add = '+', sub = '-'
};
+ static inline const char *getAddrOpcStr(AddrOpc Op) {
+ return Op == sub ? "-" : "";
+ }
+
static inline const char *getShiftOpcStr(ShiftOpc Op) {
switch (Op) {
default: assert(0 && "Unknown shift opc!");
if ((rotr32(Imm, RotAmt) & ~255U) == 0)
return (32-RotAmt)&31; // HW rotates right, not left.
- // For values like 0xF000000F, we should skip the first run of ones, then
+ // For values like 0xF000000F, we should ignore the low 6 bits, then
// retry the hunt.
- if (Imm & 1) {
- unsigned TrailingOnes = CountTrailingZeros_32(~Imm);
- if (TrailingOnes != 32) { // Avoid overflow on 0xFFFFFFFF
- // Restart the search for a high-order bit after the initial seconds of
- // ones.
- unsigned TZ2 = CountTrailingZeros_32(Imm & ~((1 << TrailingOnes)-1));
-
- // Rotate amount must be even.
- unsigned RotAmt2 = TZ2 & ~1;
-
- // If this fits, use it.
- if (RotAmt2 != 32 && (rotr32(Imm, RotAmt2) & ~255U) == 0)
- return (32-RotAmt2)&31; // HW rotates right, not left.
- }
+ if (Imm & 63U) {
+ unsigned TZ2 = CountTrailingZeros_32(Imm & ~63U);
+ unsigned RotAmt2 = TZ2 & ~1;
+ if ((rotr32(Imm, RotAmt2) & ~255U) == 0)
+ return (32-RotAmt2)&31; // HW rotates right, not left.
}
// Otherwise, we have no way to cover this span of bits with a single
// IB - Increment before
// DA - Decrement after
// DB - Decrement before
- //
- // If the 4th bit (writeback)is set, then the base register is updated after
- // the memory transfer.
static inline AMSubMode getAM4SubMode(unsigned Mode) {
return (AMSubMode)(Mode & 0x7);
}
- static inline unsigned getAM4ModeImm(AMSubMode SubMode, bool WB = false) {
- return (int)SubMode | ((int)WB << 3);
- }
-
- static inline bool getAM4WBFlag(unsigned Mode) {
- return (Mode >> 3) & 1;
+ static inline unsigned getAM4ModeImm(AMSubMode SubMode) {
+ return (int)SubMode;
}
//===--------------------------------------------------------------------===//
// operation in bit 8 and the immediate in bits 0-7.
//
// This is also used for FP load/store multiple ops. The second operand
- // encodes the writeback mode in bit 8 and the number of registers (or 2
- // times the number of registers for DPR ops) in bits 0-7. In addition,
- // bits 9-11 encode one of the following two sub-modes:
+ // encodes the number of registers (or 2 times the number of registers
+ // for DPR ops) in bits 0-7. In addition, bits 8-10 encode one of the
+ // following two sub-modes:
//
// IA - Increment after
// DB - Decrement before
/// getAM5Opc - This function encodes the addrmode5 opc field for VLDM and
/// VSTM instructions.
- static inline unsigned getAM5Opc(AMSubMode SubMode, bool WB,
- unsigned char Offset) {
+ static inline unsigned getAM5Opc(AMSubMode SubMode, unsigned char Offset) {
assert((SubMode == ia || SubMode == db) &&
"Illegal addressing mode 5 sub-mode!");
- return ((int)SubMode << 9) | ((int)WB << 8) | Offset;
+ return ((int)SubMode << 8) | Offset;
}
static inline AMSubMode getAM5SubMode(unsigned AM5Opc) {
- return (AMSubMode)((AM5Opc >> 9) & 0x7);
- }
- static inline bool getAM5WBFlag(unsigned AM5Opc) {
- return ((AM5Opc >> 8) & 1);
+ return (AMSubMode)((AM5Opc >> 8) & 0x7);
}
//===--------------------------------------------------------------------===//
//
// This is used for NEON load / store instructions.
