Commit Graph

154 Commits

Author SHA1 Message Date
Stefan Maksimovic 58f225b371 [mips] Alter register classes for MSA pseudo f16 instructions
This change introduces additional machine instructions in functions
dealing with the expansion of msa pseudo f16 instructions due to
register classes being inappropriate when checked with machine
verifier.

Differential Revision: https://reviews.llvm.org/D34276

llvm-svn: 308301
2017-07-18 12:05:35 +00:00
Stefan Maksimovic b794c0a5ca [mips][msa] Splat.d endianness check
Before this change, it was always the first element of a vector that got splatted since the lower 6 bits of vshf.d $wd were always zero for little endian.
Additionally, masking has been performed for vshf via which splat.d is created.

Vshf has a property where if its first operand's elements have either bit 6 or 7 set, destination element is set to zero.
Initially masked with 63 to avoid this property, which would result in generation of and.v + vshf.d in all cases.
Masking with one results in generating a single splati.d instruction when possible.

Differential Revision: https://reviews.llvm.org/D32216

llvm-svn: 306090
2017-06-23 09:09:31 +00:00
Nirav Dave da8f221273 Elide stores which are overwritten without being observed.
Summary:
In SelectionDAG, when a store is immediately chained to another store
to the same address, elide the first store as it has no observable
effects. This is causes small improvements dealing with intrinsics
lowered to stores.

Test notes:

* Many testcases overwrite store addresses multiple times and needed
  minor changes, mainly making stores volatile to prevent the
  optimization from optimizing the test away.

* Many X86 test cases optimized out instructions associated with
  associated with va_start.

* Note that test_splat in CodeGen/AArch64/misched-stp.ll no longer has
  dependencies to check and can probably be removed and potentially
  replaced with another test.

Reviewers: rnk, john.brawn

Subscribers: aemerson, rengolin, qcolombet, jyknight, nemanjai, nhaehnle, javed.absar, llvm-commits

Differential Revision: https://reviews.llvm.org/D33206

llvm-svn: 303198
2017-05-16 19:43:56 +00:00
Petar Jovanovic 2b6fe3ffa6 [mips][msa] Mask vectors holding shift amounts
Masked vectors which hold shift amounts when creating the following nodes:
ISD::SHL, ISD::SRL or ISD::SRA.
Instructions that use said nodes, which have had their arguments altered are
sll, srl, sra, bneg, bclr and bset.

For said instructions, the shift amount or the bit position that is
specified in the corresponding vector elements will be interpreted as the
shift amount/bit position modulo the size of the element in bits.

The problem lies in compiling with -O2 enabled, where the instructions for
formats .w and .d are not generated, but are instead optimized away.
In this case, having shift amounts that are either negative or greater than
the element bit size results in generation of incorrect results when
constant folding.

We remedy this by masking the operands for the nodes mentioned above before
actually creating them, so that the final result is correct before placed
into the constant pool.

Patch by Stefan Maksimovic.

Differential Revision: https://reviews.llvm.org/D31331

llvm-svn: 300839
2017-04-20 13:26:46 +00:00
Petar Jovanovic bc54eb89ad [mips][msa] Fix generation of bm(n)zi and bins[lr]i instructions
We have two cases here, the first one being the following instruction
selection from the builtin function:
bm(n)zi builtin -> vselect node -> bins[lr]i machine instruction

In case of bm(n)zi having an immediate which has either its high or low bits
set, a bins[lr] instruction can be selected through the selectVSplatMask[LR]
function. The function counts the number of bits set, and that value is
being passed to the bins[lr]i instruction as its immediate, which in turn
copies immediate modulo the size of the element in bits plus 1 as per specs,
where we get the off-by-one-error.

The other case is:
bins[lr]i -> vselect node -> bsel.v

In this case, a bsel.v instruction gets selected with a mask having one bit
less set than required.

Patch by Stefan Maksimovic.

Differential Revision: https://reviews.llvm.org/D30579

llvm-svn: 299768
2017-04-07 13:31:36 +00:00
Petar Jovanovic 9bff3b7818 [mips][msa] Prevent output operand from commuting for dpadd_[su].df ins
Implementation of TargetInstrInfo::findCommutedOpIndices for MIPS target,
restricting commutativity to second and third operand only for
dpaadd_[su].df instructions therein.

