Commit Graph

8079 Commits

Author SHA1 Message Date
Nirav Dave e9ca32ae52 [SDAG] Fix zeroExtend assertion error
Move CombineTo preventing deleted node from being returned in
visitZERO_EXTEND.

Fixes PR32284.

Reviewers: RKSimon, bogner

Reviewed By: RKSimon

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D31254

llvm-svn: 298604
2017-03-23 15:01:50 +00:00
Reid Kleckner b518054b87 Rename AttributeSet to AttributeList
Summary:
This class is a list of AttributeSetNodes corresponding the function
prototype of a call or function declaration. This class used to be
called ParamAttrListPtr, then AttrListPtr, then AttributeSet. It is
typically accessed by parameter and return value index, so
"AttributeList" seems like a more intuitive name.

Rename AttributeSetImpl to AttributeListImpl to follow suit.

It's useful to rename this class so that we can rename AttributeSetNode
to AttributeSet later. AttributeSet is the set of attributes that apply
to a single function, argument, or return value.

Reviewers: sanjoy, javed.absar, chandlerc, pete

Reviewed By: pete

Subscribers: pete, jholewinski, arsenm, dschuff, mehdi_amini, jfb, nhaehnle, sbc100, void, llvm-commits

Differential Revision: https://reviews.llvm.org/D31102

llvm-svn: 298393
2017-03-21 16:57:19 +00:00
Matt Arsenault dce313c3cf DAG: Fold bitcast/extract_vector_elt of undef to undef
Fixes not eliminating store when intrinsic is lowered to undef.

llvm-svn: 298385
2017-03-21 16:20:16 +00:00
Jonas Paulsson 54c7680e1f [DAGTypeLegalizer] Handle widening truncate to vector of i1.
Previously, PromoteIntRes_TRUNCATE() did not handle the case where
the operand needs widening, which resulted in llvm_unreachable().

This patch adds the needed handling, along with a test case.

Review: Eli Friedman, Simon Pilgrim.
https://reviews.llvm.org/D31077

llvm-svn: 298357
2017-03-21 10:24:14 +00:00
Simon Pilgrim 8424df7dea Fix constant folding of fp2int to large integers
We make the assumption in most of our constant folding code that a fp2int will target an integer of 128-bits or less, calling the APFloat::convertToInteger with only uint64_t[2] of raw bits for the result.

Fuzz testing (PR24662) showed that we don't handle other cases at all, resulting in stack overflows and all sorts of crashes.

This patch uses the APSInt version of APFloat::convertToInteger instead to better handle such cases.

Differential Revision: https://reviews.llvm.org/D31074

llvm-svn: 298226
2017-03-19 16:50:25 +00:00
Nirav Dave ac6081cb67 Make library calls sensitive to regparm module flag (Fixes PR3997).
Reviewers: mkuper, rnk

Subscribers: mehdi_amini, jyknight, aemerson, llvm-commits, rengolin

Differential Revision: https://reviews.llvm.org/D27050

llvm-svn: 298179
2017-03-18 00:44:07 +00:00
Nirav Dave 6de2c77944 Capitalize ArgListEntry fields. NFC.
llvm-svn: 298178
2017-03-18 00:43:57 +00:00
Eli Friedman 46ddab3810 [SelectionDAG] Remove redundant stores more aggressively.
Handle TokenFactors more aggressively in
SDValue::reachesChainWithoutSideEffects.  This isn't really a
very effective change anymore because of other changes to
chain handling, but it's a cheap check, and the expanded
comments are still useful.

It might be possible to loosen the hasOneUse() requirement with a
deeper analysis, but a naive implementation of that check would be
expensive.

Differential Revision: https://reviews.llvm.org/D29845

llvm-svn: 298156
2017-03-17 22:15:50 +00:00
Simon Pilgrim 5a68d401c7 [SelectionDAG] Add SelectionDAG.computeKnownBits test support for ISD::ABS
llvm-svn: 298108
2017-03-17 17:45:36 +00:00
Reid Kleckner 45707d4d5a Remove getArgumentList() in favor of arg_begin(), args(), etc
Users often call getArgumentList().size(), which is a linear way to get
the number of function arguments. arg_size(), on the other hand, is
constant time.

In general, the fact that arguments are stored in an iplist is an
implementation detail, so I've removed it from the Function interface
and moved all other users to the argument container APIs (arg_begin(),
arg_end(), args(), arg_size()).

