Commit Graph

844 Commits

Author SHA1 Message Date
Sumanth Gundapaneni a04ab2ec08 [Pipeliner] Fix the bug in pragma that disables the pipeliner.
Differential Revision: https://reviews.llvm.org/D76303.
2020-04-10 12:52:16 -05:00
Jonathan Roelofs 7c5d2bec76 [llvm] Fix missing FileCheck directive colons
https://reviews.llvm.org/D77352
2020-04-06 09:59:08 -06:00
Hiroshi Yamauchi c3417592c8 Revert "Include static prof data when collecting loop BBs"
This reverts commit 129c911efa.

Due to an internal benchmark regression.
2020-03-24 09:41:16 -07:00
Fangrui Song ecd6d7254e [test] llvm/test/: change llvm-objdump single-dash long options to double-dash options
As announced here: http://lists.llvm.org/pipermail/llvm-dev/2019-April/131786.html

Grouped option syntax (POSIX Utility Conventions) does not play well with -long-option
A subsequent change will reject -long-option.
2020-03-15 17:46:23 -07:00
Krzysztof Parzyszek 44205891ed [Hexagon] Fix match pattern in a testcase 2020-03-09 09:09:58 -05:00
Simon Pilgrim 7a2ab876fd [Hexagon] Fix fshl/fshr -> combine() bug identified in D75114 2020-03-06 17:23:10 +00:00
Simon Pilgrim f78b9a3398 [Hexagon] Add fshl/fshr -> combine() tests identified in D75114
Added tests showing that the fshl/fshr -> combine() is working the wrong way around
2020-03-06 17:23:10 +00:00
Krzysztof Parzyszek 37a604c296 [Hexagon] Recognize undefined registers in expandPostRAPseudo 2020-03-06 08:27:42 -06:00
Fangrui Song 71e2ca6e32 [llvm-objdump] -d: print `00000000 <foo>:` instead of `00000000 foo:`
The new behavior matches GNU objdump. A pair of angle brackets makes tests slightly easier.

`.foo:` is not unique and thus cannot be used in a `CHECK-LABEL:` directive.
Without `-LABEL`, the CHECK line can match the `Disassembly of section`
line and causes the next `CHECK-NEXT:` to fail.

```
Disassembly of section .foo:

0000000000001634 .foo:
```

Bdragon: <> has metalinguistic connotation. it just "feels right"

Reviewed By: rupprecht

Differential Revision: https://reviews.llvm.org/D75713
2020-03-05 18:05:28 -08:00
Sumanth Gundapaneni 9897daa6bf Update LSR's logic that identifies a post-increment SCEV value.
One of the checks has been removed as it seem invalid.
The LoopStep size is always almost a 32-bit.

Differential Revision: https://reviews.llvm.org/D75079
2020-03-02 16:34:18 -06:00
Stanislav Mekhanoshin 1bacdcf48d Extend LaneBitmask to 64 bit
This is needed for D74873, AMDGPU going to have 16 bit subregs
and the largest tuple is 32 VGPRs, which results in 64 lanes.

Differential Revision: https://reviews.llvm.org/D75378
2020-03-02 12:10:52 -08:00
Krzysztof Parzyszek e7b9a20584 [Hexagon] Map dcfetch intrinsic to Y2_dcfetchbo, not Y2_dcfetch 2020-02-28 14:19:20 -06:00
Krzysztof Parzyszek c8bfed05e2 Reland 7691790dfd with a MSAN fix
In some cases when HexagonTargetLowering::allowsMemoryAccess returned
true, it did not set the "Fast" argument, leaving it uninitialized.

[Hexagon] Improve casting of boolean HVX vectors to scalars

- Mark memory access for bool vectors as disallowed in target lowering.
  This will prevent combining bitcasts of bool vectors with stores.
- Replace the actual bitcasting code with a faster version.
- Handle casting of v16i1 to i16.
2020-02-28 08:32:58 -06:00
Kirill Bobyrev 014728413f Revert "[Hexagon] Improve casting of boolean HVX vectors to scalars"
This reverts commit 7691790dfd.