Prior to this change, there were cases where the vector that is to be added
to the dot product of the other two could take a position other than the
first one in the instruction, generating false output in the destination
vector.

Such behavior has been noticed in the two functions generating v2i64 output
values so far. Other ones may exhibit such behavior as well, just not for
the vector operands which are present in the test at the moment.

Tests altered so that the function's first operand is a constant splat so
that it can be loaded with a ldi instruction, since that is the case in
which the erroneous instruction operand placement has occurred. We check
that the register which is present in the ldi instruction is placed as the
first operand in the corresponding dpadd instruction.

Patch by Stefan Maksimovic.

Differential Revision: https://reviews.llvm.org/D30827

llvm-svn: 299223
2017-03-31 14:31:55 +00:00
Nirav Dave 54e22f33d9 In visitSTORE, always use FindBetterChain, rather than only when UseAA is enabled.
Recommiting with compiler time improvements

    Recommitting after fixup of 32-bit aliasing sign offset bug in DAGCombiner.

    * Simplify Consecutive Merge Store Candidate Search

    Now that address aliasing is much less conservative, push through
    simplified store merging search and chain alias analysis 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.

    When 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 the output
    Codegen (save perhaps for some ARM cases where we correctly constructs
    wider loads, but then promotes them to float operations which appear
    but requires more expensive constant generation).

    Some minor peephole optimizations to deal with improved SubDAG shapes (listed below)

    Additional Minor Changes:

      1. Finishes removing unused AliasLoad code

      2. Unifies 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 seems sufficient to not cause regressions in
         tests.

      5. Remove Chain dependencies of Memory operations on CopyfromReg
         nodes as these are captured by data dependence

      6. Forward loads-store values through tokenfactors containing
          {CopyToReg,CopyFromReg} Values.

      7. Peephole to convert buildvector of extract_vector_elt to
         extract_subvector if possible (see
         CodeGen/AArch64/store-merge.ll)

      8. Store merging for the ARM target is restricted to 32-bit as
         some in some contexts invalid 64-bit operations are being
         generated. This can be removed once appropriate checks are
         added.

    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, improving load-store forwarding. One test in
    particular is worth noting:

      CodeGen/PowerPC/ppc64-align-long-double.ll - Improved load-store
      forwarding converts a load-store pair into a parallel store and
      a memory-realized bitcast of the same value. However, because we
      lose the sharing of the explicit and implicit store values we
      must create another local store. A similar transformation
      happens before SelectionDAG as well.

    Reviewers: arsenm, hfinkel, tstellarAMD, jyknight, nhaehnle

llvm-svn: 297695
2017-03-14 00:34:14 +00:00
Simon Dardis 7090d145e8 [mips][msa] Accept more values for constant splats
This patches teaches the MIPS backend to accept more values for constant
splats. Previously, only 10 bit signed immediates or values that could be
loaded using an ldi.[bhwd] instruction would be acceptted. This patch relaxes
that constraint so that any constant value that be splatted is accepted.

As a result, the constant pool is used less for vector operations, and the
suite of bit manipulation instructions b(clr|set|neg)i can now be used with
the full range of their immediate operand.

Reviewers: slthakur

Differential Revision: https://reviews.llvm.org/D30640

llvm-svn: 297457
2017-03-10 13:27:14 +00:00
Chandler Carruth ce52b80744 [SDAG] Revert r296476 (and r296486, r296668, r296690).
This patch causes compile times for some patterns to explode. I have
a (large, unreduced) test case that slows down by more than 20x and
several test cases slow down by 2x. I'm sending some of the test cases
directly to Nirav and following up with more details in the review log,
but this should unblock anyone else hitting this.

llvm-svn: 296862
2017-03-03 10:02:25 +00:00
Nirav Dave f830dec3f2 In visitSTORE, always use FindBetterChain, rather than only when UseAA is enabled.
Recommiting after fixup of 32-bit aliasing sign offset bug in DAGCombiner.

    * Simplify Consecutive Merge Store Candidate Search

    Now that address aliasing is much less conservative, push through
    simplified store merging search and chain alias analysis 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.

