<div dir="ltr">Revert done.<div><br></div><div>Not sure if there is a way to show updated commit messages somewhere in phabricator, so going to paste them in a gist (<a href="https://gist.github.com/minglotus-6/63b68e320512a3f933b49363d322e526">https://gist.github.com/minglotus-6/63b68e320512a3f933b49363d322e526</a>). This is basically a copy of the summary in phabricator.</div><div><br></div><div>If it looks good, I'll go ahead to reapply the change. </div><div></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Tue, May 10, 2022 at 1:55 PM Philip Reames <<a href="mailto:listmail@philipreames.com">listmail@philipreames.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
  
    
  
  <div>
    <p>Thanks!</p>
    <p>Philip<br>
    </p>
    <div>On 5/10/22 13:45, Mingming Liu wrote:<br>
    </div>
    <blockquote type="cite">
      
      <div dir="ltr">Okay, working on it. Will update when it's
        complete. </div>
      <br>
      <div class="gmail_quote">
        <div dir="ltr" class="gmail_attr">On Tue, May 10, 2022 at 1:43
          PM Philip Reames <<a href="mailto:listmail@philipreames.com" target="_blank">listmail@philipreames.com</a>>
          wrote:<br>
        </div>
        <blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
          <div>
            <p>Revert and recommit please.  The commit comment needs to
              contain the information, not just the phab review.</p>
            <p>Philip<br>
            </p>
            <div>On 5/10/22 13:27, Mingming Liu wrote:<br>
            </div>
            <blockquote type="cite">
              <div dir="ltr">Hello Philip!
                <div>   A differential revision is attached in the
                  commit message, and has more context of the commit.</div>
                <div><br>
                </div>
                <div>   Shall I just use differential revision or still
                  revert and re-commit?</div>
              </div>
              <br>
              <div class="gmail_quote">
                <div dir="ltr" class="gmail_attr">On Tue, May 10, 2022
                  at 1:17 PM Philip Reames <<a href="mailto:listmail@philipreames.com" target="_blank">listmail@philipreames.com</a>>
                  wrote:<br>
                </div>
                <blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">Please revert and
                  reapply with a descriptive commit message.<br>
                  <br>
                  Philip<br>
                  <br>
                  On 5/10/22 12:39, Mingming Liu via llvm-commits wrote:<br>
                  > Author: Mingming Liu<br>
                  > Date: 2022-05-10T12:35:35-07:00<br>
                  > New Revision:
                  d84ca05ef7f897fdd51900ea07e3c5344632130a<br>
                  ><br>
                  > URL: <a href="https://github.com/llvm/llvm-project/commit/d84ca05ef7f897fdd51900ea07e3c5344632130a" rel="noreferrer" target="_blank">https://github.com/llvm/llvm-project/commit/d84ca05ef7f897fdd51900ea07e3c5344632130a</a><br>
                  > DIFF: <a href="https://github.com/llvm/llvm-project/commit/d84ca05ef7f897fdd51900ea07e3c5344632130a.diff" rel="noreferrer" target="_blank">https://github.com/llvm/llvm-project/commit/d84ca05ef7f897fdd51900ea07e3c5344632130a.diff</a><br>
                  ><br>
                  > LOG: Enhance peephole optimization.<br>
                  ><br>
                  > Differential Revision: <a href="https://reviews.llvm.org/D124118" rel="noreferrer" target="_blank">https://reviews.llvm.org/D124118</a><br>
                  ><br>
                  > Added:<br>
                  >     
                  llvm/test/CodeGen/X86/peephole-test-after-add.mir<br>
                  ><br>
                  > Modified:<br>
                  >      llvm/lib/Target/X86/X86InstrInfo.cpp<br>
                  ><br>
                  > Removed:<br>
                  >      <br>
                  ><br>
                  ><br>
                  >
################################################################################<br>
