Commit 3c94b278 authored by Jonas Paulsson's avatar Jonas Paulsson Committed by Hans Wennborg
Browse files

[SystemZ] Bugfix in emitSelect() 

When more than one SelectPseudo instruction is handled a new MBB is
returned. This must not be done if that would result in leaving an undhandled
isel pseudo behind in the original MBB.

Fixes https://bugs.llvm.org/show_bug.cgi?id=44849.

Review: Ulrich Weigand

Differential Revision: https://reviews.llvm.org/D74352

(cherry picked from commit 0311e28e)
parent fd04cb43

llvm/lib/Target/SystemZ/SystemZISelLowering.cpp

+3 −2
Original line number Diff line number Diff line
@@ -6859,8 +6859,6 @@ SystemZTargetLowering::emitSelect(MachineInstr &MI, 
  for (MachineBasicBlock::iterator NextMIIt =

         std::next(MachineBasicBlock::iterator(MI));

       NextMIIt != MBB->end(); ++NextMIIt) {

    if (NextMIIt->definesRegister(SystemZ::CC))

      break;

    if (isSelectPseudo(*NextMIIt)) {

      assert(NextMIIt->getOperand(3).getImm() == CCValid &&

             "Bad CCValid operands since CC was not redefined.");
@@ -6871,6 +6869,9 @@ SystemZTargetLowering::emitSelect(MachineInstr &MI, 
      }

      break;

    }

    if (NextMIIt->definesRegister(SystemZ::CC) ||

        NextMIIt->usesCustomInsertionHook())

      break;

    bool User = false;

    for (auto SelMI : Selects)

      if (NextMIIt->readsVirtualRegister(SelMI->getOperand(0).getReg())) {

llvm/test/CodeGen/SystemZ/multiselect-02.mir

0 → 100644
+43 −0
Original line number Diff line number Diff line 
# RUN: llc -mtriple=s390x-linux-gnu -mcpu=z10 -run-pass=finalize-isel -o - %s \

# RUN:   | FileCheck %s

#

# Test that an instruction (ZEXT128) that uses custom insertion gets treated

# correctly also when it lies between two Select instructions that could

# potentially be handled together.

#

# CHECK-LABEL: bb.0.entry:

# CHECK-NOT: ZEXT128



--- |

  declare void @bar(i32)

  define i32 @fun() { entry: ret i32 0 }

---

name:            fun

body:             |

  bb.0.entry:

    %1:addr64bit = IMPLICIT_DEF

    %0:gr32bit = LLC %1, 0, $noreg :: (load 1 from `i8* undef`)

    CHI killed %0, 0, implicit-def $cc

    %2:gr32bit = LHI 2

    %3:gr32bit = LHI 8

    %4:gr32bit = Select32 killed %3, killed %2, 14, 8, implicit $cc

    %5:gr32bit = LHI 128

    %7:gr64bit = IMPLICIT_DEF

    %6:gr64bit = INSERT_SUBREG %7, killed %5, %subreg.subreg_l32

    %8:gr128bit = ZEXT128 killed %6

    %10:addr64bit = IMPLICIT_DEF

    %9:gr128bit = DL %8, %10, 0, $noreg :: (load 4 from `i64* undef` + 4)

    %11:gr32bit = COPY %9.subreg_l32

    %12:gr64bit = LGHI 2

    %13:gr64bit = LGHI 8

    %14:gr64bit = Select64 killed %13, killed %12, 14, 8, implicit $cc

    CR %4, %11, implicit-def $cc

    %15:gr32bit = Select32 %11, %4, 14, 4, implicit $cc

    ADJCALLSTACKDOWN 0, 0

    $r2d = COPY %14

    CallBRASL @bar, $r2d, csr_systemz, implicit-def dead $r14d, implicit-def dead $cc, implicit $fpc

    ADJCALLSTACKUP 0, 0

    $r2l = COPY %15

    Return implicit $r2l



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