Commit Graph

1438 Commits

Author SHA1 Message Date
Nemanja Ivanovic 96c3d626a2 [PowerPC] Eliminate integer compare instructions - vol. 1
This patch is the first in a series of patches to provide code gen for
doing compares in GPRs when the compare result is required in a GPR.

It adds the infrastructure to select GPR sequences for i1->i32 and i1->i64
extensions. This first patch handles equality comparison on i32 operands with
the result sign or zero extended.

Differential Revision: https://reviews.llvm.org/D31847

llvm-svn: 302810
2017-05-11 16:54:23 +00:00
Serge Pavlov d526b13e61 Add extra operand to CALLSEQ_START to keep frame part set up previously
Using arguments with attribute inalloca creates problems for verification
of machine representation. This attribute instructs the backend that the
argument is prepared in stack prior to  CALLSEQ_START..CALLSEQ_END
sequence (see http://llvm.org/docs/InAlloca.htm for details). Frame size
stored in CALLSEQ_START in this case does not count the size of this
argument. However CALLSEQ_END still keeps total frame size, as caller can
be responsible for cleanup of entire frame. So CALLSEQ_START and
CALLSEQ_END keep different frame size and the difference is treated by
MachineVerifier as stack error. Currently there is no way to distinguish
this case from actual errors.

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

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

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

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

llvm-svn: 302527
2017-05-09 13:35:13 +00:00
Krzysztof Parzyszek 038a0546db [PPC] When restoring R30 (PIC base pointer), mark it as <def>
This happened on the PPC32/SVR4 path and was discovered when building
FreeBSD on PPC32. It was a typo-class error in the frame lowering code.

This fixes PR26519.

llvm-svn: 302183
2017-05-04 19:14:54 +00:00
Tim Shen e59d06fe78 [PowerPC, DAGCombiner] Fold a << (b % (sizeof(a) * 8)) back to a single instruction
Summary:
This is the corresponding llvm change to D28037 to ensure no performance
regression.

Reviewers: bogner, kbarton, hfinkel, iteratee, echristo

Subscribers: nemanjai, llvm-commits

Differential Revision: https://reviews.llvm.org/D28329

llvm-svn: 301990
2017-05-03 00:07:02 +00:00
Nemanja Ivanovic b89c27f515 [PowerPC] Emit VMX loads/stores for aligned ops to avoid adding swaps on LE
Fixes PR30730.
This is a re-commit of a pulled commit. The commit was pulled because some
software projects contained uses of Altivec vectors that violated alignment
requirements. Known issues have now been fixed.

Committing on behalf of Lei Huang.

Differential Revision: https://reviews.llvm.org/D26861

llvm-svn: 301892
2017-05-02 01:47:34 +00:00
Sanjoy Das ba0daee6b2 [StackMaps] Increase the size of the "location size" field
Summary:
In some cases LLVM (especially the SLP vectorizer) will create vectors
that are 256 bytes (or larger).  Given that this is intentional[0] is
likely to get more common, this patch updates the StackMap binary
format to deal with the spill locations for said vectors.

This change also bumps the stack map version from 2 to 3.

[0]: https://reviews.llvm.org/D32533#738350

Reviewers: reames, kavon, skatkov, javed.absar

Subscribers: mcrosier, nemanjai, llvm-commits

Differential Revision: https://reviews.llvm.org/D32629

llvm-svn: 301615
2017-04-28 04:48:42 +00:00
Adrian Prantl 083e6a5b5c Don't emit CFI instructions at the end of a function
When functions are terminated by unreachable instructions, the last
instruction might trigger a CFI instruction to be generated. However,
emitting it would be be illegal since the function (and thus the FDE
the CFI is in) has already ended with the previous instruction.

Darwin's dwarfdump --verify --eh-frame complains about this and the
specification supports this.
Relevant bits from the DWARF 5 standard (6.4 Call Frame Information):

"[The] address_range [field in an FDE]: The number of bytes of
 program instructions described by this entry."

"Row creation instructions: [...]
 The new location value is always greater than the current one."
The first quotation implies that a CFI cannot describe a target
address outside of the enclosing FDE's range.

rdar://problem/26244988

Differential Revision: https://reviews.llvm.org/D32246

llvm-svn: 301219
2017-04-24 18:45:59 +00:00
Sanjay Patel ae382bb6af [DAG] add splat vector support for 'xor' in SimplifyDemandedBits
This allows forming more 'not' ops, so we get improvements for ISAs that have and-not.