                  > diff  --git
                  a/llvm/lib/Target/X86/X86InstrInfo.cpp
                  b/llvm/lib/Target/X86/X86InstrInfo.cpp<br>
                  > index 0c45094b6e2f6..f4ffb42d9972d 100644<br>
                  > --- a/llvm/lib/Target/X86/X86InstrInfo.cpp<br>
                  > +++ b/llvm/lib/Target/X86/X86InstrInfo.cpp<br>
                  > @@ -25,13 +25,16 @@<br>
                  >   #include "llvm/CodeGen/MachineConstantPool.h"<br>
                  >   #include "llvm/CodeGen/MachineDominators.h"<br>
                  >   #include "llvm/CodeGen/MachineFrameInfo.h"<br>
                  > +#include "llvm/CodeGen/MachineInstr.h"<br>
                  >   #include "llvm/CodeGen/MachineInstrBuilder.h"<br>
                  >   #include "llvm/CodeGen/MachineModuleInfo.h"<br>
                  > +#include "llvm/CodeGen/MachineOperand.h"<br>
                  >   #include "llvm/CodeGen/MachineRegisterInfo.h"<br>
                  >   #include "llvm/CodeGen/StackMaps.h"<br>
                  >   #include "llvm/IR/DebugInfoMetadata.h"<br>
                  >   #include "llvm/IR/DerivedTypes.h"<br>
                  >   #include "llvm/IR/Function.h"<br>
                  > +#include "llvm/IR/InstrTypes.h"<br>
                  >   #include "llvm/MC/MCAsmInfo.h"<br>
                  >   #include "llvm/MC/MCExpr.h"<br>
                  >   #include "llvm/MC/MCInst.h"<br>
                  > @@ -964,6 +967,101 @@ inline static bool
                  isTruncatedShiftCountForLEA(unsigned ShAmt) {<br>
                  >     return ShAmt < 4 && ShAmt > 0;<br>
                  >   }<br>
                  >   <br>
                  > +static bool findRedundantFlagInstr(MachineInstr
                  &CmpInstr,<br>
                  > +                                   MachineInstr
                  &CmpValDefInstr,<br>
                  > +                                   const
                  MachineRegisterInfo *MRI,<br>
                  > +                                   MachineInstr
                  **AndInstr,<br>
                  > +                                   const
                  TargetRegisterInfo *TRI,<br>
                  > +                                   bool
                  &NoSignFlag, bool &ClearsOverflowFlag) {<br>
                  > +  if (CmpValDefInstr.getOpcode() !=
                  X86::SUBREG_TO_REG)<br>
                  > +    return false;<br>
                  > +<br>
                  > +  if (CmpInstr.getOpcode() != X86::TEST64rr)<br>
                  > +    return false;<br>
                  > +<br>
                  > +  // CmpInstr is a TEST64rr instruction, and
                  `X86InstrInfo::analyzeCompare`<br>
                  > +  // guarantees that it's analyzable only if two
                  registers are identical.<br>
                  > +  assert(<br>
                  > +      (CmpInstr.getOperand(0).getReg() ==
                  CmpInstr.getOperand(1).getReg()) &&<br>
                  > +      "CmpInstr is an analyzable TEST64rr, and
                  `X86InstrInfo::analyzeCompare` "<br>
                  > +      "requires two reg operands are the
                  same.");<br>
                  > +<br>
                  > +  // Caller
                  (`X86InstrInfo::optimizeCompareInstr`) guarantees that<br>
                  > +  // `CmpValDefInstr` defines the value that's
                  used by `CmpInstr`; in this case<br>
                  > +  // if `CmpValDefInstr` sets the EFLAGS, it is
                  likely that `CmpInstr` is<br>
                  > +  // redundant.<br>
                  > +  assert(<br>
                  > +     
                  (MRI->getVRegDef(CmpInstr.getOperand(0).getReg())
                  == &CmpValDefInstr) &&<br>
                  > +      "Caller guarantees that TEST64rr is a user
                  of SUBREG_TO_REG.");<br>
                  > +<br>
                  > +  // As seen in X86 td files,
                  CmpValDefInstr.getOperand(1).getImm() is typically<br>
