#include <cassert>
namespace llvm {
-
+
/// ARM_AM - ARM Addressing Mode Stuff
namespace ARM_AM {
enum ShiftOpc {
ror,
rrx
};
-
+
enum AddrOpc {
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!");
case ARM_AM::rrx: return "rrx";
}
}
-
+
static inline ShiftOpc getShiftOpcForNode(SDValue N) {
switch (N.getOpcode()) {
default: return ARM_AM::no_shift;
}
}
- static inline const char *getAMSubModeAltStr(AMSubMode Mode, bool isLD) {
- switch (Mode) {
- default: assert(0 && "Unknown addressing sub-mode!");
- case ARM_AM::ia: return isLD ? "fd" : "ea";
- case ARM_AM::ib: return isLD ? "ed" : "fa";
- case ARM_AM::da: return isLD ? "fa" : "ed";
- case ARM_AM::db: return isLD ? "ea" : "fd";
- }
- }
-
/// rotr32 - Rotate a 32-bit unsigned value right by a specified # bits.
///
static inline unsigned rotr32(unsigned Val, unsigned Amt) {
assert(Amt < 32 && "Invalid rotate amount");
return (Val >> Amt) | (Val << ((32-Amt)&31));
}
-
+
/// rotl32 - Rotate a 32-bit unsigned value left by a specified # bits.
///
static inline unsigned rotl32(unsigned Val, unsigned Amt) {
assert(Amt < 32 && "Invalid rotate amount");
return (Val << Amt) | (Val >> ((32-Amt)&31));
}
-
+
//===--------------------------------------------------------------------===//
// Addressing Mode #1: shift_operand with registers
//===--------------------------------------------------------------------===//
static inline unsigned getSOImmValRot(unsigned Imm) {
return (Imm >> 8) * 2;
}
-
+
/// getSOImmValRotate - Try to handle Imm with an immediate shifter operand,
/// computing the rotate amount to use. If this immediate value cannot be
/// handled with a single shifter-op, determine a good rotate amount that will
// 8-bit (or less) immediates are trivially shifter_operands with a rotate
// of zero.
if ((Imm & ~255U) == 0) return 0;
-
+
// Use CTZ to compute the rotate amount.
unsigned TZ = CountTrailingZeros_32(Imm);
-
+
// Rotate amount must be even. Something like 0x200 must be rotated 8 bits,
// not 9.
unsigned RotAmt = TZ & ~1;
-
+
// If we can handle this spread, return it.
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
// shifter_op immediate. Return a chunk of bits that will be useful to
// handle.
// 8-bit (or less) immediates are trivially shifter_operands with a rotate
// of zero.
if ((Arg & ~255U) == 0) return Arg;
-
+
unsigned RotAmt = getSOImmValRotate(Arg);
// If this cannot be handled with a single shifter_op, bail out.
if (rotr32(~255U, RotAmt) & Arg)
return -1;
-
+
// Encode this correctly.
return rotl32(Arg, RotAmt) | ((RotAmt>>1) << 8);
}
-
+
/// isSOImmTwoPartVal - Return true if the specified value can be obtained by
/// or'ing together two SOImmVal's.
static inline bool isSOImmTwoPartVal(unsigned V) {
V = rotr32(~255U, getSOImmValRotate(V)) & V;
if (V == 0)
return false;
-
+
// If this can be handled with two shifter_op's, accept.
V = rotr32(~255U, getSOImmValRotate(V)) & V;
return V == 0;
}
-
+
/// getSOImmTwoPartFirst - If V is a value that satisfies isSOImmTwoPartVal,
/// return the first chunk of it.
static inline unsigned getSOImmTwoPartFirst(unsigned V) {
/// getSOImmTwoPartSecond - If V is a value that satisfies isSOImmTwoPartVal,
/// return the second chunk of it.
static inline unsigned getSOImmTwoPartSecond(unsigned V) {
- // Mask out the first hunk.
+ // Mask out the first hunk.
V = rotr32(~255U, getSOImmValRotate(V)) & V;
-
+
// Take what's left.
assert(V == (rotr32(255U, getSOImmValRotate(V)) & V));
return V;
}
-
+
/// getThumbImmValShift - Try to handle Imm with a 8-bit immediate followed
/// by a left shift. Returns the shift amount to use.
static inline unsigned getThumbImmValShift(unsigned Imm) {
/// isThumbImmShiftedVal - Return true if the specified value can be obtained
/// by left shifting a 8-bit immediate.
static inline bool isThumbImmShiftedVal(unsigned V) {
- // If this can be handled with
+ // If this can be handled with
V = (~255U << getThumbImmValShift(V)) & V;
return V == 0;
}
+ /// getThumbImm16ValShift - Try to handle Imm with a 16-bit immediate followed
+ /// by a left shift. Returns the shift amount to use.
