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Author SHA1 Message Date
Jay Foad 33f78d0903 [TwoAddressInstruction] Fix stale LiveVariables info in processStatepoint 
D129213 improves verification of LiveVariables, and caused
CodeGen/X86/statepoint-cmp-sunk-past-statepoint.ll to fail with:
*** Bad machine code: LiveVariables: Block should not be in AliveBlocks ***
after Two-Address instruction pass.

Fix it by clearing AliveBlocks for a register which is no longer used.

Differential Revision: https://reviews.llvm.org/D136445
 2022-10-21 14:57:03 +01:00
Matt Arsenault 94ebd7d9ff MachineVerifier: Verify REG_SEQUENCE 
Somehow there was no verification of this, other than an ad-hoc
assertion in TwoAddressInstructions.
 2022-09-22 09:51:15 -04:00
Denis Antrushin d1fd791e72 [TwoAddressInstruction] Handle pointer compare sunk past statepoint. 
CodeGenPrepare pass can sink pointer comparison across statepoint
to the point of use (see comment in IR/SafepointIRVerifier.cpp)
Due to specifics of statepoints, it is still legal to have tied
def and use rewritten to the same register in TwoAddress pass.
However, properly updating LiveIntervals and LiveVariables becomes
complicated. For simplicity, let's fall back to generic handling of
tied registers when we detect such case.
TODO: This fixes functional (assertion) failure. Ideally we should
try to recompute new live range/liveness in place.

Reviewed By: skatkov

Differential Revision: https://reviews.llvm.org/D132255
 2022-08-23 12:34:11 +03:00
Kazu Hirata 76e18cc4f6 [llvm] Use llvm::any_of and llvm::none_of (NFC) 2022-07-20 00:36:19 -07:00
Denis Antrushin 7047d79fde [TwoAddressInstructionPass] Relax assert in statepoint processing. 
D124631 added special processing for STATEPOINT instructions.
It appears that assertion added there is too strong. We can get two
tied operands with the same register tied to different defs. If we
hit such case, do not process it in statepoint-specific code and
delegate it to common case.
 2022-06-01 21:34:52 +07:00
Denis Antrushin 85322e82be [TwoAddressInstructionPass] Special processing of STATEPOINT instruction. 
STATEPOINT is a special pseudo instruction which represent Moving GC semantic to LLVM.
Every tied def/use VReg pair in STATEPOINT represent same physical register which can
'magically' change during call wrapped by statepoint.
(By construction, tied use operand  is not live across  STATEPOINT).

This means that when converting into two-address form, there is not need to insert COPY
instruction before stateppoint, what TwoAddressInstruction pass does for 'regular'
instructions.

Reviewed By: MatzeB

Differential Revision: https://reviews.llvm.org/D124631
 2022-05-30 19:07:30 +03:00
Shengchen Kan 37b378386e [NFC][CodeGen] Rename some functions in MachineInstr.h and remove duplicated comments 2022-03-16 20:25:42 +08:00
serge-sans-paille 989f1c72e0 Cleanup codegen includes 
This is a (fixed) recommit of https://reviews.llvm.org/D121169

after:  1061034926
before: 1063332844

Discourse thread: https://discourse.llvm.org/t/include-what-you-use-include-cleanup
Differential Revision: https://reviews.llvm.org/D121681
 2022-03-16 08:43:00 +01:00
Nico Weber a278250b0f Revert "Cleanup codegen includes" 
This reverts commit 7f230feeea.
Breaks CodeGenCUDA/link-device-bitcode.cu in check-clang,
and many LLVM tests, see comments on https://reviews.llvm.org/D121169
 2022-03-10 07:59:22 -05:00
serge-sans-paille 7f230feeea Cleanup codegen includes 
after:  1061034926
before: 1063332844

Differential Revision: https://reviews.llvm.org/D121169
 2022-03-10 10:00:30 +01:00
Guozhi Wei f1d8345a2a [TwoAddressInstructionPass] Create register mapping for registers with multiple uses in the current MBB 
Currently we create register mappings for registers used only once in current
MBB. For registers with multiple uses, when all the uses are in the current MBB,
we can also create mappings for them similarly according to the last use.
For example

    %reg101 = ...
            = ... reg101
    %reg103 = ADD %reg101, %reg102

We can create mapping between %reg101 and %reg103.