    When 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 the output
    Codegen (save perhaps for some ARM cases where we correctly constructs
    wider loads, but then promotes them to float operations which appear
    but requires more expensive constant generation).

    Some minor peephole optimizations to deal with improved SubDAG shapes (listed below)

    Additional Minor Changes:

      1. Finishes removing unused AliasLoad code

      2. Unifies 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 seems sufficient to not cause regressions in
         tests.

      5. Remove Chain dependencies of Memory operations on CopyfromReg
         nodes as these are captured by data dependence

      6. Forward loads-store values through tokenfactors containing
          {CopyToReg,CopyFromReg} Values.

      7. Peephole to convert buildvector of extract_vector_elt to
         extract_subvector if possible (see
         CodeGen/AArch64/store-merge.ll)

      8. Store merging for the ARM target is restricted to 32-bit as
         some in some contexts invalid 64-bit operations are being
         generated. This can be removed once appropriate checks are
         added.

    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, improving load-store forwarding. One test in
    particular is worth noting:

      CodeGen/PowerPC/ppc64-align-long-double.ll - Improved load-store
      forwarding converts a load-store pair into a parallel store and
      a memory-realized bitcast of the same value. However, because we
      lose the sharing of the explicit and implicit store values we
      must create another local store. A similar transformation
      happens before SelectionDAG as well.

    Reviewers: arsenm, hfinkel, tstellarAMD, jyknight, nhaehnle

llvm-svn: 296476
2017-02-28 14:24:15 +00:00
Nirav Dave 73cd0194cf Revert "In visitSTORE, always use FindBetterChain, rather than only when UseAA is enabled."
This reverts commit r296252 until 256-bit operations are more efficiently generated in X86.

llvm-svn: 296279
2017-02-26 01:27:32 +00:00
Nirav Dave beabf456df In visitSTORE, always use FindBetterChain, rather than only when UseAA is enabled.
Recommiting after fixup of 32-bit aliasing sign offset bug in DAGCombiner.

    * Simplify Consecutive Merge Store Candidate Search

    Now that address aliasing is much less conservative, push through
    simplified store merging search and chain alias analysis 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.

    When 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 the output
    Codegen (save perhaps for some ARM cases where we correctly constructs
    wider loads, but then promotes them to float operations which appear
    but requires more expensive constant generation).

    Some minor peephole optimizations to deal with improved SubDAG shapes (listed below)

    Additional Minor Changes:

      1. Finishes removing unused AliasLoad code

      2. Unifies 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 seems sufficient to not cause regressions in
         tests.

      5. Remove Chain dependencies of Memory operations on CopyfromReg
         nodes as these are captured by data dependence

      6. Forward loads-store values through tokenfactors containing
          {CopyToReg,CopyFromReg} Values.

      7. Peephole to convert buildvector of extract_vector_elt to
         extract_subvector if possible (see
         CodeGen/AArch64/store-merge.ll)

      8. Store merging for the ARM target is restricted to 32-bit as
         some in some contexts invalid 64-bit operations are being
         generated. This can be removed once appropriate checks are
         added.

    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, improving load-store forwarding. One test in
    particular is worth noting:

      CodeGen/PowerPC/ppc64-align-long-double.ll - Improved load-store
      forwarding converts a load-store pair into a parallel store and
      a memory-realized bitcast of the same value. However, because we
      lose the sharing of the explicit and implicit store values we
      must create another local store. A similar transformation
      happens before SelectionDAG as well.

    Reviewers: arsenm, hfinkel, tstellarAMD, jyknight, nhaehnle

llvm-svn: 296252
2017-02-25 11:43:58 +00:00
Nirav Dave 93f9d5ce04 Revert "In visitSTORE, always use FindBetterChain, rather than only when UseAA is enabled."
This reverts commit r293893 which is miscompiling lua on ARM and
bootstrapping for x86-windows.

llvm-svn: 293915
2017-02-02 18:24:55 +00:00
Nirav Dave 4442667fc5 In visitSTORE, always use FindBetterChain, rather than only when UseAA is enabled.
Recommiting after fixing X86 inc/dec chain bug.

    * Simplify Consecutive Merge Store Candidate Search

    Now that address aliasing is much less conservative, push through
    simplified store merging search and chain alias analysis 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.

