Commit Graph

1336 Commits

Author SHA1 Message Date
Matt Arsenault 92fede361f DAG: Fold out out of bounds insert_vector_elt
getNode already prevents formation of out of bounds constant
extract_vector_elts. Do the same for insert_vector_elt.

llvm-svn: 288603
2016-12-03 23:03:26 +00:00
Nemanja Ivanovic f57f150b1b Revert https://reviews.llvm.org/rL287679
This commit caused some miscompiles that did not show up on any of the bots.
Reverting until we can investigate the cause of those failures.

llvm-svn: 288214
2016-11-29 23:00:33 +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
Nirav Dave a413361798 Revert "[DAG] Improve loads-from-store forwarding to handle TokenFactor"
This reverts commit r287773 which caused issues with ppc64le builds.

llvm-svn: 288035
2016-11-28 14:30:29 +00:00
Nirav Dave cf34556330 [DAG] Improve loads-from-store forwarding to handle TokenFactor
Forward store values to matching loads down through token
factors. Factored from D14834.

Reviewers: jyknight, hfinkel

Subscribers: hfinkel, nemanjai, llvm-commits

Differential Revision: https://reviews.llvm.org/D26080

llvm-svn: 287773
2016-11-23 16:48:35 +00:00
Nemanja Ivanovic b8e30d6db6 [PowerPC] Emit VMX loads/stores for aligned ops to avoid adding swaps on LE
This patch corresponds to review:
https://reviews.llvm.org/D26861

It also fixes PR30730.

Committing on behalf of Lei Huang.

llvm-svn: 287679
2016-11-22 19:02:07 +00:00
Ehsan Amiri ff0942e6ea [Power9] Add patterns for vnegd, vnegw
Exploit new instructions by adding patterns to .td file.
https://reviews.llvm.org/D26551

llvm-svn: 287334
2016-11-18 11:05:55 +00:00
Ehsan Amiri 85818684c6 [PPC][DAGCombine] Convert SETCC to subtract when the result is zero extended
When we see a SETCC whose only users are zero extend operations, we can replace
it with a subtraction. This results in doing all calculations in GPRs and
avoids CR use.

Currently we do this only for ULT, ULE, UGT and UGE condition codes. There are
ways that this can be extended. For example for signed condition codes. In that
case we will be introducing additional sign extend instructions, so more careful
profitability analysis may be required.

Another direction to extend this is for equal, not equal conditions. Also when
users of SETCC are any_ext or sign_ext, we might be able to do something 
similar.

llvm-svn: 287329
2016-11-18 10:41:44 +00:00
Joerg Sonnenberger 8c1a9ac52b Always use relative jump table encodings on PowerPC64.
For the default, small and medium code model, use the existing
difference from the jump table towards the label. For all other code
models, setup the picbase and use the difference between the picbase and
the block address.

Overall, this results in smaller data tables at the expensive of one or
two more arithmetic operation at the jump site. Given that we only create
jump tables with a lot more than two entries, it is a net win in size.
For larger code models the assumption remains that individual functions
are no larger than 2GB.

Differential Revision: https://reviews.llvm.org/D26336

llvm-svn: 287059
2016-11-16 00:37:30 +00:00
Zaara Syeda a19c9e60e9 vector load store with length (left justified) llvm portion
llvm-svn: 286993
2016-11-15 17:54:19 +00:00
Tony Jiang 5f850cd1b1 [PowerPC] Implement BE VSX load/store builtins - llvm portion.
This patch implements all the overloads for vec_xl_be and vec_xst_be. On BE,
they behaves exactly the same with vec_xl and vec_xst, therefore they are
simply implemented by defining a matching macro. On LE, they are implemented
by defining new builtins and intrinsics. For int/float/long long/double, it
is just a load (lxvw4x/lxvd2x) or store(stxvw4x/stxvd2x). For char/char/short,
we also need some extra shuffling before or after call the builtins to get the
desired BE order. For int128, simply call vec_xl or vec_xst.

llvm-svn: 286967
2016-11-15 14:25:56 +00:00
Sean Fertile a435e07de8 [PPC] Add intrinsic mapping to the xscvhpsp instruction
add an intrinsic to expose the 'VSX Scalar Convert Half-Precision to
Single-Precision' instruction.

