiler by default uses FastISel when invoked with -O0, which
is also the default. In that case, passing of -mxgot does not get honored,
i.e. the code path that is to deal with large got is not taken.
Clang produces same output regardless of -mxgot being present or not.
This change checks whether -mxgot is passed as an option, and turns off
FastISel if it is.

Patch by Stefan Maksimovic.

Differential Revision: https://reviews.llvm.org/D33593

llvm-svn: 304906
2017-06-07 12:59:53 +00:00
Chandler Carruth 6bda14b313 Sort the remaining #include lines in include/... and lib/....
I did this a long time ago with a janky python script, but now
clang-format has built-in support for this. I fed clang-format every
line with a #include and let it re-sort things according to the precise
LLVM rules for include ordering baked into clang-format these days.

I've reverted a number of files where the results of sorting includes
isn't healthy. Either places where we have legacy code relying on
particular include ordering (where possible, I'll fix these separately)
or where we have particular formatting around #include lines that
I didn't want to disturb in this patch.

This patch is *entirely* mechanical. If you get merge conflicts or
anything, just ignore the changes in this patch and run clang-format
over your #include lines in the files.

Sorry for any noise here, but it is important to keep these things
stable. I was seeing an increasing number of patches with irrelevant
re-ordering of #include lines because clang-format was used. This patch
at least isolates that churn, makes it easy to skip when resolving
conflicts, and gets us to a clean baseline (again).

llvm-svn: 304787
2017-06-06 11:49:48 +00:00
Craig Topper f6d4dc5b4a [SelectionDAG] Set ISD::FPOWI to Expand by default
Summary:
Currently FPOWI defaults to Legal and LegalizeDAG.cpp turns Legal into Expand for this opcode because Legal is a "lie".

This patch changes the default for this opcode to Expand and removes the hack from LegalizeDAG.cpp. It also removes all the code in the targets that set this opcode to Expand themselves since they can just rely on the default.

Reviewers: spatel, RKSimon, efriedma

Reviewed By: RKSimon

Subscribers: jfb, dschuff, sbc100, jgravelle-google, nemanjai, javed.absar, andrew.w.kaylor, llvm-commits

Differential Revision: https://reviews.llvm.org/D33530

llvm-svn: 304215
2017-05-30 15:27:55 +00:00
Davide Italiano ef9bfe9531 [Mips] Placate GCC's -Wmisleading-indentation. NFCI.
llvm-svn: 304041
2017-05-26 21:56:19 +00:00
Strahinja Petrovic ab9573f37c [MIPS] Add support to match more patterns for DINS instruction
This patch adds support for recognizing patterns to match
DINS instruction.

Differential Revision: https://reviews.llvm.org/D31465

llvm-svn: 303537
2017-05-22 09:06:44 +00:00
Serge Pavlov d526b13e61 Add extra operand to CALLSEQ_START to keep frame part set up previously
Using arguments with attribute inalloca creates problems for verification
of machine representation. This attribute instructs the backend that the
argument is prepared in stack prior to  CALLSEQ_START..CALLSEQ_END
sequence (see http://llvm.org/docs/InAlloca.htm for details). Frame size
stored in CALLSEQ_START in this case does not count the size of this
argument. However CALLSEQ_END still keeps total frame size, as caller can
be responsible for cleanup of entire frame. So CALLSEQ_START and
CALLSEQ_END keep different frame size and the difference is treated by
MachineVerifier as stack error. Currently there is no way to distinguish
this case from actual errors.

This patch adds additional argument to CALLSEQ_START and its
target-specific counterparts to keep size of stack that is set up prior to
the call frame sequence. This argument allows MachineVerifier to calculate
actual frame size associated with frame setup instruction and correctly
process the case of inalloca arguments.

The changes made by the patch are:
- Frame setup instructions get the second mandatory argument. It
  affects all targets that use frame pseudo instructions and touched many
  files although the changes are uniform.
- Access to frame properties are implemented using special instructions
  rather than calls getOperand(N).getImm(). For X86 and ARM such
  replacement was made previously.
- Changes that reflect appearance of additional argument of frame setup
  instruction. These involve proper instruction initialization and
  methods that access instruction arguments.
- MachineVerifier retrieves frame size using method, which reports sum of
  frame parts initialized inside frame instruction pair and outside it.

The patch implements approach proposed by Quentin Colombet in
https://bugs.llvm.org/show_bug.cgi?id=27481#c1.
It fixes 9 tests failed with machine verifier enabled and listed
in PR27481.

Differential Revision: https://reviews.llvm.org/D32394

llvm-svn: 302527
2017-05-09 13:35:13 +00:00
Simon Dardis 659c43f11a Revert "[MIPS] Add support to match more patterns for DINS instruction"
This reverts commit rL302512. This broke the mips buildbots.

llvm-svn: 302526
2017-05-09 13:18:48 +00:00
Strahinja Petrovic 27ae4c3259 [MIPS] Add support to match more patterns for DINS instruction
This patch adds support for recognizing patterns to match
DINS instruction.