Follow-up to:
https://reviews.llvm.org/rL300725

llvm-svn: 300763
2017-04-19 21:23:09 +00:00
Sanjay Patel c9d36f181f [PowerPC] add test and auto-generate checks; NFC
llvm-svn: 300700
2017-04-19 14:58:09 +00:00
Hal Finkel cef9e52736 [PowerPC] multiply-with-overflow might use the CTR register
Check the legality of ISD::[US]MULO to see whether
Intrinsic::[us]mul_with_overflow will legalize into a function call (and, thus,
will use the CTR register).  Fixes PR32485.

Patch by Tim Neumann!

Differential Revision: https://reviews.llvm.org/D31790

llvm-svn: 299910
2017-04-11 02:03:17 +00:00
Matt Arsenault f10061ec70 Add address space mangling to lifetime intrinsics
In preparation for allowing allocas to have non-0 addrspace.

llvm-svn: 299876
2017-04-10 20:18:21 +00:00
Eli Friedman 5fba1e53f2 Turn on -addr-sink-using-gep by default.
The new codepath has been in the tree for years, and there isn't any
reason to use two codepaths here.

Differential Revision: https://reviews.llvm.org/D30596

llvm-svn: 299723
2017-04-06 22:42:18 +00:00
Sanjay Patel b2f1621bb1 [DAGCombiner] add and use TLI hook to convert and-of-seteq / or-of-setne to bitwise logic+setcc (PR32401)
This is a generic combine enabled via target hook to reduce icmp logic as discussed in:
https://bugs.llvm.org/show_bug.cgi?id=32401

It's likely that other targets will want to enable this hook for scalar transforms, 
and there are probably other patterns that can use bitwise logic to reduce comparisons.

Note that we are missing an IR canonicalization for these patterns, and we will probably
prefer the pair-of-compares form in IR (shorter, more likely to fold).

Differential Revision: https://reviews.llvm.org/D31483

llvm-svn: 299542
2017-04-05 14:09:39 +00:00
Sanjay Patel a4546efbc8 add/move codegen tests for and/or of setcc; NFC
llvm-svn: 299396
2017-04-03 22:45:46 +00:00
Sanjay Patel 665021e7ee [DAGCombiner] enable vector transforms for any/all {sign} bits set/clear
The code already allowed vector types in via "isInteger" (which might want
a more specific name), so use splat-friendly constant predicates to match
those types.

llvm-svn: 299304
2017-04-01 15:05:54 +00:00
Sanjay Patel fe9340c168 [PowerPC, x86] add vector tests for any/all {sign} bits set/clear; NFC
llvm-svn: 299303
2017-04-01 14:32:18 +00:00
Sanjay Patel 34da36e74f [DAGCombiner] add fold for 'All sign bits set?'
(and (setlt X,  0), (setlt Y,  0)) --> (setlt (and X, Y),  0)

We have 7 similar folds, but this one got away. The fact that the
x86 test with a branch didn't change is probably a separate bug. We
may also be missing this and the related folds in instcombine.

llvm-svn: 299252
2017-03-31 20:28:06 +00:00
Sanjay Patel a97d36fdda [PowerPC] add tests for setcc+setcc+logic; NFC
These are the same tests added for x86 with r299238,
but PPC doesn't specify all branches as cheap, so we 
see different patterns in tests with branches.

llvm-svn: 299244
2017-03-31 18:51:03 +00:00
Eric Christopher 9fd267c221 Temporarily revert "[PPC] In PPCBoolRetToInt change the bool value to i64 if the target is ppc64" as it's causing test failures, I've given Carrot a testcase offline.
This reverts commit r298955.

llvm-svn: 299153
2017-03-31 02:16:54 +00:00
Eric Christopher bf8f759305 Add testcase for r299124.
Patch by Tim Shen!

llvm-svn: 299125
2017-03-30 22:35:10 +00:00
Adam Nemet edaec6de73 [DAGCombiner] Initial support for the fast-math flag contract
Now alternatively to the TargetOption.AllowFPOpFusion global flag, FMUL->FADD
can also use the per operation FMF to allow fusion.

The idea here is not to port everything to the new scheme (e.g. fused
multiply-and-sub will be ported later) but that this work all the way from
clang.

The transformation is conditionalized on *both* the FADD and the FMUL having
the FMF contract flag.