+ static inline unsigned getThumbImm16ValShift(unsigned Imm) {
+ // 16-bit (or less) immediates are trivially immediate operand with a shift
+ // of zero.
+ if ((Imm & ~65535U) == 0) return 0;
+
+ // Use CTZ to compute the shift amount.
+ return CountTrailingZeros_32(Imm);
+ }
+
+ /// isThumbImm16ShiftedVal - Return true if the specified value can be
+ /// obtained by left shifting a 16-bit immediate.
+ static inline bool isThumbImm16ShiftedVal(unsigned V) {
+ // If this can be handled with
+ V = (~65535U << getThumbImm16ValShift(V)) & V;
+ return V == 0;
+ }
+
/// getThumbImmNonShiftedVal - If V is a value that satisfies
/// isThumbImmShiftedVal, return the non-shiftd value.
static inline unsigned getThumbImmNonShiftedVal(unsigned V) {
return V >> getThumbImmValShift(V);
}
+
+ /// getT2SOImmValSplat - Return the 12-bit encoded representation
+ /// if the specified value can be obtained by splatting the low 8 bits
+ /// into every other byte or every byte of a 32-bit value. i.e.,
+ /// 00000000 00000000 00000000 abcdefgh control = 0
+ /// 00000000 abcdefgh 00000000 abcdefgh control = 1
+ /// abcdefgh 00000000 abcdefgh 00000000 control = 2
+ /// abcdefgh abcdefgh abcdefgh abcdefgh control = 3
+ /// Return -1 if none of the above apply.
+ /// See ARM Reference Manual A6.3.2.
+ static inline int getT2SOImmValSplatVal(unsigned V) {
+ unsigned u, Vs, Imm;
+ // control = 0
+ if ((V & 0xffffff00) == 0)
+ return V;
+
+ // If the value is zeroes in the first byte, just shift those off
+ Vs = ((V & 0xff) == 0) ? V >> 8 : V;
+ // Any passing value only has 8 bits of payload, splatted across the word
+ Imm = Vs & 0xff;
+ // Likewise, any passing values have the payload splatted into the 3rd byte
+ u = Imm | (Imm << 16);
+
+ // control = 1 or 2
+ if (Vs == u)
+ return (((Vs == V) ? 1 : 2) << 8) | Imm;
+
+ // control = 3
+ if (Vs == (u | (u << 8)))
+ return (3 << 8) | Imm;
+
+ return -1;
+ }
+
+ /// getT2SOImmValRotateVal - Return the 12-bit encoded representation if the
+ /// specified value is a rotated 8-bit value. Return -1 if no rotation
+ /// encoding is possible.
+ /// See ARM Reference Manual A6.3.2.
+ static inline int getT2SOImmValRotateVal(unsigned V) {
+ unsigned RotAmt = CountLeadingZeros_32(V);
+ if (RotAmt >= 24)
+ return -1;
+
+ // If 'Arg' can be handled with a single shifter_op return the value.
+ if ((rotr32(0xff000000U, RotAmt) & V) == V)
+ return (rotr32(V, 24 - RotAmt) & 0x7f) | ((RotAmt + 8) << 7);
+
+ return -1;
+ }
+
+ /// getT2SOImmVal - Given a 32-bit immediate, if it is something that can fit
+ /// into a Thumb-2 shifter_operand immediate operand, return the 12-bit
+ /// encoding for it. If not, return -1.
+ /// See ARM Reference Manual A6.3.2.
+ static inline int getT2SOImmVal(unsigned Arg) {
+ // If 'Arg' is an 8-bit splat, then get the encoded value.
+ int Splat = getT2SOImmValSplatVal(Arg);
+ if (Splat != -1)
+ return Splat;
+
+ // If 'Arg' can be handled with a single shifter_op return the value.
+ int Rot = getT2SOImmValRotateVal(Arg);
+ if (Rot != -1)
+ return Rot;
+
+ return -1;
+ }
+
+ static inline unsigned getT2SOImmValRotate(unsigned V) {
+ if ((V & ~255U) == 0) return 0;
+ // Use CTZ to compute the rotate amount.
+ unsigned RotAmt = CountTrailingZeros_32(V);
+ return (32 - RotAmt) & 31;
+ }
+
+ static inline bool isT2SOImmTwoPartVal (unsigned Imm) {
+ unsigned V = Imm;
+ // Passing values can be any combination of splat values and shifter
+ // values. If this can be handled with a single shifter or splat, bail
+ // out. Those should be handled directly, not with a two-part val.
+ if (getT2SOImmValSplatVal(V) != -1)
+ return false;
+ V = rotr32 (~255U, getT2SOImmValRotate(V)) & V;
+ if (V == 0)
+ return false;
+
+ // If this can be handled as an immediate, accept.
+ if (getT2SOImmVal(V) != -1) return true;
+
+ // Likewise, try masking out a splat value first.