The patch is failing tests with MSAN:
http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-fast/builds/39054/steps/check-llvm%20msan/logs/stdio
2020-02-27 11:58:32 +01:00
Krzysztof Parzyszek 7691790dfd [Hexagon] Improve casting of boolean HVX vectors to scalars
- Mark memory access for bool vectors as disallowed in target lowering.
  This will prevent combining bitcasts of bool vectors with stores.
- Replace the actual bitcasting code with a faster version.
- Handle casting of v16i1 to i16.
2020-02-26 12:46:52 -06:00
Ikhlas Ajbar 820df6e679 [Hexagon] Lower vector predicate store
This patch lowers store of vector predicate of type v128i1.
2020-02-24 15:43:04 -06:00
Ikhlas Ajbar a8a4f99afb [Hexagon] Lower bitcast of a vector predicate
This patch lowers bitcast of vector predicate of type v32i1/v64i1
to i32/i64 type.
2020-02-24 15:25:51 -06:00
Krzysztof Parzyszek c51b0bede8 [Hexagon] Introduce noop intrinsic to cast between vector predicate types
The (overloaded) intrinsic is llvm.hexagon.V6.pred.typecast[.128B]. The
types of the operand and the return value are HVX boolean vector types.
For each cast, there needs to be a corresponding intrinsic declared,
with different suffixes appended to the name, e.g.
  ; cast <128 x i1> to <32 x i1>
  declare <32 x i1> @llvm.hexagon.V6.pred.typecast.128B.s1(<128 x i1>)
  ; cast <32 x i1> to <64 x i1>
  declare <64 x i1> @llvm.hexagon.V6.pred.typecast.128B.s2(<32 x i1>)
etc.
2020-02-21 07:37:59 -06:00
Krzysztof Parzyszek b1d47467e2 [Hexagon] Change HVX vector predicate types from v512/1024i1 to v64/128i1
This commit removes the artificial types <512 x i1> and <1024 x i1>
from HVX intrinsics, and makes v512i1 and v1024i1 no longer legal on
Hexagon.

It may cause existing bitcode files to become invalid.

* Converting between vector predicates and vector registers must be
  done explicitly via vandvrt/vandqrt instructions (their intrinsics),
  i.e. (for 64-byte mode):
    %Q = call <64 x i1> @llvm.hexagon.V6.vandvrt(<16 x i32> %V, i32 -1)
    %V = call <16 x i32> @llvm.hexagon.V6.vandqrt(<64 x i1> %Q, i32 -1)

  The conversion intrinsics are:
    declare  <64 x i1> @llvm.hexagon.V6.vandvrt(<16 x i32>, i32)
    declare <128 x i1> @llvm.hexagon.V6.vandvrt.128B(<32 x i32>, i32)
    declare <16 x i32> @llvm.hexagon.V6.vandqrt(<64 x i1>, i32)
    declare <32 x i32> @llvm.hexagon.V6.vandqrt.128B(<128 x i1>, i32)
  They are all pure.

* Vector predicate values cannot be loaded/stored directly. This directly
  reflects the architecture restriction. Loading and storing or vector
  predicates must be done indirectly via vector registers and explicit
  conversions via vandvrt/vandqrt instructions.
2020-02-19 14:14:56 -06:00
Bill Wendling 129c911efa Include static prof data when collecting loop BBs
Summary:
If the programmer adds static profile data to a branch---i.e. uses
"__builtin_expect()" or similar---then we should honor it. Otherwise,
"__builtin_expect()" is ignored in crucial situations. So we trust that
the programmer knows what they're doing until proven wrong.

Subscribers: hiraditya, JDevlieghere, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D74809
2020-02-19 11:33:48 -08:00
Brian Cain bf3b86bc2f [Hexagon] v67+ HVX register pairs should support either direction
Assembler now permits pairs like 'v0:1', which are encoded
differently from the odd-first pairs like 'v1:0'.

The compiler will require more work to leverage these new register
pairs.
2020-02-14 12:43:43 -06:00
Yuanfang Chen 4ad7685258 Revert "Revert "Reland "[Support] make report_fatal_error `abort` instead of `exit`"""
This reverts commit 80a34ae311 with fixes.