Differential Revision: https://reviews.llvm.org/D113193
 2021-11-29 19:01:59 -08:00
Kazu Hirata 259cd6f893 [llvm] Use range-based for loops (NFC) 2021-11-25 22:17:10 -08:00
Zarko Todorovski 95875d246a [LLVM][NFC]Inclusive language: remove occurances of sanity check/test from llvm 
Part of work to use more inclusive language in clang/llvm. Rewording
some comments and change function and variable names.
 2021-11-24 17:29:55 -05:00
Jay Foad 3264e95938 [CodeGen] Update LiveIntervals in TargetInstrInfo::convertToThreeAddress 
Delegate updating of LiveIntervals to each target's
convertToThreeAddress implementation, instead of repairing LiveIntervals
after the fact in TwoAddressInstruction::convertInstTo3Addr.

Differential Revision: https://reviews.llvm.org/D113493
 2021-11-17 10:16:47 +00:00
Jay Foad 491beae71d [TwoAddressInstruction] Update LiveIntervals after rewriting INSERT_SUBREG to COPY 
Also add subranges to an existing live interval when introducing a new
subreg def.

Differential Revision: https://reviews.llvm.org/D113044
 2021-11-11 12:24:59 +00:00
Jay Foad 6abbc3a420 [LiveIntervals] Update subranges in processTiedPairs 
In TwoAddressInstructionPass::processTiedPairs when updating live
intervals after moving the last use of RegB back to the newly inserted
copy, update any affected subranges as well as the main range.

Differential Revision: https://reviews.llvm.org/D110411
 2021-11-11 12:24:59 +00:00
Jay Foad 5c3c7adf3a [CodeGen] Fix assertion failure in TwoAddressInstructionPass::rescheduleMIBelowKill 
This fixes an assertion failure with -early-live-intervals when trying
to update the live intervals for a debug instruction, which don't even
have slot indexes.

Differential Revision: https://reviews.llvm.org/D113116
 2021-11-09 09:24:21 +00:00
Jay Foad bdaa181007 [TwoAddressInstructionPass] Update existing physreg live intervals 
In TwoAddressInstructionPass::processTiedPairs with
-early-live-intervals, update any preexisting physreg live intervals,
as well as virtreg live intervals. By default (without
-precompute-phys-liveness) physreg live intervals only exist for
registers that are live-in to some basic block.

Differential Revision: https://reviews.llvm.org/D113191
 2021-11-05 21:20:30 +00:00
Jay Foad 0321bd64e6 Revert "[TwoAddressInstructionPass] Update existing physreg live intervals" 
This reverts commit ec0e1e88d2.

It was pushed by mistake.
 2021-11-05 09:54:26 +00:00
Jay Foad ec0e1e88d2 [TwoAddressInstructionPass] Update existing physreg live intervals 
In TwoAddressInstructionPass::processTiedPairs with
-early-live-intervals, update any preexisting physreg live intervals,
as well as virtreg live intervals. By default (without
-precompute-phys-liveness) physreg live intervals only exist for
registers that are live-in to some basic block.

Differential Revision: https://reviews.llvm.org/D113191
 2021-11-05 09:10:24 +00:00
Guozhi Wei 1e46dcb77b [TwoAddressInstructionPass] Put all new instructions into DistanceMap 
In function convertInstTo3Addr, after converting a two address instruction into
three address instruction, only the last new instruction is inserted into
DistanceMap. This is wrong, DistanceMap should track all instructions from the
beginning of current MBB to the working instruction. When a two address
instruction is converted to three address instruction, multiple instructions may
be generated (usually an extra COPY is generated), all of them should be
inserted into DistanceMap.

Similarly when unfolding memory operand in function tryInstructionTransform
DistanceMap is not maintained correctly.

