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-rw-r--r--llvm/lib/Target/AVR/AVRISelLowering.cpp12
-rw-r--r--llvm/test/CodeGen/AVR/rotate.ll22
2 files changed, 19 insertions, 15 deletions
diff --git a/llvm/lib/Target/AVR/AVRISelLowering.cpp b/llvm/lib/Target/AVR/AVRISelLowering.cpp
index d0314fb..ee0693c 100644
--- a/llvm/lib/Target/AVR/AVRISelLowering.cpp
+++ b/llvm/lib/Target/AVR/AVRISelLowering.cpp
@@ -427,6 +427,18 @@ SDValue AVRTargetLowering::LowerShifts(SDValue Op, SelectionDAG &DAG) const {
Victim = DAG.getNode(AVRISD::ASRBN, dl, VT, Victim,
DAG.getConstant(7, dl, VT));
ShiftAmount = 0;
+ } else if (Op.getOpcode() == ISD::ROTL && ShiftAmount == 3) {
+ // Optimize left rotation 3 bits to swap then right rotation 1 bit.
+ Victim = DAG.getNode(AVRISD::SWAP, dl, VT, Victim);
+ Victim =
+ DAG.getNode(AVRISD::ROR, dl, VT, Victim, DAG.getConstant(1, dl, VT));
+ ShiftAmount = 0;
+ } else if (Op.getOpcode() == ISD::ROTR && ShiftAmount == 3) {
+ // Optimize right rotation 3 bits to swap then left rotation 1 bit.
+ Victim = DAG.getNode(AVRISD::SWAP, dl, VT, Victim);
+ Victim =
+ DAG.getNode(AVRISD::ROL, dl, VT, Victim, DAG.getConstant(1, dl, VT));
+ ShiftAmount = 0;
} else if (Op.getOpcode() == ISD::ROTL && ShiftAmount == 7) {
// Optimize left rotation 7 bits to right rotation 1 bit.
Victim =
diff --git a/llvm/test/CodeGen/AVR/rotate.ll b/llvm/test/CodeGen/AVR/rotate.ll
index 938b64f..79ff792 100644
--- a/llvm/test/CodeGen/AVR/rotate.ll
+++ b/llvm/test/CodeGen/AVR/rotate.ll
@@ -15,12 +15,10 @@ start:
define i8 @rotl8_3(i8 %x) {
; CHECK-LABEL: rotl8_3:
; 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: swap r24
+; 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 3)
@@ -85,15 +83,9 @@ start:
define i8 @rotr8_3(i8 %x) {
; CHECK-LABEL: rotr8_3:
; 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: swap r24
+; CHECK-NEXT: lsl r24
+; CHECK-NEXT: adc r24, r1
; CHECK-NEXT: ret
start:
%0 = call i8 @llvm.fshr.i8(i8 %x, i8 %x, i8 3)