diff --git a/llvm/lib/Target/AVR/AVRISelLowering.cpp b/llvm/lib/Target/AVR/AVRISelLowering.cpp --- a/llvm/lib/Target/AVR/AVRISelLowering.cpp +++ b/llvm/lib/Target/AVR/AVRISelLowering.cpp @@ -427,6 +427,21 @@ Victim = DAG.getNode(AVRISD::ASRBN, dl, VT, Victim, DAG.getConstant(7, dl, VT)); ShiftAmount = 0; + } else if (Op.getOpcode() == ISD::ROTL && ShiftAmount == 7) { + // Optimize left rotation 7 bits to right rotation 1 bit. + Victim = + DAG.getNode(AVRISD::ROR, dl, VT, Victim, DAG.getConstant(1, dl, VT)); + ShiftAmount = 0; + } else if (Op.getOpcode() == ISD::ROTR && ShiftAmount == 7) { + // Optimize right rotation 7 bits to left rotation 1 bit. + Victim = + DAG.getNode(AVRISD::ROL, dl, VT, Victim, DAG.getConstant(1, dl, VT)); + ShiftAmount = 0; + } else if ((Op.getOpcode() == ISD::ROTR || Op.getOpcode() == ISD::ROTL) && + ShiftAmount >= 4) { + // Optimize left/right rotation with the SWAP instruction. + Victim = DAG.getNode(AVRISD::SWAP, dl, VT, Victim); + ShiftAmount -= 4; } } else if (VT.getSizeInBits() == 16) { if (Op.getOpcode() == ISD::SRA) diff --git a/llvm/test/CodeGen/AVR/rotate.ll b/llvm/test/CodeGen/AVR/rotate.ll --- a/llvm/test/CodeGen/AVR/rotate.ll +++ b/llvm/test/CodeGen/AVR/rotate.ll @@ -30,14 +30,7 @@ define i8 @rotl8_5(i8 %x) { ; CHECK-LABEL: rotl8_5: ; CHECK: ; %bb.0: ; %start -; CHECK-NEXT: lsl r24 -; CHECK-NEXT: adc r24, r1 -; CHECK-NEXT: lsl r24 -; CHECK-NEXT: adc r24, r1 -; CHECK-NEXT: lsl r24 -; CHECK-NEXT: adc r24, r1 -; CHECK-NEXT: lsl r24 -; CHECK-NEXT: adc r24, r1 +; CHECK-NEXT: swap r24 ; CHECK-NEXT: lsl r24 ; CHECK-NEXT: adc r24, r1 ; CHECK-NEXT: ret @@ -49,20 +42,9 @@ define i8 @rotl8_7(i8 %x) { ; CHECK-LABEL: rotl8_7: ; CHECK: ; %bb.0: ; %start -; CHECK-NEXT: lsl r24 -; CHECK-NEXT: adc r24, r1 -; CHECK-NEXT: lsl r24 -; CHECK-NEXT: adc r24, r1 -; CHECK-NEXT: lsl r24 -; CHECK-NEXT: adc r24, r1 -; CHECK-NEXT: lsl r24 -; CHECK-NEXT: adc r24, r1 -; CHECK-NEXT: lsl r24 -; CHECK-NEXT: adc r24, r1 -; CHECK-NEXT: lsl r24 -; CHECK-NEXT: adc r24, r1 -; CHECK-NEXT: lsl r24 -; CHECK-NEXT: adc r24, r1 +; CHECK-NEXT: bst r24, 0 +; CHECK-NEXT: ror r24 +; CHECK-NEXT: bld r24, 7 ; CHECK-NEXT: ret start: %0 = call i8 @llvm.fshl.i8(i8 %x, i8 %x, i8 7) @@ -121,18 +103,7 @@ define i8 @rotr8_5(i8 %x) { ; CHECK-LABEL: rotr8_5: ; CHECK: ; %bb.0: ; %start -; CHECK-NEXT: bst r24, 0 -; CHECK-NEXT: ror r24 -; CHECK-NEXT: bld r24, 7 -; CHECK-NEXT: bst r24, 0 -; CHECK-NEXT: ror r24 -; CHECK-NEXT: bld r24, 7 -; CHECK-NEXT: bst r24, 0 -; CHECK-NEXT: ror r24 -; CHECK-NEXT: bld r24, 7 -; CHECK-NEXT: bst r24, 0 -; CHECK-NEXT: ror r24 -; CHECK-NEXT: bld r24, 7 +; CHECK-NEXT: swap r24 ; CHECK-NEXT: bst r24, 0 ; CHECK-NEXT: ror r24 ; CHECK-NEXT: bld r24, 7 @@ -145,27 +116,8 @@ define i8 @rotr8_7(i8 %x) { ; CHECK-LABEL: rotr8_7: ; CHECK: ; %bb.0: ; %start -; CHECK-NEXT: bst r24, 0 -; CHECK-NEXT: ror r24 -; CHECK-NEXT: bld r24, 7 -; CHECK-NEXT: bst r24, 0 -; CHECK-NEXT: ror r24 -; CHECK-NEXT: bld r24, 7 -; CHECK-NEXT: bst r24, 0 -; CHECK-NEXT: ror r24 -; CHECK-NEXT: bld r24, 7 -; CHECK-NEXT: bst r24, 0 -; CHECK-NEXT: ror r24 -; CHECK-NEXT: bld r24, 7 -; CHECK-NEXT: bst r24, 0 -; CHECK-NEXT: ror r24 -; CHECK-NEXT: bld r24, 7 -; CHECK-NEXT: bst r24, 0 -; CHECK-NEXT: ror r24 -; CHECK-NEXT: bld r24, 7 -; CHECK-NEXT: bst r24, 0 -; CHECK-NEXT: ror r24 -; CHECK-NEXT: bld r24, 7 +; CHECK-NEXT: lsl r24 +; CHECK-NEXT: adc r24, r1 ; CHECK-NEXT: ret start: %0 = call i8 @llvm.fshr.i8(i8 %x, i8 %x, i8 7)