ARM backend contribution from Apple.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@33353 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMAddressingModes.h b/lib/Target/ARM/ARMAddressingModes.h
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+//===- ARMAddressingModes.h - ARM Addressing Modes --------------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file was developed by Chris Lattner and 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/CodeGen/SelectionDAGNodes.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 {
+ add = '+', 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 ShiftOpc getShiftOpcForNode(SDOperand N) {
+ switch (N.getOpcode()) {
+ default: return ARM_AM::no_shift;
+ case ISD::SHL: return ARM_AM::lsl;
+ case ISD::SRL: return ARM_AM::lsr;
+ case ISD::SRA: return ARM_AM::asr;
+ case ISD::ROTR: return ARM_AM::ror;
+ //case ISD::ROTL: // Only if imm -> turn into ROTR.
+ // Can't handle RRX here, because it would require folding a flag into
+ // the addressing mode. :( This causes us to miss certain things.
+ //case ARMISD::RRX: return ARM_AM::rrx;
+ }
+ }
+
+ 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";
+ }
+ }
+
+ 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
+ //===--------------------------------------------------------------------===//
+ //
+ // 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;
+ }
+ /// getSOImmValRotate - 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 skip the first run of ones, 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.
+ }
+ }
+
+ // 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;
+ }
+
+ /// getThumbImmNonShiftedVal - If V is a value that satisfies
+ /// isThumbImmShiftedVal, return the non-shiftd value.
+ static inline unsigned getThumbImmNonShiftedVal(unsigned V) {
+ return V >> getThumbImmValShift(V);
+ }
+
+ //===--------------------------------------------------------------------===//
+ // 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.
+ //
+ // 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;
+ return Imm12 | ((int)isSub << 12) | (SO << 13);
+ }
+ 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);
+ }
+
+
+ //===--------------------------------------------------------------------===//
+ // 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.
+
+ /// getAM3Opc - This function encodes the addrmode3 opc field.
+ static inline unsigned getAM3Opc(AddrOpc Opc, unsigned char Offset) {
+ bool isSub = Opc == sub;
+ return ((int)isSub << 8) | Offset;
+ }
+ static inline unsigned char getAM3Offset(unsigned AM3Opc) {
+ return AM3Opc & 0xFF;
+ }
+ static inline AddrOpc getAM3Op(unsigned AM3Opc) {
+ return ((AM3Opc >> 8) & 1) ? sub : add;
+ }
+
+ //===--------------------------------------------------------------------===//
+ // 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
+ //
+ // 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;
+ }
+
+ //===--------------------------------------------------------------------===//
+ // 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 third field encodes the operation
+ // in bit 8, 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
+ // 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 ((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;
+ }
+
+ /// getAM5Opc - This function encodes the addrmode5 opc field for FLDM and
+ /// FSTM instructions.
+ static inline unsigned getAM5Opc(AMSubMode SubMode, bool WB,
+ unsigned char Offset) {
+ assert((SubMode == ia || SubMode == db) &&
+ "Illegal addressing mode 5 sub-mode!");
+ return ((int)SubMode << 9) | ((int)WB << 8) | Offset;
+ }
+ static inline AMSubMode getAM5SubMode(unsigned AM5Opc) {
+ return (AMSubMode)((AM5Opc >> 9) & 0x7);
+ }
+ static inline bool getAM5WBFlag(unsigned AM5Opc) {
+ return ((AM5Opc >> 8) & 1);
+ }
+
+} // end namespace ARM_AM
+} // end namespace llvm
+
+#endif
+