[llvm] 43a1756 - m68k: Support bit shifts on 64-bit integers

via llvm-commits llvm-commits at lists.llvm.org
Fri Feb 11 14:12:13 PST 2022


Author: Annika
Date: 2022-02-12T06:11:49+08:00
New Revision: 43a1756a5d533bbf29bc39f49f04fc76f5c30ce9

URL: https://github.com/llvm/llvm-project/commit/43a1756a5d533bbf29bc39f49f04fc76f5c30ce9
DIFF: https://github.com/llvm/llvm-project/commit/43a1756a5d533bbf29bc39f49f04fc76f5c30ce9.diff

LOG: m68k: Support bit shifts on 64-bit integers

As per https://bugs.llvm.org/show_bug.cgi?id=52119.

Reviewed By: myhsu

Differential Revision: https://reviews.llvm.org/D111497

Added: 
    

Modified: 
    llvm/lib/Target/M68k/M68kISelLowering.cpp
    llvm/lib/Target/M68k/M68kISelLowering.h
    llvm/lib/Target/M68k/M68kRegisterInfo.h
    llvm/test/CodeGen/M68k/Arith/bitwise.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Target/M68k/M68kISelLowering.cpp b/llvm/lib/Target/M68k/M68kISelLowering.cpp
index dba190a2ebc08..a190057840cdf 100644
--- a/llvm/lib/Target/M68k/M68kISelLowering.cpp
+++ b/llvm/lib/Target/M68k/M68kISelLowering.cpp
@@ -101,6 +101,9 @@ M68kTargetLowering::M68kTargetLowering(const M68kTargetMachine &TM,
     setOperationAction(OP, MVT::i32, Expand);
   }
 
+  for (auto OP : {ISD::SHL_PARTS, ISD::SRA_PARTS, ISD::SRL_PARTS})
+    setOperationAction(OP, MVT::i32, Custom);
+
   // Add/Sub overflow ops with MVT::Glues are lowered to CCR dependences.
   for (auto VT : {MVT::i8, MVT::i16, MVT::i32}) {
     setOperationAction(ISD::ADDC, VT, Custom);
@@ -1354,6 +1357,12 @@ SDValue M68kTargetLowering::LowerOperation(SDValue Op,
     return LowerVASTART(Op, DAG);
   case ISD::DYNAMIC_STACKALLOC:
     return LowerDYNAMIC_STACKALLOC(Op, DAG);
+  case ISD::SHL_PARTS:
+    return LowerShiftLeftParts(Op, DAG);
+  case ISD::SRA_PARTS:
+    return LowerShiftRightParts(Op, DAG, true);
+  case ISD::SRL_PARTS:
+    return LowerShiftRightParts(Op, DAG, false);
   }
 }
 
@@ -3239,6 +3248,102 @@ SDValue M68kTargetLowering::LowerDYNAMIC_STACKALLOC(SDValue Op,
   return DAG.getMergeValues(Ops, DL);
 }
 