    When 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 the output
    Codegen (save perhaps for some ARM cases where we correctly constructs
    wider loads, but then promotes them to float operations which appear
    but requires more expensive constant generation).

    Some minor peephole optimizations to deal with improved SubDAG shapes (listed below)

    Additional Minor Changes:

      1. Finishes removing unused AliasLoad code

      2. Unifies 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 seems sufficient to not cause regressions in
         tests.

      5. Remove Chain dependencies of Memory operations on CopyfromReg
         nodes as these are captured by data dependence

      6. Forward loads-store values through tokenfactors containing
          {CopyToReg,CopyFromReg} Values.

      7. Peephole to convert buildvector of extract_vector_elt to
         extract_subvector if possible (see
         CodeGen/AArch64/store-merge.ll)

      8. Store merging for the ARM target is restricted to 32-bit as
         some in some contexts invalid 64-bit operations are being
         generated. This can be removed once appropriate checks are
         added.

    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, improving load-store forwarding. One test in
    particular is worth noting:

      CodeGen/PowerPC/ppc64-align-long-double.ll - Improved load-store
      forwarding converts a load-store pair into a parallel store and
      a memory-realized bitcast of the same value. However, because we
      lose the sharing of the explicit and implicit store values we
      must create another local store. A similar transformation
      happens before SelectionDAG as well.

    Reviewers: arsenm, hfinkel, tstellarAMD, jyknight, nhaehnle

llvm-svn: 293893
2017-02-02 14:39:42 +00:00
Nirav Dave d32a421f75 Revert "In visitSTORE, always use FindBetterChain, rather than only when UseAA is enabled."
This reverts commit r293184 which is failing in LTO builds

llvm-svn: 293188
2017-01-26 16:46:13 +00:00
Nirav Dave de6516c466 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 and chain alias analysis 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.

    When 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 the output
    Codegen (save perhaps for some ARM cases where we correctly constructs
    wider loads, but then promotes them to float operations which appear
    but requires more expensive constant generation).

    Some minor peephole optimizations to deal with improved SubDAG shapes (listed below)

    Additional Minor Changes:

      1. Finishes removing unused AliasLoad code

      2. Unifies 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 seems sufficient to not cause regressions in
         tests.

      5. Remove Chain dependencies of Memory operations on CopyfromReg
         nodes as these are captured by data dependence

      6. Forward loads-store values through tokenfactors containing
          {CopyToReg,CopyFromReg} Values.

      7. Peephole to convert buildvector of extract_vector_elt to
         extract_subvector if possible (see
         CodeGen/AArch64/store-merge.ll)

      8. Store merging for the ARM target is restricted to 32-bit as
         some in some contexts invalid 64-bit operations are being
         generated. This can be removed once appropriate checks are
         added.

    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, improving load-store forwarding. One test in
    particular is worth noting:

      CodeGen/PowerPC/ppc64-align-long-double.ll - Improved load-store
      forwarding converts a load-store pair into a parallel store and
      a memory-realized bitcast of the same value. However, because we
      lose the sharing of the explicit and implicit store values we
      must create another local store. A similar transformation
      happens before SelectionDAG as well.

    Reviewers: arsenm, hfinkel, tstellarAMD, jyknight, nhaehnle

llvm-svn: 293184
2017-01-26 16:02:24 +00:00
Simon Dardis 548a53f5ee [mips] Fix Mips MSA instrinsics
The usage of some MIPS MSA instrinsics that took immediates could crash LLVM
during lowering. This patch addresses that behaviour. Crucially this patch
also makes the use of intrinsics with out of range immediates as producing an
internal error.

The ld,st instrinsics would trigger an assertion failure for MIPS64 as their
lowering would attempt to add an i32 offset to a i64 pointer.

Reviewers: vkalintiris, slthakur

Differential Revision: https://reviews.llvm.org/D25438

llvm-svn: 291571
2017-01-10 16:40:57 +00:00
Simon Dardis 0e9e237310 [mips] Honour -mno-odd-spreg for vector splat (again)
Previous the lowering of FILL_FW would use the MSA128W register class when
performing a vector splat. Instead it should be honouring -mno-odd-spreg and
only use the even registers when performing a splat from word to vector
register.