                  > +  // 0.<br>
                  > +  if (CmpValDefInstr.getOperand(1).getImm() !=
                  0)<br>
                  > +    return false;<br>
                  > +<br>
                  > +  // As seen in X86 td files,
                  CmpValDefInstr.getOperand(3) is typically<br>
                  > +  // sub_32bit or sub_xmm.<br>
                  > +  if (CmpValDefInstr.getOperand(3).getImm() !=
                  X86::sub_32bit)<br>
                  > +    return false;<br>
                  > +<br>
                  > +  MachineInstr *VregDefInstr =<br>
                  > +     
                  MRI->getVRegDef(CmpValDefInstr.getOperand(2).getReg());<br>
                  > +<br>
                  > +  assert(VregDefInstr && "Must have a
                  definition (SSA)");<br>
                  > +<br>
                  > +  // Requires `CmpValDefInstr` and
                  `VregDefInstr` are from the same MBB<br>
                  > +  // to simplify the subsequent analysis.<br>
                  > +  //<br>
                  > +  // FIXME: If `VregDefInstr->getParent()` is
                  the only predecessor of<br>
                  > +  // `CmpValDefInstr.getParent()`, this could be
                  handled.<br>
                  > +  if (VregDefInstr->getParent() !=
                  CmpValDefInstr.getParent())<br>
                  > +    return false;<br>
                  > +<br>
                  > +  if (X86::isAND(VregDefInstr->getOpcode()))
                  {<br>
                  > +    // Get a sequence of instructions like<br>
                  > +    //   %reg = and* ...                    //
                  Set EFLAGS<br>
                  > +    //   ...                                //
                  EFLAGS not changed<br>
                  > +    //   %extended_reg = subreg_to_reg 0, %reg,
                  %subreg.sub_32bit<br>
                  > +    //   test64rr %extended_reg, %extended_reg,
                  implicit-def $eflags<br>
                  > +    //<br>
                  > +    // If subsequent readers use a subset of
                  bits that don't change<br>
                  > +    // after `and*` instructions, it's likely
                  that the test64rr could<br>
                  > +    // be optimized away.<br>
                  > +    for (const MachineInstr &Instr :<br>
                  > +       
                   make_range(std::next(MachineBasicBlock::iterator(VregDefInstr)),<br>
                  > +                   
                  MachineBasicBlock::iterator(CmpValDefInstr))) {<br>
                  > +      // There are instructions between
                  'VregDefInstr' and<br>
                  > +      // 'CmpValDefInstr' that modifies EFLAGS.<br>
                  > +      if (Instr.modifiesRegister(X86::EFLAGS,
                  TRI))<br>
                  > +        return false;<br>
                  > +    }<br>
                  > +<br>
                  > +    *AndInstr = VregDefInstr;<br>
                  > +<br>
                  > +    // AND instruction will essentially update
                  SF and clear OF, so<br>
                  > +    // NoSignFlag should be false in the sense
                  that SF is modified by `AND`.<br>
                  > +    //<br>
                  > +    // However, the implementation artifically
                  sets `NoSignFlag` to true<br>
                  > +    // to poison the SF bit; that is to say, if
                  SF is looked at later, the<br>
                  > +    // optimization (to erase TEST64rr) will be
                  disabled.<br>
                  > +    //<br>
                  > +    // The reason to poison SF bit is that SF
                  bit value could be<br>
                  > diff erent<br>
                  > +    // in the `AND` and `TEST` operation; signed
                  bit is not known for `AND`,<br>
                  > +    // and is known to be 0 as a result of
                  `TEST64rr`.<br>
