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+//===- ARMAddressingModes.h - ARM Addressing Modes --------------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains the ARM addressing mode implementation stuff.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_TARGET_ARM_ARMADDRESSINGMODES_H
+#define LLVM_TARGET_ARM_ARMADDRESSINGMODES_H
+
+#include "llvm/ADT/APFloat.h"
+#include "llvm/ADT/APInt.h"
+#include "llvm/Support/MathExtras.h"
+#include <cassert>
+
+namespace llvm {
+
+/// ARM_AM - ARM Addressing Mode Stuff
+namespace ARM_AM {
+ enum ShiftOpc {
+ no_shift = 0,
+ asr,
+ lsl,
+ lsr,
+ ror,
+ rrx
+ };
+
+ enum AddrOpc {
+ sub = 0,
+ add
+ };
+
+ 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::asr: return "asr";
+ case ARM_AM::lsl: return "lsl";
+ case ARM_AM::lsr: return "lsr";
+ case ARM_AM::ror: return "ror";
+ case ARM_AM::rrx: return "rrx";
+ }
+ }
+
+ static inline unsigned getShiftOpcEncoding(ShiftOpc Op) {
+ switch (Op) {
+ default: assert(0 && "Unknown shift opc!");
+ case ARM_AM::asr: return 2;
+ case ARM_AM::lsl: return 0;
+ case ARM_AM::lsr: return 1;
+ case ARM_AM::ror: return 3;
+ }
+ }
+
+ enum AMSubMode {
+ bad_am_submode = 0,
+ ia,
+ ib,
+ da,
+ db
+ };
+
+ static inline const char *getAMSubModeStr(AMSubMode Mode) {
+ switch (Mode) {
+ default: assert(0 && "Unknown addressing sub-mode!");
+ case ARM_AM::ia: return "ia";
+ case ARM_AM::ib: return "ib";
+ case ARM_AM::da: return "da";
+ case ARM_AM::db: return "db";
+ }
+ }
+
+ /// 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
+ //===--------------------------------------------------------------------===//
+ //
+ // This 'addressing mode' is used for arithmetic instructions. It can
+ // represent things like:
+ // reg
+ // reg [asr|lsl|lsr|ror|rrx] reg
+ // reg [asr|lsl|lsr|ror|rrx] imm
+ //
+ // This is stored three operands [rega, regb, opc]. The first is the base
+ // reg, the second is the shift amount (or reg0 if not present or imm). The
+ // third operand encodes the shift opcode and the imm if a reg isn't present.
+ //
+ static inline unsigned getSORegOpc(ShiftOpc ShOp, unsigned Imm) {
+ return ShOp | (Imm << 3);
+ }
+ static inline unsigned getSORegOffset(unsigned Op) {
+ return Op >> 3;
+ }
+ static inline ShiftOpc getSORegShOp(unsigned Op) {
+ return (ShiftOpc)(Op & 7);
+ }
+
+ /// getSOImmValImm - Given an encoded imm field for the reg/imm form, return
+ /// the 8-bit imm value.
+ static inline unsigned getSOImmValImm(unsigned Imm) {
+ return Imm & 0xFF;
+ }
+ /// getSOImmValRot - Given an encoded imm field for the reg/imm form, return
+ /// the rotate amount.
+ 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
+ /// take a maximal chunk of bits out of the immediate.
+ static inline unsigned getSOImmValRotate(unsigned Imm) {
+ // 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 ignore the low 6 bits, then
+ // retry the hunt.
+ 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.
+ return (32-RotAmt)&31; // HW rotates right, not left.
+ }
+
+ /// getSOImmVal - Given a 32-bit immediate, if it is something that can fit
+ /// into an shifter_operand immediate operand, return the 12-bit encoding for
+ /// it. If not, return -1.
+ static inline int getSOImmVal(unsigned Arg) {
+ // 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) {
+ // If this can be handled with a single shifter_op, bail out.
+ 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) {
+ return rotr32(255U, getSOImmValRotate(V)) & 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.
+ 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) {
+ // 8-bit (or less) immediates are trivially immediate operand with a shift
+ // of zero.
+ if ((Imm & ~255U) == 0) return 0;
+
+ // Use CTZ to compute the shift amount.
