From 5edb03ee57f5289aa768fabb441c2ab5e33d2328 Mon Sep 17 00:00:00 2001
From: Jim Grosbach <grosbach@apple.com>
Date: Thu, 21 Oct 2010 22:03:21 +0000
Subject: [PATCH] ARM Binary encoding information for BFC/BFI instructions.

llvm-svn: 117072
---
 llvm/lib/Target/ARM/ARMCodeEmitter.cpp   |  2 ++
 llvm/lib/Target/ARM/ARMInstrInfo.td      | 25 ++++++++++++++++++------
 llvm/lib/Target/ARM/ARMMCCodeEmitter.cpp | 14 +++++++++++++
 llvm/test/MC/ARM/simple-encoding.ll      |  7 +++++++
 4 files changed, 42 insertions(+), 6 deletions(-)

diff --git a/llvm/lib/Target/ARM/ARMCodeEmitter.cpp b/llvm/lib/Target/ARM/ARMCodeEmitter.cpp
index 0220e7ddacb2..2b1239d921bd 100644
--- a/llvm/lib/Target/ARM/ARMCodeEmitter.cpp
+++ b/llvm/lib/Target/ARM/ARMCodeEmitter.cpp
@@ -172,6 +172,8 @@ namespace {
       const { return 0; }
     unsigned getImmMinusOneOpValue(const MachineInstr &MI, unsigned Op)
       const { return 0; }
+    unsigned getBitfieldInvertedMaskOpValue(const MachineInstr &MI,
+                                            unsigned Op) const { return 0; }
 
     /// getMovi32Value - Return binary encoding of operand for movw/movt. If the
     /// machine operand requires relocation, record the relocation and return
diff --git a/llvm/lib/Target/ARM/ARMInstrInfo.td b/llvm/lib/Target/ARM/ARMInstrInfo.td
index df698f9e21f6..7d6942250dca 100644
--- a/llvm/lib/Target/ARM/ARMInstrInfo.td
+++ b/llvm/lib/Target/ARM/ARMInstrInfo.td
@@ -232,6 +232,7 @@ def bf_inv_mask_imm : Operand<i32>,
                       PatLeaf<(imm), [{
   return ARM::isBitFieldInvertedMask(N->getZExtValue());
 }] > {
+  string EncoderMethod = "getBitfieldInvertedMaskOpValue";
   let PrintMethod = "printBitfieldInvMaskImmOperand";
 }
 
@@ -2174,24 +2175,36 @@ defm BIC   : AsI1_bin_irs<0b1110, "bic",
                           IIC_iBITi, IIC_iBITr, IIC_iBITsr,
                           BinOpFrag<(and node:$LHS, (not node:$RHS))>>;
 
-def BFC    : I<(outs GPR:$dst), (ins GPR:$src, bf_inv_mask_imm:$imm),
+def BFC    : I<(outs GPR:$Rd), (ins GPR:$src, bf_inv_mask_imm:$imm),
                AddrMode1, Size4Bytes, IndexModeNone, DPFrm, IIC_iUNAsi,
-               "bfc", "\t$dst, $imm", "$src = $dst",
-               [(set GPR:$dst, (and GPR:$src, bf_inv_mask_imm:$imm))]>,
+               "bfc", "\t$Rd, $imm", "$src = $Rd",
+               [(set GPR:$Rd, (and GPR:$src, bf_inv_mask_imm:$imm))]>,
                Requires<[IsARM, HasV6T2]> {
+  bits<4> Rd;
+  bits<10> imm;
   let Inst{27-21} = 0b0111110;
   let Inst{6-0}   = 0b0011111;
+  let Inst{15-12} = Rd;
+  let Inst{11-7}  = imm{4-0}; // lsb
+  let Inst{20-16} = imm{9-5}; // width
 }
 
