hotspot/src/cpu/aarch64/vm/decode_aarch64.hpp
changeset 29183 0cc8699f7372
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/cpu/aarch64/vm/decode_aarch64.hpp	Tue Jan 20 11:34:17 2015 -0800
@@ -0,0 +1,412 @@
+/*
+ * Copyright (c) 2014, Red Hat Inc. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef _DECODE_H
+#define _DECODE_H
+
+#include <sys/types.h>
+#include "cpustate_aarch64.hpp"
+
+// bitfield immediate expansion helper
+
+extern int expandLogicalImmediate(u_int32_t immN, u_int32_t immr,
+                                    u_int32_t imms, u_int64_t &bimm);
+
+
+/*
+ * codes used in conditional instructions
+ *
+ * these are passed to conditional operations to identify which
+ * condition to test for
+ */
+enum CondCode {
+  EQ = 0b0000, // meaning Z == 1
+  NE = 0b0001, // meaning Z == 0
+  HS = 0b0010, // meaning C == 1
+  CS = HS,
+  LO = 0b0011, // meaning C == 0
+  CC = LO,
+  MI = 0b0100, // meaning N == 1
+  PL = 0b0101, // meaning N == 0
+  VS = 0b0110, // meaning V == 1
+  VC = 0b0111, // meaning V == 0
+  HI = 0b1000, // meaning C == 1 && Z == 0
+  LS = 0b1001, // meaning !(C == 1 && Z == 0)
+  GE = 0b1010, // meaning N == V
+  LT = 0b1011, // meaning N != V
+  GT = 0b1100, // meaning Z == 0 && N == V
+  LE = 0b1101, // meaning !(Z == 0 && N == V)
+  AL = 0b1110, // meaning ANY
+  NV = 0b1111  // ditto
+};
+
+/*
+ * certain addressing modes for load require pre or post writeback of
+ * the computed address to a base register
+ */
+enum WriteBack {
+  Post = 0,
+  Pre = 1
+};
+
+/*
+ * certain addressing modes for load require an offset to
+ * be optionally scaled so the decode needs to pass that
+ * through to the execute routine
+ */
+enum Scaling {
+  Unscaled = 0,
+  Scaled = 1
+};
+
+/*
+ * when we do have to scale we do so by shifting using
+ * log(bytes in data element - 1) as the shift count.
+ * so we don't have to scale offsets when loading
+ * bytes.
+ */
+enum ScaleShift {
+  ScaleShift16 = 1,
+  ScaleShift32 = 2,
+  ScaleShift64 = 3,
+  ScaleShift128 = 4
+};
+
+/*
+ * one of the addressing modes for load requires a 32-bit register
+ * value to be either zero- or sign-extended for these instructions
+ * UXTW or SXTW should be passed
+ *
+ * arithmetic register data processing operations can optionally
+ * extend a portion of the second register value for these
+ * instructions the value supplied must identify the portion of the
+ * register which is to be zero- or sign-exended
+ */
+enum Extension {
+  UXTB = 0,
+  UXTH = 1,
+  UXTW = 2,
+  UXTX = 3,
+  SXTB = 4,
+  SXTH = 5,
+  SXTW = 6,
+  SXTX = 7
+};
+
+/*
+ * arithmetic and logical register data processing operations
+ * optionally perform a shift on the second register value
+ */
+enum Shift {
+  LSL = 0,
+  LSR = 1,
+  ASR = 2,
+  ROR = 3
+};
+
+/*
+ * bit twiddling helpers for instruction decode
+ */
+
+// 32 bit mask with bits [hi,...,lo] set
+
+static inline u_int32_t mask32(int hi = 31, int lo = 0)
+{
+  int nbits = (hi + 1) - lo;
+  return ((1 << nbits) - 1) << lo;
+}
+
+static inline u_int64_t mask64(int hi = 63, int lo = 0)
+{
+  int nbits = (hi + 1) - lo;
+  return ((1L << nbits) - 1) << lo;
+}
+
+// pick bits [hi,...,lo] from val
+static inline u_int32_t pick32(u_int32_t val, int hi = 31, int lo = 0)
+{
+  return (val & mask32(hi, lo));
