Commit 2875d5f8 authored by Tom Stellard's avatar Tom Stellard
Browse files

Merging r332680: 

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r332680 | kfischer | 2018-05-17 17:40:52 -0700 (Thu, 17 May 2018) | 13 lines

[X86DomainReassignment] Don't delete IMPLICIT_DEF nodes

Summary:
We cannot simply delete IMPLICIT_DEF nodes. They may be used
later (e.g. by a PHI) and deleting them will cause later passes (e.g.
LiveVariables) to crash. However, it seems fine to ignore them for
purposes of the domain reassignment (as we do with PHI).

Fixes PR37430
Fixes JuliaLang/julia#27080

Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D46797
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llvm-svn: 333469
parent e8deffb8

llvm/lib/Target/X86/X86DomainReassignment.cpp

+1 −20
Original line number Diff line number Diff line
@@ -262,25 +262,6 @@ public: 
  }

};



/// An Instruction Converter which completely deletes an instruction.

/// For example, IMPLICIT_DEF instructions can be deleted when converting from

/// GPR to mask.

class InstrDeleter : public InstrConverterBase {

public:

  InstrDeleter(unsigned SrcOpcode) : InstrConverterBase(SrcOpcode) {}



  bool convertInstr(MachineInstr *MI, const TargetInstrInfo *TII,

                    MachineRegisterInfo *MRI) const override {

    assert(isLegal(MI, TII) && "Cannot convert instruction");

    return true;

  }



  double getExtraCost(const MachineInstr *MI,

                      MachineRegisterInfo *MRI) const override {

    return 0;

  }

};



// Key type to be used by the Instruction Converters map.

// A converter is identified by <destination domain, source opcode>

typedef std::pair<int, unsigned> InstrConverterBaseKeyTy;
@@ -587,7 +568,7 @@ void X86DomainReassignment::initConverters() { 
      new InstrIgnore(TargetOpcode::PHI);



  Converters[{MaskDomain, TargetOpcode::IMPLICIT_DEF}] =

      new InstrDeleter(TargetOpcode::IMPLICIT_DEF);

      new InstrIgnore(TargetOpcode::IMPLICIT_DEF);



  Converters[{MaskDomain, TargetOpcode::INSERT_SUBREG}] =

      new InstrReplaceWithCopy(TargetOpcode::INSERT_SUBREG, 2);

llvm/test/CodeGen/X86/domain-reassignment-implicit-def.ll

0 → 100644
+24 −0
Original line number Diff line number Diff line 
; RUN: llc -mcpu=skylake-avx512 -mtriple=x86_64-unknown-linux-gnu %s -o - | FileCheck %s



; Check that the X86 Domain Reassignment pass doesn't drop IMPLICIT_DEF nodes,

; which would later cause crashes (e.g. in LiveVariables) - see PR37430

define void @domain_reassignment_implicit_def(i1 %cond, i8 *%mem, float %arg) {

; CHECK:    vxorps %xmm1, %xmm1, %xmm1

; CHECK:    vcmpneqss %xmm1, %xmm0, %k0

; CHECK:    kmovb %k0, (%rsi)

top:

  br i1 %cond, label %L19, label %L15



L15:                                              ; preds = %top

  %tmp47 = fcmp une float 0.000000e+00, %arg

  %tmp48 = zext i1 %tmp47 to i8

  br label %L21



L19:                                              ; preds = %top

  br label %L21



L21:                                              ; preds = %L19, %L15

  %.sroa.0.0 = phi i8 [ undef, %L19 ], [ %tmp48, %L15 ]

  store i8 %.sroa.0.0, i8* %mem, align 1

  ret void

}