Differential Revision: https://reviews.llvm.org/D111857
 2021-10-28 11:11:59 -07:00
Jay Foad f7ee21aa32 [TwoAddressInstruction] Remove ad hoc machine verification 
With the -early-live-intervals command line flag,
TwoAddressInstructionPass::runOnMachineFunction would call
MachineFunction::verify before returning to check the live intervals.
But there was not much benefit to doing this since -verify-machineinstrs
and LLVM_ENABLE_EXPENSIVE_CHECKS provide a more general way of
scheduling machine verification after every pass.

Also it caused problems on targets like Lanai which are marked as "not
machine verifier clean", since verification would fail for known
target-specific problems which are nothing to do with LiveIntervals.

Differential Revision: https://reviews.llvm.org/D111618
 2021-10-12 16:09:18 +01:00
Guozhi Wei 6599961c17 [TwoAddressInstructionPass] Improve the SrcRegMap and DstRegMap computation 
This patch contains following enhancements to SrcRegMap and DstRegMap:

  1 In findOnlyInterestingUse not only check if the Reg is two address usage,
    but also check after commutation can it be two address usage.

  2 If a physical register is clobbered, remove SrcRegMap entries that are
    mapped to it.

  3 In processTiedPairs, when create a new COPY instruction, add a SrcRegMap
    entry only when the COPY instruction is coalescable. (The COPY src is
    killed)

With these enhancements isProfitableToCommute can do better commute decision,
and finally more register copies are removed.

Differential Revision: https://reviews.llvm.org/D108731
 2021-10-11 15:28:31 -07:00
Jay Foad df2d4bc4cb [TwoAddressInstruction] Fix ReplacedAllUntiedUses in processTiedPairs 
Fix the calculation of ReplacedAllUntiedUses when any of the tied defs
are early-clobber. The effect of this is to fix the placement of kill
flags on an instruction like this (from @f2 in
 test/CodeGen/SystemZ/asm-18.ll):

  INLINEASM &"stepb $1, $2" [attdialect], $0:[regdef-ec:GRH32Bit], def early-clobber %3:grh32bit, $1:[reguse tiedto:$0], killed %4:grh32bit(tied-def 3), $2:[reguse:GRH32Bit], %4:grh32bit

After TwoAddressInstruction without this patch:

  %3:grh32bit = COPY killed %4:grh32bit
  INLINEASM &"stepb $1, $2" [attdialect], $0:[regdef-ec:GRH32Bit], def early-clobber %3:grh32bit, $1:[reguse tiedto:$0], %3:grh32bit(tied-def 3), $2:[reguse:GRH32Bit], %4:grh32bit

Note that the COPY kills %4, even though there is a later use of %4 in
the INLINEASM. This fails machine verification if you force it to run
after TwoAddressInstruction (currently it is disabled for other
reasons).

After TwoAddressInstruction with this patch:

  %3:grh32bit = COPY %4:grh32bit
  INLINEASM &"stepb $1, $2" [attdialect], $0:[regdef-ec:GRH32Bit], def early-clobber %3:grh32bit, $1:[reguse tiedto:$0], %3:grh32bit(tied-def 3), $2:[reguse:GRH32Bit], %4:grh32bit

Differential Revision: https://reviews.llvm.org/D110848
 2021-10-07 10:10:11 +01:00
Jay Foad dff3454bda [TwoAddressInstruction] Tweak constraining of tied operands 
In collectTiedOperands, when handling an undef use that is tied to a
def, constrain the dst reg with the actual register class of the src
reg, instead of with the register class from the instructions's
MCInstrDesc. This makes a difference in some AMDGPU test cases like
this, before:

  %16:sgpr_96 = INSERT_SUBREG undef %15:sgpr_96_with_sub0_sub1(tied-def 0), killed %11:sreg_64_xexec, %subreg.sub0_sub1

After, without this patch:

  undef %16.sub0_sub1:sgpr_96 = COPY killed %11:sreg_64_xexec

This fails machine verification if you force it to run after
TwoAddressInstruction (currently it is disabled) with:

