Commit Graph

1350 Commits

Author SHA1 Message Date
Craig Topper 92ea7a7b48 [X86] Enable commuting of VUNPCKHPD to VMOVLHPS to enable load folding by using VMOVLPS with a modified address.
This required an annoying amount of tablegen multiclass changes to make only VUNPCKHPDZ128rr commutable.

llvm-svn: 337357
2018-07-18 07:31:32 +00:00
Craig Topper cdb0ed2910 [X86] Add custom execution domain fixing for 128/256-bit integer logic operations with AVX512F, but not AVX512DQ.
AVX512F only has integer domain logic instructions. AVX512DQ added FP domain logic instructions.

Execution domain fixing runs before EVEX->VEX. So if we have AVX512F and not AVX512DQ we fail to do execution domain switching of the logic operations. This leads to mismatches in execution domain and more test differences.

This patch adds custom domain fixing that switches EVEX integer logic operations to VEX fp logic operations if XMM16-31 are not used.

llvm-svn: 337137
2018-07-15 23:32:36 +00:00
Craig Topper 7426cf6717 [X86] Fix a subtle bug in the custom execution domain fixing for blends.
The code tried to find the immediate by using getNumOperands() on the MachineInstr, but there might be implicit-defs after the immediate that get counted.

Instead use getNumOperands() from the instruction description which will only count the operands that are defined in the td file.

llvm-svn: 337088
2018-07-14 06:30:30 +00:00
Craig Topper 02867f0fa3 [X86] The TEST instruction is eliminated when BSF/TZCNT is used
Summary:
These changes cover the PR#31399.
Now the ffs(x) function is lowered to (x != 0) ? llvm.cttz(x) + 1 : 0
and it corresponds to the following llvm code:
  %cnt = tail call i32 @llvm.cttz.i32(i32 %v, i1 true)
  %tobool = icmp eq i32 %v, 0
  %.op = add nuw nsw i32 %cnt, 1
  %add = select i1 %tobool, i32 0, i32 %.op
and x86 asm code:
  bsfl     %edi, %ecx
  addl     $1, %ecx
  testl    %edi, %edi
  movl     $0, %eax
  cmovnel  %ecx, %eax
In this case the 'test' instruction can't be eliminated because
the 'add' instruction modifies the EFLAGS, namely, ZF flag
that is set by the 'bsf' instruction when 'x' is zero.

We now produce the following code:
  bsfl     %edi, %ecx
  movl     $-1, %eax
  cmovnel  %ecx, %eax
  addl     $1, %eax

Patch by Ivan Kulagin

Reviewers: davide, craig.topper, spatel, RKSimon

Reviewed By: craig.topper

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D48765

llvm-svn: 336768
2018-07-11 06:57:42 +00:00
Craig Topper 860ab496d3 [X86] Teach X86InstrInfo::commuteInstructionImpl to use MOVSD/MOVSS for BLEND under optsize when the immediate allows it.
Isel currently emits movss/movsd a lot of the time and an accidental double commute turns it into a blend.

Ideally we'd select blend directly in isel under optspeed and not rely on the double commute to create blend.

llvm-svn: 336731
2018-07-10 22:02:23 +00:00
Yvan Roux eaececf5e0 [MachineOutliner] Fix typo in getOutliningCandidateInfo function name
getOutlininingCandidateInfo -> getOutliningCandidateInfo

Differential Revision: https://reviews.llvm.org/D48867

llvm-svn: 336285
2018-07-04 15:37:08 +00:00
Craig Topper 0661f67296 [X86] Remove FMA3Info DenseMap. Break into sorted tables that we can binary search.
I separated out the rounding and broadcast groups into their own tables because it made the ordering in the main table easier.

Further splitting of the tables might make it possible to directly index using bits from the TSFlags, but its probably not worth it right now.

llvm-svn: 336075
2018-07-02 06:23:39 +00:00
Craig Topper c004aa6c5f [X86] Remove the places that return nullptr from X86InstrInfo::commuteInstructionImpl.
findCommutedOpIndices does the pre-checking for whether commuting is possible. There should be no reason left to fail in commuteInstructionImpl. There was a missing pre-check that I've added there and changed the check to an assert in commuteInstructionImpl.

llvm-svn: 336070
2018-07-01 23:27:41 +00:00
Craig Topper 4e78213ae4 [X86] Move the memory unfolding table creation into its own class and make it a ManagedStatic.
Also move the static folding tables, their search functions and the new class into new cpp/h files.

The unfolding table is effectively static data. It's just a different ordering and a subset of the static folding tables.

By putting it in a separate ManagedStatic we ensure we only have one copy instead of one per X86InstrInfo object. This way also makes it only get initialized when really needed.

llvm-svn: 336056
2018-07-01 05:47:49 +00:00
Craig Topper 84199deb17 [X86] Move the X86InstrFMA3Info class into the cpp file. Expose only a getFMA3Group free function. NFCI
The class only exists to hold a DenseMap and is only created as a ManagedStatic. It used to expose a single static method that outside code was expected to use.

This patch moves that static function out of the class and moves it implementation into the cpp file. It can now access the ManagedStatic directly by name without the need for the other static method that accessed the ManagedStatic.

llvm-svn: 336055
2018-06-30 22:38:42 +00:00
Craig Topper 7c96f051d2 [X86] Use a std::vector for the memory unfolding table.
Previously we used a DenseMap which is costly to set up due to multiple full table rehashes as the size increases and causes the table to be reallocated.

This patch changes the table to a vector of structs. We now walk the reg->mem tables and push new entries in the mem->reg table for each row not marked TB_NO_REVERSE. Once all the table entries have been created, we sort the vector. Then we can use a binary search for lookups.

Differential Revision: https://reviews.llvm.org/D48585

llvm-svn: 335994
2018-06-29 17:11:26 +00:00
Jonas Devlieghere b757fc3878 Revert "Re-land r335297 "[X86] Implement more of x86-64 large and medium PIC code models""
Reverting because this is causing failures in the LLDB test suite on
GreenDragon.