Differential review: https://reviews.llvm.org/D26536

llvm-svn: 286862
2016-11-14 18:43:59 +00:00
Sean Fertile adda5b2d2b [PPC] add intrinsics for vec extract exp/significand and vec test data class.
Differential Revision: https://reviews.llvm.org/D26272

llvm-svn: 286829
2016-11-14 14:42:37 +00:00
Nemanja Ivanovic ec4b0c360f [PowerPC] Add remaining vector permute builtins in altivec.h - LLVM portion
This patch corresponds to review:
https://reviews.llvm.org/D26480

Adds all the intrinsics used for various permute builtins that will
be added to altivec.h.

llvm-svn: 286638
2016-11-11 21:42:01 +00:00
Nemanja Ivanovic 2efc3cb968 [PowerPC] Add vector conversion builtins to altivec.h - LLVM portion
This patch corresponds to review:
https://reviews.llvm.org/D26307

Adds all the intrinsics used for various conversion builtins that will
be added to altivec.h. These are type conversions between various types of
vectors.

llvm-svn: 286596
2016-11-11 14:41:19 +00:00
Matthias Braun 325cd2c98a ScheduleDAGInstrs: Add condjump deps to addSchedBarrierDeps()
addSchedBarrierDeps() is supposed to add use operands to the ExitSU
node. The current implementation adds uses for calls/barrier instruction
and the MBB live-outs in all other cases. The use
operands of conditional jump instructions were missed.

Also added code to macrofusion to set the latencies between nodes to
zero to avoid problems with the fusing nodes lingering around in the
pending list now.

Differential Revision: https://reviews.llvm.org/D25140

llvm-svn: 286544
2016-11-11 01:34:21 +00:00
Nemanja Ivanovic e70fa63390 [PowerPC] Implement vector shift builtins - llvm portion
This patch corresponds to review https://reviews.llvm.org/D26095.
Committing on behalf of Tony Jiang.

llvm-svn: 285681
2016-11-01 09:42:32 +00:00
Nemanja Ivanovic 60bdfe5a7c [PPC] add absolute difference altivec instructions and matching intrinsics
This patch corresponds to review https://reviews.llvm.org/D26072.
Committing on behalf of Sean Fertile.

llvm-svn: 285627
2016-10-31 19:47:52 +00:00
Nemanja Ivanovic e28a0fc72a Implement vector count leading/trailing bytes with zero lsb and vector parity
builtins - llvm portion

This patch corresponds to review https://reviews.llvm.org/D26003.
Committing on behalf of Zaara Syeda.

llvm-svn: 285434
2016-10-28 19:38:24 +00:00
Ehsan Amiri 2492721c36 [PPC] Adding the removed testcase again
This testcase was originally part of r284995, but I put it in a wrong directory.
So I removed it. Before adding it back I did some small enhancements. Also I
changed the assertions a little bit, to take into account the impact of some
changes performed since code review is done.

This is similar to changes done for another testcase in the original commit.
See: https://reviews.llvm.org/D23614#577749
Basically for instead of vxor we now generate xxlxor in some cases, which is
better.

llvm-svn: 285333
2016-10-27 19:10:09 +00:00
Nemanja Ivanovic 32b5fed639 [PowerPC] - No SExt/ZExt needed for count trailing zeros
This patch corresponds to review:
https://reviews.llvm.org/D25896

It just eliminates the redundant ZExt after a count trailing zeros instruction.

llvm-svn: 285267
2016-10-27 05:17:58 +00:00
Nemanja Ivanovic 275853e777 Do not assume that FP vector operands are never legalized by expanding
This patch ensures that if a floating point vector operand is legalized by
expanding, it is legalized through the stack rather than by calling
DAGTypeLegalizer::IntegerToVector which will cause a failure since the operand
is a non-integer type.

This fixes PR 30715.

llvm-svn: 285231
2016-10-26 19:51:35 +00:00
Nemanja Ivanovic 0f45998bc6 [PowerPC] Implement vec_insert_exp builtins - llvm portion
This revision corresponds to review: https://reviews.llvm.org/D25957.
Committing on behalf of Zaara Syeda.

llvm-svn: 285225
2016-10-26 19:03:40 +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
Ehsan Amiri 1f31e9157d [PPC] Better codegen for AND, ANY_EXT, SRL sequence
https://reviews.llvm.org/D24924

This improves the code generated for a sequence of AND, ANY_EXT, SRL instructions. This is a targetted fix for this special pattern. The pattern is generated by target independet dag combiner and so a more general fix may not be necessary. If we come across other similar cases, some ideas for handling it are discussed on the code review.

llvm-svn: 284983
2016-10-24 15:46:58 +00:00
Sanjay Patel 3a3aaf67e0 [DAG] optimize negation of bool
Use mask and negate for legalization of i1 source type with SIGN_EXTEND_INREG.
With the mask, this should be no worse than 2 shifts. The mask can be eliminated
in some cases, so that should be better than 2 shifts.