+ return CountTrailingZeros_32(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
+ 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
+ //===--------------------------------------------------------------------===//
+ //
+ // This is used for most simple load/store instructions.
+ //
+ // addrmode2 := reg +/- reg shop imm
+ // addrmode2 := reg +/- imm12
+ //
+ // 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 12, the immediate in bits 0-11, and the shift op in 13-15. The
+ // fourth operand 16-17 encodes the index mode.
+ //
+ // 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,
+ unsigned IdxMode = 0) {
+ assert(Imm12 < (1 << 12) && "Imm too large!");
+ bool isSub = Opc == sub;
+ return Imm12 | ((int)isSub << 12) | (SO << 13) | (IdxMode << 16) ;
+ }
+ static inline unsigned getAM2Offset(unsigned AM2Opc) {
+ return AM2Opc & ((1 << 12)-1);
+ }
+ static inline AddrOpc getAM2Op(unsigned AM2Opc) {
+ return ((AM2Opc >> 12) & 1) ? sub : add;
+ }
+ static inline ShiftOpc getAM2ShiftOpc(unsigned AM2Opc) {
+ return (ShiftOpc)((AM2Opc >> 13) & 7);
+ }
+ static inline unsigned getAM2IdxMode(unsigned AM2Opc) {
+ return (AM2Opc >> 16);
+ }
+
+
+ //===--------------------------------------------------------------------===//
+ // Addressing Mode #3
+ //===--------------------------------------------------------------------===//
+ //
+ // This is used for sign-extending loads, and load/store-pair instructions.
+ //
+ // addrmode3 := reg +/- reg
+ // addrmode3 := reg +/- imm8
+ //
+ // 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. The fourth operand 9-10 encodes the
+ // index mode.
+
+ /// getAM3Opc - This function encodes the addrmode3 opc field.
+ static inline unsigned getAM3Opc(AddrOpc Opc, unsigned char Offset,
+ unsigned IdxMode = 0) {
+ bool isSub = Opc == sub;
+ return ((int)isSub << 8) | Offset | (IdxMode << 9);
+ }
+ static inline unsigned char getAM3Offset(unsigned AM3Opc) {
+ return AM3Opc & 0xFF;
+ }
+ static inline AddrOpc getAM3Op(unsigned AM3Opc) {
+ return ((AM3Opc >> 8) & 1) ? sub : add;
+ }
+ static inline unsigned getAM3IdxMode(unsigned AM3Opc) {
+ return (AM3Opc >> 9);
+ }
+
+ //===--------------------------------------------------------------------===//
+ // Addressing Mode #4
+ //===--------------------------------------------------------------------===//
+ //
+ // This is used for load / store multiple instructions.
+ //
+ // addrmode4 := reg, <mode>
+ //
+ // The four modes are:
+ // IA - Increment after
+ // IB - Increment before
+ // DA - Decrement after
+ // DB - Decrement before
+ // For VFP instructions, only the IA and DB modes are valid.
+
+ static inline AMSubMode getAM4SubMode(unsigned Mode) {
+ return (AMSubMode)(Mode & 0x7);
+ }
+
+ static inline unsigned getAM4ModeImm(AMSubMode SubMode) {
+ return (int)SubMode;
+ }
+
+ //===--------------------------------------------------------------------===//
+ // Addressing Mode #5
+ //===--------------------------------------------------------------------===//
+ //
+ // This is used for coprocessor instructions, such as FP load/stores.
+ //
+ // addrmode5 := reg +/- imm8*4
+ //
+ // The first operand is always a Reg. The second operand encodes the
+ // operation in bit 8 and the immediate in bits 0-7.
+
+ /// getAM5Opc - This function encodes the addrmode5 opc field.
