Commit Graph

1420 Commits

Author SHA1 Message Date
Petar Avramovic 153bd24eda [MIPS GlobalISel] Select integer to floating point conversions
Select G_SITOFP and G_UITOFP for MIPS32.

Differential Revision: https://reviews.llvm.org/D63542

llvm-svn: 363912
2019-06-20 09:05:02 +00:00
Petar Avramovic 4b4dae1c76 [MIPS GlobalISel] Select floating point to integer conversions
Select G_FPTOSI and G_FPTOUI for MIPS32.

Differential Revision: https://reviews.llvm.org/D63541

llvm-svn: 363911
2019-06-20 08:52:53 +00:00
Matt Arsenault 9cac4e6d14 Rename ExpandISelPseudo->FinalizeISel, delay register reservation
This allows targets to make more decisions about reserved registers
after isel. For example, now it should be certain there are calls or
stack objects in the frame or not, which could have been introduced by
legalization.

Patch by Matthias Braun

llvm-svn: 363757
2019-06-19 00:25:39 +00:00
Fangrui Song ac14f7b10c [lit] Delete empty lines at the end of lit.local.cfg NFC
llvm-svn: 363538
2019-06-17 09:51:07 +00:00
Sander de Smalen 5d6ee76c16 Describe stack-id as an enum
This patch changes MIR stack-id from an integer to an enum,
and adds printing/parsing support for this in MIR files. The default
stack-id '0' is now renamed to 'default'.

This should make MIR tests that have stack objects with different stack-ids
more descriptive. It also clarifies code operating on StackID.

Reviewers: arsenm, thegameg, qcolombet

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D60137

llvm-svn: 363533
2019-06-17 09:13:29 +00:00
Francis Visoiu Mistrih a438432acc [FastISel] Skip creating unnecessary vregs for arguments
This behavior was added in r130928 for both FastISel and SD, and then
disabled in r131156 for FastISel.

This re-enables it for FastISel with the corresponding fix.

This is triggered only when FastISel can't lower the arguments and falls
back to SelectionDAG for it.

FastISel contains a map of "register fixups" where at the end of the
selection phase it replaces all uses of a register with another
register that FastISel sometimes pre-assigned. Code at the end of
SelectionDAGISel::runOnMachineFunction is doing the replacement at the
very end of the function, while other pieces that come in before that
look through the MachineFunction and assume everything is done. In this
case, the real issue is that the code emitting COPY instructions for the
liveins (physreg to vreg) (EmitLiveInCopies) is checking if the vreg
assigned to the physreg is used, and if it's not, it will skip the COPY.
If a register wasn't replaced with its assigned fixup yet, the copy will
be skipped and we'll end up with uses of undefined registers.

This fix moves the replacement of registers before the emission of
copies for the live-ins.

The initial motivation for this fix is to enable tail calls for
swiftself functions, which were blocked because we couldn't prove that
the swiftself argument (which is callee-save) comes from a function
argument (live-in), because there was an extra copy (vreg to vreg).

A few tests are affected by this:

* llvm/test/CodeGen/AArch64/swifterror.ll: we used to spill x21
(callee-save) but never reload it because it's attached to the return.
We now don't even spill it anymore.
* llvm/test/CodeGen/*/swiftself.ll: we tail-call now.
* llvm/test/CodeGen/AMDGPU/mubuf-legalize-operands.ll: I believe this
test was not really testing the right thing, but it worked because the
same registers were re-used.
* llvm/test/CodeGen/ARM/cmpxchg-O0.ll: regalloc changes
* llvm/test/CodeGen/ARM/swifterror.ll: get rid of a copy
* llvm/test/CodeGen/Mips/*: get rid of spills and copies
* llvm/test/CodeGen/SystemZ/swift-return.ll: smaller stack
* llvm/test/CodeGen/X86/atomic-unordered.ll: smaller stack
* llvm/test/CodeGen/X86/swifterror.ll: same as AArch64
* llvm/test/DebugInfo/X86/dbg-declare-arg.ll: stack size changed

Differential Revision: https://reviews.llvm.org/D62361

llvm-svn: 362963
2019-06-10 16:53:37 +00:00
Petar Avramovic 81132ce0e9 [MIPS GlobalISel] Select sqrt
Select G_FSQRT for MIPS32.