+SDValue M68kTargetLowering::LowerShiftLeftParts(SDValue Op,
+                                                SelectionDAG &DAG) const {
+  SDLoc DL(Op);
+  SDValue Lo = Op.getOperand(0);
+  SDValue Hi = Op.getOperand(1);
+  SDValue Shamt = Op.getOperand(2);
+  EVT VT = Lo.getValueType();
+
+  // if Shamt - register size < 0: // Shamt < register size
+  //   Lo = Lo << Shamt
+  //   Hi = (Hi << Shamt) | ((Lo >>u 1) >>u (register size - 1 ^ Shamt))
+  // else:
+  //   Lo = 0
+  //   Hi = Lo << (Shamt - register size)
+
+  SDValue Zero = DAG.getConstant(0, DL, VT);
+  SDValue One = DAG.getConstant(1, DL, VT);
+  SDValue MinusRegisterSize = DAG.getConstant(-32, DL, VT);
+  SDValue RegisterSizeMinus1 = DAG.getConstant(32 - 1, DL, VT);
+  SDValue ShamtMinusRegisterSize =
+      DAG.getNode(ISD::ADD, DL, VT, Shamt, MinusRegisterSize);
+  SDValue RegisterSizeMinus1Shamt =
+      DAG.getNode(ISD::XOR, DL, VT, RegisterSizeMinus1, Shamt);
+
+  SDValue LoTrue = DAG.getNode(ISD::SHL, DL, VT, Lo, Shamt);
+  SDValue ShiftRight1Lo = DAG.getNode(ISD::SRL, DL, VT, Lo, One);
+  SDValue ShiftRightLo =
+      DAG.getNode(ISD::SRL, DL, VT, ShiftRight1Lo, RegisterSizeMinus1Shamt);
+  SDValue ShiftLeftHi = DAG.getNode(ISD::SHL, DL, VT, Hi, Shamt);
+  SDValue HiTrue = DAG.getNode(ISD::OR, DL, VT, ShiftLeftHi, ShiftRightLo);
+  SDValue HiFalse = DAG.getNode(ISD::SHL, DL, VT, Lo, ShamtMinusRegisterSize);
+
+  SDValue CC =
+      DAG.getSetCC(DL, MVT::i8, ShamtMinusRegisterSize, Zero, ISD::SETLT);
+
+  Lo = DAG.getNode(ISD::SELECT, DL, VT, CC, LoTrue, Zero);
+  Hi = DAG.getNode(ISD::SELECT, DL, VT, CC, HiTrue, HiFalse);
+
+  return DAG.getMergeValues({Lo, Hi}, DL);
+}
+
+SDValue M68kTargetLowering::LowerShiftRightParts(SDValue Op, SelectionDAG &DAG,
+                                                 bool IsSRA) const {
+  SDLoc DL(Op);
+  SDValue Lo = Op.getOperand(0);
+  SDValue Hi = Op.getOperand(1);
+  SDValue Shamt = Op.getOperand(2);
+  EVT VT = Lo.getValueType();
+
+  // SRA expansion:
+  //   if Shamt - register size < 0: // Shamt < register size
+  //     Lo = (Lo >>u Shamt) | ((Hi << 1) << (register size - 1 ^ Shamt))
+  //     Hi = Hi >>s Shamt
+  //   else:
+  //     Lo = Hi >>s (Shamt - register size);
+  //     Hi = Hi >>s (register size - 1)
+  //
+  // SRL expansion:
+  //   if Shamt - register size < 0: // Shamt < register size
+  //     Lo = (Lo >>u Shamt) | ((Hi << 1) << (register size - 1 ^ Shamt))
+  //     Hi = Hi >>u Shamt
+  //   else:
+  //     Lo = Hi >>u (Shamt - register size);
+  //     Hi = 0;
+
+  unsigned ShiftRightOp = IsSRA ? ISD::SRA : ISD::SRL;
+
+  SDValue Zero = DAG.getConstant(0, DL, VT);
+  SDValue One = DAG.getConstant(1, DL, VT);
+  SDValue MinusRegisterSize = DAG.getConstant(-32, DL, VT);
+  SDValue RegisterSizeMinus1 = DAG.getConstant(32 - 1, DL, VT);
+  SDValue ShamtMinusRegisterSize =
+      DAG.getNode(ISD::ADD, DL, VT, Shamt, MinusRegisterSize);
+  SDValue RegisterSizeMinus1Shamt =
+      DAG.getNode(ISD::XOR, DL, VT, RegisterSizeMinus1, Shamt);
+
+  SDValue ShiftRightLo = DAG.getNode(ISD::SRL, DL, VT, Lo, Shamt);
+  SDValue ShiftLeftHi1 = DAG.getNode(ISD::SHL, DL, VT, Hi, One);
+  SDValue ShiftLeftHi =
+      DAG.getNode(ISD::SHL, DL, VT, ShiftLeftHi1, RegisterSizeMinus1Shamt);
+  SDValue LoTrue = DAG.getNode(ISD::OR, DL, VT, ShiftRightLo, ShiftLeftHi);
+  SDValue HiTrue = DAG.getNode(ShiftRightOp, DL, VT, Hi, Shamt);
+  SDValue LoFalse =
+      DAG.getNode(ShiftRightOp, DL, VT, Hi, ShamtMinusRegisterSize);
+  SDValue HiFalse =
+      IsSRA ? DAG.getNode(ISD::SRA, DL, VT, Hi, RegisterSizeMinus1) : Zero;
+
+  SDValue CC =
+      DAG.getSetCC(DL, MVT::i8, ShamtMinusRegisterSize, Zero, ISD::SETLT);
+
+  Lo = DAG.getNode(ISD::SELECT, DL, VT, CC, LoTrue, LoFalse);
+  Hi = DAG.getNode(ISD::SELECT, DL, VT, CC, HiTrue, HiFalse);
+
+  return DAG.getMergeValues({Lo, Hi}, DL);
+}
+
 //===----------------------------------------------------------------------===//
 // DAG Combine
 //===----------------------------------------------------------------------===//

diff  --git a/llvm/lib/Target/M68k/M68kISelLowering.h b/llvm/lib/Target/M68k/M68kISelLowering.h
index 9375a99962eb6..f759a7d939c87 100644
--- a/llvm/lib/Target/M68k/M68kISelLowering.h
+++ b/llvm/lib/Target/M68k/M68kISelLowering.h
@@ -220,6 +220,8 @@ class M68kTargetLowering : public TargetLowering {
   SDValue LowerGlobalAddress(SDValue Op, SelectionDAG &DAG) const;
   SDValue LowerVASTART(SDValue Op, SelectionDAG &DAG) const;
   SDValue LowerDYNAMIC_STACKALLOC(SDValue Op, SelectionDAG &DAG) const;
+  SDValue LowerShiftLeftParts(SDValue Op, SelectionDAG &DAG) const;
+  SDValue LowerShiftRightParts(SDValue Op, SelectionDAG &DAG, bool IsSRA) const;
 