Reviewed By: chandlerc

Differential Revision: https://reviews.llvm.org/D31052

llvm-svn: 298010
2017-03-16 22:59:15 +00:00
Jonas Paulsson 84319bfc40 [SelectionDAG] Optimize VSELECT->SETCC of incompatible or illegal types.
Don't scalarize VSELECT->SETCC when operands/results needs to be widened,
or when the type of the SETCC operands are different from those of the VSELECT.

(VSELECT SETCC) and (VSELECT (AND/OR/XOR (SETCC,SETCC))) are handled.

The previous splitting of VSELECT->SETCC in DAGCombiner::visitVSELECT() is
no longer needed and has been removed.

Updated tests:

test/CodeGen/ARM/vuzp.ll
test/CodeGen/NVPTX/f16x2-instructions.ll
test/CodeGen/X86/2011-10-19-widen_vselect.ll
test/CodeGen/X86/2011-10-21-widen-cmp.ll
test/CodeGen/X86/psubus.ll
test/CodeGen/X86/vselect-pcmp.ll

Review: Eli Friedman, Simon Pilgrim
https://reviews.llvm.org/D29489

llvm-svn: 297930
2017-03-16 07:17:12 +00:00
Zvi Rackover 48cdde0e59 [DAGCombine] Bail out if can't create a vector with at least two elements
Summary:

Fixes pr32278

Reviewers: igorb, craig.topper, RKSimon, spatel, hfinkel

Reviewed By: RKSimon

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D30978

llvm-svn: 297878
2017-03-15 19:48:36 +00:00
Craig Topper bcb6093610 [CodeGen] Use APInt::setLowBits/setHighBits/setBitsFrom in more places
This patch replaces ORs with getHighBits/getLowBits etc. with setLowBits/setHighBits/setBitsFrom.

In a few of the places we weren't ORing, but the KnownZero/KnownOne vectors were already initialized to zero. We exploit this in most places already there were just some that were inconsistent.

Differential Revision: https://reviews.llvm.org/D30965

llvm-svn: 297860
2017-03-15 16:53:53 +00:00
Simon Pilgrim 018eedd9a5 [SelectionDAG] Support BUILD_VECTOR implicit truncation in SelectionDAG::ComputeNumSignBits (PR32273)
llvm-svn: 297852
2017-03-15 16:22:24 +00:00
Nuno Lopes ae455c562d fix gcc -Wmisleading-indentation [NFC]
llvm-svn: 297816
2017-03-15 09:33:33 +00:00
Simon Pilgrim cf2da96c82 [SelectionDAG] Add a signed integer absolute ISD node
Reduced version of D26357 - based on the discussion on llvm-dev about canonicalization of UMIN/UMAX/SMIN/SMAX as well as ABS I've reduced that patch to just the ABS ISD node (with x86/sse support) to improve basic combines and lowering.

ARM/AArch64, Hexagon, PowerPC and NVPTX all have similar instructions allowing us to make this a generic opcode and move away from the hard coded tablegen patterns which makes it tricky to match more complex patterns.

At the moment this patch doesn't attempt legalization as we only create an ABS node if its legal/custom.

Differential Revision: https://reviews.llvm.org/D29639

llvm-svn: 297780
2017-03-14 21:26:58 +00:00
Sanjay Patel 8dd99dce6c [DAG] vector div/rem with any zero element in divisor is undef
This is the backend counterpart to:
https://reviews.llvm.org/rL297390
https://reviews.llvm.org/rL297409
and follow-up to:
https://reviews.llvm.org/rL297384

It surprised me that we need to duplicate the check in FoldConstantArithmetic and FoldConstantVectorArithmetic, 
but one or the other doesn't catch all of the test cases. There is an existing code comment about merging those 
someday.

Differential Revision: https://reviews.llvm.org/D30826

llvm-svn: 297762
2017-03-14 18:06:28 +00:00
Sam Parker 916b1ba617 [ARM] Move SMULW[B|T] isel to DAG Combine
Create nodes for smulwb and smulwt and move their selection from
DAGToDAG to DAG combine. smlawb and smlawt can then be selected
using tablegen. Added some helper functions to detect shift patterns
as well as a wrapper around SimplifyDemandBits. Added a couple of
extra tests.