//
- // addrmode6 := reg with optional writeback and alignment
+ // addrmode6 := reg with optional alignment
//
- // This is stored in four operands [regaddr, regupdate, opc, align]. The
- // first is the address register. The second register holds the value of
- // a post-access increment for writeback or reg0 if no writeback or if the
- // writeback increment is the size of the memory access. The third
- // operand encodes whether there is writeback to the address register. The
- // fourth operand is the value of the alignment specifier to use or zero if
- // no explicit alignment.
+ // This is stored in two operands [regaddr, align]. The first is the
+ // address register. The second operand is the value of the alignment
+ // specifier in bytes or zero if no explicit alignment.
+ // Valid alignments depend on the specific instruction.
- static inline unsigned getAM6Opc(bool WB = false) {
- return (int)WB;
- }
-
- static inline bool getAM6WBFlag(unsigned Mode) {
- return Mode & 1;
+ //===--------------------------------------------------------------------===//
+ // NEON Modified Immediates
+ //===--------------------------------------------------------------------===//
+ //
+ // Several NEON instructions (e.g., VMOV) take a "modified immediate"
+ // vector operand, where a small immediate encoded in the instruction
+ // specifies a full NEON vector value. These modified immediates are
+ // represented here as encoded integers. The low 8 bits hold the immediate
+ // value; bit 12 holds the "Op" field of the instruction, and bits 11-8 hold
+ // the "Cmode" field of the instruction. The interfaces below treat the
+ // Op and Cmode values as a single 5-bit value.
+
+ static inline unsigned createNEONModImm(unsigned OpCmode, unsigned Val) {
+ return (OpCmode << 8) | Val;
+ }
+ static inline unsigned getNEONModImmOpCmode(unsigned ModImm) {
+ return (ModImm >> 8) & 0x1f;
+ }
+ static inline unsigned getNEONModImmVal(unsigned ModImm) {
+ return ModImm & 0xff;
+ }
+
+ /// decodeNEONModImm - Decode a NEON modified immediate value into the
+ /// element value and the element size in bits. (If the element size is
+ /// smaller than the vector, it is splatted into all the elements.)
+ static inline uint64_t decodeNEONModImm(unsigned ModImm, unsigned &EltBits) {
+ unsigned OpCmode = getNEONModImmOpCmode(ModImm);
+ unsigned Imm8 = getNEONModImmVal(ModImm);
+ uint64_t Val = 0;
+
+ if (OpCmode == 0xe) {
+ // 8-bit vector elements
+ Val = Imm8;
+ EltBits = 8;
+ } else if ((OpCmode & 0xc) == 0x8) {
+ // 16-bit vector elements
+ unsigned ByteNum = (OpCmode & 0x6) >> 1;
+ Val = Imm8 << (8 * ByteNum);
+ EltBits = 16;
+ } else if ((OpCmode & 0x8) == 0) {
+ // 32-bit vector elements, zero with one byte set
+ unsigned ByteNum = (OpCmode & 0x6) >> 1;
+ Val = Imm8 << (8 * ByteNum);
+ EltBits = 32;
+ } else if ((OpCmode & 0xe) == 0xc) {
+ // 32-bit vector elements, one byte with low bits set
+ unsigned ByteNum = 1 + (OpCmode & 0x1);
+ Val = (Imm8 << (8 * ByteNum)) | (0xffff >> (8 * (2 - ByteNum)));
+ EltBits = 32;
+ } else if (OpCmode == 0x1e) {
+ // 64-bit vector elements
+ for (unsigned ByteNum = 0; ByteNum < 8; ++ByteNum) {
+ if ((ModImm >> ByteNum) & 1)
+ Val |= (uint64_t)0xff << (8 * ByteNum);
+ }
+ EltBits = 64;
+ } else {
+ assert(false && "Unsupported NEON immediate");
+ }
+ return Val;
}
} // end namespace ARM_AM
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