Previously, since bots turning on EXPENSIVE_CHECKS are essentially turning on
MachineVerifierPass by default on X86 and the fact that
inline-asm-avx-v-constraint-32bit.ll and inline-asm-avx512vl-v-constraint-32bit.ll
are not expected to generate functioning machine code, this would go
down to `report_fatal_error` in MachineVerifierPass. Here passing
`-verify-machineinstrs=0` to make the intent explicit.
2020-02-13 10:16:06 -08:00
Yuanfang Chen 17122ec10a Revert "Revert "Revert "Reland "[Support] make report_fatal_error `abort` instead of `exit`""""
This reverts commit bb51d24330.
2020-02-13 10:08:05 -08:00
Yuanfang Chen bb51d24330 Revert "Revert "Reland "[Support] make report_fatal_error `abort` instead of `exit`"""
This reverts commit 80a34ae311 with fixes.

On bots llvm-clang-x86_64-expensive-checks-ubuntu and
llvm-clang-x86_64-expensive-checks-debian only,
llc returns 0 for these two tests unexpectedly. I tweaked the RUN line a little
bit in the hope that LIT is the culprit since this change is not in the
codepath these tests are testing.
llvm\test\CodeGen\X86\inline-asm-avx-v-constraint-32bit.ll
llvm\test\CodeGen\X86\inline-asm-avx512vl-v-constraint-32bit.ll
2020-02-13 10:02:53 -08:00
Yuanfang Chen 80a34ae311 Revert "Reland "[Support] make report_fatal_error `abort` instead of `exit`""
This reverts commit rGcd5b308b828e, rGcd5b308b828e, rG8cedf0e2994c.

There are issues to be investigated for polly bots and bots turning on
EXPENSIVE_CHECKS.
2020-02-11 20:41:53 -08:00
Yuanfang Chen 8cedf0e299 Reland "[Support] make report_fatal_error `abort` instead of `exit`"
Summary:
Reland D67847 after D73742 is committed. Replace `sys::Process::Exit(1)`
with `abort` in `report_fatal_error`.

After this patch, for tools turning on `CrashRecoveryContext`,
crash handler installed by `CrashRecoveryContext` is called unless
they installed a non-returning handler using `llvm::install_fatal_error_handler`
like `cc1_main` currently does.

Reviewers: rnk, MaskRay, aganea, hans, espindola, jhenderson

Subscribers: jholewinski, qcolombet, dschuff, jyknight, emaste, sdardis, nemanjai, jvesely, nhaehnle, sbc100, jgravelle-google, hiraditya, aheejin, kbarton, fedor.sergeev, asb, rbar, johnrusso, simoncook, sabuasal, niosHD, jrtc27, zzheng, edward-jones, atanasyan, steven_wu, rogfer01, MartinMosbeck, brucehoult, the_o, dexonsmith, PkmX, rupprecht, jocewei, jsji, Jim, dmgreen, lenary, s.egerton, pzheng, sameer.abuasal, apazos, luismarques, kerbowa, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D74456
2020-02-11 18:20:40 -08:00
Krzysztof Parzyszek 61ca996e79 [Hexagon] Don't generate short vectors in ISD::SELECT in preprocessing
Selection DAG preprocessing runs long after legalization, so make sure
that the types can be handled by the selection code.
2020-02-11 15:27:33 -06:00
Krzysztof Parzyszek 6cf95ac223 [Hexagon] Add REQUIRES: asserts to a testcase using -debug-only 2020-01-21 13:22:01 -06:00
Krzysztof Parzyszek 305bf5b21d [Hexagon] Add support for Hexagon v67t microarchitecture (tiny core) 2020-01-21 11:35:10 -06:00
Krzysztof Parzyszek c12a5917d2 [Hexagon] Add support for Hexagon/HVX v67 ISA 2020-01-20 16:16:49 -06:00
Sid Manning 7fee4fed4c Add support for Linux/Musl ABI
Differential revision: https://reviews.llvm.org/D72701

The patch adds a new option ABI for Hexagon. It primary deals with
the way variable arguments are passed and is use in the Hexagon Linux Musl
environment.

If a callee function has a variable argument list, it must perform the
following operations to set up its function prologue:

  1. Determine the number of registers which could have been used for passing
     unnamed arguments. This can be calculated by counting the number of
     registers used for passing named arguments. For example, if the callee
     function is as follows:

         int foo(int a, ...){ ... }

     ... then register R0 is used to access the argument ' a '. The registers
     available for passing unnamed arguments are R1, R2, R3, R4, and R5.