Differential Revision: https://reviews.llvm.org/D31465

llvm-svn: 302512
2017-05-09 10:02:00 +00:00
Simon Dardis 70f79251bc [mips] Rework a portion of MipsCC interface. (NFC)
r299766 contained a "conditional move or jump depends on uninitialized value"
fault, identified by valgrind. This occurred as MipsFastISel::finishCall(..)
used CCState over MipsCCState. The latter is required for the TableGen'd calling
convention logic due to reliance on pre-analyzing type information to lower call
results/returns of vectors correctly.

This change modifies the MipsCC AnalyzeCallResult to be useful with both the
SelectionDAG and FastISel lowering logic.

Reviewers: slthakur

Differential Revision: https://reviews.llvm.org/D32004

llvm-svn: 301392
2017-04-26 11:10:38 +00:00
Simon Dardis f7e4388e3b Revert "[SelectionDAG] Enable target specific vector scalarization of calls and returns"
This reverts commit r299766. This change appears to have broken the MIPS
buildbots. Reverting while I investigate.

Revert "[mips] Remove usage of debug only variable (NFC)"

This reverts commit r299769. Follow up commit.

llvm-svn: 299788
2017-04-07 17:25:05 +00:00
Simon Dardis 6470ff0b24 [SelectionDAG] Enable target specific vector scalarization of calls and returns
By target hookifying getRegisterType, getNumRegisters, getVectorBreakdown,
backends can request that LLVM to scalarize vector types for calls
and returns.

The MIPS vector ABI requires that vector arguments and returns are passed in
integer registers. With SelectionDAG's new hooks, the MIPS backend can now
handle LLVM-IR with vector types in calls and returns. E.g.
'call @foo(<4 x i32> %4)'.

Previously these cases would be scalarized for the MIPS O32/N32/N64 ABI for
calls and returns if vector types were not legal. If vector types were legal,
a single 128bit vector argument would be assigned to a single 32 bit / 64 bit
integer register.

By teaching the MIPS backend to inspect the original types, it can now
implement the MIPS vector ABI which requires a particular method of
scalarizing vectors.

Previously, the MIPS backend relied on clang to scalarize types such as "call
@foo(<4 x float> %a) into "call @foo(i32 inreg %1, i32 inreg %2, i32 inreg %3,
i32 inreg %4)".

This patch enables the MIPS backend to take either form for vector types.

Reviewers: zoran.jovanovic, jaydeep, vkalintiris, slthakur

Differential Revision: https://reviews.llvm.org/D27845

llvm-svn: 299766
2017-04-07 13:03:52 +00:00
Nirav Dave ac6081cb67 Make library calls sensitive to regparm module flag (Fixes PR3997).
Reviewers: mkuper, rnk

Subscribers: mehdi_amini, jyknight, aemerson, llvm-commits, rengolin

Differential Revision: https://reviews.llvm.org/D27050

llvm-svn: 298179
2017-03-18 00:44:07 +00:00
Petar Jovanovic b71386a4a4 [Mips] Add support to match more patterns for DEXT and CINS
This patch adds support for recognizing more patterns to match to DEXT and
CINS instructions.
It finds cases where multiple instructions could be replaced with a single
DEXT or CINS instruction.

For example, for the following:

define i64 @dext_and32(i64 zeroext %a) {
entry:

 %and = and i64 %a, 4294967295
 ret i64 %and
}

instead of generating:

 0000000000000088 <dext_and32>:

 88:   64010001        daddiu  at,zero,1
 8c:   0001083c        dsll32  at,at,0x0
 90:   6421ffff        daddiu  at,at,-1
 94:   03e00008        jr      ra
 98:   00811024        and     v0,a0,at
 9c:   00000000        nop

the following gets generated:

 0000000000000068 <dext_and32>:

 68:   03e00008        jr      ra
 6c:   7c82f803        dext    v0,a0,0x0,0x20

Cases that are covered:

DEXT:

 1. and $src, mask where mask > 0xffff
 2. zext $src zero extend from i32 to i64

CINS:

 1. and (shl $src, pos), mask
 2. shl (and $src, mask), pos
 3. zext (shl $src, pos) zero extend from i32 to i64

Patch by Violeta Vukobrat.

Differential Revision: https://reviews.llvm.org/D30464

llvm-svn: 297832
2017-03-15 13:10:08 +00:00
Simon Dardis 7577ce2140 [mips] Revert fixes for PR32020.
The fix introduces segfaults and clobbers the value to be stored when
the atomic sequence loops.

Revert "[Target/MIPS] Kill dead code, no functional change intended."

This reverts commit r296153.

Revert "Recommit "[mips] Fix atomic compare and swap at O0.""

This reverts commit r296134.

llvm-svn: 297380
2017-03-09 14:03:26 +00:00
Davide Italiano 74f27b80d4 [Target/MIPS] Kill dead code, no functional change intended.
Hopefully placates gcc with -Werror.

llvm-svn: 296153
2017-02-24 18:48:10 +00:00