                  > +    //<br>
                  > +    // FIXME: As opposed to poisoning the SF bit
                  direclty, consider peeking into<br>
                  > +    // the AND instruction and using the static
                  information to guide peephole optimization if
                  possible.<br>
                  > +    // For example, it's possible to fold a
                  conditional move into a copy<br>
                  > +    // if the relevant EFLAG bits could be
                  deduced from an immediate operand of and operation.<br>
                  > +    //<br>
                  > +    NoSignFlag = true;<br>
                  > +    // ClearsOverflowFlag is true for AND
                  operation (no surprise).<br>
                  > +    ClearsOverflowFlag = true;<br>
                  > +    return true;<br>
                  > +  }<br>
                  > +  return false;<br>
                  > +}<br>
                  > +<br>
                  >   bool X86InstrInfo::classifyLEAReg(MachineInstr
                  &MI, const MachineOperand &Src,<br>
                  >                                     unsigned Opc,
                  bool AllowSP, Register &NewSrc,<br>
                  >                                     bool
                  &isKill, MachineOperand &ImplicitOp,<br>
                  > @@ -4226,6 +4324,23 @@ bool
                  X86InstrInfo::optimizeCompareInstr(MachineInstr
                  &CmpInstr, Register SrcReg,<br>
                  >             MI = &Inst;<br>
                  >             break;<br>
                  >           }<br>
                  > +<br>
                  > +        // Look back for the following pattern,
                  in which case the test64rr<br>
                  > +        // instruction could be erased.<br>
                  > +        //<br>
                  > +        // Example:<br>
                  > +        //  %reg = and32ri %in_reg, 5<br>
                  > +        //  ...                         //
                  EFLAGS not changed.<br>
                  > +        //  %src_reg = subreg_to_reg 0, %reg,
                  %subreg.sub_index<br>
                  > +        //  test64rr %src_reg, %src_reg,
                  implicit-def $eflags<br>
                  > +        MachineInstr *AndInstr = nullptr;<br>
                  > +        if (IsCmpZero &&<br>
                  > +            findRedundantFlagInstr(CmpInstr,
                  Inst, MRI, &AndInstr, TRI,<br>
                  > +                                   NoSignFlag,
                  ClearsOverflowFlag)) {<br>
                  > +          assert(AndInstr != nullptr &&
                  X86::isAND(AndInstr->getOpcode()));<br>
                  > +          MI = AndInstr;<br>
                  > +          break;<br>
                  > +        }<br>
                  >           // Cannot find other candidates before
                  definition of SrcReg.<br>
                  >           return false;<br>
                  >         }<br>
                  ><br>
                  > diff  --git
                  a/llvm/test/CodeGen/X86/peephole-test-after-add.mir
                  b/llvm/test/CodeGen/X86/peephole-test-after-add.mir<br>
                  > new file mode 100644<br>
                  > index 0000000000000..65a90fafa655c<br>
                  > --- /dev/null<br>
                  > +++
                  b/llvm/test/CodeGen/X86/peephole-test-after-add.mir<br>
                  > @@ -0,0 +1,196 @@<br>
                  > +# NOTE: Assertions have been autogenerated by
                  utils/update_mir_test_checks.py<br>
                  > +# RUN: llc -o - %s
                  -mtriple=x86_64-unknown-linux-gnu
                  --run-pass=peephole-opt | FileCheck %s<br>
                  > +<br>
                  > +# Test that TEST64rr is erased in `test_erased`,
                  and kept in `test_not_erased_when_sf_used`<br>
                  > +# and `test_not_erased_when_eflags_change`.<br>