  LLVM ERROR: unsupported relocation with subtraction expression, symbol
  '__GLOBAL_OFFSET_TABLE_' can not be undefined in a subtraction
  expression

llvm-svn: 335894
2018-06-28 17:56:43 +00:00
Benjamin Kramer f9613b2995 Unify sorted asserts to use the existing atomic pattern
These are all benign races and only visible in !NDEBUG. tsan complains
about it, but a simple atomic bool is sufficient to make it happy.

llvm-svn: 335823
2018-06-28 10:03:45 +00:00
Benjamin Kramer e214f046af [X86] Make folding table checking threadsafe
This is a benign race, but tsan likes to complain about it. Just make it
happy.

llvm-svn: 335788
2018-06-27 21:01:53 +00:00
Craig Topper 33aba0eb4c [X86] Don't store register and memory FMA3 opcodes in the same X86InstrFMA3Group.
Nothing was using this relationship. By splitting them we no longer need to worry about register or memory entries being empty in a group.

The memory folding tables in X86InstrInfo.cpp can be used to access this relationship if needed.

llvm-svn: 335694
2018-06-27 00:42:24 +00:00
Craig Topper 614f192471 [X86] Add comment about the sorting of the memory folding tables added in r335501.
llvm-svn: 335517
2018-06-25 20:11:16 +00:00
Reid Kleckner 88fee5fdbc Re-land r335297 "[X86] Implement more of x86-64 large and medium PIC code models"
The large code model allows code and data segments to exceed 2GB, which
means that some symbol references may require a displacement that cannot
be encoded as a displacement from RIP. The large PIC model even relaxes
the assumption that the GOT itself is within 2GB of all code. Therefore,
we need a special code sequence to materialize it:
  .LtmpN:
    leaq .LtmpN(%rip), %rbx
    movabsq $_GLOBAL_OFFSET_TABLE_-.LtmpN, %rax # Scratch
    addq %rax, %rbx # GOT base reg

From that, non-local references go through the GOT base register instead
of being PC-relative loads. Local references typically use GOTOFF
symbols, like this:
    movq extern_gv@GOT(%rbx), %rax
    movq local_gv@GOTOFF(%rbx), %rax

All calls end up being indirect:
    movabsq $local_fn@GOTOFF, %rax
    addq %rbx, %rax
    callq *%rax

The medium code model retains the assumption that the code segment is
less than 2GB, so calls are once again direct, and the RIP-relative
loads can be used to access the GOT. Materializing the GOT is easy:
    leaq _GLOBAL_OFFSET_TABLE_(%rip), %rbx # GOT base reg

DSO local data accesses will use it:
    movq local_gv@GOTOFF(%rbx), %rax

Non-local data accesses will use RIP-relative addressing, which means we
may not always need to materialize the GOT base:
    movq extern_gv@GOTPCREL(%rip), %rax

Direct calls are basically the same as they are in the small code model:
They use direct, PC-relative addressing, and the PLT is used for calls
to non-local functions.

This patch adds reasonably comprehensive testing of LEA, but there are
lots of interesting folding opportunities that are unimplemented.

I restricted the MCJIT/eh-lg-pic.ll test to Linux, since the large PIC
code model is not implemented for MachO yet.

Differential Revision: https://reviews.llvm.org/D47211

llvm-svn: 335508
2018-06-25 18:16:27 +00:00
Craig Topper 3cc6cb1d35 [X86] Sort the static memory folding tables by reg opcode. Remove the reg->mem DenseMaps in favor of binary search.
With the static tables sorted we can binary search them directly for reg->mem lookups. This removes 6 DenseMaps that had to be created when X86InstrInfo is constructed.

We still have one Mem->Reg DenseMap for the reverse direction. This is created just as before by walking the reg->mem arrays to populate it.

Differential Revision: https://reviews.llvm.org/D48527

llvm-svn: 335501
2018-06-25 17:26:56 +00:00
Craig Topper facea6b4a6 [X86] Block commuting operand 1 of FMA*_Int instructions in findThreeSrcCommutedOpIndices. Remove uncommutable returns from getThreeSrcCommuteCase/getFMA3OpcodeToCommuteOperands.
We should be blocking the operand while we are in the routine that tries to find commutable operand indices. Doing it later means we might have missed out on another valid set of operands we could have commuted.

The intrinsic case was the only case that could really prevent commuting in getFMA3OpcodeToCommuteOperands. All the other cases in getThreeSrcCommuteCase were not reachable conditions as they were protected by findThreeSrcCommutedOpIndices.

With that abort case pushed earlier, we can remove all the abort checks and replace with asserts.

llvm-svn: 335446
2018-06-25 06:05:37 +00:00
Craig Topper 19772c89c7 [X86] Rename VFPCLASSSS and VFPCLASSSD internal instruction names to include a Z to match other EVEX instructions.
llvm-svn: 335428
2018-06-24 06:29:50 +00:00
Reid Kleckner 3a2fd1c2f3 Revert r335297 "[X86] Implement more of x86-64 large and medium PIC code models"
MCJIT can't handle R_X86_64_GOT64 yet.

llvm-svn: 335300
2018-06-21 22:19:05 +00:00
Reid Kleckner 3286a6c896 [X86] Commit some comments that weren't in the medium code model patch
llvm-svn: 335298
2018-06-21 21:57:44 +00:00
Reid Kleckner 247fe6aeab [X86] Implement more of x86-64 large and medium PIC code models
Summary:
The large code model allows code and data segments to exceed 2GB, which
means that some symbol references may require a displacement that cannot
be encoded as a displacement from RIP. The large PIC model even relaxes
the assumption that the GOT itself is within 2GB of all code. Therefore,
we need a special code sequence to materialize it:
  .LtmpN:
    leaq .LtmpN(%rip), %rbx
    movabsq $_GLOBAL_OFFSET_TABLE_-.LtmpN, %rax # Scratch
    addq %rax, %rbx # GOT base reg