Differential Revision: https://reviews.llvm.org/D31169

llvm-svn: 299096
2017-03-30 18:53:04 +00:00
Sanjay Patel b8a728f993 [CodeGen] clean up and add tests for scalar and-of-setcc; NFC
https://bugs.llvm.org/show_bug.cgi?id=32401

llvm-svn: 299034
2017-03-29 21:58:52 +00:00
Guozhi Wei f8d40181c9 [PPC] In PPCBoolRetToInt change the bool value to i64 if the target is ppc64
In PPCBoolRetToInt bool value is changed to i32 type. On ppc64 it may introduce an extra zero extension for the return value. This patch changes the integer type to i64 to avoid the zero extension on ppc64.

This patch fixed PR32442.

Differential Revision: https://reviews.llvm.org/D31407

llvm-svn: 298955
2017-03-28 22:55:01 +00:00
Dehao Chen b197d5b0a0 Fix trellis layout to avoid mis-identify triangle.
Summary:
For the following CFG:

A->B
B->C
A->C

If there is another edge B->D, then ABC should not be considered as triangle.

Reviewers: davidxl, iteratee

Reviewed By: iteratee

Subscribers: nemanjai, llvm-commits

Differential Revision: https://reviews.llvm.org/D31310

llvm-svn: 298661
2017-03-23 23:28:09 +00:00
Tim Shen ce26a45f7c [PPC] Add generated tests for all atomic operations
Summary: Add tests for all atomic operations for powerpc64le, so that all changes can be easily examined.

Reviewers: kbarton, hfinkel, echristo

Subscribers: mehdi_amini, nemanjai, llvm-commits

Differential Revision: https://reviews.llvm.org/D31285

llvm-svn: 298614
2017-03-23 16:02:47 +00:00
Oren Ben Simhon 9ce0ec5dbc CalleeSavedRegister was removed from MIR and is recalculated upon MIR parsing.
llvm-svn: 298210
2017-03-19 11:18:09 +00:00
Kyle Butt d609d6ebf0 CodeGen: BlockPlacement: Adjust test case so it covers rL297925. NFC
I had ajusted the test case before when testing a chain of length 2, and then
reverted it with rL296845 when I switched to 3 triangles. After running
benchmarks and examining generated code at length 2 I forgot to put the test
back.

llvm-svn: 298000
2017-03-16 21:33:29 +00:00
Nemanja Ivanovic ffcf0fb1cc [PowerPC][Altivec] Add mfvrd and mffprd extended mnemonic
mfvrd and mffprd are both alias to mfvrsd.
This patch enables correct parsing of the aliases, but we still emit a mfvrsd.

Committing on behalf of brunoalr (Bruno Rosa).

Differential Revision: https://reviews.llvm.org/D29177

llvm-svn: 297849
2017-03-15 16:04:53 +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
Tim Shen c7472d912b Revert "Revert "[PowerPC][ELFv2ABI] Allocate parameter area on-demand to reduce stack frame size""
After inspection, it's an UB in our code base. Someone cast a var-arg
function pointer to a non-var-arg one. :/

Re-commit r296771 to continue testing on the patch.

Sorry for the trouble!

llvm-svn: 297256
2017-03-08 02:41:35 +00:00
Tim Shen 70054bb827 Revert "[PowerPC][ELFv2ABI] Allocate parameter area on-demand to reduce stack frame size"
This reverts commit r296771.

We found some wide spread test failures internally. I'm working on a
testcase. Politely revert the patch in the mean time. :)

llvm-svn: 297124
2017-03-07 07:40:10 +00:00
Nemanja Ivanovic 12e67d868a [PowerPC] Fix failure with STBRX when store is narrower than the bswap
Fixes a crash caused by r296811 by truncating the input of the STBRX node
when the bswap is wider than i32.

Fixes https://bugs.llvm.org/show_bug.cgi?id=32140

Differential Revision: https://reviews.llvm.org/D30615

llvm-svn: 297001
2017-03-06 07:32:13 +00:00
Sanjay Patel 066f3208bf [DAGCombiner] allow transforming (select Cond, C +/- 1, C) to (add(ext Cond), C)
select Cond, C +/- 1, C --> add(ext Cond), C -- with a target hook.

This is part of the ongoing process to obsolete D24480.  The motivation is to 
canonicalize to select IR in InstCombine whenever possible, so we need to have a way to
undo that easily in codegen.
 