This change exposed some missing folds related to negation:
https://reviews.llvm.org/rL284239
https://reviews.llvm.org/rL284395

There may be others, so please let me know if you see any regressions.

Differential Revision: https://reviews.llvm.org/D25485

llvm-svn: 284611
2016-10-19 16:58:59 +00:00
Tim Northover 22bff66a9a PowerPC: specify full triple to avoid different Darwin asm syntax.
llvm-svn: 284281
2016-10-14 21:25:29 +00:00
Sanjay Patel 928f3d73f6 [PowerPC] add tests for PR30661
llvm-svn: 284279
2016-10-14 20:51:41 +00:00
Guozhi Wei 0cd65429be [PPC] Shorter sequence to load 64bit constant with same hi/lo words
This is a patch to implement pr30640.

When a 64bit constant has the same hi/lo words, we can use rldimi to copy the low word into high word of the same register.

This optimization caused failure of test case bperm.ll because of not optimal heuristic in function SelectAndParts64. It chooses AND or ROTATE to extract bit groups from a register, and OR them together. This optimization lowers the cost of loading 64bit constant mask used in AND method, and causes different code sequence. But actually ROTATE method is better in this test case. The reason is in ROTATE method the final OR operation can be avoided since rldimi can insert the rotated bits into target register directly. So this patch also enhances SelectAndParts64 to prefer ROTATE method when the two methods have same cost and there are multiple bit groups need to be ORed together.

Differential Revision: https://reviews.llvm.org/D25521

llvm-svn: 284276
2016-10-14 20:41:50 +00:00
Nirav Dave a81682aad4 Revert "In visitSTORE, always use FindBetterChain, rather than only when UseAA is enabled."
This reverts commit r284151 which appears to be triggering a LTO
failures on Hexagon

llvm-svn: 284157
2016-10-13 20:23:25 +00:00
Nirav Dave 4b36957243 In visitSTORE, always use FindBetterChain, rather than only when UseAA is enabled.
Retrying after upstream changes.

   Simplify Consecutive Merge Store Candidate Search

   Now that address aliasing is much less conservative, push through
   simplified store merging search which only checks for parallel stores
   through the chain subgraph. This is cleaner as the separation of
   non-interfering loads/stores from the store-merging logic.

   Whem merging stores, search up the chain through a single load, and
   finds all possible stores by looking down from through a load and a
   TokenFactor to all stores visited. This improves the quality of the
   output SelectionDAG and generally the output CodeGen (with some
   exceptions).

   Additional Minor Changes:

       1. Finishes removing unused AliasLoad code
       2. Unifies the the chain aggregation in the merged stores across
       code paths
       3. Re-add the Store node to the worklist after calling
       SimplifyDemandedBits.
       4. Increase GatherAllAliasesMaxDepth from 6 to 18. That number is
       arbitrary, but seemed sufficient to not cause regressions in
       tests.

   This finishes the change Matt Arsenault started in r246307 and
   jyknight's original patch.

   Many tests required some changes as memory operations are now
   reorderable. Some tests relying on the order were changed to use
   volatile memory operations

   Noteworthy tests:

    CodeGen/AArch64/argument-blocks.ll -
      It's not entirely clear what the test_varargs_stackalign test is
      supposed to be asserting, but the new code looks right.

    CodeGen/AArch64/arm64-memset-inline.lli -
    CodeGen/AArch64/arm64-stur.ll -
    CodeGen/ARM/memset-inline.ll -

      The backend now generates *worse* code due to store merging
      succeeding, as we do do a 16-byte constant-zero store efficiently.

    CodeGen/AArch64/merge-store.ll -
      Improved, but there still seems to be an extraneous vector insert
      from an element to itself?

    CodeGen/PowerPC/ppc64-align-long-double.ll -
      Worse code emitted in this case, due to the improved store->load
      forwarding.