Differential Revision: https://reviews.llvm.org/D30708

llvm-svn: 297716
2017-03-14 09:13:22 +00:00
Nirav Dave 4fc8401abf Recommitting Craig Topper's patch now that r296476 has been recommitted.
When checking if chain node is foldable, make sure the intermediate nodes have a single use across all results not just the result that was used to reach the chain node.

This recovers a test case that was severely broken by r296476, my making sure we don't create ADD/ADC that loads and stores when there is also a flag dependency.

llvm-svn: 297698
2017-03-14 01:42:23 +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
Amaury Sechet d1ec5d54cf Use setBits in SelectionDAG
Summary: As per title.

Reviewers: RKSimon

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D30836

llvm-svn: 297559
2017-03-11 11:24:03 +00:00
Simon Pilgrim 7dedbfa89d [SelectionDAG] Add support for BUILD_VECTOR to ComputeNumSignBits
llvm-svn: 297492
2017-03-10 18:36:46 +00:00
Amaury Sechet 62e0759d56 [SelectionDAG] Make SelectionDAG aware of the known bits in USUBO and SSUBO and SUBC.
Summary:
Depends on D30379

This improves the state of things for the sub class of operation.

Reviewers: jyknight, nemanjai, mkuper, spatel, RKSimon, zvi, bkramer

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D30436

llvm-svn: 297482
2017-03-10 17:26:44 +00:00
Amaury Sechet 69fa16c810 [SelectionDAG] Make SelectionDAG aware of the known bits in UADDO and SADDO.
Summary: As per title. This is extracted from D29872 and I threw SADDO in.

Reviewers: jyknight, nemanjai, mkuper, spatel, RKSimon, zvi, bkramer

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D30379

llvm-svn: 297479
2017-03-10 17:06:52 +00:00
Simon Pilgrim b02667c469 [APInt] Add APInt::insertBits() method to insert an APInt into a larger APInt
We currently have to insert bits via a temporary variable of the same size as the target with various shift/mask stages, resulting in further temporary variables, all of which require the allocation of memory for large APInts (MaskSizeInBits > 64).

This is another of the compile time issues identified in PR32037 (see also D30265).

This patch adds the APInt::insertBits() helper method which avoids the temporary memory allocation and masks/inserts the raw bits directly into the target.

Differential Revision: https://reviews.llvm.org/D30780

llvm-svn: 297458
2017-03-10 13:44:32 +00:00
Amaury Sechet e7d102cf02 [DAGCombiner] Do various combine on uaddo.
Summary: This essentially does the same transform as for ADC.

Reviewers: jyknight, nemanjai, mkuper, spatel, RKSimon, zvi, bkramer

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D30417

llvm-svn: 297416
2017-03-09 22:47:00 +00:00
Amaury Sechet 10425de063 [DAGCombiner] Do various combine on usubo.
Summary: This essentially does the same transform as for SUBC.

Reviewers: jyknight, nemanjai, mkuper, spatel, RKSimon, zvi, bkramer

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D30437

llvm-svn: 297404
2017-03-09 19:28:00 +00:00
Sanjay Patel df21979db7 [DAG] recognize div/rem by 0 as undef before trying constant folding
As discussed in the review thread for rL297026, this is actually 2 changes that 
would independently fix all of the test cases in the patch:

1. Return undef in FoldConstantArithmetic for div/rem by 0.
2. Move basic undef simplifications for div/rem (simplifyDivRem()) before 
   foldBinopIntoSelect() as a matter of efficiency.

I will handle the case of vectors with any zero element as a follow-up. That change
is the DAG sibling for D30665 + adding a check of vector elements to FoldConstantVectorArithmetic().

I'm deleting the test for PR30693 because it does not test for the actual bug any more
(dangers of using bugpoint).

Differential Revision:
https://reviews.llvm.org/D30741

llvm-svn: 297384
2017-03-09 15:02:25 +00:00
Matt Arsenault 9a3fd87523 DAG: Check no signed zeros instead of unsafe math attribute
llvm-svn: 297354
2017-03-09 01:36:39 +00:00
Eli Friedman c2c2e21d77 [DAGCombine] Simplify ISD::AND in GetDemandedBits.
This helps in cases involving bitfields where an AND is exposed by
legalization.