PowerPC is an obvious winner for this kind of transform because it has fast and complete 
bit-twiddling abilities but generally lousy conditional execution perf (although this might
have changed in recent implementations).

x86 also sees some wins, but the effect is limited because these transforms already mostly
exist in its target-specific combineSelectOfTwoConstants(). The fact that we see any x86 
changes just shows that that code is a mess of special-case holes. We may be able to remove 
some of that logic now.

My guess is that other targets will want to enable this hook for most cases. The likely 
follow-ups would be to add value type and/or the constants themselves as parameters for the
hook. As the tests in select_const.ll show, we can transform any select-of-constants to 
math/logic, but the general transform for any 2 constants needs one more instruction 
(multiply or 'and').

ARM is one target that I think may not want this for most cases. I see infinite loops there
because it wants to use selects to enable conditionally executed instructions.

Differential Revision: https://reviews.llvm.org/D30537

llvm-svn: 296977
2017-03-04 19:18:09 +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
Kyle Butt 1fa6030767 CodeGen: BlockPlacement: Precompute layout for chains of triangles.
For chains of triangles with small join blocks that can be tail duplicated, a
simple calculation of probabilities is insufficient. Tail duplication
can be profitable in 3 different ways for these cases:

1) The post-dominators marked 50% are actually taken 56% (This shrinks with
   longer chains)
2) The chains are statically correlated. Branch probabilities have a very
   U-shaped distribution.
   [http://nrs.harvard.edu/urn-3:HUL.InstRepos:24015805]
   If the branches in a chain are likely to be from the same side of the
   distribution as their predecessor, but are independent at runtime, this
   transformation is profitable. (Because the cost of being wrong is a small
   fixed cost, unlike the standard triangle layout where the cost of being
   wrong scales with the # of triangles.)
3) The chains are dynamically correlated. If the probability that a previous
   branch was taken positively influences whether the next branch will be
   taken
We believe that 2 and 3 are common enough to justify the small margin in 1.

The code pre-scans a function's CFG to identify this pattern and marks the edges
so that the standard layout algorithm can use the computed results.

llvm-svn: 296845
2017-03-03 01:00:22 +00:00
Guozhi Wei ed28e742ee [PPC] Fix code generation for bswap(int32) followed by store16
This patch fixes pr32063.

Current code in PPCTargetLowering::PerformDAGCombine can transform

bswap
store

into a single PPCISD::STBRX instruction. but it doesn't consider the case that the operand size of bswap may be larger than store size. When it occurs, we need 2 modifications,

1 For the last operand of PPCISD::STBRX, we should not use DAG.getValueType(N->getOperand(1).getValueType()), instead we should use cast<StoreSDNode>(N)->getMemoryVT().

2 Before PPCISD::STBRX, we need to shift the original operand of bswap to the right side.

Differential Revision: https://reviews.llvm.org/D30362

llvm-svn: 296811
2017-03-02 21:07:59 +00:00
Nemanja Ivanovic db8425eff0 [PowerPC][ELFv2ABI] Allocate parameter area on-demand to reduce stack frame size
This patch reduces the stack frame size by not allocating the parameter area if
it is not required. In the current implementation LowerFormalArguments_64SVR4
already handles the parameter area, but LowerCall_64SVR4 does not
(when calculating the stack frame size). What this patch does is make
LowerCall_64SVR4 consistent with LowerFormalArguments_64SVR4.

Committing on behalf of Hiroshi Inoue.

Differential Revision: https://reviews.llvm.org/D29881

llvm-svn: 296771
2017-03-02 17:38:59 +00:00
Sanjay Patel 92938657a0 [DAGCombiner] fold binops with constant into select-of-constants
This is part of the ongoing attempt to improve select codegen for all targets and select 
canonicalization in IR (see D24480 for more background). The transform is a subset of what
is done in InstCombine's FoldOpIntoSelect().

I first noticed a regression in the x86 avx512-insert-extract.ll tests with a patch that 
hopes to convert more selects to basic math ops. This appears to be a general missing DAG
transform though, so I added tests for all standard binops in rL296621 
(PowerPC was chosen semi-randomly; it has scripted FileCheck support, but so do ARM and x86).

The poor output for "sel_constants_shl_constant" is tracked with:
https://bugs.llvm.org/show_bug.cgi?id=32105

Differential Revision: https://reviews.llvm.org/D30502

llvm-svn: 296699
2017-03-01 22:51:31 +00:00
Nemanja Ivanovic b223cfabcc Improve scheduling with branch coalescing
This patch adds a MachineSSA pass that coalesces blocks that branch
on the same condition.