From that, non-local references go through the GOT base register instead
of being PC-relative loads. Local references typically use GOTOFF
symbols, like this:
    movq extern_gv@GOT(%rbx), %rax
    movq local_gv@GOTOFF(%rbx), %rax

All calls end up being indirect:
    movabsq $local_fn@GOTOFF, %rax
    addq %rbx, %rax
    callq *%rax

The medium code model retains the assumption that the code segment is
less than 2GB, so calls are once again direct, and the RIP-relative
loads can be used to access the GOT. Materializing the GOT is easy:
    leaq _GLOBAL_OFFSET_TABLE_(%rip), %rbx # GOT base reg

DSO local data accesses will use it:
    movq local_gv@GOTOFF(%rbx), %rax

Non-local data accesses will use RIP-relative addressing, which means we
may not always need to materialize the GOT base:
    movq extern_gv@GOTPCREL(%rip), %rax

Direct calls are basically the same as they are in the small code model:
They use direct, PC-relative addressing, and the PLT is used for calls
to non-local functions.

This patch adds reasonably comprehensive testing of LEA, but there are
lots of interesting folding opportunities that are unimplemented.

Reviewers: chandlerc, echristo

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D47211

llvm-svn: 335297
2018-06-21 21:55:08 +00:00
Craig Topper c2696d577b [X86] Use setcc ISD opcode for AVX512 integer comparisons all the way to isel
I don't believe there is any real reason to have separate X86 specific opcodes for vector compares. Setcc has the same behavior just uses a different encoding for the condition code.

I had to change the CondCodeAction for SETLT and SETLE to prevent some transforms from changing SETGT lowering.

Differential Revision: https://reviews.llvm.org/D43608

llvm-svn: 335173
2018-06-20 21:05:02 +00:00
Jessica Paquette 32de26d432 [MachineOutliner] NFC: Remove insertOutlinerPrologue, rename insertOutlinerEpilogue
insertOutlinerPrologue was not used by any target, and prologue-esque code was
beginning to appear in insertOutlinerEpilogue. Refactor that into one function,
buildOutlinedFrame.

This just removes insertOutlinerPrologue and renames insertOutlinerEpilogue.

llvm-svn: 335076
2018-06-19 21:14:48 +00:00
Craig Topper 9fe45d846e [X86] Add all the FMA instructions direclty to the load folding table instead of proxying through X86InstrFMA3Info.
These increases the size of the static tables, but is closer to what we would get if used the autogenerated table directly. This reduces the remaining large deltas between what's in the manual table and what's in the autogenerated table.

llvm-svn: 334915
2018-06-17 18:00:16 +00:00
Craig Topper 29f22d7baa [X86] More additions to the load folding tables based on the autogenerated tables.
Including more additions for NotMemoryFoldable to remove some entries from the autogenerated table.

llvm-svn: 334898
2018-06-16 23:25:50 +00:00
Craig Topper d00e375310 [X86] Add more instructions to the hasUndefRegUpdate list.
Not sure any of these matter today because I don't think we ever produce them with IMPLICIT_DEF as an input. But by listing them we don't be suprised in the future.

llvm-svn: 334867
2018-06-15 22:25:04 +00:00
Craig Topper 1657b7b8d2 [X86] Prevent folding stack reloads into instructions in hasUndefRegUpdate.
An earlier commit prevented folds from the peephole pass by checking for IMPLICIT_DEF. But later in the pipeline IMPLICIT_DEF just becomes and Undef flag on the input register so we need to check for that case too.

llvm-svn: 334848
2018-06-15 17:56:17 +00:00
Craig Topper c8a763ed84 Revert r334802 "[X86] Prevent folding stack reloads with instructions that have an undefined register update."
There's a typo causing the build to fail.

llvm-svn: 334803
2018-06-15 06:15:26 +00:00
Craig Topper 5ec210cc27 [X86] Prevent folding stack reloads with instructions that have an undefined register update.
We want to keep the load unfolded so we can use the same register for both sources to avoid a false dependency.

llvm-svn: 334802
2018-06-15 06:11:36 +00:00
Craig Topper 3c4cc01226 [X86] Add more instructions to the memory folding tables using the autogenerated table as a guide.
I think this covers most of the unmasked vector instructions. We're still missing a lot of the masked instructions.

There are some test changes here because of the new folding support. I don't think these particular cases should be folded because it creates an undef register dependency. I think the changes introduced in r334175 are not handling stack folding. They're only blocking the peephole pass.

llvm-svn: 334800
2018-06-15 05:49:19 +00:00
Craig Topper f43807dd89 [X86] Add 'Z' to the internal names of various EVEX instructions for overall consistency.
llvm-svn: 334785
2018-06-15 04:42:54 +00:00
Craig Topper bfa94d5086 [X86] Fix stale comment in folding tables.
llvm-svn: 334758
2018-06-14 19:28:31 +00:00
Craig Topper 3ffeb41f6b [X86] Add more vector instructions to the memory folding table using the autogenerated table as a guide.
The test cahnge is because we now fold stack reload into RNDSCALE and RNDSCALE can be turned into ROUND by EVEX->VEX.

llvm-svn: 334728
2018-06-14 15:40:31 +00:00
Craig Topper b0742bf30d [X86] Disable load unfolding for a bunch of instruction where unfolding would increase the size of the load.
Found by an audit of the manual table vs the autogenerated table.

llvm-svn: 334726
2018-06-14 15:40:29 +00:00
Craig Topper f7f663e0a9 [X86] Move RCPSSr_Int, RSQRTSSr_Int, SQRTSDr_Int, SQRTSSr_Int to the correct load folding table.
They were in the operand 1 folding table, but their foldable operand is operand 2.

llvm-svn: 334648
2018-06-13 20:03:42 +00:00
Craig Topper ede97c9548 [X86] Remove TB_ALIGN_16 from VEXTRACTF128/VEXTRACTI128 in the memory folding table.
llvm-svn: 334511
2018-06-12 15:48:03 +00:00
Tomasz Krupa f8c7637027 [X86] Block UndefRegUpdate
Summary: Prevent folding of operations with memory loads when one of the sources has undefined register update.