 // A8.6.18  BFI - Bitfield insert (Encoding A1)
-def BFI    : I<(outs GPR:$dst), (ins GPR:$src, GPR:$val, bf_inv_mask_imm:$imm),
+def BFI    : I<(outs GPR:$Rd), (ins GPR:$src, GPR:$Rn, bf_inv_mask_imm:$imm),
                AddrMode1, Size4Bytes, IndexModeNone, DPFrm, IIC_iUNAsi,
-               "bfi", "\t$dst, $val, $imm", "$src = $dst",
-               [(set GPR:$dst, (ARMbfi GPR:$src, GPR:$val,
+               "bfi", "\t$Rd, $Rn, $imm", "$src = $Rd",
+               [(set GPR:$Rd, (ARMbfi GPR:$src, GPR:$Rn,
                                 bf_inv_mask_imm:$imm))]>,
                Requires<[IsARM, HasV6T2]> {
+  bits<4> Rd;
+  bits<4> Rn;
+  bits<10> imm;
   let Inst{27-21} = 0b0111110;
   let Inst{6-4}   = 0b001; // Rn: Inst{3-0} != 15
+  let Inst{15-12} = Rd;
+  let Inst{11-7}  = imm{4-0}; // lsb
+  let Inst{20-16} = imm{9-5}; // width
+  let Inst{3-0}   = Rn;
 }
 
 def  MVNr  : AsI1<0b1111, (outs GPR:$dst), (ins GPR:$src), DPFrm, IIC_iMVNr,
diff --git a/llvm/lib/Target/ARM/ARMMCCodeEmitter.cpp b/llvm/lib/Target/ARM/ARMMCCodeEmitter.cpp
index ea7789c073c2..f0680e82508d 100644
--- a/llvm/lib/Target/ARM/ARMMCCodeEmitter.cpp
+++ b/llvm/lib/Target/ARM/ARMMCCodeEmitter.cpp
@@ -88,6 +88,8 @@ public:
     return MI.getOperand(Op).getImm() - 1;
   }
 
+  unsigned getBitfieldInvertedMaskOpValue(const MCInst &MI, unsigned Op) const;
+
   unsigned getNumFixupKinds() const {
     assert(0 && "ARMMCCodeEmitter::getNumFixupKinds() not yet implemented.");
     return 0;
@@ -238,6 +240,18 @@ unsigned ARMMCCodeEmitter::getSORegOpValue(const MCInst &MI,
   return Binary | ARM_AM::getSORegOffset(MO2.getImm()) << 7;
 }
 
+unsigned ARMMCCodeEmitter::getBitfieldInvertedMaskOpValue(const MCInst &MI,
+                                                          unsigned Op) const {
+  // 10 bits. lower 5 bits are are the lsb of the mask, high five bits are the
+  // msb of the mask.
+  const MCOperand &MO = MI.getOperand(Op);
+  uint32_t v = ~MO.getImm();
+  uint32_t lsb = CountTrailingZeros_32(v);
+  uint32_t msb = (32 - CountLeadingZeros_32 (v)) - 1;
+  assert (v != 0 && lsb < 32 && msb < 32 && "Illegal bitfield mask!");
+  return lsb | (msb << 5);
+}
+
 void ARMMCCodeEmitter::
 EncodeInstruction(const MCInst &MI, raw_ostream &OS,
                   SmallVectorImpl<MCFixup> &Fixups) const {
diff --git a/llvm/test/MC/ARM/simple-encoding.ll b/llvm/test/MC/ARM/simple-encoding.ll
index 650990bfc497..e4ac2f58915e 100644
--- a/llvm/test/MC/ARM/simple-encoding.ll
+++ b/llvm/test/MC/ARM/simple-encoding.ll
@@ -114,4 +114,11 @@ entry:
   ret i32 %mul
 }
 
+define i32 @f12(i32 %a) {
+; CHECK: f12:
+; CHECK: bfc  r0, #4, #20             @ encoding: [0x1f,0x02,0xd7,0xe7]
+    %tmp = and i32 %a, 4278190095
+    ret i32 %tmp
+}
+
 declare void @llvm.trap() nounwind