*** Bad machine code: Invalid register class for subregister index ***
- function:    s_load_constant_v3i32_align4
- basic block: %bb.0  (0xa011a88)
- instruction: undef %16.sub0_sub1:sgpr_96 = COPY killed %11:sreg_64_xexec
- operand 0:   undef %16.sub0_sub1:sgpr_96
Register class SGPR_96 does not fully support subreg index 4

After, with this patch:

  undef %16.sub0_sub1:sgpr_96_with_sub0_sub1 = COPY killed %11:sreg_64_xexec

See also svn r159120 which introduced the code to handle tied undef
uses.

Differential Revision: https://reviews.llvm.org/D110944
 2021-10-01 20:57:58 +01:00
Jay Foad 845b93e692 [LiveIntervals] Fix another asan debug build failure 
Call RemoveMachineInstrFromMaps before erasing instrs.
repairIntervalsInRange will do this for you after erasing the
instruction, but it's not safe to rely on it because assertions in
SlotIndexes::removeMachineInstrFromMaps refer to fields in the erased
instruction.

This fixes asan buildbot failures caused by D110335.
 2021-09-28 11:09:38 +01:00
Jay Foad 20c0280733 [LiveIntervals] Repair subreg ranges in processTiedPairs 
In TwoAddressInstructionPass::processTiedPairs, update subranges of the
live interval for RegB as well as the main range.

This is a small step towards switching TwoAddressInstructionPass over
from LiveVariables to LiveIntervals. Currently this path is only tested
if you explicitly enable -early-live-intervals.

Differential Revision: https://reviews.llvm.org/D110526
 2021-09-28 08:10:16 +01:00
Jay Foad b2b1a8b833 [LiveIntervals] Improve repair after convertToThreeAddress 
After TwoAddressInstructionPass calls
TargetInstrInfo::convertToThreeAddress, improve the LiveIntervals repair
to cope with convertToThreeAddress creating more than one new
instruction.

This mostly seems to benefit X86. For example in
test/CodeGen/X86/zext-trunc.ll it converts:

  %4:gr32 = ADD32rr %3:gr32(tied-def 0), %2:gr32, implicit-def dead $eflags

to:

  undef %6.sub_32bit:gr64 = COPY %3:gr32
  undef %7.sub_32bit:gr64_nosp = COPY %2:gr32
  %4:gr32 = LEA64_32r killed %6:gr64, 1, killed %7:gr64_nosp, 0, $noreg

Differential Revision: https://reviews.llvm.org/D110335
 2021-09-28 08:10:08 +01:00
Jay Foad ac51ad24a7 [LiveIntervals] Fix asan debug build failures 
Call RemoveMachineInstrFromMaps before erasing instrs.
repairIntervalsInRange will do this for you after erasing the
instruction, but it's not safe to rely on it because assertions in
SlotIndexes::removeMachineInstrFromMaps refer to fields in the erased
instruction.

This fixes asan buildbot failures caused by D110328.
 2021-09-24 19:14:57 +01:00
Jay Foad 6cef28ed2d [TII] Remove the MFI argument to convertToThreeAddress. NFC. 
This simplifies the API and addresses a FIXME in
TwoAddressInstructionPass::convertInstTo3Addr.

Differential Revision: https://reviews.llvm.org/D110229
 2021-09-23 08:58:46 +01:00
Kazu Hirata 84b07c9b3a [llvm] Use pop_back_val (NFC) 2021-09-19 13:44:23 -07:00
Guozhi Wei 5609c8b607 [X86FixupLEAs] Try again to transform the sequence LEA/SUB to SUB/SUB 
This patch transforms the sequence
    lea (reg1, reg2), reg3
    sub reg3, reg4
to two sub instructions
    sub reg1, reg4
    sub reg2, reg4

Similar optimization can also be applied to LEA/ADD sequence.

The modifications to TwoAddressInstructionPass is to ensure the operands of ADD
instruction has expected order (the dest register of LEA should be src register
of ADD).