Reviewers: craig.topper

Subscribers: llvm-commits, mike.dvoretsky, ashlykov

Differential Revision: https://reviews.llvm.org/D47621

llvm-svn: 334175
2018-06-07 08:48:45 +00:00
Petar Jovanovic 8cb6a521be Change TII isCopyInstr way of returning arguments(NFC)
Make TII isCopyInstr() return MachineOperands through pointer to pointer
instead via reference.

Patch by Nikola Prica.

Differential Revision: https://reviews.llvm.org/D47364

llvm-svn: 334105
2018-06-06 16:36:30 +00:00
Jessica Paquette aa087327ce [MachineOutliner] NFC - Move intermediate data structures to MachineOutliner.h
This is setting up to fix bug 37573 cleanly.

This moves data structures that are technically both used in some way by the
target and the general-purpose outlining algorithm into MachineOutliner.h. In
particular, the `Candidate` class is of importance.

Before, the outliner passed the locations of `Candidates` to the target, which
would then make some decisions about the prospective outlined function. This
change allows us to just pass `Candidates` along to the target. This will allow
the target to discard `Candidates` that would be considered unsafe before cost
calculation. Thus, we will be able to remove the unsafe candidates described in
the bug without resorting to torching the entire prospective function.

Also, as a side-effect, it makes the outliner a bit cleaner.

https://bugs.llvm.org/show_bug.cgi?id=37573

llvm-svn: 333952
2018-06-04 21:14:16 +00:00
Craig Topper 6b545182fb [X86] Fix typo in comment. NFC
llvm-svn: 333382
2018-05-28 19:33:06 +00:00
Petar Jovanovic c051000b83 [X86][MIPS][ARM] New machine instruction property 'isMoveReg'
This property is needed in order to follow values movement between
registers. This property is used in TII to implement method that
returns true if simple copy like instruction is recognized, along
with source and destination machine operands.

Patch by Nikola Prica.

Differential Revision: https://reviews.llvm.org/D45204

llvm-svn: 333093
2018-05-23 15:28:28 +00:00
Eli Friedman d268bf0a4d Fix unused lambda capture.
llvm-svn: 332686
2018-05-18 02:11:25 +00:00
Eli Friedman 4081a57af7 [MachineOutliner] Count savings from outlining in bytes.
Counting the number of instructions is both unintuitive and inaccurate.
On AArch64, this only affects the generated remarks and certain rare
pseudo-instructions, but it will have a bigger impact on other targets.

Differential Revision: https://reviews.llvm.org/D46921

llvm-svn: 332685
2018-05-18 01:52:16 +00:00
Nicola Zaghen d34e60ca85 Rename DEBUG macro to LLVM_DEBUG.
The DEBUG() macro is very generic so it might clash with other projects.
The renaming was done as follows:
- git grep -l 'DEBUG' | xargs sed -i 's/\bDEBUG\s\?(/LLVM_DEBUG(/g'
- git diff -U0 master | ../clang/tools/clang-format/clang-format-diff.py -i -p1 -style LLVM
- Manual change to APInt
- Manually chage DOCS as regex doesn't match it.

In the transition period the DEBUG() macro is still present and aliased
to the LLVM_DEBUG() one.

Differential Revision: https://reviews.llvm.org/D43624

llvm-svn: 332240
2018-05-14 12:53:11 +00:00
Shiva Chen 801bf7ebbe [DebugInfo] Examine all uses of isDebugValue() for debug instructions.
Because we create a new kind of debug instruction, DBG_LABEL, we need to
check all passes which use isDebugValue() to check MachineInstr is debug
instruction or not. When expelling debug instructions, we should expel
both DBG_VALUE and DBG_LABEL. So, I create a new function,
isDebugInstr(), in MachineInstr to check whether the MachineInstr is
debug instruction or not.

This patch has no new test case. I have run regression test and there is
no difference in regression test.

Differential Revision: https://reviews.llvm.org/D45342

Patch by Hsiangkai Wang.

llvm-svn: 331844
2018-05-09 02:42:00 +00:00
Adrian Prantl 5f8f34e459 Remove \brief commands from doxygen comments.
We've been running doxygen with the autobrief option for a couple of
years now. This makes the \brief markers into our comments
redundant. Since they are a visual distraction and we don't want to
encourage more \brief markers in new code either, this patch removes
them all.

Patch produced by

  for i in $(git grep -l '\\brief'); do perl -pi -e 's/\\brief //g' $i & done

Differential Revision: https://reviews.llvm.org/D46290

llvm-svn: 331272
2018-05-01 15:54:18 +00:00
Andrea Di Biagio d4c58400c5 [X86] Correct spill slot size.
This patch fixes a bug introduced by revision 330778 (originally reviewed at:
https://reviews.llvm.org/D44782), where function isFrameLoadOpcode returned
the wrong number of bytes read for opcodes VMOVSSrm and VMOVSDrm.

This corrects that mistake, and extends the regression test to catch cases where
the dead stores should be removed.

Patch by Jeremy Morse.

Differential Revision: https://reviews.llvm.org/D46256

llvm-svn: 331252
2018-05-01 10:29:38 +00:00
Craig Topper 8a6532ae84 [X86] Rename BNDMOV instructions and hide redundant instruction encoding from the assembler.
Favor the 0x1a encoding for register/register move to match gas.