Logical follow-on from r230235.

This fixes PR/31369.

A previous commit was missing the test case and had another differential
in it.

Reviewers: slthakur

Differential Revision: https://reviews.llvm.org/D28373

llvm-svn: 291566
2017-01-10 15:53:10 +00:00
Nirav Dave f5bf03c7ef Revert "In visitSTORE, always use FindBetterChain, rather than only when UseAA is enabled."
Reverting due to ARM MCJIT and MIPS LLD error.

This reverts commit r289659.

llvm-svn: 289667
2016-12-14 16:43:44 +00:00
Nirav Dave 8527ab0ad2 In visitSTORE, always use FindBetterChain, rather than only when UseAA is enabled.
Retrying after fixing after removing load-store factoring through
token factors in favor of improved token factor operand pruning

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.

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: 289659
2016-12-14 15:44:26 +00:00
Nirav Dave bedb5d906c Revert "In visitSTORE, always use FindBetterChain, rather than only when UseAA is enabled."
This reverts commit r289221 which appears to be triggering an assertion

llvm-svn: 289226
2016-12-09 17:18:24 +00:00
Nirav Dave fd51ff4fd8 In visitSTORE, always use FindBetterChain, rather than only when UseAA is enabled.
Retrying after fixing overly aggressive load-store forwarding optimization.

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.

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: 289221
2016-12-09 16:15:12 +00:00
Simon Dardis 40a5040cd8 [mips] Add tests for half precision floating point support.
These should have been part of r287349.

llvm-svn: 287574
2016-11-21 20:34:10 +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
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
Hrvoje Varga 00d96ee7b9 [mips] Clang generates unaligned offset for MSA instruction st.d
Differential Revision: https://reviews.llvm.org/D19475

llvm-svn: 277323
2016-08-01 06:46:20 +00:00
Daniel Sanders 6a73883c48 [mips] Correct label prefixes for N32 and N64.
Summary:
N32 and N64 follow the standard ELF conventions (.L) whereas O32 uses its own
($).

This fixes the majority of object differences between -fintegrated-as and
-fno-integrated-as.

Reviewers: sdardis

Subscribers: dsanders, sdardis, llvm-commits

Differential Revision: https://reviews.llvm.org/D22412

llvm-svn: 275967
2016-07-19 10:49:03 +00:00
Daniel Sanders 0d97270ae5 [mips] Use --check-prefixes where appropriate. NFC.
llvm-svn: 273669
2016-06-24 12:23:17 +00:00
Daniel Sanders d3bb20821d [mips][msa] Fix register/register-class mismatches in emitINSERT_DF_VIDX().
Reviewers: sdardis

Subscribers: dsanders, sdardis, llvm-commits

Differential Revision: http://reviews.llvm.org/D21068

llvm-svn: 272765
2016-06-15 08:43:23 +00:00
Daniel Sanders d2a49ec3ab [mips][msa] copyPhysReg() should not set RegState::Define on result of CTCMSA.
Summary:
The machine verifier reports 'Explicit operand marked as def' when it is
manually specified even though it agrees with the operand info.

Reviewers: sdardis

Subscribers: dsanders, sdardis, llvm-commits

Differential Revision: http://reviews.llvm.org/D21065

llvm-svn: 272646
2016-06-14 09:11:33 +00:00
Petar Jovanovic e578e970cb [mips] Make Static a default relocation model for MIPS codegen
This change follows up defaults for GCC and Clang, so LLVM does not differ
from them. While number of the test files are touched with this change, they
all keep the old (expected) behaviour with the explicit option:
"-relocation-model=pic"
The tests that have not been touched are insensitive to relocation model.

Differential Revision: http://reviews.llvm.org/D17995

llvm-svn: 265949
2016-04-11 15:24:23 +00:00
Daniel Sanders 0f596814e9 [mips][msa] Remove copy_u.d and move copy_u.w to MSA64.
Summary:
The forwards compatibility strategy employed by MIPS is to consider registers
to be infinitely sign-extended. Then on ISA's with a wider register, the result
of existing instructions are sign-extended to register width and zero-extended
counterparts are added. copy_u.w on MSA32 and copy_u.w on MSA64 violate this
strategy and we have therefore corrected the MSA specs to fix this.