Differential Revision: https://reviews.llvm.org/D62905

llvm-svn: 362692
2019-06-06 10:00:41 +00:00
Petar Avramovic 0a1fd355b2 [MIPS GlobalISel] Select fabs
Select G_FABS for MIPS32.

Differential Revision: https://reviews.llvm.org/D62903

llvm-svn: 362690
2019-06-06 09:22:37 +00:00
Petar Avramovic a7d0006447 [MIPS GlobalISel] Select fpext and fptrunc
Select G_FPEXT and G_FPTRUNC for MIPS32.

Differential Revision: https://reviews.llvm.org/D62902

llvm-svn: 362689
2019-06-06 09:16:58 +00:00
Petar Avramovic faaa2b5d21 [MIPS GlobalISel] Select floor and ceil
Select G_FFLOOR and G_FCEIL for MIPS32.

Differential Revision: https://reviews.llvm.org/D62901

llvm-svn: 362688
2019-06-06 09:02:24 +00:00
Petar Avramovic 22e99c434f [MIPS GlobalISel] Select fcmp
Select floating point compare for MIPS32.

Differential Revision: https://reviews.llvm.org/D62721

llvm-svn: 362603
2019-06-05 14:03:13 +00:00
Roman Lebedev 3dce0326fe [DAGCombine][X86][AArch64][MIPS][LANAI] (C - x) - y -> C - (x + y) fold (PR41952)
Summary:
This *might* be the last fold for `sink-addsub-of-const.ll`, but i'm not sure yet.

As far as i can tell, there are no regressions here (ignoring x86-32),
all changes are either good or neutral.

This, almost surprisingly to me, fixes the motivational tests (in `shift-amount-mod.ll`)
`@reg32_lshr_by_sub_from_negated` from [[ https://bugs.llvm.org/show_bug.cgi?id=41952 | PR41952 ]].

https://rise4fun.com/Alive/vMd3

Reviewers: RKSimon, t.p.northover, craig.topper, spatel, efriedma

Reviewed By: RKSimon

Subscribers: sdardis, javed.absar, arichardson, kristof.beyls, jrtc27, atanasyan, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62774

llvm-svn: 362488
2019-06-04 11:06:21 +00:00
Simon Atanasyan 25694e0084 [mips] Extend range of register indexes accepted by cfcmsa/ctcmsa
The `cfcmsa` and `ctcmsa` instructions accept index of MSA control
register. The MIPS64 SIMD Architecture define eight MSA control
registers. But register index for `cfcmsa` and `ctcmsa` instructions
might be any number in 0..31 range. If the index is greater then 7,
`cfcmsa` writes zero to the destination registers and `ctcmsa` does
nothing [1].

[1] MIPS Architecture for Programmers Volume IV-j:
    The MIPS64 SIMD Architecture Module
https://www.mips.com/?do-download=the-mips64-simd-architecture-module

Differential Revision: https://reviews.llvm.org/D62597

llvm-svn: 362299
2019-06-01 13:55:18 +00:00
Petar Avramovic f317debdb8 [MIPS GlobalISel] Add detailed tests for lower call
Test different operand types of callee and their behavior whether
relocation model is pic or not.
Possible operand types are:
Register (function pointer),
External symbol (used for libcalls e.g. __udivdi3 or memcpy),
Global address.

Global address has different handling depending on relocation model
and linkage type. Register and external symbol do not.

Differential Revision: https://reviews.llvm.org/D62590

llvm-svn: 362212
2019-05-31 08:40:08 +00:00
Petar Avramovic efcd3c0009 [MIPS GlobalISel] Handle position independent code
Handle position independent code for MIPS32.
When callee is global address, lower call will emit callee
as G_GLOBAL_VALUE and add target flag if needed.
Support $gp in getRegBankFromRegClass().
Select G_GLOBAL_VALUE, specially handle case when
there are target flags attached by lowerCall.