                  > +<br>
                  > +--- |<br>
                  > +  ; ModuleID = 'tmp.ll'<br>
                  > +  source_filename = "tmp.ll"<br>
                  > +  target datalayout =
                  "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"<br>
                  > +<br>
                  > +  define i64 @test_erased(ptr %0, i64 %1, i64
                  %2) {<br>
                  > +    %4 = load i64, ptr %0, align 8<br>
                  > +    %5 = and i64 %4, 3<br>
                  > +    %6 = icmp eq i64 %5, 0<br>
                  > +    %7 = select i1 %6, i64 %1, i64 %5<br>
                  > +    store i64 %7, ptr %0, align 8<br>
                  > +    ret i64 %5<br>
                  > +  }<br>
                  > +<br>
                  > +  define i64 @test_not_erased_when_sf_used(ptr
                  %0, i64 %1, i64 %2, i64 %3) {<br>
                  > +    %5 = load i64, ptr %0, align 8<br>
                  > +    %6 = and i64 %5, 3<br>
                  > +    %7 = icmp slt i64 %6, 0<br>
                  > +    %8 = select i1 %7, i64 %1, i64 %6<br>
                  > +    store i64 %8, ptr %0, align 8<br>
                  > +    ret i64 %5<br>
                  > +  }<br>
                  > +<br>
                  > +  define void
                  @test_not_erased_when_eflags_change(ptr %0, i64 %1,
                  i64 %2, i64 %3, ptr %4) {<br>
                  > +    %6 = load i64, ptr %0, align 8<br>
                  > +    %7 = and i64 %6, 3<br>
                  > +    %8 = xor i64 %3, 5<br>
                  > +    %9 = icmp eq i64 %7, 0<br>
                  > +    %10 = select i1 %9, i64 %1, i64 %7<br>
                  > +    store i64 %10, ptr %0, align 8<br>
                  > +    store i64 %8, ptr %4, align 8<br>
                  > +    ret void<br>
                  > +  }<br>
                  > +<br>
                  > +...<br>
                  > +---<br>
                  > +name:            test_erased<br>
                  > +alignment:       16<br>
                  > +tracksDebugUserValues: false<br>
                  > +registers:<br>
                  > +  - { id: 0, class: gr64, preferred-register: ''
                  }<br>
                  > +  - { id: 1, class: gr64, preferred-register: ''
                  }<br>
                  > +  - { id: 2, class: gr64, preferred-register: ''
                  }<br>
                  > +  - { id: 3, class: gr64, preferred-register: ''
                  }<br>
                  > +  - { id: 4, class: gr32, preferred-register: ''
                  }<br>
                  > +  - { id: 5, class: gr32, preferred-register: ''
                  }<br>
                  > +  - { id: 6, class: gr64, preferred-register: ''
                  }<br>
                  > +  - { id: 7, class: gr64, preferred-register: ''
                  }<br>
                  > +liveins:<br>
                  > +  - { reg: '$rdi', virtual-reg: '%0' }<br>
                  > +  - { reg: '$rsi', virtual-reg: '%1' }<br>
                  > +frameInfo:<br>
                  > +  maxAlignment:    1<br>
                  > +machineFunctionInfo: {}<br>
                  > +body:             |<br>
                  > +  bb.0 (%ir-block.3):<br>
                  > +    liveins: $rdi, $rsi<br>
                  > +<br>
                  > +    ; CHECK-LABEL: name: test_erased<br>
                  > +    ; CHECK: [[COPY:%[0-9]+]]:gr64 = COPY $rsi<br>
                  > +    ; CHECK-NEXT: [[COPY1:%[0-9]+]]:gr64 = COPY
                  $rdi<br>
                  > +    ; CHECK-NEXT: [[MOV64rm:%[0-9]+]]:gr64 =
                  MOV64rm [[COPY1]], 1, $noreg, 0, $noreg :: (load (s64)
                  from %ir.0)<br>
                  > +    ; CHECK-NEXT: [[COPY2:%[0-9]+]]:gr32 = COPY
                  [[MOV64rm]].sub_32bit<br>
                  > +    ; CHECK-NEXT: [[AND32ri8_:%[0-9]+]]:gr32 =
                  AND32ri8 [[COPY2]], 3, implicit-def $eflags<br>
                  > +    ; CHECK-NEXT: [[SUBREG_TO_REG:%[0-9]+]]:gr64