    CodeGen/X86/dag-merge-fast-accesses.ll -
    CodeGen/X86/MergeConsecutiveStores.ll -
    CodeGen/X86/stores-merging.ll -
    CodeGen/Mips/load-store-left-right.ll -
      Restored correct merging of non-aligned stores

    CodeGen/AMDGPU/promote-alloca-stored-pointer-value.ll -
      Improved. Correctly merges buffer_store_dword calls

    CodeGen/AMDGPU/si-triv-disjoint-mem-access.ll -
      Improved. Sidesteps loading a stored value and
      merges two stores

    CodeGen/X86/pr18023.ll -
      This test has been removed, as it was asserting incorrect
      behavior. Non-volatile stores *CAN* be moved past volatile loads,
      and now are.

    CodeGen/X86/vector-idiv.ll -
    CodeGen/X86/vector-lzcnt-128.ll -
      It's basically impossible to tell what these tests are actually
      testing. But, looks like the code got better due to the memory
      operations being recognized as non-aliasing.

    CodeGen/X86/win32-eh.ll -
      Both loads of the securitycookie are now merged.

    CodeGen/AMDGPU/vgpr-spill-emergency-stack-slot-compute.ll -
      This test appears to work but no longer exhibits the spill behavior.

Reviewers: arsenm, hfinkel, tstellarAMD, jyknight, nhaehnle

Subscribers: wdng, nhaehnle, nemanjai, arsenm, weimingz, niravd, RKSimon, aemerson, qcolombet, dsanders, resistor, tstellarAMD, t.p.northover, spatel

Differential Revision: https://reviews.llvm.org/D14834

llvm-svn: 284151
2016-10-13 19:20:16 +00:00
Tim Shen 4ff62b187e [PPCMIPeephole] Fix splat elimination
Summary:
In PPCMIPeephole, when we see two splat instructions, we can't simply do the following transformation:
  B = Splat A
  C = Splat B
=>
  C = Splat A
because B may still be used between these two instructions. Instead, we should make the second Splat a PPC::COPY and let later passes decide whether to remove it or not:
  B = Splat A
  C = Splat B
=>
  B = Splat A
  C = COPY B

Fixes PR30663.

Reviewers: echristo, iteratee, kbarton, nemanjai

Subscribers: mehdi_amini, llvm-commits

Differential Revision: https://reviews.llvm.org/D25493

llvm-svn: 283961
2016-10-12 00:48:25 +00:00
Kyle Butt 0846e56e63 Codegen: Tail-duplicate during placement.
The tail duplication pass uses an assumed layout when making duplication
decisions. This is fine, but passes up duplication opportunities that
may arise when blocks are outlined. Because we want the updated CFG to
affect subsequent placement decisions, this change must occur during
placement.

In order to achieve this goal, TailDuplicationPass is split into a
utility class, TailDuplicator, and the pass itself. The pass delegates
nearly everything to the TailDuplicator object, except for looping over
the blocks in a function. This allows the same code to be used for tail
duplication in both places.

This change, in concert with outlining optional branches, allows
triangle shaped code to perform much better, esepecially when the
taken/untaken branches are correlated, as it creates a second spine when
the tests are small enough.

Issue from previous rollback fixed, and a new test was added for that
case as well. Issue was worklist/scheduling/taildup issue in layout.

Issue from 2nd rollback fixed, with 2 additional tests. Issue was
tail merging/loop info/tail-duplication causing issue with loops that share
a header block.

Issue with early tail-duplication of blocks that branch to a fallthrough
predecessor fixed with test case: tail-dup-branch-to-fallthrough.ll

Differential revision: https://reviews.llvm.org/D18226

llvm-svn: 283934
2016-10-11 20:36:43 +00:00
Daniel Jasper 0c42dc4784 Revert "Codegen: Tail-duplicate during placement."
This reverts commit r283842.

test/CodeGen/X86/tail-dup-repeat.ll causes and llc crash with our
internal testing. I'll share a link with you.

llvm-svn: 283857
2016-10-11 07:36:11 +00:00
Kyle Butt ae068a320c Codegen: Tail-duplicate during placement.
The tail duplication pass uses an assumed layout when making duplication
decisions. This is fine, but passes up duplication opportunities that
may arise when blocks are outlined. Because we want the updated CFG to
affect subsequent placement decisions, this change must occur during
placement.