   SDValue LowerCallResult(SDValue Chain, SDValue InFlag,
                           CallingConv::ID CallConv, bool IsVarArg,

diff  --git a/llvm/lib/Target/M68k/M68kRegisterInfo.h b/llvm/lib/Target/M68k/M68kRegisterInfo.h
index 7f822e1cb34f4..fc55e19a958be 100644
--- a/llvm/lib/Target/M68k/M68kRegisterInfo.h
+++ b/llvm/lib/Target/M68k/M68kRegisterInfo.h
@@ -97,6 +97,14 @@ class M68kRegisterInfo : public M68kGenRegisterInfo {
   bool canRealignStack(const MachineFunction &MF) const override;
 
   Register getFrameRegister(const MachineFunction &MF) const override;
+
+  const TargetRegisterClass *
+  getCrossCopyRegClass(const TargetRegisterClass *RC) const override {
+    if (RC == &M68k::CCRCRegClass)
+      return &M68k::DR32RegClass;
+    return RC;
+  }
+
   unsigned getStackRegister() const { return StackPtr; }
   unsigned getBaseRegister() const { return BasePtr; }
   unsigned getGlobalBaseRegister() const { return GlobalBasePtr; }

diff  --git a/llvm/test/CodeGen/M68k/Arith/bitwise.ll b/llvm/test/CodeGen/M68k/Arith/bitwise.ll
index d5fe191ab1742..fa8ea1370f866 100644
--- a/llvm/test/CodeGen/M68k/Arith/bitwise.ll
+++ b/llvm/test/CodeGen/M68k/Arith/bitwise.ll
@@ -230,3 +230,123 @@ define i32 @eoril(i32 %a) nounwind {
   %1 = xor i32 %a, 305419896
   ret i32 %1
 }
+
+define i64 @lshr64(i64 %a, i64 %b) nounwind {
+; CHECK-LABEL: lshr64:
+; CHECK:       ; %bb.0:
+; CHECK-NEXT:    suba.l #12, %sp
+; CHECK-NEXT:    movem.l %d2-%d4, (0,%sp) ; 16-byte Folded Spill
+; CHECK-NEXT:    move.l (28,%sp), %d3
+; CHECK-NEXT:    move.l (16,%sp), %d2
+; CHECK-NEXT:    move.l %d3, %d1
+; CHECK-NEXT:    add.l #-32, %d1
+; CHECK-NEXT:    bmi .LBB18_1
+; CHECK-NEXT:  ; %bb.2:
+; CHECK-NEXT:    move.l #0, %d0
+; CHECK-NEXT:    bra .LBB18_3
+; CHECK-NEXT:  .LBB18_1:
+; CHECK-NEXT:    move.l %d2, %d0
+; CHECK-NEXT:    lsr.l %d3, %d0
+; CHECK-NEXT:  .LBB18_3:
+; CHECK-NEXT:    move.l %d3, %d4
+; CHECK-NEXT:    add.l #-32, %d4
+; CHECK-NEXT:    bmi .LBB18_4
+; CHECK-NEXT:  ; %bb.5:
+; CHECK-NEXT:    lsr.l %d1, %d2
+; CHECK-NEXT:    move.l %d2, %d1
+; CHECK-NEXT:    bra .LBB18_6
+; CHECK-NEXT:  .LBB18_4:
+; CHECK-NEXT:    move.l %d3, %d4
+; CHECK-NEXT:    eori.l #31, %d4
+; CHECK-NEXT:    lsl.l #1, %d2
+; CHECK-NEXT:    move.l (20,%sp), %d1
+; CHECK-NEXT:    lsl.l %d4, %d2
+; CHECK-NEXT:    lsr.l %d3, %d1
+; CHECK-NEXT:    or.l %d2, %d1
+; CHECK-NEXT:  .LBB18_6:
+; CHECK-NEXT:    movem.l (0,%sp), %d2-%d4 ; 16-byte Folded Reload
+; CHECK-NEXT:    adda.l #12, %sp
+; CHECK-NEXT:    rts
+  %1 = lshr i64 %a, %b
+  ret i64 %1
+}
+