The instructions used RM and MR in their name along with rr/rm/mr at the end. To make more consistent with other instructions remove the RM/MR and use rr/rm/mr/rr_REV.

Hide the _REV encoding from the assembler but leave it for the disassembler.

llvm-svn: 331101
2018-04-28 06:02:39 +00:00
Craig Topper d656410293 [X86] Make the STTNI flag intrinsics use the flags from pcmpestrm/pcmpistrm if the mask instrinsics are also used in the same basic block.
Summary:
Previously the flag intrinsics always used the index instructions even if a mask instruction also exists.

To fix fix this I've created a single ISD node type that returns index, mask, and flags. The SelectionDAG CSE process will merge all flavors of intrinsics with the same inputs to a s ingle node. Then during isel we just have to look at which results are used to know what instruction to generate. If both mask and index are used we'll need to emit two instructions. But for all other cases we can emit a single instruction.

Since I had to do manual isel anyway, I've removed the pseudo instructions and custom inserter code that was working around tablegen limitations with multiple implicit defs.

I've also renamed the recently added sse42.ll test case to sttni.ll since it focuses on that subset of the sse4.2 instructions.

Reviewers: chandlerc, RKSimon, spatel

Reviewed By: chandlerc

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D46202

llvm-svn: 331091
2018-04-27 22:15:33 +00:00
Chandler Carruth eb631ef51e [x86] Allow folding unaligned memory operands into pcmp[ei]str*
instructions.

These have special permission according to the x86 manual to read
unaligned memory, and this folding is done by ICC and GCC as well.

This corrects one of the issues identified in PR37246.

llvm-svn: 330896
2018-04-26 03:17:25 +00:00
Warren Ristow b960d2cb40 [X86] Account for partial stack slot spills (PR30821)
Previously, _any_ store or load instruction was considered to be
operating on a spill if it had a frameindex as an operand, and thus
was fair game for optimisations such as "StackSlotColoring". This
usually works, except on architectures where spills can be partially
restored, for example on X86 where a spilt vector can have a single
component loaded (zeroing the rest of the target register). This can be
mis-interpreted and the zero extension unsoundly eliminated, see
pr30821.

To avoid this, this commit optionally provides the caller to
isLoadFromStackSlot and isStoreToStackSlot with the number of bytes
spilt/loaded by the given instruction. Optimisations can then determine
that a full spill followed by a partial load (or vice versa), for
example, cannot necessarily be commuted.

Patch by Jeremy Morse!

Differential Revision: https://reviews.llvm.org/D44782

llvm-svn: 330778
2018-04-24 22:01:50 +00:00
Chandler Carruth 0ca3bd0729 [x86] Model the direction flag (DF) separately from the rest of EFLAGS.
This cleans up a number of operations that only claimed te use EFLAGS
due to using DF. But no instructions which we think of us setting EFLAGS
actually modify DF (other than things like popf) and so this needlessly
creates uses of EFLAGS that aren't really there.

In fact, DF is so restrictive it is pretty easy to model. Only STD, CLD,
and the whole-flags writes (WRFLAGS and POPF) need to model this.

I've also somewhat cleaned up some of the flag management instruction
definitions to be in the correct .td file.

Adding this extra register also uncovered a failure to use the correct
datatype to hold X86 registers, and I've corrected that as necessary
here.

Differential Revision: https://reviews.llvm.org/D45154

llvm-svn: 329673
2018-04-10 06:40:51 +00:00
Chandler Carruth 19618fc639 [x86] Introduce a pass to begin more systematically fixing PR36028 and similar issues.
The key idea is to lower COPY nodes populating EFLAGS by scanning the
uses of EFLAGS and introducing dedicated code to preserve the necessary
state in a GPR. In the vast majority of cases, these uses are cmovCC and
jCC instructions. For such cases, we can very easily save and restore
the necessary information by simply inserting a setCC into a GPR where
the original flags are live, and then testing that GPR directly to feed
the cmov or conditional branch.

However, things are a bit more tricky if arithmetic is using the flags.
This patch handles the vast majority of cases that seem to come up in
practice: adc, adcx, adox, rcl, and rcr; all without taking advantage of
partially preserved EFLAGS as LLVM doesn't currently model that at all.

There are a large number of operations that techinaclly observe EFLAGS
currently but shouldn't in this case -- they typically are using DF.
Currently, they will not be handled by this approach. However, I have
never seen this issue come up in practice. It is already pretty rare to
have these patterns come up in practical code with LLVM. I had to resort
to writing MIR tests to cover most of the logic in this pass already.
I suspect even with its current amount of coverage of arithmetic users
of EFLAGS it will be a significant improvement over the current use of
pushf/popf. It will also produce substantially faster code in most of
the common patterns.

This patch also removes all of the old lowering for EFLAGS copies, and
the hack that forced us to use a frame pointer when EFLAGS copies were
found anywhere in a function so that the dynamic stack adjustment wasn't
a problem. None of this is needed as we now lower all of these copies
directly in MI and without require stack adjustments.

Lots of thanks to Reid who came up with several aspects of this
approach, and Craig who helped me work out a couple of things tripping
me up while working on this.

Differential Revision: https://reviews.llvm.org/D45146

llvm-svn: 329657
2018-04-10 01:41:17 +00:00
Jessica Paquette 5fa2a63785 [MachineOutliner] Test for X86FI->getUsesRedZone() as well as Attribute::NoRedZone
This commit is similar to r329120, but uses the existing getUsesRedZone() function
in X86MachineFunctionInfo. This teaches the outliner to look at whether or not a
function *truly* uses a redzone instead of just the noredzone attribute on a
function.

Thus, after this commit, it's possible to outline from x86 without using
-mno-red-zone and still get outlining results.