+ static inline unsigned getAM5Opc(AddrOpc Opc, unsigned char Offset) {
+ bool isSub = Opc == sub;
+ return ((int)isSub << 8) | Offset;
+ }
+ static inline unsigned char getAM5Offset(unsigned AM5Opc) {
+ return AM5Opc & 0xFF;
+ }
+ static inline AddrOpc getAM5Op(unsigned AM5Opc) {
+ return ((AM5Opc >> 8) & 1) ? sub : add;
+ }
+
+ //===--------------------------------------------------------------------===//
+ // 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 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;
+ }
+
+ AMSubMode getLoadStoreMultipleSubMode(int Opcode);
+
+ //===--------------------------------------------------------------------===//
+ // Floating-point Immediates
+ //
+ static inline float getFPImmFloat(unsigned Imm) {
+ // We expect an 8-bit binary encoding of a floating-point number here.
+ union {
+ uint32_t I;
+ float F;
+ } FPUnion;
+
+ uint8_t Sign = (Imm >> 7) & 0x1;
+ uint8_t Exp = (Imm >> 4) & 0x7;
+ uint8_t Mantissa = Imm & 0xf;
+
+ // 8-bit FP iEEEE Float Encoding
+ // abcd efgh aBbbbbbc defgh000 00000000 00000000
+ //
+ // where B = NOT(b);
+
+ FPUnion.I = 0;
+ FPUnion.I |= Sign << 31;
+ FPUnion.I |= ((Exp & 0x4) != 0 ? 0 : 1) << 30;
+ FPUnion.I |= ((Exp & 0x4) != 0 ? 0x1f : 0) << 25;
+ FPUnion.I |= (Exp & 0x3) << 23;
+ FPUnion.I |= Mantissa << 19;
+ return FPUnion.F;
+ }
+
+ /// getFP32Imm - Return an 8-bit floating-point version of the 32-bit
+ /// floating-point value. If the value cannot be represented as an 8-bit
+ /// floating-point value, then return -1.
+ static inline int getFP32Imm(const APInt &Imm) {
+ uint32_t Sign = Imm.lshr(31).getZExtValue() & 1;
+ int32_t Exp = (Imm.lshr(23).getSExtValue() & 0xff) - 127; // -126 to 127
+ int64_t Mantissa = Imm.getZExtValue() & 0x7fffff; // 23 bits
+
+ // We can handle 4 bits of mantissa.
+ // mantissa = (16+UInt(e:f:g:h))/16.
+ if (Mantissa & 0x7ffff)
+ return -1;
+ Mantissa >>= 19;
+ if ((Mantissa & 0xf) != Mantissa)
+ return -1;
+
+ // We can handle 3 bits of exponent: exp == UInt(NOT(b):c:d)-3
+ if (Exp < -3 || Exp > 4)
+ return -1;
+ Exp = ((Exp+3) & 0x7) ^ 4;
+
+ return ((int)Sign << 7) | (Exp << 4) | Mantissa;
+ }
+
+ static inline int getFP32Imm(const APFloat &FPImm) {
+ return getFP32Imm(FPImm.bitcastToAPInt());
+ }
+
+ /// getFP64Imm - Return an 8-bit floating-point version of the 64-bit
+ /// floating-point value. If the value cannot be represented as an 8-bit
+ /// floating-point value, then return -1.
+ static inline int getFP64Imm(const APInt &Imm) {
+ uint64_t Sign = Imm.lshr(63).getZExtValue() & 1;
+ int64_t Exp = (Imm.lshr(52).getSExtValue() & 0x7ff) - 1023; // -1022 to 1023
+ uint64_t Mantissa = Imm.getZExtValue() & 0xfffffffffffffULL;
+
+ // We can handle 4 bits of mantissa.
+ // mantissa = (16+UInt(e:f:g:h))/16.
+ if (Mantissa & 0xffffffffffffULL)
+ return -1;
+ Mantissa >>= 48;
+ if ((Mantissa & 0xf) != Mantissa)
+ return -1;
+
+ // We can handle 3 bits of exponent: exp == UInt(NOT(b):c:d)-3
+ if (Exp < -3 || Exp > 4)
+ return -1;
+ Exp = ((Exp+3) & 0x7) ^ 4;
+
+ return ((int)Sign << 7) | (Exp << 4) | Mantissa;
+ }
+
+ static inline int getFP64Imm(const APFloat &FPImm) {
+ return getFP64Imm(FPImm.bitcastToAPInt());
+ }
+
+} // end namespace ARM_AM
+} // end namespace llvm
+
+#endif
+
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