Committing on behalf of Lei Huang.

Differential Revision: https://reviews.llvm.org/D28249

llvm-svn: 296670
2017-03-01 20:29:34 +00:00
Artur Pilipenko e1b2d31468 [DAGCombiner] Support {a|s}ext, {a|z|s}ext load nodes in load combine
Resubmit r295336 after the bug with non-zero offset patterns on BE targets is fixed (r296336).

Support {a|s}ext, {a|z|s}ext load nodes as a part of load combine patters.

Reviewed By: filcab

Differential Revision: https://reviews.llvm.org/D29591

llvm-svn: 296651
2017-03-01 18:12:29 +00:00
Sanjay Patel ffc6943011 [PPC] add tests for select-of-constants with binop; NFC
llvm-svn: 296621
2017-03-01 14:26:49 +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
Michael Kuperstein 13bf8a2684 [CGP] Split some critical edges coming out of indirect branches
Splitting critical edges when one of the source edges is an indirectbr
is hard in general (because it requires changing the memory the indirectbr
reads). But if a block only has a single indirectbr predecessor (which is
the common case), we can simulate splitting that edge by splitting
the destination block, and retargeting the *direct* branches.

This is motivated by the use of computed gotos in python 2.7: PyEval_EvalFrame()
ends up using an indirect branch with ~100 successors, and passing a constant to
each of those. Since MachineSink can't break indirect critical edges on demand
(and doing this in MIR doesn't look feasible), this causes us to emit about ~100
defs of registers containing constants, which we in the predecessor block, where
only one of those constants is used in each successor. So, at each computed goto,
we needlessly spill about a 100 constants to stack. The end result is that a
clang-compiled python interpreter can be about ~2.5x slower on a simple python
reduction loop than a gcc-compiled interpreter.

Differential Revision: https://reviews.llvm.org/D29916

llvm-svn: 296416
2017-02-28 00:11:34 +00:00
Amaury Sechet 681472cd0f Do full codegen for various tests. NFC
llvm-svn: 296305
2017-02-27 01:15:57 +00:00
Daniel Jasper 3ca4525612 Revert "[CGP] Split some critical edges coming out of indirect branches"
This reverts commit r296149 as it leads to crashes when compiling for
PPC.

llvm-svn: 296295
2017-02-26 11:09:12 +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
Michael Kuperstein 46b131e3f8 [CGP] Split some critical edges coming out of indirect branches
Splitting critical edges when one of the source edges is an indirectbr
is hard in general (because it requires changing the memory the indirectbr
reads). But if a block only has a single indirectbr predecessor (which is
the common case), we can simulate splitting that edge by splitting
the destination block, and retargeting the *direct* branches.

This is motivated by the use of computed gotos in python 2.7: PyEval_EvalFrame()
ends up using an indirect branch with ~100 successors, and passing a constant to
each of those. Since MachineSink can't break indirect critical edges on demand
(and doing this in MIR doesn't look feasible), this causes us to emit about ~100
defs of registers containing constants, which we in the predecessor block, where
only one of those constants is used in each successor. So, at each computed goto,
we needlessly spill about a 100 constants to stack. The end result is that a
clang-compiled python interpreter can be about ~2.5x slower on a simple python
reduction loop than a gcc-compiled interpreter.

Differential Revision: https://reviews.llvm.org/D29916

llvm-svn: 296149
2017-02-24 18:41:32 +00:00
Nemanja Ivanovic 195c5452d3 [PowerPC] Use subfic instruction for subtract from immediate
Provide a 64-bit pattern to use SUBFIC for subtracting from a 16-bit immediate.
The corresponding pattern already exists for 32-bit integers.

Committing on behalf of Hiroshi Inoue.

Differential Revision: https://reviews.llvm.org/D29387

llvm-svn: 296144
2017-02-24 18:16:06 +00:00
Nemanja Ivanovic 82d53ed492 [PowerPC] Use rldicr instruction for AND with an immediate if possible
Emit clrrdi (extended mnemonic for rldicr) for AND-ing with masks that
clear bits from the right hand size.

Committing on behalf of Hiroshi Inoue.

Differential Revision: https://reviews.llvm.org/D29388

llvm-svn: 296143
2017-02-24 18:03:16 +00:00