Differential Revision: https://reviews.llvm.org/D62589

llvm-svn: 362210
2019-05-31 08:27:06 +00:00
Petar Avramovic f4a6dd28b6 [MIPS GlobalISel] Lower call for callee that is register
Lower call for callee that is register for MIPS32.
Register should contain callee function address.

Differential Revision: https://reviews.llvm.org/D62585

llvm-svn: 362204
2019-05-31 08:06:17 +00:00
Simon Atanasyan 909c8c2b0d [mips] Use reg-exp in tests to tolerate register indexes changing. NFC
llvm-svn: 361966
2019-05-29 14:59:07 +00:00
Adhemerval Zanella 6d7bf5e8df [CodeGen] Add lrint/llrint builtins
This patch add the ISD::LRINT and ISD::LLRINT along with new
intrinsics.  The changes are straightforward as for other
floating-point rounding functions, with just some adjustments
required to handle the return value being an interger.

The idea is to optimize lrint/llrint generation for AArch64
in a subsequent patch.  Current semantic is just route it to libm
symbol.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D62017

llvm-svn: 361875
2019-05-28 20:47:44 +00:00
Roman Lebedev caeec8501e [NFC][MIPS] Autogenerater madd-msub.ll test
Being affected by upcoming patch

llvm-svn: 361860
2019-05-28 18:31:36 +00:00
David L. Jones 0ff41b8a5a Revert r361356: "[MIR] Add simple PRE pass to MachineCSE"
This is problematic on buildbots, as discussed here: https://reviews.llvm.org/rL361356

It seems like the plan already was to revert, but that hasn't happened yet.

llvm-svn: 361746
2019-05-27 06:00:00 +00:00
Simon Atanasyan c1b482f2a5 [mips] Always check that `shift and add` optimization is efficient.
The D45316 introduced the `shouldTransformMulToShiftsAddsSubs` function
to check that breaking down constant multiplications into a series
of shifts, adds, and subs is efficient. Unfortunately, this function
does not check maximum number of steps on all paths of the algorithm.
This patch fixes this bug.

Fix for PR41929.

Differential Revision: https://reviews.llvm.org/D62166

llvm-svn: 361606
2019-05-24 08:39:40 +00:00
Roman Lebedev a8a470c45b [NFC][Mips] Autogenerate msa/i5-s.ll test
Being affected by (sub %x, C) -> add %X, (sub 0, C) 'for vectors' patch.

llvm-svn: 361523
2019-05-23 18:08:17 +00:00
Roman Lebedev 06688fe715 [NFC][Mips] Autogenerate msa/arithmetic.ll test
Being affected by (sub %x, C) -> add %X, (sub 0, C) 'for vectors' patch.

llvm-svn: 361522
2019-05-23 18:08:13 +00:00
Kees Cook c2187c20a4 [TargetLowering] Extend bool args to inline-asm according to getBooleanType
Summary:
This extends Krzysztof Parzyszek's X86-specific solution
(https://reviews.llvm.org/D60208) to the generic code pointed out by
James Y Knight.

Reviewers: kparzysz, craig.topper, nickdesaulniers

Subscribers: efriedma, sdardis, nemanjai, javed.absar, eraman, fedor.sergeev, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, PkmX, jocewei, jsji, llvm-commits, srhines, void, nickdesaulniers, jyknight

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60224

llvm-svn: 361404
2019-05-22 16:16:15 +00:00
Anton Afanasyev df00c6a54f [MIR] Add simple PRE pass to MachineCSE
This is the second part of the commit fixing PR38917 (hoisting
partitially redundant machine instruction). Most of PRE (partitial
redundancy elimination) and CSE work is done on LLVM IR, but some of
redundancy arises during DAG legalization. Machine CSE is not enough
to deal with it. This simple PRE implementation works a little bit
intricately: it passes before CSE, looking for partitial redundancy
and transforming it to fully redundancy, anticipating that the next
CSE step will eliminate this created redundancy. If CSE doesn't
eliminate this, than created instruction will remain dead and eliminated
later by Remove Dead Machine Instructions pass.