  2. Determine the number and size of the named arguments on the stack.

  3. If the callee has named arguments on the stack, it should copy all of these
     arguments to a location below the current position on the stack, and the
     difference should be the size of the register-saved area plus padding
     (if any is necessary).

     The register-saved area constitutes all the registers that could have
     been used to pass unnamed arguments. If the number of registers forming
     the register-saved area is odd, it requires 4 bytes of padding; if the
     number is even, no padding is required. This is done to ensure an 8-byte
     alignment on the stack.  For example, if the callee is as follows:

       int foo(int a, ...){ ... }

     ... then the named arguments should be copied to the following location:

       current_position - 5 (for R1-R5) * 4 (bytes) - 4 (bytes of padding)

     If the callee is as follows:

        int foo(int a, int b, ...){ ... }

     ... then the named arguments should be copied to the following location:

        current_position - 4 (for R2-R5) * 4 (bytes) - 0 (bytes of padding)

  4. After any named arguments have been copied, copy all the registers that
     could have been used to pass unnamed arguments on the stack. If the number
     of registers is odd, leave 4 bytes of padding and then start copying them
     on the stack; if the number is even, no padding is required. This
     constitutes the register-saved area. If padding is required, ensure
     that the start location of padding is 8-byte aligned.  If no padding is
     required, ensure that the start location of the on-stack copy of the
     first register which might have a variable argument is 8-byte aligned.

  5. Decrement the stack pointer by the size of register saved area plus the
     padding.  For example, if the callee is as follows:

        int foo(int a, ...){ ... } ;

     ... then the decrement value should be the following:

        5 (for R1-R5) * 4 (bytes) + 4 (bytes of padding) = 24 bytes

     The decrement should be performed before the allocframe instruction.
     Increment the stack-pointer back by the same amount before returning
     from the function.
2020-01-20 09:59:56 -06:00
Krzysztof Parzyszek 8ee2d16896 [Hexagon] Add a target feature to disable compound instructions
This affects the following instructions:
Tag: M4_mpyrr_addr     Syntax: Ry32 = add(Ru32,mpyi(Ry32,Rs32))
Tag: M4_mpyri_addr_u2  Syntax: Rd32 = add(Ru32,mpyi(#u6:2,Rs32))
Tag: M4_mpyri_addr     Syntax: Rd32 = add(Ru32,mpyi(Rs32,#u6))
Tag: M4_mpyri_addi     Syntax: Rd32 = add(#u6,mpyi(Rs32,#U6))
Tag: M4_mpyrr_addi     Syntax: Rd32 = add(#u6,mpyi(Rs32,Rt32))
Tag: S4_addaddi        Syntax: Rd32 = add(Rs32,add(Ru32,#s6))
Tag: S4_subaddi        Syntax: Rd32 = add(Rs32,sub(#s6,Ru32))
Tag: S4_or_andix       Syntax: Rx32 = or(Ru32,and(Rx32,#s10))
Tag: S4_andi_asl_ri    Syntax: Rx32 = and(#u8,asl(Rx32,#U5))
Tag: S4_ori_asl_ri     Syntax: Rx32 = or(#u8,asl(Rx32,#U5))
Tag: S4_addi_asl_ri    Syntax: Rx32 = add(#u8,asl(Rx32,#U5))
Tag: S4_subi_asl_ri    Syntax: Rx32 = sub(#u8,asl(Rx32,#U5))
Tag: S4_andi_lsr_ri    Syntax: Rx32 = and(#u8,lsr(Rx32,#U5))
Tag: S4_ori_lsr_ri     Syntax: Rx32 = or(#u8,lsr(Rx32,#U5))
Tag: S4_addi_lsr_ri    Syntax: Rx32 = add(#u8,lsr(Rx32,#U5))
Tag: S4_subi_lsr_ri    Syntax: Rx32 = sub(#u8,lsr(Rx32,#U5))
2020-01-16 12:37:30 -06:00
Yuanfang Chen 6e24c6037f Revert "[Support] make report_fatal_error `abort` instead of `exit`"
This reverts commit 647c3f4e47.

Got bots failure from sanitizer-windows and maybe others.
2020-01-15 17:52:25 -08:00
Yuanfang Chen 647c3f4e47 [Support] make report_fatal_error `abort` instead of `exit`
Summary:
This patch could be treated as a rebase of D33960. It also fixes PR35547.
A fix for `llvm/test/Other/close-stderr.ll` is proposed in D68164. Seems
the consensus is that the test is passing by chance and I'm not
sure how important it is for us. So it is removed like in D33960 for now.
The rest of the test fixes are just adding `--crash` flag to `not` tool.