                  = SUBREG_TO_REG 0, killed [[AND32ri8_]],
                  %subreg.sub_32bit<br>
                  > +    ; CHECK-NEXT: [[CMOV64rr:%[0-9]+]]:gr64 =
                  CMOV64rr [[SUBREG_TO_REG]], [[COPY]], 4, implicit
                  $eflags<br>
                  > +    ; CHECK-NEXT: MOV64mr [[COPY1]], 1, $noreg,
                  0, $noreg, killed [[CMOV64rr]] :: (store (s64) into
                  %ir.0)<br>
                  > +    ; CHECK-NEXT: $rax = COPY [[SUBREG_TO_REG]]<br>
                  > +    ; CHECK-NEXT: RET 0, $rax<br>
                  > +    %1:gr64 = COPY $rsi<br>
                  > +    %0:gr64 = COPY $rdi<br>
                  > +    %3:gr64 = MOV64rm %0, 1, $noreg, 0, $noreg
                  :: (load (s64) from %ir.0)<br>
                  > +    %4:gr32 = COPY %3.sub_32bit<br>
                  > +    %5:gr32 = AND32ri8 %4, 3, implicit-def dead
                  $eflags<br>
                  > +    %6:gr64 = SUBREG_TO_REG 0, killed %5,
                  %subreg.sub_32bit<br>
                  > +    TEST64rr %6, %6, implicit-def $eflags<br>
                  > +    %7:gr64 = CMOV64rr %6, %1, 4, implicit
                  $eflags<br>
                  > +    MOV64mr %0, 1, $noreg, 0, $noreg, killed %7
                  :: (store (s64) into %ir.0)<br>
                  > +    $rax = COPY %6<br>
                  > +    RET 0, $rax<br>
                  > +<br>
                  > +...<br>
                  > +---<br>
                  > +name:            test_not_erased_when_sf_used<br>
                  > +alignment:       16<br>
                  > +tracksDebugUserValues: false<br>
                  > +registers:<br>
                  > +  - { id: 0, class: gr64, preferred-register: ''
                  }<br>
                  > +  - { id: 1, class: gr64, preferred-register: ''
                  }<br>
                  > +  - { id: 2, class: gr64, preferred-register: ''
                  }<br>
                  > +  - { id: 3, class: gr64, preferred-register: ''
                  }<br>
                  > +  - { id: 4, class: gr64, preferred-register: ''
                  }<br>
                  > +  - { id: 5, class: gr32, preferred-register: ''
                  }<br>
                  > +  - { id: 6, class: gr32, preferred-register: ''
                  }<br>
                  > +  - { id: 7, class: gr64, preferred-register: ''
                  }<br>
                  > +  - { id: 8, class: gr64, preferred-register: ''
                  }<br>
                  > +liveins:<br>
                  > +  - { reg: '$rdi', virtual-reg: '%0' }<br>
                  > +  - { reg: '$rsi', virtual-reg: '%1' }<br>
                  > +frameInfo:<br>
                  > +  maxAlignment:    1<br>
                  > +machineFunctionInfo: {}<br>
                  > +body:             |<br>
                  > +  bb.0 (%ir-block.4):<br>
                  > +    liveins: $rdi, $rsi<br>
                  > +<br>
                  > +    ; CHECK-LABEL: name:
                  test_not_erased_when_sf_used<br>
                  > +    ; CHECK: [[COPY:%[0-9]+]]:gr64 = COPY $rsi<br>
                  > +    ; CHECK-NEXT: [[COPY1:%[0-9]+]]:gr64 = COPY
                  $rdi<br>
                  > +    ; CHECK-NEXT: [[MOV64rm:%[0-9]+]]:gr64 =
                  MOV64rm [[COPY1]], 1, $noreg, 0, $noreg :: (load (s64)
                  from %ir.0)<br>
                  > +    ; CHECK-NEXT: [[COPY2:%[0-9]+]]:gr32 = COPY
                  [[MOV64rm]].sub_32bit<br>
                  > +    ; CHECK-NEXT: [[AND32ri8_:%[0-9]+]]:gr32 =
                  AND32ri8 [[COPY2]], 3, implicit-def dead $eflags<br>
                  > +    ; CHECK-NEXT: [[SUBREG_TO_REG:%[0-9]+]]:gr64
                  = SUBREG_TO_REG 0, killed [[AND32ri8_]],
                  %subreg.sub_32bit<br>
                  > +    ; CHECK-NEXT: TEST64rr [[SUBREG_TO_REG]],
                  [[SUBREG_TO_REG]], implicit-def $eflags<br>
                  > +    ; CHECK-NEXT: [[CMOV64rr:%[0-9]+]]:gr64 =
                  CMOV64rr [[SUBREG_TO_REG]], [[COPY]], 8, implicit