The third part of the commit is supposed to refactor MachineCSE,
to make it more clear and to merge MachinePRE with MachineCSE,
so one need no rely on further Remove Dead pass to clear instrs
not eliminated by CSE.

First step: https://reviews.llvm.org/D54839

Fixes llvm.org/PR38917

llvm-svn: 361356
2019-05-22 07:41:34 +00:00
Adhemerval Zanella 73643b5041 [CodeGen] Add lround/llround builtins
This patch add the ISD::LROUND and ISD::LLROUND along with new
intrinsics.  The changes are straightforward as for other
floating-point rounding functions, with just some adjustments
required to handle the return value being an interger.

The idea is to optimize lround/llround generation for AArch64
in a subsequent patch.  Current semantic is just route it to libm
symbol.

llvm-svn: 360889
2019-05-16 13:15:27 +00:00
Matt Arsenault 828b685ebe RegAllocFast: Improve hinting heuristic
Trace through multiple COPYs when looking for a physreg source. Add
hinting for vregs that will be copied into physregs (we only hinted
for vregs getting copied to a physreg previously).  Give hinted a
register a bonus when deciding which value to spill.  This is part of
my rewrite regallocfast series. In fact this one doesn't even have an
effect unless you also flip the allocation to happen from back to
front of a basic block. Nonetheless it helps to split this up to ease
review of D52010

Patch by Matthias Braun

llvm-svn: 360887
2019-05-16 12:50:39 +00:00
Fangrui Song f4dfd63c74 [IR] Disallow llvm.global_ctors and llvm.global_dtors of the 2-field form in textual format
The 3-field form was introduced by D3499 in 2014 and the legacy 2-field
form was planned to be removed in LLVM 4.0

For the textual format, this patch migrates the existing 2-field form to
use the 3-field form and deletes the compatibility code.
test/Verifier/global-ctors-2.ll checks we have a friendly error message.

For bitcode, lib/IR/AutoUpgrade UpgradeGlobalVariables will upgrade the
2-field form (add i8* null as the third field).

Reviewed By: rnk, dexonsmith

Differential Revision: https://reviews.llvm.org/D61547

llvm-svn: 360742
2019-05-15 02:35:32 +00:00
Matt Arsenault b6c599afd3 Reapply r359906, "RegAllocFast: Add heuristic to detect values not live-out of a block"
This reverts commit r359912.

This should pass now, since the clang test was made less fragile in
r359918.

llvm-svn: 359919
2019-05-03 19:06:57 +00:00
Nico Weber bb852a9672 Revert r359906, "RegAllocFast: Add heuristic to detect values not live-out of a block"
Makes clang/test/Misc/backend-stack-frame-diagnostics-fallback.cpp fail.

llvm-svn: 359912
2019-05-03 18:08:03 +00:00
Matt Arsenault daf2d653fa RegAllocFast: Add heuristic to detect values not live-out of a block
Add an improved/new heuristic to catch more cases when values are not
live out of a basic block.

Patch by Matthias Braun

llvm-svn: 359906
2019-05-03 17:03:24 +00:00
Anton Afanasyev 6d08b8dbae Revert "[MIR] Add simple PRE pass to MachineCSE"
This reverts commit 9c20156de3.
It breaks stage 2 of clang-ppc64be-linux-multistage.

llvm-svn: 359875
2019-05-03 12:36:22 +00:00
Anton Afanasyev 9c20156de3 [MIR] Add simple PRE pass to MachineCSE
This is the second part of the commit fixing PR38917 (hoisting
partitially redundant machine instruction). Most of PRE (partitial
redundancy elimination) and CSE work is done on LLVM IR, but some of
redundancy arises during DAG legalization. Machine CSE is not enough
to deal with it. This simple PRE implementation works a little bit
intricately: it passes before CSE, looking for partitial redundancy
and transforming it to fully redundancy, anticipating that the next
CSE step will eliminate this created redundancy. If CSE doesn't
eliminate this, than created instruction will remain dead and eliminated
later by Remove Dead Machine Instructions pass.