We still keep track of sign/zero-extension during legalization but we now
match copy_s.[wd] where required.

No change required to clang since __builtin_msa_copy_u_[wd] will map to
copy_s.[wd] where appropriate for the target.

Reviewers: vkalintiris

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D13472

llvm-svn: 250887
2015-10-21 09:58:54 +00:00
Daniel Sanders c8cd58fa26 [mips] Correct and improve special-case shuffle instructions.
Summary:
The documentation writes vectors highest-index first whereas LLVM-IR writes
them lowest-index first. As a result, instructions defined in terms of
left_half() and right_half() had the halves reversed.

In addition to correcting them, they have been improved to allow shuffles
that use the same operand twice or in reverse order. For example, ilvev
used to accept masks of the form:
  <0, n, 2, n+2, 4, n+4, ...>
but now accepts:
  <0, 0, 2, 2, 4, 4, ...>
  <n, n, n+2, n+2, n+4, n+4, ...>
  <0, n, 2, n+2, 4, n+4, ...>
  <n, 0, n+2, 2, n+4, 4, ...>

One further improvement is that splati.[bhwd] is now the preferred instruction
for splat-like operations. The other special shuffles are no longer used
for splats. This lead to the discovery that <0, 0, ...> would not cause
splati.[hwd] to be selected and this has also been fixed.

This fixes the enc-3des test from the test-suite on Mips64r6 with MSA.

Reviewers: vkalintiris

Reviewed By: vkalintiris

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D9660

llvm-svn: 237689
2015-05-19 12:24:52 +00:00
Daniel Sanders eda60d217b [mips] Generate code for insert/extract operations when using the N64 ABI and MSA.
Summary:
When using the N64 ABI, element-indices use the i64 type instead of i32.
In many cases, we can use iPTR to account for this but additional patterns
and pseudo's are also required.

This fixes most (but not quite all) failures in the test-suite when using
N64 and MSA together.

Reviewers: vkalintiris

Reviewed By: vkalintiris

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D9342

llvm-svn: 236494
2015-05-05 10:32:24 +00:00
Daniel Sanders 4160c802d9 [mips][msa] Test basic operations for the N32 ABI too.
Summary:
This required adding instruction aliases for dneg.

N64 will be enabled shortly but requires additional bugfixes.

Reviewers: vkalintiris

Reviewed By: vkalintiris

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D9341

llvm-svn: 236489
2015-05-05 08:48:35 +00:00
Daniel Sanders 59f89aa8ed [mips][msa] Rename main check prefix to 'ALL' in basic operations tests. NFC
Summary:
The majority of the checks are subtarget independent. The few that aren't
will be corrected shortly.

Reviewers: vkalintiris

Reviewed By: vkalintiris

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D9340

llvm-svn: 236220
2015-04-30 09:57:37 +00:00
Daniel Sanders fa159165be [mips][msa] Use CHECK-LABEL where missing, and remove checks matching the .size directive. NFC.
Summary: 

Reviewers: vkalintiris

Reviewed By: vkalintiris

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D9339

llvm-svn: 236219
2015-04-30 09:56:30 +00:00
Daniel Sanders 90b059d555 [mips] Add missing signext attributes to MSA basic operations tests. NFC.
Summary:
This doesn't make much difference to MIPS32, but it will simplify a
MIPS64r6 bugfix which will follow shortly by removing unnecessary
sign-extension of parameters.

Reviewers: vkalintiris

Reviewed By: vkalintiris

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D9338

llvm-svn: 236216
2015-04-30 09:24:09 +00:00
David Blaikie a79ac14fa6 [opaque pointer type] Add textual IR support for explicit type parameter to load instruction
Essentially the same as the GEP change in r230786.