+define i64 @ashr64(i64 %a, i64 %b) nounwind {
+; CHECK-LABEL: ashr64:
+; CHECK:       ; %bb.0:
+; CHECK-NEXT:    suba.l #8, %sp
+; CHECK-NEXT:    movem.l %d2-%d3, (0,%sp) ; 12-byte Folded Spill
+; CHECK-NEXT:    move.l (24,%sp), %d2
+; CHECK-NEXT:    move.l (12,%sp), %d0
+; CHECK-NEXT:    move.l %d2, %d3
+; CHECK-NEXT:    add.l #-32, %d3
+; CHECK-NEXT:    move.l %d2, %d1
+; CHECK-NEXT:    add.l #-32, %d1
+; CHECK-NEXT:    bmi .LBB19_1
+; CHECK-NEXT:  ; %bb.2:
+; CHECK-NEXT:    move.l %d0, %d1
+; CHECK-NEXT:    asr.l %d3, %d1
+; CHECK-NEXT:    bra .LBB19_3
+; CHECK-NEXT:  .LBB19_1:
+; CHECK-NEXT:    move.l %d2, %d1
+; CHECK-NEXT:    eori.l #31, %d1
+; CHECK-NEXT:    move.l %d0, %d3
+; CHECK-NEXT:    lsl.l #1, %d3
+; CHECK-NEXT:    lsl.l %d1, %d3
+; CHECK-NEXT:    move.l (16,%sp), %d1
+; CHECK-NEXT:    lsr.l %d2, %d1
+; CHECK-NEXT:    or.l %d3, %d1
+; CHECK-NEXT:  .LBB19_3:
+; CHECK-NEXT:    move.l %d2, %d3
+; CHECK-NEXT:    add.l #-32, %d3
+; CHECK-NEXT:    bmi .LBB19_5
+; CHECK-NEXT:  ; %bb.4:
+; CHECK-NEXT:    move.l #31, %d2
+; CHECK-NEXT:  .LBB19_5:
+; CHECK-NEXT:    asr.l %d2, %d0
+; CHECK-NEXT:    movem.l (0,%sp), %d2-%d3 ; 12-byte Folded Reload
+; CHECK-NEXT:    adda.l #8, %sp
+; CHECK-NEXT:    rts
+  %1 = ashr i64 %a, %b
+  ret i64 %1
+}
+
+define i64 @shl64(i64 %a, i64 %b) nounwind {
+; CHECK-LABEL: shl64:
+; CHECK:       ; %bb.0:
+; CHECK-NEXT:    suba.l #12, %sp
+; CHECK-NEXT:    movem.l %d2-%d4, (0,%sp) ; 16-byte Folded Spill
+; CHECK-NEXT:    move.l (28,%sp), %d3
+; CHECK-NEXT:    move.l (20,%sp), %d2
+; CHECK-NEXT:    move.l %d3, %d0
+; CHECK-NEXT:    add.l #-32, %d0
+; CHECK-NEXT:    bmi .LBB20_1
+; CHECK-NEXT:  ; %bb.2:
+; CHECK-NEXT:    move.l #0, %d1
+; CHECK-NEXT:    bra .LBB20_3
+; CHECK-NEXT:  .LBB20_1:
+; CHECK-NEXT:    move.l %d2, %d1
+; CHECK-NEXT:    lsl.l %d3, %d1
+; CHECK-NEXT:  .LBB20_3:
+; CHECK-NEXT:    move.l %d3, %d4
+; CHECK-NEXT:    add.l #-32, %d4
+; CHECK-NEXT:    bmi .LBB20_4
+; CHECK-NEXT:  ; %bb.5:
+; CHECK-NEXT:    lsl.l %d0, %d2
+; CHECK-NEXT:    move.l %d2, %d0
+; CHECK-NEXT:    bra .LBB20_6
+; CHECK-NEXT:  .LBB20_4:
+; CHECK-NEXT:    move.l %d3, %d4
+; CHECK-NEXT:    eori.l #31, %d4
+; CHECK-NEXT:    lsr.l #1, %d2
+; CHECK-NEXT:    move.l (16,%sp), %d0
+; CHECK-NEXT:    lsr.l %d4, %d2
+; CHECK-NEXT:    lsl.l %d3, %d0
+; CHECK-NEXT:    or.l %d2, %d0
+; CHECK-NEXT:  .LBB20_6:
+; CHECK-NEXT:    movem.l (0,%sp), %d2-%d4 ; 16-byte Folded Reload
+; CHECK-NEXT:    adda.l #12, %sp
+; CHECK-NEXT:    rts
+  %1 = shl i64 %a, %b
+  ret i64 %1
+}


        


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