This also adds a new test for the new redzone behaviour.

llvm-svn: 329134
2018-04-03 23:32:41 +00:00
Chandler Carruth 06b343c6ed [x86] Expose more of the condition conversion routines in the public API
for X86's instruction information. I've now got a second patch under
review that needs these same APIs. This bit is nicely orthogonal and
obvious, so landing it. NFC.

llvm-svn: 328944
2018-04-01 21:47:55 +00:00
Craig Topper 40d3b32e12 [X86] Rename VROUNDYPS* and VROUNDYPD* instructions to VROUNDPSY* and VROUNDPDY*. Fix itinerary mistake on all memory forms of VROUNDPD
This makes the Y position consistent with other instructions.

This should have been NFC, but while refactoring the multiclass I noticed that VROUNDPD memory forms were using the register itinerary.

llvm-svn: 328254
2018-03-22 21:55:20 +00:00
Craig Topper ad7c685791 [X86] Rename MOVSX32_NOREXrr8 to MOVSX32rr8_NOREX so that the scheduler model regular expressions will pick it up with the regular version.
Do the same for MOVSX32_NOREXrm8, MOVZX32_NOREXrr8, and MOVZX32_NOREXrm8

llvm-svn: 327948
2018-03-20 05:00:20 +00:00
Jessica Paquette b3e7dc9144 [MachineOutliner] Make KILLs invisible
At the point the outliner runs, KILLs don't impact anything, but they're still
considered unique instructions. This commit makes them invisible like
DebugValues so that they can still be outlined without impacting outlining
decisions.

llvm-svn: 327760
2018-03-16 22:53:34 +00:00
Craig Topper cb7881c649 [X86] Stop passing two arguments by reference. NFC
I think these used to be out parameters, but they haven't been for a while.

llvm-svn: 326417
2018-03-01 06:25:13 +00:00
Craig Topper 688d1eb919 Revert r326225 "[X86] Move the load folding tables to a separate .inc file"
The bots don't seem to like the .inc file. I must be missing some cmake incantation.

llvm-svn: 326228
2018-02-27 19:15:40 +00:00
Craig Topper c0a1291478 [X86] Move the load folding tables to a separate .inc file
These tables add 3000 lines to X86InstrInfo.cpp. And if we ever manage to auto generate them they'll be a separate file anyway.

Differential Revision: https://reviews.llvm.org/D43806

llvm-svn: 326225
2018-02-27 18:46:11 +00:00
Craig Topper a05ed17316 [X86] Make XOP VPCOM instructions commutable to fold loads during isel.
llvm-svn: 325547
2018-02-20 03:58:13 +00:00
Craig Topper 9b64bf54b9 [X86] Make a helper function for commuting AVX512 VPCMP immediates since we do it in two places.
llvm-svn: 325546
2018-02-20 03:58:11 +00:00
Chandler Carruth 0be0cfa65b [x86] Fix nasty bug in the x86 backend that is essentially impossible to
hit from IR but creates a minefield for MI passes.

The x86 backend has fairly powerful logic to try and fold loads that
feed register operands to instructions into a memory operand on the
instruction. This is almost always a good thing, but there are specific
relocated loads that are only allowed to appear in specific
instructions. Notably, R_X86_64_GOTTPOFF is only allowed in `movq` and
`addq`. This patch blocks folding of memory operands using this
relocation unless the target is in fact `addq`.

The particular relocation indicates why we simply don't hit this under
normal circumstances. This relocation is only used for TLS, and it gets
used in very specific ways in conjunction with %fs-relative addressing.
The result is that loads using this relocation are essentially never
eligible for folding into an instruction's memory operands. Unless, of
course, you have an MI pass that inserts usage of such a load. I have
exactly such an MI pass and was greeted by truly mysterious miscompiles
where the linker replaced my instruction with a completely garbage byte
sequence. Go team.

This is the only such relocation I'm aware of in x86, but there may be
others that need to be similarly restricted.

Fixes PR36165.

Differential Revision: https://reviews.llvm.org/D42732

llvm-svn: 324546
2018-02-07 23:59:14 +00:00
Craig Topper 8baa9c77e3 [X86] When doing callee save/restore for k-registers make sure we don't use KMOVQ on non-BWI targets
If we are saving/restoring k-registers, the default behavior of getMinimalRegisterClass will find the VK64 class with a spill size of 64 bits. This will cause the KMOVQ opcode to be used for save/restore. If we don't have have BWI instructions we need to constrain the class returned to give us VK16 with a 16-bit spill size. We can do this by passing the either v16i1 or v64i1 into getMinimalRegisterClass.

Also add asserts to make sure BWI is enabled anytime we use KMOVD/KMOVQ. These are what caught this bug.

Fixes PR36256

Differential Revision: https://reviews.llvm.org/D42989

llvm-svn: 324533
2018-02-07 21:41:50 +00:00
Nirav Dave eedb663221 [X86] Teach DAG unfoldMemoryOperand to reconvert CMPs to tests
Summary:
Copy MI-level cmp->test conversion to SelectionDAG-level memory unfold.
This fixes a regression from upcoming D41293 change.

Reviewers: craig.topper, RKSimon

Reviewed By: craig.topper

Subscribers: llvm-commits, hiraditya

Differential Revision: https://reviews.llvm.org/D42808

llvm-svn: 324261
2018-02-05 18:58:58 +00:00
Amaury Sechet f89f188ddb [X86] Avoid using high register trick for test instruction
Summary:
It seems it's main effect is to create addition copies when values are inr register that do not support this trick, which increase register pressure and makes the code bigger.

Reviewers: craig.topper, niravd, spatel, hfinkel

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D42646

llvm-svn: 323888
2018-01-31 16:48:54 +00:00
Eric Liu 0b69b5ed85 Revert "[X86] Avoid using high register trick for test instruction"
This reverts commit r323690. This causes crash in llc. See the original commit thread for details.

llvm-svn: 323761
2018-01-30 14:18:33 +00:00
Amaury Sechet 015184b79e [X86] Avoid using high register trick for test instruction
Summary:
It seems it's main effect is to create addition copies when values are inr register that do not support this trick, which increase register pressure and makes the code bigger.