The third part of the commit is supposed to refactor MachineCSE,
to make it more clear and to merge MachinePRE with MachineCSE,
so one need no rely on further Remove Dead pass to clear instrs
not eliminated by CSE.

First step: https://reviews.llvm.org/D54839

Fixes llvm.org/PR38917

Reviewers: RKSimon

Subscribers: hfinkel, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D56772

llvm-svn: 359870
2019-05-03 10:30:59 +00:00
Fangrui Song e29e30b139 [llvm-readobj] Change -long-option to --long-option in tests. NFC
We use both -long-option and --long-option in tests. Switch to --long-option for consistency.

In the "llvm-readelf" mode, -long-option is discouraged as it conflicts with grouped short options and it is not accepted by GNU readelf.

While updating the tests, change llvm-readobj -s to llvm-readobj -S to reduce confusion ("s" is --section-headers in llvm-readobj but --symbols in llvm-readelf).

llvm-svn: 359649
2019-05-01 05:27:20 +00:00
Nick Desaulniers 7ab164c4a4 [AsmPrinter] refactor to support %c w/ GlobalAddress'
Summary:
Targets like ARM, MSP430, PPC, and SystemZ have complex behavior when
printing the address of a MachineOperand::MO_GlobalAddress. Move that
handling into a new overriden method in each base class. A virtual
method was added to the base class for handling the generic case.

Refactors a few subclasses to support the target independent %a, %c, and
%n.

The patch also contains small cleanups for AVRAsmPrinter and
SystemZAsmPrinter.

It seems that NVPTXTargetLowering is possibly missing some logic to
transform GlobalAddressSDNodes for
TargetLowering::LowerAsmOperandForConstraint to handle with "i" extended
inline assembly asm constraints.

Fixes:
- https://bugs.llvm.org/show_bug.cgi?id=41402
- https://github.com/ClangBuiltLinux/linux/issues/449

Reviewers: echristo, void

Reviewed By: void

Subscribers: void, craig.topper, jholewinski, dschuff, jyknight, dylanmckay, sdardis, nemanjai, javed.absar, sbc100, jgravelle-google, eraman, kristof.beyls, hiraditya, aheejin, kbarton, fedor.sergeev, jrtc27, atanasyan, jsji, llvm-commits, kees, tpimh, nathanchance, peter.smith, srhines

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60887

llvm-svn: 359337
2019-04-26 18:45:04 +00:00
Simon Atanasyan a0291110da [MIPS] Use custom bitcast lowering to avoid excessive instructions
On Mips32r2 bitcast can be expanded to two sw instructions and an ldc1
when using bitcast i64 to double or an sdc1 and two lw instructions when
using bitcast double to i64. By introducing custom lowering that uses
mtc1/mthc1 we can avoid excessive instructions.

Patch by Mirko Brkusanin.

Differential Revision: https://reviews.llvm.org/D61069

llvm-svn: 359171
2019-04-25 07:47:28 +00:00
Amara Emerson 946b1246d6 [GlobalISel] Enable CSE in the IRTranslator & legalizer for -O0 with constants only.
Other opcodes shouldn't be CSE'd until we can be sure debug info quality won't
be degraded.

This change also improves the IRTranslator so that in most places, but not all,
it creates constants using the MIRBuilder directly instead of first creating a
new destination vreg and then creating a constant. By doing this, the
buildConstant() method can just return the vreg of an existing G_CONSTANT
instead of having to create a COPY from it.

I measured a 0.2% improvement in compile time and a 0.9% improvement in code
size at -O0 ARM64.