                  $eflags<br>
                  > +    ; CHECK-NEXT: MOV64mr [[COPY1]], 1, $noreg,
                  0, $noreg, killed [[CMOV64rr]] :: (store (s64) into
                  %ir.0)<br>
                  > +    ; CHECK-NEXT: $rax = COPY [[MOV64rm]]<br>
                  > +    ; CHECK-NEXT: RET 0, $rax<br>
                  > +    %1:gr64 = COPY $rsi<br>
                  > +    %0:gr64 = COPY $rdi<br>
                  > +    %4:gr64 = MOV64rm %0, 1, $noreg, 0, $noreg
                  :: (load (s64) from %ir.0)<br>
                  > +    %5:gr32 = COPY %4.sub_32bit<br>
                  > +    %6:gr32 = AND32ri8 %5, 3, implicit-def dead
                  $eflags<br>
                  > +    %7:gr64 = SUBREG_TO_REG 0, killed %6,
                  %subreg.sub_32bit<br>
                  > +    TEST64rr %7, %7, implicit-def $eflags<br>
                  > +    %8:gr64 = CMOV64rr %7, %1, 8, implicit
                  $eflags<br>
                  > +    MOV64mr %0, 1, $noreg, 0, $noreg, killed %8
                  :: (store (s64) into %ir.0)<br>
                  > +    $rax = COPY %4<br>
                  > +    RET 0, $rax<br>
                  > +<br>
                  > +...<br>
                  > +---<br>
                  > +name:           
                  test_not_erased_when_eflags_change<br>
                  > +alignment:       16<br>
                  > +tracksDebugUserValues: false<br>
                  > +registers:<br>
                  > +  - { id: 0, class: gr64, preferred-register: ''
                  }<br>
                  > +  - { id: 1, class: gr64, preferred-register: ''
                  }<br>
                  > +  - { id: 2, class: gr64, preferred-register: ''
                  }<br>
                  > +  - { id: 3, class: gr64, preferred-register: ''
                  }<br>
                  > +  - { id: 4, class: gr64, preferred-register: ''
                  }<br>
                  > +  - { id: 5, class: gr64, preferred-register: ''
                  }<br>
                  > +  - { id: 6, class: gr32, preferred-register: ''
                  }<br>
                  > +  - { id: 7, class: gr32, preferred-register: ''
                  }<br>
                  > +  - { id: 8, class: gr64, preferred-register: ''
                  }<br>
                  > +  - { id: 9, class: gr64, preferred-register: ''
                  }<br>
                  > +  - { id: 10, class: gr64, preferred-register:
                  '' }<br>
                  > +liveins:<br>
                  > +  - { reg: '$rdi', virtual-reg: '%0' }<br>
                  > +  - { reg: '$rsi', virtual-reg: '%1' }<br>
                  > +  - { reg: '$rcx', virtual-reg: '%3' }<br>
                  > +  - { reg: '$r8', virtual-reg: '%4' }<br>
                  > +frameInfo:<br>
                  > +  maxAlignment:    1<br>
                  > +machineFunctionInfo: {}<br>
                  > +body:             |<br>
                  > +  bb.0 (%ir-block.5):<br>
                  > +    liveins: $rdi, $rsi, $rcx, $r8<br>
                  > +<br>
                  > +    ; CHECK-LABEL: name:
                  test_not_erased_when_eflags_change<br>
                  > +    ; CHECK: [[COPY:%[0-9]+]]:gr64 = COPY $r8<br>
                  > +    ; CHECK-NEXT: [[COPY1:%[0-9]+]]:gr64 = COPY
                  $rcx<br>
                  > +    ; CHECK-NEXT: [[COPY2:%[0-9]+]]:gr64 = COPY
                  $rsi<br>
                  > +    ; CHECK-NEXT: [[COPY3:%[0-9]+]]:gr64 = COPY
                  $rdi<br>
                  > +    ; CHECK-NEXT: [[MOV64rm:%[0-9]+]]:gr64 =
                  MOV64rm [[COPY3]], 1, $noreg, 0, $noreg :: (load (s64)
                  from %ir.0)<br>
                  > +    ; CHECK-NEXT: [[COPY4:%[0-9]+]]:gr32 = COPY
                  [[MOV64rm]].sub_32bit<br>
                  > +    ; CHECK-NEXT: [[AND32ri8_:%[0-9]+]]:gr32 =
                  AND32ri8 [[COPY4]], 3, implicit-def dead $eflags<br>
                  > +    ; CHECK-NEXT: [[SUBREG_TO_REG:%[0-9]+]]:gr64