Differential Revision: https://reviews.llvm.org/D104684
 2021-07-16 10:16:03 -07:00
Florian Hahn 5cd66420cc
Revert "[X86FixupLEAs] Transform the sequence LEA/SUB to SUB/SUB" 
This reverts commit 1b748faf2b because it
breaks building the llvm-test-suite with -verify-machineinstrs on X86:
http://green.lab.llvm.org/green/job/test-suite-verify-machineinstrs-x86_64-O3/9585/

Running llc -verify-machineinstr on X86 crashes on the IR below:

    target datalayout = "e-m:o-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"

    %struct.widget = type { i32, i32, i32, i32, i32*, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, [16 x [16 x i16]], [6 x [32 x i32]], [16 x [16 x i32]], [4 x [12 x [4 x [4 x i32]]]], [16 x i32], i8**, i32*, i32***, i32**, i32, i32, i32, i32, %struct.baz*, %struct.wobble.1*, i32, i32, i32, i32, i32, i32, %struct.quux.2*, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, [3 x i32], i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32***, i32***, i32****, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, [3 x [2 x i32]], [3 x [2 x i32]], i32, i32, i64, i64, %struct.zot.3, %struct.zot.3, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32 }
    %struct.baz = type { i32, i32, i32, i32, i32, i32, i32, i32, i32, %struct.snork*, %struct.wombat.0*, %struct.wobble*, i32, i32*, i32*, i32*, i32, i32*, i32*, i32*, i32 (%struct.widget*, %struct.eggs*)*, i32, i32, i32, i32 }
    %struct.snork = type { %struct.spam*, %struct.zot, i32 (%struct.wombat*, %struct.widget*, %struct.snork*)* }
    %struct.spam = type { i32, i32, i32, i32, i8*, i32 }
    %struct.zot = type { i32, i32, i32, i32, i32, i8*, i32* }
    %struct.wombat = type { i32, i32, i32, i32, i32, i32, i32, i32, void (i32, i32, i32*, i32*)*, void (%struct.wombat*, %struct.widget*, %struct.zot*)* }
    %struct.wombat.0 = type { [4 x [11 x %struct.quux]], [2 x [9 x %struct.quux]], [2 x [10 x %struct.quux]], [2 x [6 x %struct.quux]], [4 x %struct.quux], [4 x %struct.quux], [3 x %struct.quux] }
    %struct.quux = type { i16, i8 }
    %struct.wobble = type { [2 x %struct.quux], [4 x %struct.quux], [3 x [4 x %struct.quux]], [10 x [4 x %struct.quux]], [10 x [15 x %struct.quux]], [10 x [15 x %struct.quux]], [10 x [5 x %struct.quux]], [10 x [5 x %struct.quux]], [10 x [15 x %struct.quux]], [10 x [15 x %struct.quux]] }
    %struct.eggs = type { [1000 x i8], [1000 x i8], [1000 x i8], i32, i32, i32, i32, i32, i32, i32, i32 }
    %struct.wobble.1 = type { i32, [2 x i32], i32, i32, %struct.wobble.1*, %struct.wobble.1*, i32, [2 x [4 x [4 x [2 x i32]]]], i32, i64, i64, i32, i32, [4 x i8], [4 x i8], i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32 }
    %struct.quux.2 = type { i32, i32, i32, i32, i32, %struct.quux.2* }
    %struct.zot.3 = type { i64, i16, i16, i16 }