** The reason it fixes PR35547 is

`exit` does cleanup including calling class destructor whereas `abort`
does not do any cleanup. In multithreading environment such as ThinLTO or JIT,
threads may share states which mostly are ManagedStatic<>. If faulting thread
tearing down a class when another thread is using it, there are chances of
memory corruption. This is bad 1. It will stop error reporting like pretty
stack printer; 2. The memory corruption is distracting and nondeterministic in
terms of error message, and corruption type (depending one the timing, it
could be double free, heap free after use, etc.).

Reviewers: rnk, chandlerc, zturner, sepavloff, MaskRay, espindola

Reviewed By: rnk, MaskRay

Subscribers: wuzish, jholewinski, qcolombet, dschuff, jyknight, emaste, sdardis, nemanjai, jvesely, nhaehnle, sbc100, arichardson, jgravelle-google, aheejin, kbarton, fedor.sergeev, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, PkmX, jocewei, jsji, lenary, s.egerton, pzheng, cfe-commits, MaskRay, filcab, davide, MatzeB, mehdi_amini, hiraditya, steven_wu, dexonsmith, rupprecht, seiya, llvm-commits

Tags: #llvm, #clang

Differential Revision: https://reviews.llvm.org/D67847
2020-01-15 17:05:13 -08:00
QingShan Zhang 2133d3c558 [DAGCombine] Initialize the default operation action for SIGN_EXTEND_INREG for vector type as 'expand' instead of 'legal'
For now, we didn't set the default operation action for SIGN_EXTEND_INREG for
vector type, which is 0 by default, that is legal. However, most target didn't
have native instructions to support this opcode. It should be set as expand by
default, as what we did for ANY_EXTEND_VECTOR_INREG.

Differential Revision: https://reviews.llvm.org/D70000
2020-01-03 03:26:41 +00:00
Fangrui Song a36ddf0aa9 Migrate function attribute "no-frame-pointer-elim"="false" to "frame-pointer"="none" as cleanups after D56351 2019-12-24 16:27:51 -08:00
Fangrui Song eb16435b5e Migrate function attribute "no-frame-pointer-elim-non-leaf" to "frame-pointer"="non-leaf" as cleanups after D56351 2019-12-24 16:05:15 -08:00
Fangrui Song 502a77f125 Migrate function attribute "no-frame-pointer-elim" to "frame-pointer"="all" as cleanups after D56351 2019-12-24 15:57:33 -08:00
Thomas Raoux e0297a8bee [ModuloSchedule] Fix a bug in experimental expander
Fix two problems that popped up after my last patch. One is that the
stiching of prologue/epilogue can be wrong when reading a value from a
previsou stage. Also changed how we duplicate phi instructions to avoid
generating extra phi that we delete later.

Differential Revision: https://reviews.llvm.org/D70213
2019-11-23 16:01:47 -08:00
Krzysztof Parzyszek e8d1578131 [Hexagon] Remove incorrect intrinsic definition and invalid testcase
The intrinsic int_hexagon_S2_asr_i_vh was mapped to S2_asr_r_vh, which
is wrong. The testcase vasrh.select.ll was using an invalid immediate
for that intrinsic. This is not a proper testcase, since at the MIR
level such use of this intrinsic should never appear.