In order to achieve this goal, TailDuplicationPass is split into a
utility class, TailDuplicator, and the pass itself. The pass delegates
nearly everything to the TailDuplicator object, except for looping over
the blocks in a function. This allows the same code to be used for tail
duplication in both places.

This change, in concert with outlining optional branches, allows
triangle shaped code to perform much better, esepecially when the
taken/untaken branches are correlated, as it creates a second spine when
the tests are small enough.

Issue from previous rollback fixed, and a new test was added for that
case as well. Issue was worklist/scheduling/taildup issue in layout.

Issue from 2nd rollback fixed, with 2 additional tests. Issue was
tail merging/loop info/tail-duplication causing issue with loops that share
a header block.

Issue with early tail-duplication of blocks that branch to a fallthrough
predecessor fixed with test case: tail-dup-branch-to-fallthrough.ll

Differential revision: https://reviews.llvm.org/D18226

llvm-svn: 283842
2016-10-11 01:20:33 +00:00
Kyle Butt 2facd194a2 Revert "Codegen: Tail-duplicate during placement."
This reverts commit 71c312652c10f1855b28d06697c08d47e7a243e4.

llvm-svn: 283647
2016-10-08 01:47:05 +00:00
Kyle Butt 37e676d857 Codegen: Tail-duplicate during placement.
The tail duplication pass uses an assumed layout when making duplication
decisions. This is fine, but passes up duplication opportunities that
may arise when blocks are outlined. Because we want the updated CFG to
affect subsequent placement decisions, this change must occur during
placement.

In order to achieve this goal, TailDuplicationPass is split into a
utility class, TailDuplicator, and the pass itself. The pass delegates
nearly everything to the TailDuplicator object, except for looping over
the blocks in a function. This allows the same code to be used for tail
duplication in both places.

This change, in concert with outlining optional branches, allows
triangle shaped code to perform much better, esepecially when the
taken/untaken branches are correlated, as it creates a second spine when
the tests are small enough.

Issue from previous rollback fixed, and a new test was added for that
case as well. Issue was worklist/scheduling/taildup issue in layout.

Issue from 2nd rollback fixed, with 2 additional tests. Issue was
tail merging/loop info/tail-duplication causing issue with loops that share
a header block.

Differential revision: https://reviews.llvm.org/D18226

llvm-svn: 283619
2016-10-07 22:33:20 +00:00
Michael Kuperstein 7cc2123847 [DAG] Generalize build_vector -> vector_shuffle combine for more than 2 inputs
This generalizes the build_vector -> vector_shuffle combine to support any
number of inputs. The idea is to create a binary tree of shuffles, where
the first layer performs pairwise shuffles of the input vectors placing each
input element into the correct lane, and the rest of the tree blends these
shuffles together.

This doesn't try to be smart and create any sort of "optimal" shuffles.
The assumption is that even a "poor" shuffle sequence is better than extracting
and inserting the elements one by one.

Differential Revision: https://reviews.llvm.org/D24683

llvm-svn: 283480
2016-10-06 18:58:24 +00:00
Kyle Butt 25ac35d822 Revert "Codegen: Tail-duplicate during placement."
This reverts commit 062ace9764953e9769142c1099281a345f9b6bdc.

Issue with loop info and block removal revealed by polly.
I have a fix for this issue already in another patch, I'll re-roll this
together with that fix, and a test case.

llvm-svn: 283292
2016-10-05 01:39:29 +00:00
Kyle Butt adabac2d57 Codegen: Tail-duplicate during placement.
The tail duplication pass uses an assumed layout when making duplication
decisions. This is fine, but passes up duplication opportunities that
may arise when blocks are outlined. Because we want the updated CFG to
affect subsequent placement decisions, this change must occur during
placement.

In order to achieve this goal, TailDuplicationPass is split into a
utility class, TailDuplicator, and the pass itself. The pass delegates
nearly everything to the TailDuplicator object, except for looping over
the blocks in a function. This allows the same code to be used for tail
duplication in both places.

This change, in concert with outlining optional branches, allows
triangle shaped code to perform much better, esepecially when the
taken/untaken branches are correlated, as it creates a second spine when
the tests are small enough.

Issue from previous rollback fixed, and a new test was added for that
case as well.