Compile time:
Program                                        base   cse    diff
test-suite...ark/tramp3d-v4/tramp3d-v4.test     9.04   9.12  0.8%
test-suite...Mark/mafft/pairlocalalign.test     2.68   2.66 -0.7%
test-suite...-typeset/consumer-typeset.test     5.53   5.51 -0.4%
test-suite :: CTMark/lencod/lencod.test         5.30   5.28 -0.3%
test-suite :: CTMark/Bullet/bullet.test        25.82  25.76 -0.2%
test-suite...:: CTMark/ClamAV/clamscan.test     6.92   6.90 -0.2%
test-suite...TMark/7zip/7zip-benchmark.test    34.24  34.17 -0.2%
test-suite :: CTMark/SPASS/SPASS.test           6.25   6.24 -0.1%
test-suite...:: CTMark/sqlite3/sqlite3.test     1.66   1.66 -0.1%
test-suite :: CTMark/kimwitu++/kc.test         13.61  13.60 -0.0%
Geomean difference                                          -0.2%

Code size:
Program                                        base     cse      diff
test-suite...-typeset/consumer-typeset.test    1315632  1266480 -3.7%
test-suite...:: CTMark/ClamAV/clamscan.test    1313892  1297508 -1.2%
test-suite :: CTMark/lencod/lencod.test        1439504  1423112 -1.1%
test-suite...TMark/7zip/7zip-benchmark.test    2936980  2904172 -1.1%
test-suite :: CTMark/Bullet/bullet.test        3478276  3445460 -0.9%
test-suite...ark/tramp3d-v4/tramp3d-v4.test    8082868  8033492 -0.6%
test-suite :: CTMark/kimwitu++/kc.test         3870380  3853972 -0.4%
test-suite :: CTMark/SPASS/SPASS.test          1434904  1434896 -0.0%
test-suite...Mark/mafft/pairlocalalign.test    764528   764528   0.0%
test-suite...:: CTMark/sqlite3/sqlite3.test    782092   782092   0.0%
Geomean difference                                              -0.9%

Differential Revision: https://reviews.llvm.org/D60580

llvm-svn: 358369
2019-04-15 05:04:20 +00:00
Petar Avramovic afa3afa384 [MIPS GlobalISel] Select floating point arithmetic operations
Select 32 and 64 bit floating point add, sub, mul and div for MIPS32.

Differential Revision: https://reviews.llvm.org/D60191

llvm-svn: 357584
2019-04-03 14:12:59 +00:00
Simon Atanasyan 2634a141fd [mips] Use AltOrders to prevent using odd FP-registers
To disable using of odd floating-point registers (O32 ABI and
-mno-odd-spreg command line option) such registers and their
super-registers added to the set of reserved registers. In general, it
works. But there is at least one problem - in case of enabled machine
verifier pass some floating-point tests failed because live ranges of
register units that are reserved is not empty and verification pass
failed with "Live segment doesn't end at a valid instruction" error
message.

There is D35985 patch which tries to solve the problem by explicit
removing of register units. This solution did not get approval.

I would like to use another approach for prevent using odd floating
point registers - define `AltOrders` and `AltOrderSelect` for MIPS
floating point register classes. Such `AltOrders` contains reduced set
of registers. At first glance, such solution does not break any test
cases and allows enabling machine instruction verification for all MIPS
test cases.

Differential Revision: http://reviews.llvm.org/D59799

llvm-svn: 357472
2019-04-02 13:57:32 +00:00
Simon Pilgrim 513e6b9d58 [MIPS] Remove fcmp undef from reduced test
Pre-commit for D60006 (Add fcmp UNDEF handling to SelectionDAG::FoldSetCC)

Approved by @atanasyan (Simon Atanasyan)

llvm-svn: 357354
2019-03-30 20:16:16 +00:00
Simon Pilgrim 05e2621342 [MIPS] Regenerate double constant comparison test
Prep work for PR40800 (Add UNDEF handling to SelectionDAG::FoldSetCC) 

llvm-svn: 357294
2019-03-29 18:22:18 +00:00
Simon Atanasyan f26f56d6d3 [mips] Fix lowering a signed immediate for *.d MSA instructions
The `lowerMSASplatImm` function zero-extends `i32` immediates while
building constant. If target type is `i64`, negative immediate loses
the sign. As a result, for example `__builtin_msa_ldi_d(-1)` lowered
to series of instruction loads incorrect value 0xffffffff to the `$w0`
register instead of single `ldi.d $w0, -1` instruction.

