AArch64: Add backend intrinsic for rbit.

Define an intrinsic for the frontend to use and pattern match it to
the RBIT instruction.

rdar://9283021

llvm-svn: 211058

2 files changed, 11 insertions, 0 deletions

diff --git a/llvm/include/llvm/IR/IntrinsicsAArch64.td b/llvm/include/llvm/IR/IntrinsicsAArch64.td
index 23757aaef5c..e3c0fb35990 100644
--- a/llvm/include/llvm/IR/IntrinsicsAArch64.td
+++ b/llvm/include/llvm/IR/IntrinsicsAArch64.td
@@ -31,6 +31,13 @@ def int_aarch64_sdiv : Intrinsic<[llvm_anyint_ty], [LLVMMatchType<0>,
                                 LLVMMatchType<0>], [IntrNoMem]>;
 def int_aarch64_udiv : Intrinsic<[llvm_anyint_ty], [LLVMMatchType<0>,
                                 LLVMMatchType<0>], [IntrNoMem]>;
+
+//===----------------------------------------------------------------------===//
+// RBIT
+
+def int_aarch64_rbit : Intrinsic<[llvm_anyint_ty], [LLVMMatchType<0>],
+                                 [IntrNoMem]>;
+
 }
 
 //===----------------------------------------------------------------------===//
diff --git a/llvm/lib/Target/AArch64/AArch64InstrInfo.td b/llvm/lib/Target/AArch64/AArch64InstrInfo.td
index 9ad36e8740d..b1e8fa64c2d 100644
--- a/llvm/lib/Target/AArch64/AArch64InstrInfo.td
+++ b/llvm/lib/Target/AArch64/AArch64InstrInfo.td
@@ -737,6 +737,10 @@ def : Pat<(not GPR64:$Xm), (ORNXrr XZR, GPR64:$Xm)>;
 defm CLS    : OneOperandData<0b101, "cls">;
 defm CLZ    : OneOperandData<0b100, "clz", ctlz>;
 defm RBIT   : OneOperandData<0b000, "rbit">;
+
+def : Pat<(int_aarch64_rbit GPR32:$Rn), (RBITWr $Rn)>;
+def : Pat<(int_aarch64_rbit GPR64:$Rn), (RBITXr $Rn)>;
+
 def  REV16Wr : OneWRegData<0b001, "rev16",
                                   UnOpFrag<(rotr (bswap node:$LHS), (i64 16))>>;
 def  REV16Xr : OneXRegData<0b001, "rev16", null_frag>;