Differential revision: https://reviews.llvm.org/D18226

llvm-svn: 283274
2016-10-04 23:54:18 +00:00
Sanjay Patel bfdbea6481 [Target] move reciprocal estimate settings from TargetOptions to TargetLowering
The motivation for the change is that we can't have pseudo-global settings for
codegen living in TargetOptions because that doesn't work with LTO.

Ideally, these reciprocal attributes will be moved to the instruction-level via
FMF, metadata, or something else. But making them function attributes is at least
an improvement over the current state.

The ingredients of this patch are:

    Remove the reciprocal estimate command-line debug option.
    Add TargetRecip to TargetLowering.
    Remove TargetRecip from TargetOptions.
    Clean up the TargetRecip implementation to work with this new scheme.
    Set the default reciprocal settings in TargetLoweringBase (everything is off).
    Update the PowerPC defaults, users, and tests.
    Update the x86 defaults, users, and tests.

Note that if this patch needs to be reverted, the related clang patch checked in
at r283251 should be reverted too.

Differential Revision: https://reviews.llvm.org/D24816

llvm-svn: 283252
2016-10-04 20:46:43 +00:00
Nemanja Ivanovic 6354d23555 [Power9] Exploit D-Form VSX Scalar memory ops that target full VSX register set
This patch corresponds to review:

The newly added VSX D-Form (register + offset) memory ops target the upper half
of the VSX register set. The existing ones target the lower half. In order to
unify these and have the ability to target all the VSX registers using D-Form
operations, this patch defines Pseudo-ops for the loads/stores which are
expanded post-RA. The expansion then choses the correct opcode based on the
register that was allocated for the operation.

llvm-svn: 283212
2016-10-04 11:25:52 +00:00
Nemanja Ivanovic a565d9e612 Fix a test case failure on Apple PPC.
llvm-svn: 283191
2016-10-04 07:37:38 +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
Kyle Butt 3ffb8529bc Revert "Codegen: Tail-duplicate during placement."
This reverts commit ff234efbe23528e4f4c80c78057b920a51f434b2.

Causing crashes on aarch64 build.

llvm-svn: 283172
2016-10-04 00:38:23 +00:00
Kyle Butt 396bfdd707 Codegen: Tail-duplicate during placement.
The tail duplication pass uses an assumed layout when making duplication
decisions. This is fine, but passes up duplication opportunities that
may arise when blocks are outlined. Because we want the updated CFG to
affect subsequent placement decisions, this change must occur during
placement.

In order to achieve this goal, TailDuplicationPass is split into a
utility class, TailDuplicator, and the pass itself. The pass delegates
nearly everything to the TailDuplicator object, except for looping over
the blocks in a function. This allows the same code to be used for tail
duplication in both places.

This change, in concert with outlining optional branches, allows
triangle shaped code to perform much better, esepecially when the
taken/untaken branches are correlated, as it creates a second spine when
the tests are small enough.

llvm-svn: 283164
2016-10-04 00:00:09 +00:00
Hal Finkel a9321059b9 [PowerPC] Refactor soft-float support, and enable PPC64 soft float
This change enables soft-float for PowerPC64, and also makes soft-float disable
all vector instruction sets for both 32-bit and 64-bit modes. This latter part
is necessary because the PPC backend canonicalizes many Altivec vector types to
floating-point types, and so soft-float breaks scalarization support for many
operations. Both for embedded targets and for operating-system kernels desiring
soft-float support, it seems reasonable that disabling hardware floating-point
also disables vector instructions (embedded targets without hardware floating
point support are unlikely to have Altivec, etc. and operating system kernels
desiring not to use floating-point registers to lower syscall cost are unlikely
to want to use vector registers either). If someone needs this to work, we'll
need to change the fact that we promote many Altivec operations to act on
v4f32. To make it possible to disable Altivec when soft-float is enabled,
hardware floating-point support needs to be expressed as a positive feature,
like the others, and not a negative feature, because target features cannot
have dependencies on the disabling of some other feature. So +soft-float has
now become -hard-float.

Fixes PR26970.

llvm-svn: 283060
2016-10-02 02:10:20 +00:00
Nirav Dave e524f50882 Revert "In visitSTORE, always use FindBetterChain, rather than only when UseAA is enabled."
This reverts commit r282600 due to test failues with MCJIT

llvm-svn: 282604
2016-09-28 16:37:50 +00:00
Nirav Dave e17e055b75 In visitSTORE, always use FindBetterChain, rather than only when UseAA is enabled.
Simplify Consecutive Merge Store Candidate Search

  Now that address aliasing is much less conservative, push through
  simplified store merging search which only checks for parallel stores
  through the chain subgraph. This is cleaner as the separation of
  non-interfering loads/stores from the store-merging logic.