                  = SUBREG_TO_REG 0, killed [[AND32ri8_]],
                  %subreg.sub_32bit<br>
                  > +    ; CHECK-NEXT: [[XOR64ri8_:%[0-9]+]]:gr64 =
                  XOR64ri8 [[COPY1]], 5, implicit-def dead $eflags<br>
                  > +    ; CHECK-NEXT: TEST64rr [[SUBREG_TO_REG]],
                  [[SUBREG_TO_REG]], implicit-def $eflags<br>
                  > +    ; CHECK-NEXT: [[CMOV64rr:%[0-9]+]]:gr64 =
                  CMOV64rr [[SUBREG_TO_REG]], [[COPY2]], 4, implicit
                  $eflags<br>
                  > +    ; CHECK-NEXT: MOV64mr [[COPY3]], 1, $noreg,
                  0, $noreg, killed [[CMOV64rr]] :: (store (s64) into
                  %ir.0)<br>
                  > +    ; CHECK-NEXT: MOV64mr [[COPY]], 1, $noreg,
                  0, $noreg, killed [[XOR64ri8_]] :: (store (s64) into
                  %ir.4)<br>
                  > +    ; CHECK-NEXT: RET 0<br>
                  > +    %4:gr64 = COPY $r8<br>
                  > +    %3:gr64 = COPY $rcx<br>
                  > +    %1:gr64 = COPY $rsi<br>
                  > +    %0:gr64 = COPY $rdi<br>
                  > +    %5:gr64 = MOV64rm %0, 1, $noreg, 0, $noreg
                  :: (load (s64) from %ir.0)<br>
                  > +    %6:gr32 = COPY %5.sub_32bit<br>
                  > +    %7:gr32 = AND32ri8 %6, 3, implicit-def dead
                  $eflags<br>
                  > +    %8:gr64 = SUBREG_TO_REG 0, killed %7,
                  %subreg.sub_32bit<br>
                  > +    %9:gr64 = XOR64ri8 %3, 5, implicit-def dead
                  $eflags<br>
                  > +    TEST64rr %8, %8, implicit-def $eflags<br>
                  > +    %10:gr64 = CMOV64rr %8, %1, 4, implicit
                  $eflags<br>
                  > +    MOV64mr %0, 1, $noreg, 0, $noreg, killed %10
                  :: (store (s64) into %ir.0)<br>
                  > +    MOV64mr %4, 1, $noreg, 0, $noreg, killed %9
                  :: (store (s64) into %ir.4)<br>
                  > +    RET 0<br>
                  > +<br>
                  > +...<br>
                  ><br>
                  ><br>
                  >          <br>
                  > _______________________________________________<br>
                  > llvm-commits mailing list<br>
                  > <a href="mailto:llvm-commits@lists.llvm.org" target="_blank">llvm-commits@lists.llvm.org</a><br>
                  > <a href="https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-commits" rel="noreferrer" target="_blank">https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-commits</a><br>
                </blockquote>
              </div>
              <br clear="all">
              <div><br>
              </div>
              -- <br>
              <div dir="ltr">
                <div dir="ltr">
                  <div>
                    <div dir="ltr">
                      <div>
                        <div><font size="2" face="sans-serif" color="#555555">Thanks,</font></div>
                        <div><font size="2" face="sans-serif" color="#555555">Mingming</font></div>
                      </div>
                    </div>
                  </div>
                </div>
              </div>
            </blockquote>
          </div>
        </blockquote>
      </div>
      <br clear="all">
      <div><br>
      </div>
      -- <br>
      <div dir="ltr">
        <div dir="ltr">
          <div>
            <div dir="ltr">
              <div>
                <div><font size="2" face="sans-serif" color="#555555">Thanks,</font></div>
                <div><font size="2" face="sans-serif" color="#555555">Mingming</font></div>
              </div>
            </div>
          </div>
        </div>
      </div>
    </blockquote>
  </div>

</blockquote></div><br clear="all"><div><br></div>-- <br><div dir="ltr" class="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><div><font color="#555555" face="sans-serif" size="2">Thanks,</font></div><div><font color="#555555" face="sans-serif" size="2">Mingming</font></div></div></div></div></div></div>