    define void @blam(%struct.widget* %arg, i32 %arg1) local_unnamed_addr {
    bb:
      %tmp = load i32, i32* undef, align 4
      %tmp2 = sdiv i32 %tmp, 6
      %tmp3 = sdiv i32 undef, 6
      %tmp4 = load i32, i32* undef, align 4
      %tmp5 = icmp eq i32 %tmp4, 4
      %tmp6 = select i1 %tmp5, i32 %tmp3, i32 %tmp2
      %tmp7 = getelementptr inbounds [4 x [4 x i32]], [4 x [4 x i32]]* undef, i64 0, i64 0, i64 0
      %tmp8 = zext i16 undef to i32
      %tmp9 = zext i16 undef to i32
      %tmp10 = load i16, i16* undef, align 2
      %tmp11 = zext i16 %tmp10 to i32
      %tmp12 = zext i16 undef to i32
      %tmp13 = zext i16 undef to i32
      %tmp14 = zext i16 undef to i32
      %tmp15 = load i16, i16* undef, align 2
      %tmp16 = zext i16 %tmp15 to i32
      %tmp17 = zext i16 undef to i32
      %tmp18 = sub nsw i32 %tmp8, %tmp9
      %tmp19 = shl nsw i32 undef, 1
      %tmp20 = add nsw i32 %tmp19, %tmp18
      %tmp21 = sub nsw i32 %tmp11, %tmp12
      %tmp22 = shl nsw i32 undef, 1
      %tmp23 = add nsw i32 %tmp22, %tmp21
      %tmp24 = sub nsw i32 %tmp13, %tmp14
      %tmp25 = shl nsw i32 undef, 1
      %tmp26 = add nsw i32 %tmp25, %tmp24
      %tmp27 = sub nsw i32 %tmp16, %tmp17
      %tmp28 = shl nsw i32 undef, 1
      %tmp29 = add nsw i32 %tmp28, %tmp27
      %tmp30 = sub nsw i32 %tmp20, %tmp29
      %tmp31 = sub nsw i32 %tmp23, %tmp26
      %tmp32 = shl nsw i32 %tmp30, 1
      %tmp33 = add nsw i32 %tmp32, %tmp31
      store i32 %tmp33, i32* undef, align 4
      %tmp34 = mul nsw i32 %tmp31, -2
      %tmp35 = add nsw i32 %tmp34, %tmp30
      store i32 %tmp35, i32* undef, align 4
      %tmp36 = select i1 %tmp5, i32 undef, i32 undef
      br label %bb37

    bb37:                                             ; preds = %bb
      %tmp38 = load i32, i32* undef, align 4
      %tmp39 = ashr i32 %tmp38, %tmp6
      %tmp40 = load i32, i32* undef, align 4
      %tmp41 = sdiv i32 %tmp39, %tmp40
      store i32 %tmp41, i32* undef, align 4
      ret void
    }
 2021-06-12 11:41:38 +01:00
Guozhi Wei 1b748faf2b [X86FixupLEAs] Transform the sequence LEA/SUB to SUB/SUB 
This patch transforms the sequence

    lea (reg1, reg2), reg3
    sub reg3, reg4

to two sub instructions

    sub reg1, reg4
    sub reg2, reg4

Similar optimization can also be applied to LEA/ADD sequence.
The modifications to TwoAddressInstructionPass is to ensure the operands of ADD
instruction has expected order (the dest register of LEA should be src register of ADD).

Differential Revision: https://reviews.llvm.org/D101970
 2021-06-01 10:31:30 -07:00
Simon Pilgrim 707fc2e2f2 Revert rG528bc10e95d5f9d6a338f9bab5e91d7265d1cf05 : "[X86FixupLEAs] Transform the sequence LEA/SUB to SUB/SUB" 
Reports on D101970 indicate this is causing failures on multi-stage compiles.
 2021-05-19 15:01:20 +01:00
Guozhi Wei 528bc10e95 [X86FixupLEAs] Transform the sequence LEA/SUB to SUB/SUB 
This patch transforms the sequence

    lea (reg1, reg2), reg3
    sub reg3, reg4

to two sub instructions

    sub reg1, reg4
    sub reg2, reg4

Similar optimization can also be applied to LEA/ADD sequence.
The modifications to TwoAddressInstructionPass is to ensure the operands of ADD
instruction has expected order (the dest register of LEA should be src register
of ADD).