A similar migration script can be used to update test cases, though a few more
test case improvements/changes were required this time around: (r229269-r229278)

import fileinput
import sys
import re

pat = re.compile(r"((?:=|:|^)\s*load (?:atomic )?(?:volatile )?(.*?))(| addrspace\(\d+\) *)\*($| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$)")

for line in sys.stdin:
  sys.stdout.write(re.sub(pat, r"\1, \2\3*\4", line))

Reviewers: rafael, dexonsmith, grosser

Differential Revision: http://reviews.llvm.org/D7649

llvm-svn: 230794
2015-02-27 21:17:42 +00:00
David Blaikie 79e6c74981 [opaque pointer type] Add textual IR support for explicit type parameter to getelementptr instruction
One of several parallel first steps to remove the target type of pointers,
replacing them with a single opaque pointer type.

This adds an explicit type parameter to the gep instruction so that when the
first parameter becomes an opaque pointer type, the type to gep through is
still available to the instructions.

* This doesn't modify gep operators, only instructions (operators will be
  handled separately)

* Textual IR changes only. Bitcode (including upgrade) and changing the
  in-memory representation will be in separate changes.

* geps of vectors are transformed as:
    getelementptr <4 x float*> %x, ...
  ->getelementptr float, <4 x float*> %x, ...
  Then, once the opaque pointer type is introduced, this will ultimately look
  like:
    getelementptr float, <4 x ptr> %x
  with the unambiguous interpretation that it is a vector of pointers to float.

* address spaces remain on the pointer, not the type:
    getelementptr float addrspace(1)* %x
  ->getelementptr float, float addrspace(1)* %x
  Then, eventually:
    getelementptr float, ptr addrspace(1) %x

Importantly, the massive amount of test case churn has been automated by
same crappy python code. I had to manually update a few test cases that
wouldn't fit the script's model (r228970,r229196,r229197,r229198). The
python script just massages stdin and writes the result to stdout, I
then wrapped that in a shell script to handle replacing files, then
using the usual find+xargs to migrate all the files.

update.py:
import fileinput
import sys
import re

ibrep = re.compile(r"(^.*?[^%\w]getelementptr inbounds )(((?:<\d* x )?)(.*?)(| addrspace\(\d\)) *\*(|>)(?:$| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$))")
normrep = re.compile(       r"(^.*?[^%\w]getelementptr )(((?:<\d* x )?)(.*?)(| addrspace\(\d\)) *\*(|>)(?:$| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$))")

def conv(match, line):
  if not match:
    return line
  line = match.groups()[0]
  if len(match.groups()[5]) == 0:
    line += match.groups()[2]
  line += match.groups()[3]
  line += ", "
  line += match.groups()[1]
  line += "\n"
  return line

for line in sys.stdin:
  if line.find("getelementptr ") == line.find("getelementptr inbounds"):
    if line.find("getelementptr inbounds") != line.find("getelementptr inbounds ("):
      line = conv(re.match(ibrep, line), line)
  elif line.find("getelementptr ") != line.find("getelementptr ("):
    line = conv(re.match(normrep, line), line)
  sys.stdout.write(line)

apply.sh:
for name in "$@"
do
  python3 `dirname "$0"`/update.py < "$name" > "$name.tmp" && mv "$name.tmp" "$name"
  rm -f "$name.tmp"
done

The actual commands:
From llvm/src:
find test/ -name *.ll | xargs ./apply.sh
From llvm/src/tools/clang:
find test/ -name *.mm -o -name *.m -o -name *.cpp -o -name *.c | xargs -I '{}' ../../apply.sh "{}"
From llvm/src/tools/polly:
find test/ -name *.ll | xargs ./apply.sh

After that, check-all (with llvm, clang, clang-tools-extra, lld,
compiler-rt, and polly all checked out).

The extra 'rm' in the apply.sh script is due to a few files in clang's test
suite using interesting unicode stuff that my python script was throwing
exceptions on. None of those files needed to be migrated, so it seemed
sufficient to ignore those cases.

Reviewers: rafael, dexonsmith, grosser

Differential Revision: http://reviews.llvm.org/D7636

llvm-svn: 230786
2015-02-27 19:29:02 +00:00
Matt Arsenault 6cc00429ff Fix fmul combines with constant splat vectors
Fixes things like fmul x, 2 -> fadd x, x

llvm-svn: 215820
2014-08-16 10:14:19 +00:00
Toma Tabacu 726f1ea2c5 [mips] Improve robustness of some tests.
Summary:
This is done by removing some hardcoded registers like $at or expecting a single digit register to be selected.