+ V = Imm;
+ if (getT2SOImmValSplatVal(V & 0xff00ff00U) != -1)
+ V &= ~0xff00ff00U;
+ else if (getT2SOImmValSplatVal(V & 0x00ff00ffU) != -1)
+ V &= ~0x00ff00ffU;
+ // If what's left can be handled as an immediate, accept.
+ if (getT2SOImmVal(V) != -1) return true;
+
+ // Otherwise, do not accept.
+ return false;
+ }
+
+ static inline unsigned getT2SOImmTwoPartFirst(unsigned Imm) {
+ assert (isT2SOImmTwoPartVal(Imm) &&
+ "Immedate cannot be encoded as two part immediate!");
+ // Try a shifter operand as one part
+ unsigned V = rotr32 (~255, getT2SOImmValRotate(Imm)) & Imm;
+ // If the rest is encodable as an immediate, then return it.
+ if (getT2SOImmVal(V) != -1) return V;
+
+ // Try masking out a splat value first.
+ if (getT2SOImmValSplatVal(Imm & 0xff00ff00U) != -1)
+ return Imm & 0xff00ff00U;
+
+ // The other splat is all that's left as an option.
+ assert (getT2SOImmValSplatVal(Imm & 0x00ff00ffU) != -1);
+ return Imm & 0x00ff00ffU;
+ }
+
+ static inline unsigned getT2SOImmTwoPartSecond(unsigned Imm) {
+ // Mask out the first hunk
+ Imm ^= getT2SOImmTwoPartFirst(Imm);
+ // Return what's left
+ assert (getT2SOImmVal(Imm) != -1 &&
+ "Unable to encode second part of T2 two part SO immediate");
+ return Imm;
+ }
+
+
//===--------------------------------------------------------------------===//
// Addressing Mode #2
//===--------------------------------------------------------------------===//
// If this addressing mode is a frame index (before prolog/epilog insertion
// and code rewriting), this operand will have the form: FI#, reg0, <offs>
// with no shift amount for the frame offset.
- //
+ //
static inline unsigned getAM2Opc(AddrOpc Opc, unsigned Imm12, ShiftOpc SO) {
assert(Imm12 < (1 << 12) && "Imm too large!");
bool isSub = Opc == sub;
static inline ShiftOpc getAM2ShiftOpc(unsigned AM2Opc) {
return (ShiftOpc)(AM2Opc >> 13);
}
-
-
+
+
//===--------------------------------------------------------------------===//
// Addressing Mode #3
//===--------------------------------------------------------------------===//
// The first operand is always a Reg. The second operand is a reg if in
// reg/reg form, otherwise it's reg#0. The third field encodes the operation
// in bit 8, the immediate in bits 0-7.
-
+
/// getAM3Opc - This function encodes the addrmode3 opc field.
static inline unsigned getAM3Opc(AddrOpc Opc, unsigned char Offset) {
bool isSub = Opc == sub;
static inline AddrOpc getAM3Op(unsigned AM3Opc) {
return ((AM3Opc >> 8) & 1) ? sub : add;
}
-
+
//===--------------------------------------------------------------------===//
// Addressing Mode #4
//===--------------------------------------------------------------------===//
// 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;
}
//===--------------------------------------------------------------------===//
//
// addrmode5 := reg +/- imm8*4
//
- // The first operand is always a Reg. The third field encodes the operation
- // in bit 8, the immediate in bits 0-7.
+ // The first operand is always a Reg. The second operand encodes the
+ // operation in bit 8 and the immediate in bits 0-7.
//
- // This can also be used for FP load/store multiple ops. The third field encodes
- // writeback mode in bit 8, the number of registers (or 2 times the number of
- // registers for DPR ops) in bits 0-7. In addition, bit 9-11 encodes one of the
+ // This is also used for FP load/store multiple ops. The second operand
+ // 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.
static inline unsigned getAM5Opc(AddrOpc Opc, unsigned char Offset) {
bool isSub = Opc == sub;
return ((AM5Opc >> 8) & 1) ? sub : add;
}
- /// getAM5Opc - This function encodes the addrmode5 opc field for FLDM and
- /// FSTM instructions.
- static inline unsigned getAM5Opc(AMSubMode SubMode, bool WB,
- unsigned char Offset) {
+ /// getAM5Opc - This function encodes the addrmode5 opc field for VLDM and
+ /// VSTM instructions.
+ 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);
+ return (AMSubMode)((AM5Opc >> 8) & 0x7);
+ }
+
+ //===--------------------------------------------------------------------===//
+ // Addressing Mode #6
+ //===--------------------------------------------------------------------===//
+ //
+ // This is used for NEON load / store instructions.
+ //
+ // addrmode6 := reg with optional 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.
+
+ //===--------------------------------------------------------------------===//
+ // 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 bool getAM5WBFlag(unsigned AM5Opc) {
- return ((AM5Opc >> 8) & 1);
+ 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
} // end namespace llvm
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