The fix zero-extends unsigned immediates and signed-extend signed
immediates.

Differential Revision: http://reviews.llvm.org/D59884

llvm-svn: 357264
2019-03-29 15:15:22 +00:00
Petar Avramovic 1af05df3de [MIPS GlobalISel] Select float constants
Select 32 and 64 bit float constants for MIPS32.

Differential Revision: https://reviews.llvm.org/D59933

llvm-svn: 357183
2019-03-28 16:58:12 +00:00
Nirav Dave c6dfaa0e83 Revert r356996 "[DAG] Avoid smart constructor-based dangling nodes."
This patch appears to trigger very large compile time increases in
halide builds.

llvm-svn: 357116
2019-03-27 19:54:41 +00:00
Amara Emerson 381188f1f3 [GlobalISel] Fix legalizer artifact combiner from crashing with invalid dead instructions.
The artifact combiners push instructions which have been marked for deletion
onto an list for the legalizer to deal with on return. However, for trunc(ext)
combines the combiner routine recursively calls itself. When it does this the
dead instructions list may not be empty, and the other combiners don't expect
to be dealing with essentially invalid MIR (multiple vreg defs etc).

This change fixes it by ensuring that the dead instructions are processed on
entry into tryCombineInstruction.

As a result, this fix exposed a few places in tests where G_TRUNC instructions
were not being deleted even though they were dead.

Differential Revision: https://reviews.llvm.org/D59892

llvm-svn: 357101
2019-03-27 17:47:42 +00:00
Nirav Dave a28c514581 [DAG] Avoid smart constructor-based dangling nodes.
Various SelectionDAG non-combine operations (e.g. the getNode smart
constructor and legalization) may leave dangling nodes by applying
optimizations or not fully pruning unused result values. This can
result in nodes that are never added to the worklist and therefore can
not be pruned.

Add a node inserter as the current node deleter to make sure such
nodes have the chance of being pruned.

Many minor changes, mostly positive.

llvm-svn: 356996
2019-03-26 15:08:14 +00:00
Petar Avramovic a034a64f84 [MIPS GlobalISel] Select copy for arguments from FPRBRegBank
Move selectCopy into MipsInstructionSelector class.
Select copy for arguments from FPRBRegBank for MIPS32.

Differential Revision: https://reviews.llvm.org/D59644

llvm-svn: 356886
2019-03-25 11:38:06 +00:00
Petar Avramovic 3dfa368d5d [MIPS GlobalISel] Add floating point register bank
Add floating point register bank for MIPS32.
Implement getRegBankFromRegClass for float register classes.

Differential Revision: https://reviews.llvm.org/D59643

llvm-svn: 356883
2019-03-25 11:30:46 +00:00
Petar Avramovic 5a457e08f6 [MIPS GlobalISel] Lower float and double arguments in registers
Lower float and double arguments in registers for MIPS32.
When float/double argument is passed through gpr registers
select appropriate move instruction.

Differential Revision: https://reviews.llvm.org/D59642

llvm-svn: 356882
2019-03-25 11:23:41 +00:00
Matt Arsenault 9a1a1f7bb2 Mips: Don't create copy of nothing
This was creating a copy of the register the pseudo itself was
def'ing, leaving a copy of an undefined register. I'm not sure how
the verifier is not catching this, but this avoids asserting in a
future change to RegAllocFast

llvm-svn: 356716
2019-03-21 20:56:05 +00:00