Contains work done by Matheus Almeida.

Reviewers: matheusalmeida, dsanders

Reviewed By: dsanders

Subscribers: tomatabacu

Differential Revision: http://reviews.llvm.org/D4227

llvm-svn: 215640
2014-08-14 13:10:48 +00:00
Zoran Jovanovic 6a29b55a5a ps][mips64r6] Added LSA/DLSA instructions
Differential Revision: http://reviews.llvm.org/D3897

llvm-svn: 211346
2014-06-20 09:28:09 +00:00
Daniel Sanders e296a0fce5 [mips][msa] Fix vector insertions where the index is variable
Summary:
This isn't supported directly so we rotate the vector by the desired number of
elements, insert to element zero, then rotate back.

The i64 case generates rather poor code on MIPS32. There is an obvious
optimisation to be made in future (do both insert.w's inside a shared 
rotate/unrotate sequence) but for now it's sufficient to select valid code
instead of aborting.

Depends on D3536

Reviewers: matheusalmeida

Reviewed By: matheusalmeida

Differential Revision: http://reviews.llvm.org/D3537

llvm-svn: 207640
2014-04-30 12:09:32 +00:00
Daniel Sanders 6857800b67 [mips][msa] Use CHECK-LABEL in basic_operations*.ll
Differential Revision: http://reviews.llvm.org/D3536

llvm-svn: 207529
2014-04-29 14:28:58 +00:00
Daniel Sanders b3268e71e2 [mips][msa] Fix element extraction where the index is variable.
Summary:
This isn't supported directly so we splat the vector element and extract
the most convenient copy.

Reviewers: matheusalmeida

Reviewed By: matheusalmeida

Differential Revision: http://reviews.llvm.org/D3530

llvm-svn: 207524
2014-04-29 13:31:37 +00:00
Daniel Sanders f88a29e66a [mips] Correct lowering of VECTOR_SHUFFLE to VSHF.
Summary:
VECTOR_SHUFFLE concatenates the vectors in an vectorwise fashion.
  <0b00, 0b01> + <0b10, 0b11> -> <0b00, 0b01, 0b10, 0b11>
VSHF concatenates the vectors in a bitwise fashion:
  <0b00, 0b01> + <0b10, 0b11> ->
  0b0100       + 0b1110       -> 0b01001110
                                 <0b10, 0b11, 0b00, 0b01>
We must therefore swap the operands to get the correct result.

The test case that discovered the issue was MultiSource/Benchmarks/nbench.

Reviewers: matheusalmeida

Reviewed By: matheusalmeida

Differential Revision: http://llvm-reviews.chandlerc.com/D3142

llvm-svn: 204480
2014-03-21 16:56:51 +00:00
Daniel Sanders df22154579 [mips] BSEL's and BINS[RL] operands are reversed compared to the vselect node used in the pattern.
Summary:
Correct the match patterns and the lowerings that made the CodeGen tests pass despite the mistakes.

The original testcase that discovered the problem was SingleSource/UnitTests/SignlessType/factor.c in test-suite.
During review, we also found that some of the existing CodeGen tests were incorrect and fixed them:
* bitwise.ll: In bsel_v16i8 the IfSet/IfClear were reversed because bsel and bmnz have different operand orders and the test didn't correctly account for this. bmnz goes 'IfClear, IfSet, CondMask', while bsel goes 'CondMask, IfClear, IfSet'.
* vec.ll: In the cases where a bsel is emitted as a bmnz (they are the same operation with a different input tied to the result) the operands were in the wrong order.
* compare.ll and compare_float.ll: The bsel operand order was correct for a greater-than comparison, but a greater-than comparison instruction doesn't exist. Lowering this operation inverts the condition so the IfSet/IfClear need to be swapped to match.

The differences between BSEL, BMNZ, and BMZ and how they map to/from vselect are rather confusing. I've therefore added a note to MSA.txt to explain this in a single place in addition to the comments that explain each case.

Reviewers: matheusalmeida, jacksprat

Reviewed By: matheusalmeida

Differential Revision: http://llvm-reviews.chandlerc.com/D3028

llvm-svn: 203657
2014-03-12 11:54:00 +00:00