bfi A, (and B, C1), C2) -> bfi A, B, C2 iff C1 & C2 == C1. rdar://8458663

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121746 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index 3af04f104ba3e64b0f108157a52f70e419e965d5..5fbc5f8ce75953964f04f993e9d7f9cdd5da0bb5 100644 (file)
--- a/lib/Target/ARM/ARMISelLowering.cpp
+++ b/lib/Target/ARM/ARMISelLowering.cpp
@@ -4809,6 +4809,25 @@ static SDValue PerformORCombine(SDNode *N,
   return SDValue();
 }
 
+/// PerformBFICombine - (bfi A, (and B, C1), C2) -> (bfi A, B, C2) iff
+/// C1 & C2 == C1.
+static SDValue PerformBFICombine(SDNode *N,
+                                 TargetLowering::DAGCombinerInfo &DCI) {
+  SDValue N1 = N->getOperand(1);
+  if (N1.getOpcode() == ISD::AND) {
+    ConstantSDNode *N11C = dyn_cast<ConstantSDNode>(N1.getOperand(1));
+    if (!N11C)
+      return SDValue();
+    unsigned Mask = cast<ConstantSDNode>(N->getOperand(2))->getZExtValue();
+    unsigned Mask2 = N11C->getZExtValue();
+    if ((Mask & Mask2) == Mask2)
+      return DCI.DAG.getNode(ARMISD::BFI, N->getDebugLoc(), N->getValueType(0),
+                             N->getOperand(0), N1.getOperand(0),
+                             N->getOperand(2));
+  }
+  return SDValue();
+}
+
 /// PerformVMOVRRDCombine - Target-specific dag combine xforms for
 /// ARMISD::VMOVRRD.
 static SDValue PerformVMOVRRDCombine(SDNode *N,
@@ -5398,6 +5417,7 @@ SDValue ARMTargetLowering::PerformDAGCombine(SDNode *N,
   case ISD::MUL:        return PerformMULCombine(N, DCI, Subtarget);
   case ISD::OR:         return PerformORCombine(N, DCI, Subtarget);
   case ISD::AND:        return PerformANDCombine(N, DCI);
+  case ARMISD::BFI:     return PerformBFICombine(N, DCI);
   case ARMISD::VMOVRRD: return PerformVMOVRRDCombine(N, DCI);
   case ARMISD::VMOVDRR: return PerformVMOVDRRCombine(N, DCI.DAG);
   case ISD::BUILD_VECTOR: return PerformBUILD_VECTORCombine(N, DCI.DAG);

diff --git a/test/CodeGen/ARM/bfi.ll b/test/CodeGen/ARM/bfi.ll
index 157c90c753176ac9acd19289b401e65d4dd5e978..946db1909fe56cb6ddf66c2cb45380fb6fb70435 100644 (file)
--- a/test/CodeGen/ARM/bfi.ll
+++ b/test/CodeGen/ARM/bfi.ll
@@ -49,3 +49,16 @@ define i32 @f4(i32 %a) nounwind {
   %ins12 = or i32 %ins7, 3137
   ret i32 %ins12
 }
+
+; rdar://8458663
+define i32 @f5(i32 %a, i32 %b) nounwind {
+entry:
+; CHECK: f5:
+; CHECK-NOT: bfc
+; CHECK: bfi r0, r1, #20, #4
+  %0 = and i32 %a, -15728641
+  %1 = shl i32 %b, 20
+  %2 = and i32 %1, 15728640
+  %3 = or i32 %2, %0
+  ret i32 %3
+}