  Whem merging stores, search up the chain through a single load, and
  finds all possible stores by looking down from through a load and a
  TokenFactor to all stores visited. This improves the quality of the
  output SelectionDAG and generally the output CodeGen (with some
  exceptions).

  Additional Minor Changes:

    1. Finishes removing unused AliasLoad code
    2. Unifies the the chain aggregation in the merged stores across
       code paths
    3. Re-add the Store node to the worklist after calling
       SimplifyDemandedBits.
    4. Increase GatherAllAliasesMaxDepth from 6 to 18. That number is
       arbitrary, but seemed sufficient to not cause regressions in
       tests.

  This finishes the change Matt Arsenault started in r246307 and
  jyknight's original patch.

  Many tests required some changes as memory operations are now
  reorderable. Some tests relying on the order were changed to use
  volatile memory operations

  Noteworthy tests:

    CodeGen/AArch64/argument-blocks.ll -
      It's not entirely clear what the test_varargs_stackalign test is
      supposed to be asserting, but the new code looks right.

    CodeGen/AArch64/arm64-memset-inline.lli -
    CodeGen/AArch64/arm64-stur.ll -
    CodeGen/ARM/memset-inline.ll -
      The backend now generates *worse* code due to store merging
      succeeding, as we do do a 16-byte constant-zero store efficiently.

    CodeGen/AArch64/merge-store.ll -
      Improved, but there still seems to be an extraneous vector insert
      from an element to itself?

    CodeGen/PowerPC/ppc64-align-long-double.ll -
      Worse code emitted in this case, due to the improved store->load
      forwarding.

    CodeGen/X86/dag-merge-fast-accesses.ll -
    CodeGen/X86/MergeConsecutiveStores.ll -
    CodeGen/X86/stores-merging.ll -
    CodeGen/Mips/load-store-left-right.ll -
      Restored correct merging of non-aligned stores

    CodeGen/AMDGPU/promote-alloca-stored-pointer-value.ll -
      Improved. Correctly merges buffer_store_dword calls

    CodeGen/AMDGPU/si-triv-disjoint-mem-access.ll -
      Improved. Sidesteps loading a stored value and merges two stores

    CodeGen/X86/pr18023.ll -
      This test has been removed, as it was asserting incorrect
      behavior. Non-volatile stores *CAN* be moved past volatile loads,
      and now are.

    CodeGen/X86/vector-idiv.ll -
    CodeGen/X86/vector-lzcnt-128.ll -
      It's basically impossible to tell what these tests are actually
      testing. But, looks like the code got better due to the memory
      operations being recognized as non-aliasing.

    CodeGen/X86/win32-eh.ll -
      Both loads of the securitycookie are now merged.

    CodeGen/AMDGPU/vgpr-spill-emergency-stack-slot-compute.ll -
      This test appears to work but no longer exhibits the spill
      behavior.

Reviewers: arsenm, hfinkel, tstellarAMD, nhaehnle, jyknight

Subscribers: wdng, nhaehnle, nemanjai, arsenm, weimingz, niravd, RKSimon, aemerson, qcolombet, resistor, tstellarAMD, t.p.northover, spatel

Differential Revision: https://reviews.llvm.org/D14834

llvm-svn: 282600
2016-09-28 15:50:43 +00:00
Nemanja Ivanovic 6f22b41398 [Power9] Builtins for ELF v.2 API conformance - back end portion
This patch corresponds to review:
https://reviews.llvm.org/D24396

This patch adds support for the "vector count trailing zeroes",
"vector compare not equal" and "vector compare not equal or zero instructions"
as well as "scalar count trailing zeroes" instructions. It also changes the
vector negation to use XXLNOR (when VSX is enabled) so as not to increase
register pressure (previously this was done with a splat immediate of all
ones followed by an XXLXOR). This was done because the altivec.h
builtins (patch to follow) use vector negation and the use of an additional
register for the splat immediate is not optimal.

llvm-svn: 282478
2016-09-27 08:42:12 +00:00