Differential Revision: https://reviews.llvm.org/D101970
 2021-05-18 18:02:36 -07:00
serge-sans-paille 35368bbdbb [NFC] Replace loop by idiomatic llvm::find_if 2021-03-16 12:49:19 +01:00
Kazu Hirata fd04f3a30c [CodeGen] Use range-based for loops (NFC) 2021-02-18 22:46:43 -08:00
Hongtao Yu 1cb47a063e [CSSPGO] Unblock optimizations with pseudo probe instrumentation. 
The IR/MIR pseudo probe intrinsics don't get materialized into real machine instructions and therefore they don't incur runtime cost directly. However, they come with indirect cost by blocking certain optimizations. Some of the blocking are intentional (such as blocking code merge) for better counts quality while the others are accidental. This change unblocks perf-critical optimizations that do not affect counts quality. They include:

1. IR InstCombine, sinking load operation to shorten lifetimes.
2. MIR LiveRangeShrink, similar to #1
3. MIR TwoAddressInstructionPass, i.e, opeq transform
4. MIR function argument copy elision
5. IR stack protection. (though not perf-critical but nice to have).

Reviewed By: wmi

Differential Revision: https://reviews.llvm.org/D95982
 2021-02-10 12:43:17 -08:00
Kazu Hirata ee5b5b7a35 [CodeGen] Use llvm::erase_value (NFC) 2020-12-13 20:05:48 -08:00
Gaurav Jain a0b7129767 [NFC] Use [MC]Register in TwoAddressInstructionPass 
Differential Revision: https://reviews.llvm.org/D90902
 2020-11-10 19:01:56 -08:00
Jeremy Morse d73275993b [DebugInstrRef] Substitute debug value numbers to handle optimizations 
This patch touches two optimizations, TwoAddressInstruction and X86's
FixupLEAs pass, both of which optimize by re-creating instructions. For
LEAs, various bits of arithmetic are better represented as LEAs on X86,
while TwoAddressInstruction sometimes converts instrs into three address
instructions if it's profitable.

For debug instruction referencing, both of these require substitutions to
be created -- the old instruction number must be pointed to the new
instruction number, as illustrated in the added test. If this isn't done,
any variable locations based on the optimized instruction are
conservatively dropped.

Differential Revision: https://reviews.llvm.org/D85756
 2020-10-22 13:01:03 +01:00
Kai Luo 8a5858c8fd [TwoAddressInstruction][PowerPC] Call `regOverlapsSet` to find out real clobbers and uses 
In `rescheduleKillAboveMI`, current implementation uses `SmallSet` to track reg's defs and uses. When comparing, use `SmallSet.count` to find out if it's clobbered or used. It's not correct if involving subregisters. This patch uses `regOverlapsSet` already used by `rescheduleMIBelowKill` to fix the issue.

Fixed https://bugs.llvm.org/show_bug.cgi?id=47707.

Reviewed By: #powerpc, nemanjai

Differential Revision: https://reviews.llvm.org/D88716
 2020-10-09 02:34:54 +00:00
James Y Knight 60433c63ac Remove TwoAddressInstructionPass::sink3AddrInstruction. 
This function has a bug which will incorrectly reschedule instructions
after an INLINEASM_BR (which can branch). (The bug may also allow
scheduling past a throwing-CALL, I'm not certain.)

I could fix that bug, but, as the removed FIXME notes, it's better to
attempt rescheduling before converting to 3-addr form, as that may
remove the need to convert in the first place. In fact, the code to do
such reordering was added to this pass only a few months later, in
2011, via the addition of the function rescheduleMIBelowKill. That
code does not contain the same bug.

The removal of the sink3AddrInstruction function is not a no-op: in
some cases it would move an instruction post-conversion, when
rescheduleMIBelowKill would not move the instruction pre-converison.
However, this does not appear to be important: the machine instruction
scheduler can reorder the after-conversion instructions, in any case.

This patch fixes a kernel panic 4.4 LTS x86_64 Linux kernels, when
built with clang after 4b0aa5724f.