Differential Revision: https://reviews.llvm.org/D30472

llvm-svn: 297249
2017-03-08 00:56:35 +00:00
Sanjay Patel 7f18ec50ba [DAG] refactor related div/rem folds; NFCI
This is known incomplete and not called in the right order relative to
other folds, but that's the current behavior. I'm just trying to clean
this up before making actual functional changes to make the patch smaller.

The logic here should mimic the IR equivalents that are in InstSimplify's
simplifyDivRem().

llvm-svn: 297086
2017-03-06 22:32:40 +00:00
Sanjay Patel 7f7947bf41 [DAGCombiner] simplify div/rem-by-0
Refactoring of duplicated code and more fixes to follow.

This is motivated by the post-commit comments for r296699:
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20170306/435182.html

Ie, we can crash if we're missing obvious simplifications like this that
exist in the IR simplifier or if these occur later than expected.

The x86 change for non-splat division shows a potential opportunity to improve
vector codegen: we assumed that since only one lane had meaningful results, we
should do the math in scalar. But that means moving back and forth from vector
registers.

llvm-svn: 297026
2017-03-06 16:36:42 +00:00
Sanjay Patel 6b029a5380 [DAG] fix formatting; NFC
llvm-svn: 297015
2017-03-06 15:27:57 +00:00
Sanjay Patel 5273afd4bb [DAG] fix typo in comment; NFC
llvm-svn: 297011
2017-03-06 15:07:43 +00:00
Simon Pilgrim 584d6d9d91 [SelectionDAG] Fix vector splitting for *_EXTEND_VECTOR_INREG instructions
Found by fuzz testing after rL296985 landed

llvm-svn: 296989
2017-03-05 15:52:18 +00:00
Simon Pilgrim 9f5c251d57 [X86][SSE] Lower 128-bit vectors to SIGN/ZERO_EXTEND_VECTOR_IN_REG ops
As described on PR31712, we miss a variety of legalization combines because we lower these to X86ISD::VSEXT/VZEXT despite them having the same functionality. This patch makes 128-bit (SSE41) SIGN/ZERO_EXTEND_VECTOR_IN_REG ops legal, adds the necessary tablegen plumbing and uses a helper 'getExtendInVec' to decide when to use SIGN/ZERO_EXTEND_VECTOR_IN_REG or VSEXT/VZEXT.

We're missing a couple of shuffle combines that will be added in a future patch for review.

Later patches can then support the AVX2 cases as a mixture of SIGN/ZERO_EXTEND and SIGN/ZERO_EXTEND_VECTOR_IN_REG, and then finally deal with the AVX512 cases.

Differential Revision: https://reviews.llvm.org/D30549

llvm-svn: 296985
2017-03-05 09:57:20 +00:00
Craig Topper 6ffc044b2f [DAGCombine] Use APInt::operator|(uint64_t) instead of creating a temporary APInt and calling APInt::Or. NFC
This is more efficient by itself. But this is prep for a future patch that may remove APInt::Or while making operator| support rvalue references similar to add/sub.

llvm-svn: 296981
2017-03-05 01:08:16 +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
Florian Hahn 6406f98342 [legalize-types] Remove stale entries from SoftenedFloats.
Summary:
When replacing a SDValue, we should remove the replaced value from
SoftenedFloats (and possibly the other maps as well?).

When we revisit a Node because it needs analyzing again, we have to
remove all result values from SoftenedFloats (and possibly other maps?).

This fixes the fp128 test failures with expensive checks for X86.

I think we probably should also remove the values from the other maps
(PromotedIntegers and so on), let me know what you think.

Reviewers: baldrick, bogner, davidxl, ab, arsenm, pirama, chh, RKSimon

Reviewed By: chh

Subscribers: danalbert, wdng, srhines, hfinkel, sepavloff, llvm-commits

Differential Revision: https://reviews.llvm.org/D29265

llvm-svn: 296964
2017-03-04 12:00:35 +00:00
Simon Pilgrim 6dfab414db Use APInt::setBits instead of OR'ing in a separate APInt::getBitsSet call
llvm-svn: 296886
2017-03-03 17:03:52 +00:00
Simon Pilgrim cf12b5e1a6 Use APInt::getOneBitSet instead of APInt::getBitsSet for sign bit mask creation
Avoids all the unnecessary extra bitrange creation/shift stages.