+}
+
+// pick bits [hi,...,lo] from val
+static inline u_int64_t pick64(u_int64_t val, int hi = 31, int lo = 0)
+{
+  return (val & mask64(hi, lo));
+}
+
+// pick bits [hi,...,lo] from val and shift to [(hi-(newlo - lo)),newlo]
+static inline u_int32_t pickshift32(u_int32_t val, int hi = 31,
+                                    int lo = 0, int newlo = 0)
+{
+  u_int32_t bits = pick32(val, hi, lo);
+  if (lo < newlo) {
+    return (bits << (newlo - lo));
+  } else {
+    return (bits >> (lo - newlo));
+  }
+}
+// mask [hi,lo] and shift down to start at bit 0
+static inline u_int32_t pickbits32(u_int32_t val, int hi = 31, int lo = 0)
+{
+  return (pick32(val, hi, lo) >> lo);
+}
+
+// mask [hi,lo] and shift down to start at bit 0
+static inline u_int64_t pickbits64(u_int64_t val, int hi = 63, int lo = 0)
+{
+  return (pick64(val, hi, lo) >> lo);
+}
+
+/*
+ * decode registers, immediates and constants of various types
+ */
+
+static inline GReg greg(u_int32_t val, int lo)
+{
+  return (GReg)pickbits32(val, lo + 4, lo);
+}
+
+static inline VReg vreg(u_int32_t val, int lo)
+{
+  return (VReg)pickbits32(val, lo + 4, lo);
+}
+
+static inline u_int32_t uimm(u_int32_t val, int hi, int lo)
+{
+  return pickbits32(val, hi, lo);
+}
+
+static inline int32_t simm(u_int32_t val, int hi = 31, int lo = 0) {
+  union {
+    u_int32_t u;
+    int32_t n;
+  };
+
+  u = val << (31 - hi);
+  n = n >> (31 - hi + lo);
+  return n;
+}
+
+static inline int64_t simm(u_int64_t val, int hi = 63, int lo = 0) {
+  union {
+    u_int64_t u;
+    int64_t n;
+  };
+
+  u = val << (63 - hi);
+  n = n >> (63 - hi + lo);
+  return n;
+}
+
+static inline Shift shift(u_int32_t val, int lo)
+{
+  return (Shift)pickbits32(val, lo+1, lo);
+}
+
+static inline Extension extension(u_int32_t val, int lo)
+{
+  return (Extension)pickbits32(val, lo+2, lo);
+}
+
+static inline Scaling scaling(u_int32_t val, int lo)
+{
+  return (Scaling)pickbits32(val, lo, lo);
+}
+
+static inline WriteBack writeback(u_int32_t val, int lo)
+{
+  return (WriteBack)pickbits32(val, lo, lo);
+}
+
+static inline CondCode condcode(u_int32_t val, int lo)
+{
+  return (CondCode)pickbits32(val, lo+3, lo);
+}
+
+/*
+ * operation decode
+ */
+// bits [28,25] are the primary dispatch vector
+
+static inline u_int32_t dispatchGroup(u_int32_t val)
+{
+  return pickshift32(val, 28, 25, 0);
+}
+
+/*
+ * the 16 possible values for bits [28,25] identified by tags which
+ * map them to the 5 main instruction groups LDST, DPREG, ADVSIMD,
+ * BREXSYS and DPIMM.
+ *
+ * An extra group PSEUDO is included in one of the unallocated ranges
+ * for simulator-specific pseudo-instructions.
+ */
+enum DispatchGroup {
+  GROUP_PSEUDO_0000,
+  GROUP_UNALLOC_0001,
+  GROUP_UNALLOC_0010,
+  GROUP_UNALLOC_0011,
+  GROUP_LDST_0100,
+  GROUP_DPREG_0101,
+  GROUP_LDST_0110,
+  GROUP_ADVSIMD_0111,
+  GROUP_DPIMM_1000,
+  GROUP_DPIMM_1001,
+  GROUP_BREXSYS_1010,
+  GROUP_BREXSYS_1011,
+  GROUP_LDST_1100,
+  GROUP_DPREG_1101,
+  GROUP_LDST_1110,
+  GROUP_ADVSIMD_1111
+};
+
+// bits [31, 29] of a Pseudo are the secondary dispatch vector
+
+static inline u_int32_t dispatchPseudo(u_int32_t val)
+{
+  return pickshift32(val, 31, 29, 0);
+}
+
+/*
+ * the 8 possible values for bits [31,29] in a Pseudo Instruction.
+ * Bits [28,25] are always 0000.