Link: https://github.com/ClangBuiltLinux/linux/issues/1085

Differential Revision: https://reviews.llvm.org/D83708
 2020-07-16 10:02:52 -04:00
Kang Zhang 1b6602275d [MachineVerifier] Add TiedOpsRewritten flag to fix verify two-address error 
Summary:
Currently, MachineVerifier will attempt to verify that tied operands
satisfy register constraints as soon as the function is no longer in
SSA form. However, PHIElimination will take the function out of SSA
form while TwoAddressInstructionPass will actually rewrite tied operands
to match the constraints. PHIElimination runs first in the pipeline.
Therefore, whenever the MachineVerifier is run after PHIElimination,
it will encounter verification errors on any tied operands.

This patch adds a function property called TiedOpsRewritten that will be
set by TwoAddressInstructionPass and will control when the verifier checks
tied operands.

Reviewed By: nemanjai

Differential Revision: https://reviews.llvm.org/D80538
 2020-06-09 07:39:42 +00:00
Matt Arsenault ca0ace7298 CodeGen: Use Register in MachineBasicBlock 2020-04-08 12:10:58 -04:00
Craig Topper b6e2796114 [X86][TwoAddressInstructionPass] Teach tryInstructionCommute to continue checking for commutable FMA operands in more cases. 
Previously we would only check for another commutable operand if the first commute was an aggressive commute.

But if we have two kill operands and neither is tied to the def at the start, we should consider both operands as the one to use as the new def.

This improves the loop in the fma-commute-loop.ll test. This test is derived from a post from discourse here https://llvm.discourse.group/t/unnecessary-vmovapd-instructions-generated-can-you-hint-in-favor-of-vfmadd231pd/582

Differential Revision: https://reviews.llvm.org/D75016
 2020-03-01 16:38:08 -08:00
James Henderson d68904f957 [NFC] Fix trivial typos in comments 
Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D72143

Patch by Kazuaki Ishizaki.
 2020-01-06 10:50:26 +00:00
Daniel Sanders 0c47611131 Apply llvm-prefer-register-over-unsigned from clang-tidy to LLVM 
Summary:
This clang-tidy check is looking for unsigned integer variables whose initializer
starts with an implicit cast from llvm::Register and changes the type of the
variable to llvm::Register (dropping the llvm:: where possible).

Partial reverts in:
X86FrameLowering.cpp - Some functions return unsigned and arguably should be MCRegister
X86FixupLEAs.cpp - Some functions return unsigned and arguably should be MCRegister
X86FrameLowering.cpp - Some functions return unsigned and arguably should be MCRegister
HexagonBitSimplify.cpp - Function takes BitTracker::RegisterRef which appears to be unsigned&
MachineVerifier.cpp - Ambiguous operator==() given MCRegister and const Register
PPCFastISel.cpp - No Register::operator-=()
PeepholeOptimizer.cpp - TargetInstrInfo::optimizeLoadInstr() takes an unsigned&
MachineTraceMetrics.cpp - MachineTraceMetrics lacks a suitable constructor

Manual fixups in:
ARMFastISel.cpp - ARMEmitLoad() now takes a Register& instead of unsigned&
HexagonSplitDouble.cpp - Ternary operator was ambiguous between unsigned/Register
HexagonConstExtenders.cpp - Has a local class named Register, used llvm::Register instead of Register.
PPCFastISel.cpp - PPCEmitLoad() now takes a Register& instead of unsigned&

Depends on D65919

Reviewers: arsenm, bogner, craig.topper, RKSimon

Reviewed By: arsenm

Subscribers: RKSimon, craig.topper, lenary, aemerson, wuzish, jholewinski, MatzeB, qcolombet, dschuff, jyknight, dylanmckay, sdardis, nemanjai, jvesely, wdng, nhaehnle, sbc100, jgravelle-google, kristof.beyls, hiraditya, aheejin, kbarton, fedor.sergeev, javed.absar, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, tpr, PkmX, jocewei, jsji, Petar.Avramovic, asbirlea, Jim, s.egerton, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D65962

llvm-svn: 369041
 2019-08-15 19:22:08 +00:00
Daniel Sanders 2bea69bf65 Finish moving TargetRegisterInfo::isVirtualRegister() and friends to llvm::Register as started by r367614. NFC 
llvm-svn: 367633
 2019-08-01 23:27:28 +00:00