llvm-svn: 296879
2017-03-03 16:35:57 +00:00
Simon Pilgrim 10754abe7e Use APInt::getOneBitSet instead of APInt::getBitsSet for sign bit mask creation
Avoids all the unnecessary extra bitrange creation/shift stages.

llvm-svn: 296871
2017-03-03 14:25:46 +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
Taewook Oh 96c6415697 [DAGCombiner] Fix DebugLoc propagation when folding !(x cc y) -> (x !cc y)
Summary:
Currently, when 't1: i1 = setcc t2, t3, cc' followed by 't4: i1 = xor t1, Constant:i1<-1>' is folded into 't5: i1 = setcc t2, t3 !cc', SDLoc of newly created SDValue 't5' follows SDLoc of 't4', not 't1'. However, as the opcode of newly created SDValue is 'setcc', it make more sense to take DebugLoc from 't1' than 't4'. For the code below

```
extern int bar();
extern int baz();

int foo(int x, int y) {
  if (x != y)
    return bar();
  else
    return baz();
}
```

, following is the bitcode representation of 'foo' at the end of llvm-ir level optimization:

```
define i32 @foo(i32 %x, i32 %y) !dbg !4 {
entry:
  tail call void @llvm.dbg.value(metadata i32 %x, i64 0, metadata !9, metadata !11), !dbg !12
  tail call void @llvm.dbg.value(metadata i32 %y, i64 0, metadata !10, metadata !11), !dbg !13
  %cmp = icmp ne i32 %x, %y, !dbg !14
  br i1 %cmp, label %if.then, label %if.else, !dbg !16

if.then:                                          ; preds = %entry
  %call = tail call i32 (...) @bar() #3, !dbg !17
  br label %return, !dbg !18

if.else:                                          ; preds = %entry
  %call1 = tail call i32 (...) @baz() #3, !dbg !19
  br label %return, !dbg !20

return:                                           ; preds = %if.else, %if.then
  %retval.0 = phi i32 [ %call, %if.then ], [ %call1, %if.else ]
  ret i32 %retval.0, !dbg !21
}

!14 = !DILocation(line: 5, column: 9, scope: !15)
!16 = !DILocation(line: 5, column: 7, scope: !4)

```

As you can see, in 'entry' block, 'icmp' instruction and 'br' instruction have different debug locations. However, with current implementation, there's no distinction between debug locations of these two when they are lowered to asm instructions. This is because 'icmp' and 'br' become 'setcc' 'xor' and 'brcond' in SelectionDAG, where SDLoc of 'setcc' follows the debug location of 'icmp' but SDLOC of 'xor' and 'brcond' follows the debug location of 'br' instruction, and SDLoc of 'xor' overwrites SDLoc of 'setcc' when they are folded. This patch addresses this issue.

Reviewers: atrick, bogner, andreadb, craig.topper, aprantl

Reviewed By: andreadb

Subscribers: jlebar, mkuper, jholewinski, andreadb, llvm-commits

Differential Revision: https://reviews.llvm.org/D29813

llvm-svn: 296825
2017-03-02 21:58:35 +00:00
Sanjay Patel 7884dcb788 [DAG] early exit to improve readability and formatting of visitMemCmpCall(); NFCI
llvm-svn: 296824
2017-03-02 21:56:43 +00:00
Sanjay Patel 209b0f9aad [DAG] improve documentation comments; NFC
llvm-svn: 296808
2017-03-02 20:48:08 +00:00
Sanjay Patel fffa179837 [DAGCombiner] avoid assertion when folding binops with opaque constants
This bug was introduced with:
https://reviews.llvm.org/rL296699

There may be a way to loosen the restriction, but for now just bail out
on any opaque constant.

The tests show that opacity is target-specific. This goes back to cost
calculations in ConstantHoisting based on TTI->getIntImmCost().

llvm-svn: 296768
2017-03-02 17:18:56 +00:00
Sanjay Patel f7aba7ba22 fix typo in comment; NFC
llvm-svn: 296760
2017-03-02 16:37:24 +00:00
Amaury Sechet 71f511fd1e [DAGCombiner] mulhi + 1 never overflow.
Summary:
This can be used to optimize large multiplications after legalization.

Depends on D29565

Reviewers: mkuper, spatel, RKSimon, zvi, bkramer, aaboud, craig.topper

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D29587

llvm-svn: 296711
2017-03-01 23:44:17 +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