Together with 824b25fc02, this completes the fix for llvm.org/PR44090.
2019-11-21 09:18:15 -06:00
Krzysztof Parzyszek 824b25fc02 [Hexagon] Fix two testcase errors
This fixes issues discovered in https://reviews.llvm.org/D63973.
2019-11-20 15:06:35 -06:00
Sumanth Gundapaneni 7c7e368a7f [Pipeliner] Fix an assertion caused by iterator invalidation. 2019-11-14 13:08:06 -06:00
Sumanth Gundapaneni fdf1ae37cf [Hexagon] Validate the iterators before converting them to mux.
The conditional instructions that are translated to mux instructions
are deleted and the iterators to these deleted instructions are being
used later. This patch fixed this issue.
2019-11-14 13:01:16 -06:00
Krzysztof Parzyszek 592dd45924 [Hexagon] Fix vector spill expansion to use proper alignment
1. Add pseudos PS_vloadrv_ai and PS_vstorerv_ai: those are now used
   for single vector registers in loadRegFromStackSlot (and store...).
2. Remove pseudos PS_vloadrwu_ai and PS_vstorerwu_ai. The alignment is
   now checked when expanding spill pseudos (both in frame lowering
   and in expand-post-ra-pseudos), and a proper instruction is generated.
3. Update MachineMemOperands when dealigning vector spill slots.
4. Return vector predicate registers in getCallerSavedRegs.
2019-11-12 09:43:21 -06:00
Thomas Raoux e0f1d9d872 [ModuloSchedule] Fix modulo expansion for data loop carried dependencies.
The new experimental expansion has a problem when a value has a data
dependency with an instruction from a previous stage. This is due to
the way we peel out the kernel. To fix that I'm changing the way we
peel out the kernel. We now peel the kernel NumberStage - 1 times.
The code would be correct at this point if we didn't have to handle
cases where the loop iteration is smaller than the number of stages.
To handle this case we move instructions between different epilogues
based on their stage and remap the PHI instructions correctly.

Differential Revision: https://reviews.llvm.org/D69538
2019-11-11 12:09:27 -08:00
Ikhlas Ajbar 14e289eb77 Fix pattern error for S2_tstbit_i instruction
It used to generate S2_tstbit_i with constant -33 which resulted in an assert.
The reason is log2_32 was called with 64bit value 0.
2019-10-30 11:21:48 -05:00
Krzysztof Parzyszek 99f51960fd [Hexagon] Handle remaining registers in getRegisterByName()
This fixes https://llvm.org/PR43829.
2019-10-29 08:56:01 -05:00
James Molloy 12092a9691 [DFAPacketizer] Use DFAEmitter. NFC.
Summary:
This is a NFC change that removes the NFA->DFA construction and emission logic from DFAPacketizerEmitter and instead uses the generic DFAEmitter logic. This allows DFAPacketizer to use the Automaton class from Support and remove a bunch of logic there too.

After this patch, DFAPacketizer is mostly logic for grepping Itineraries and collecting functional units, with no state machine logic. This will allow us to modernize by removing the 16-functional-unit limit and supporting non-itinerary functional units. This is all for followup patches.

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D68992

llvm-svn: 375086
2019-10-17 08:34:29 +00:00
James Molloy 9972c992eb [ModuloSchedule] removeBranch() *before* creating the trip count condition
The Hexagon code assumes there's no existing terminator when inserting its
trip count condition check.

This causes swp-stages5.ll to break. The generated code looks good to me,
it is likely a permutation. I have disabled the new codegen path to keep
everything green and will investigate along with the other 3-4 tests
that have different codegen.

Fixes expensive-checks build.

llvm-svn: 373629
2019-10-03 17:10:32 +00:00
James Molloy 9026518e73 [ModuloSchedule] Peel out prologs and epilogs, generate actual code
Summary:
This extends the PeelingModuloScheduleExpander to generate prolog and epilog code,
and correctly stitch uses through the prolog, kernel, epilog DAG.

The key concept in this patch is to ensure that all transforms are *local*; only a
function of a block and its immediate predecessor and successor. By defining the problem in this way
we can inductively rewrite the entire DAG using only local knowledge that is easy to
reason about.

For example, we assume that all prologs and epilogs are near-perfect clones of the
steady-state kernel. This means that if a block has an instruction that is predicated out,
we can redirect all users of that instruction to that equivalent instruction in our
immediate predecessor. As all blocks are clones, every instruction must have an equivalent in
every other block.

Similarly we can make the assumption by construction that if a value defined in a block is used
outside that block, the only possible user is its immediate successors. We maintain this
even for values that are used outside the loop by creating a limited form of LCSSA.

This code isn't small, but it isn't complex.

Enabled a bunch of testing from Hexagon. There are a couple of tests not enabled yet;
I'm about 80% sure there isn't buggy codegen but the tests are checking for patterns
that we don't produce. Those still need a bit more investigation. In the meantime we
(Google) are happy with the code produced by this on our downstream SMS implementation,
and believe it generates correct code.

Subscribers: mgorny, hiraditya, jsji, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D68205

llvm-svn: 373462
2019-10-02 12:46:44 +00:00