The main noteworthy regression I was able to observe was pattern of the type (setcc (trunc (and X, C)), 0) where C is such as it would benefit from the hi register trick. To prevent this, a new pattern is added to materialize such pattern using a 32 bits test. This has the added benefit of working with any constant that is materializable as a 32bits immediate, not just the ones that can leverage the high register trick, as demonstrated by the test case in test-shrink.ll using the constant 2049 .

Reviewers: craig.topper, niravd, spatel, hfinkel

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D42646

llvm-svn: 323690
2018-01-29 20:54:33 +00:00
Craig Topper 066e73762d [X86] Name the MMX phaddd instruction with 3 Ds instead of just 2. NFC
llvm-svn: 323403
2018-01-25 04:45:32 +00:00
Craig Topper dbddac0915 [X86] Remove 64/128/256 from MMX/SSE/AVX instruction names for overall consistency. NFC
MMX instrutions all start with MMX_ so the 64 isn't needed for disambigutation.
SSE/AVX1 instructions are assumed 128-bit so we don't need to say 128.
AVX2 instructions should use a Y to indicate 256-bits.

llvm-svn: 323402
2018-01-25 04:45:30 +00:00
Craig Topper b85b484fee [X86] Adjust names of PINSRW/PEXTRW intructions between MMX/SSE/AVX/AVX512 for consistency and to maybe enable more regular expression compaction in the scheduler models. NFCI
llvm-svn: 323352
2018-01-24 17:58:51 +00:00
Craig Topper a55ac7b790 [X86] Rename 256-bit VFRCZ instructions to have the Y before the rr/rm to match other instructions. NFC
llvm-svn: 323304
2018-01-24 05:14:39 +00:00
Craig Topper 002657731b [X86] Move 'Int_' to the end of the name of the VCOMISS/VUCOMISS and instructions to get them picked up by the scheduler model regexs.
All other intrinsic instructions put the _Int on the end. This make these instructions consistent and gets the prefix instregexs in the scheduler models to pick them up.

llvm-svn: 323261
2018-01-23 21:37:51 +00:00
Craig Topper c2df6409c7 [X86] Add missing MOVSX/MOVZX instructions to load folding tables.
I'm not sure there's any way to generate these folding cases especially the movzx ones since even the register form is never emitted by codegen.

I'm just adding them to remove the difference with the autogenerated version of the folding table.

llvm-svn: 323200
2018-01-23 14:09:22 +00:00
Marina Yatsina 811523cc08 Fix bug in commit 323096 exposed by test in test-suite-verify-machineinstrs-x86_64h-O3
Change-Id: I0a4b10d0d6c8de606d989c567ec07944ae283a87
llvm-svn: 323126
2018-01-22 15:31:05 +00:00
Marina Yatsina 77a21dbad4 Break false dependencies for POPCNT, LZCNT, TZCNT
Add POPCNT, LZCNT, TZCNT to the list of instructions that have false dependency.
Add a test to make sure BreakFalseDeps breaks the dependencies for these instructions.
Update affected tests.

This fixes bugzilla https://bugs.llvm.org/show_bug.cgi?id=33869

This is the final of multiple patches that fix this bugzilla.
Most of the patches are intended at refactoring the existent code.

Reviews of the refactoring done to enable this change:
https://reviews.llvm.org/D40330
https://reviews.llvm.org/D40331
https://reviews.llvm.org/D40332
https://reviews.llvm.org/D40333

Differential Revision: https://reviews.llvm.org/D40334

Change-Id: If95cbf1a3f5c7dccff8f1b22ecb397542147303d
llvm-svn: 323096
2018-01-22 10:07:01 +00:00
Marina Yatsina 6fc2aaae8d Separate ExecutionDepsFix into 4 parts:
1. ReachingDefsAnalysis - Allows to identify for each instruction what is the “closest” reaching def of a certain register. Used by BreakFalseDeps (for clearance calculation) and ExecutionDomainFix (for arbitrating conflicting domains).
2. ExecutionDomainFix - Changes the variant of the instructions in order to minimize domain crossings.
3. BreakFalseDeps - Breaks false dependencies.
4. LoopTraversal - Creatws a traversal order of the basic blocks that is optimal for loops (introduced in revision L293571). Both ExecutionDomainFix and ReachingDefsAnalysis use this to determine the order they will traverse the basic blocks.

This also included the following changes to ExcecutionDepsFix original logic:
1. BreakFalseDeps and ReachingDefsAnalysis logic no longer restricted by a register class.
2. ReachingDefsAnalysis tracks liveness of reg units instead of reg indices into a given reg class.

Additional changes in affected files:
1. X86 and ARM targets now inherit from ExecutionDomainFix instead of ExecutionDepsFix. BreakFalseDeps also was added to the passes they activate.
2. Comments and references to ExecutionDepsFix replaced with ExecutionDomainFix and BreakFalseDeps, as appropriate.

Additional refactoring changes will follow.

This commit is (almost) NFC.
The only functional change is that now BreakFalseDeps will break dependency for all register classes.
Since no additional instructions were added to the list of instructions that have false dependencies, there is no actual change yet.
In a future commit several instructions (and tests) will be added.

This is the first of multiple patches that fix bugzilla https://bugs.llvm.org/show_bug.cgi?id=33869
Most of the patches are intended at refactoring the existent code.

Additional relevant reviews:
https://reviews.llvm.org/D40331
https://reviews.llvm.org/D40332
https://reviews.llvm.org/D40333
https://reviews.llvm.org/D40334

Differential Revision: https://reviews.llvm.org/D40330

Change-Id: Icaeb75e014eff96a8f721377783f9a3e6c679275
llvm-svn: 323087
2018-01-22 10:05:23 +00:00
Simon Pilgrim e5dad1365c Avoid Wparentheses warning.
llvm-svn: 322526
2018-01-15 22:40:06 +00:00
Simon Pilgrim 85bd9141ca [X86][MMX] Add support for MMX zero vector creation
As mentioned on PR35869, (and came up recently on D41517) we don't create a MMX zero register via the PXOR but instead perform a spill to stack from a XMM zero register.

