Commit 79d13bf2 authored by Amara Emerson's avatar Amara Emerson
Browse files

Revert "Revert "[GlobalISel][IRTranslator] Emit trap intrinsic for "unreachable""" 

This reverts commit d95cd811.

Re-land the original patch now that the bug this exposed in selection has been
fixed by 6bc64e24
parent e9f4fa75

llvm/include/llvm/CodeGen/GlobalISel/IRTranslator.h

+2 −3
Original line number Diff line number Diff line
@@ -467,9 +467,8 @@ private: 
  bool translateSIToFP(const User &U, MachineIRBuilder &MIRBuilder) {

    return translateCast(TargetOpcode::G_SITOFP, U, MIRBuilder);

  }

  bool translateUnreachable(const User &U, MachineIRBuilder &MIRBuilder) {

    return true;

  }

  bool translateUnreachable(const User &U, MachineIRBuilder &MIRBuilder);



  bool translateSExt(const User &U, MachineIRBuilder &MIRBuilder) {

    return translateCast(TargetOpcode::G_SEXT, U, MIRBuilder);

  }

llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp

+22 −0
Original line number Diff line number Diff line
@@ -2701,6 +2701,28 @@ bool IRTranslator::translateVAArg(const User &U, MachineIRBuilder &MIRBuilder) { 
  return true;

}



bool IRTranslator::translateUnreachable(const User &U, MachineIRBuilder &MIRBuilder) {

    if (!MF->getTarget().Options.TrapUnreachable)

    return true;



  auto &UI = cast<UnreachableInst>(U);

  // We may be able to ignore unreachable behind a noreturn call.

  if (MF->getTarget().Options.NoTrapAfterNoreturn) {

    const BasicBlock &BB = *UI.getParent();

    if (&UI != &BB.front()) {

      BasicBlock::const_iterator PredI =

        std::prev(BasicBlock::const_iterator(UI));

      if (const CallInst *Call = dyn_cast<CallInst>(&*PredI)) {

        if (Call->doesNotReturn())

          return true;

      }

    }

  }



  MIRBuilder.buildIntrinsic(Intrinsic::trap, ArrayRef<Register>(), true);

  return true;

}



bool IRTranslator::translateInsertElement(const User &U,

                                          MachineIRBuilder &MIRBuilder) {

  // If it is a <1 x Ty> vector, use the scalar as it is

llvm/test/CodeGen/AArch64/GlobalISel/irtranslator-unreachable.ll

0 → 100644
+24 −0
Original line number Diff line number Diff line 
; NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py

; RUN: llc -O0 -mtriple=aarch64-apple-ios -global-isel -stop-after=irtranslator %s -o - | FileCheck %s



declare void @llvm.trap()



define void @unreachable() {

  ; CHECK-LABEL: name: unreachable

  ; CHECK: bb.1 (%ir-block.0):

  ; CHECK-NEXT:   G_INTRINSIC_W_SIDE_EFFECTS intrinsic(@llvm.trap)

  unreachable

  ret void

}



declare void @foo() noreturn

define void @trap_call_noreturn() {

  ; CHECK-LABEL: name: trap_call_noreturn

  ; CHECK: bb.1 (%ir-block.0):

  ; CHECK-NEXT:   ADJCALLSTACKDOWN 0, 0, implicit-def $sp, implicit $sp

  ; CHECK-NEXT:   BL @foo, csr_darwin_aarch64_aapcs, implicit-def $lr, implicit $sp

  ; CHECK-NEXT:   ADJCALLSTACKUP 0, 0, implicit-def $sp, implicit $sp

  call void @foo()

  unreachable

  ret void

}