This patch adds support for direct MMX zero vector creation and should make it easier to add better constant vector creation in the future as well.

Differential Revision: https://reviews.llvm.org/D41908

llvm-svn: 322525
2018-01-15 22:32:40 +00:00
Simon Pilgrim 940eae3cc1 [X86][SSE] Add custom execution domain fixing for BLENDPD/BLENDPS/PBLENDD/PBLENDW (PR34873)
Add support for custom execution domain fixing and implement support for BLENDPD/BLENDPS/PBLENDD/PBLENDW.

Differential Revision: https://reviews.llvm.org/D42042

llvm-svn: 322524
2018-01-15 22:18:45 +00:00
Jessica Paquette 3291e7353e [MachineOutliner] AArch64: Handle instrs that use SP and will never need fixups
This commit does two things. Firstly, it adds a collection of flags which can
be passed along to the target to encode information about the MBB that an
instruction lives in to the outliner.

Second, it adds some of those flags to the AArch64 outliner in order to add
more stack instructions to the list of legal instructions that are handled
by the outliner. The two flags added check if

- There are calls in the MachineBasicBlock containing the instruction
- The link register is available in the entire block

If the link register is available and there are no calls, then a stack
instruction can always be outlined without fixups, regardless of what it is,
since in this case, the outliner will never modify the stack to create a
call or outlined frame.

The motivation for doing this was checking which instructions are most often
missed by the outliner. Instructions like, say

%sp<def> = ADDXri %sp, 32, 0; flags: FrameDestroy

are very common, but cannot be outlined in the case that the outliner might
modify the stack. This commit allows us to outline instructions like this.
  

llvm-svn: 322048
2018-01-09 00:26:18 +00:00
Craig Topper 03d8e516cf [X86] Add VSHUFF32X4 and similar instructions to load folding tables.
llvm-svn: 321978
2018-01-07 23:30:20 +00:00
Craig Topper a21f551109 [X86] Add the 16 and 8-bit CRC32 instructions to the load folding tables.
llvm-svn: 321958
2018-01-07 06:48:20 +00:00
Craig Topper d0859a03b5 [X86] Correct the load folding flags for xmm fp->mmx conversion instructions.
The instructions that load 64-bits or an xmm register should be TB_NO_REVERSE to avoid the load being widened during unfold. The instructions that load 128-bits need to ensure 128-bit alignment.

llvm-svn: 321956
2018-01-07 06:24:30 +00:00
Craig Topper aa73941176 [X86] Add TB_NO_REVERSE to some scalar intrinsic instructions in the load folding table.
llvm-svn: 321955
2018-01-07 06:24:29 +00:00
Craig Topper 85657d59a9 [X86] Don't put any EVEX_B instructions in the tablegen generated load folding tables.
EVEX_B means different things for memory and register forms. The instructions should not be considered equivalent.

llvm-svn: 321954
2018-01-07 06:24:28 +00:00
Craig Topper 89293a2a94 [X86] Add 128 and 256-bit VPOPCNTD/Q instructions to load folding tables.
llvm-svn: 321953
2018-01-07 06:24:27 +00:00
Craig Topper a124ab10ef [X86] Add some 8 and 16-bit instructions to the load folding tables.
llvm-svn: 321952
2018-01-07 06:24:25 +00:00
Craig Topper 11aede13db [X86] Add EVEX vcvtph2ps to the load folding tables.
llvm-svn: 321951
2018-01-07 06:24:24 +00:00
Craig Topper 40cc8338f7 [X86] Remove cvtps2ph xmm->xmm from store folding tables. Add the evex versions of cvtps2ph to the store folding tables.
The memory form of the xmm->xmm version only writes 64-bits. If we use it in the folding tables and its get used for a stack spill, only half the slot will be written. Then a reload may read all 128-bits which will pull in garbage. But without the spill the upper bits of the register would have been zero. By not folding we would preserve the zeros.

llvm-svn: 321950
2018-01-07 06:24:23 +00:00
Craig Topper 8fa800b834 [X86] Add CMP8ri8 to load folding tables.
llvm-svn: 321949
2018-01-07 06:24:21 +00:00
Simon Pilgrim b1b30286bf Remove superfluous break after a return. NFCI.
llvm-svn: 320941
2017-12-17 11:01:33 +00:00
Matthias Braun f1caa2833f MachineFunction: Return reference from getFunction(); NFC
The Function can never be nullptr so we can return a reference.

llvm-svn: 320884
2017-12-15 22:22:58 +00:00
Craig Topper a0be5a06c1 [X86] Rename some instructions that start with Int_ to have the _Int at the end.
This matches AVX512 version and is more consistent overall. And improves our scheduler models.

In some cases this adds _Int to instructions that didn't have any Int_ before. It's a side effect of the adjustments made to some of the multiclasses.

llvm-svn: 320325
2017-12-10 19:47:56 +00:00
Craig Topper aa904d5ab6 [X86] Fix a few instructions that were named Z512 instead of just Z.
This makes things consistent with our normal instruction naming.

llvm-svn: 320316
2017-12-10 17:42:39 +00:00
Craig Topper c89e282f7d [X86] Rename some instructions so that 'b' is added as a suffix instead of replacing an 'r'
llvm-svn: 320290
2017-12-10 09:14:38 +00:00
Craig Topper da7e78e18c [X86] Rename the rb form of scalar ADD/SUB/MUL/DIV to include _Int since they can only be selected by intrinsics.
llvm-svn: 320283
2017-12-10 04:07:28 +00:00