+ */
+
+enum DispatchPseudo {
+  PSEUDO_UNALLOC_000, // unallocated
+  PSEUDO_UNALLOC_001, // ditto
+  PSEUDO_UNALLOC_010, // ditto
+  PSEUDO_UNALLOC_011, // ditto
+  PSEUDO_UNALLOC_100, // ditto
+  PSEUDO_UNALLOC_101, // ditto
+  PSEUDO_CALLOUT_110, // CALLOUT -- bits [24,0] identify call/ret sig
+  PSEUDO_HALT_111     // HALT -- bits [24, 0] identify halt code
+};
+
+// bits [25, 23] of a DPImm are the secondary dispatch vector
+
+static inline u_int32_t dispatchDPImm(u_int32_t instr)
+{
+  return pickshift32(instr, 25, 23, 0);
+}
+
+/*
+ * the 8 possible values for bits [25,23] in a Data Processing Immediate
+ * Instruction. Bits [28,25] are always 100_.
+ */
+
+enum DispatchDPImm {
+  DPIMM_PCADR_000,  // PC-rel-addressing
+  DPIMM_PCADR_001,  // ditto
+  DPIMM_ADDSUB_010,  // Add/Subtract (immediate)
+  DPIMM_ADDSUB_011, // ditto
+  DPIMM_LOG_100,    // Logical (immediate)
+  DPIMM_MOV_101,    // Move Wide (immediate)
+  DPIMM_BITF_110,   // Bitfield
+  DPIMM_EXTR_111    // Extract
+};
+
+// bits [29,28:26] of a LS are the secondary dispatch vector
+
+static inline u_int32_t dispatchLS(u_int32_t instr)
+{
+  return (pickshift32(instr, 29, 28, 1) |
+          pickshift32(instr, 26, 26, 0));
+}
+
+/*
+ * the 8 possible values for bits [29,28:26] in a Load/Store
+ * Instruction. Bits [28,25] are always _1_0
+ */
+
+enum DispatchLS {
+  LS_EXCL_000,    // Load/store exclusive (includes some unallocated)
+  LS_ADVSIMD_001, // AdvSIMD load/store (various -- includes some unallocated)
+  LS_LIT_010,     // Load register literal (includes some unallocated)
+  LS_LIT_011,     // ditto
+  LS_PAIR_100,    // Load/store register pair (various)
+  LS_PAIR_101,    // ditto
+  LS_OTHER_110,   // other load/store formats
+  LS_OTHER_111    // ditto
+};
+
+// bits [28:24:21] of a DPReg are the secondary dispatch vector
+
+static inline u_int32_t dispatchDPReg(u_int32_t instr)
+{
+  return (pickshift32(instr, 28, 28, 2) |
+          pickshift32(instr, 24, 24, 1) |
+          pickshift32(instr, 21, 21, 0));
+}
+
+/*
+ * the 8 possible values for bits [28:24:21] in a Data Processing
+ * Register Instruction. Bits [28,25] are always _101
+ */
+
+enum DispatchDPReg {
+  DPREG_LOG_000,     // Logical (shifted register)
+  DPREG_LOG_001,     // ditto
+  DPREG_ADDSHF_010,  // Add/subtract (shifted register)
+  DPREG_ADDEXT_011,  // Add/subtract (extended register)
+  DPREG_ADDCOND_100, // Add/subtract (with carry) AND
+                     // Cond compare/select AND
+                     // Data Processing (1/2 source)
+  DPREG_UNALLOC_101, // Unallocated
+  DPREG_3SRC_110, // Data Processing (3 source)
+  DPREG_3SRC_111  // Data Processing (3 source)
+};
+
+// bits [31,29] of a BrExSys are the secondary dispatch vector
+
+static inline u_int32_t dispatchBrExSys(u_int32_t instr)
+{
+  return pickbits32(instr, 31, 29);
+}
+
+/*
+ * the 8 possible values for bits [31,29] in a Branch/Exception/System
+ * Instruction. Bits [28,25] are always 101_
+ */
+
+enum DispatchBr {
+  BR_IMM_000,     // Unconditional branch (immediate)
+  BR_IMMCMP_001,  // Compare & branch (immediate) AND
+                  // Test & branch (immediate)
+  BR_IMMCOND_010, // Conditional branch (immediate) AND Unallocated
+  BR_UNALLOC_011, // Unallocated
+  BR_IMM_100,     // Unconditional branch (immediate)
+  BR_IMMCMP_101,  // Compare & branch (immediate) AND
+                  // Test & branch (immediate)
+  BR_REG_110,     // Unconditional branch (register) AND System AND
+                  // Excn gen AND Unallocated
+  BR_UNALLOC_111  // Unallocated
+};
+
+/*
+ * TODO still need to provide secondary decode and dispatch for
+ * AdvSIMD Insructions with instr[28,25] = 0111 or 1111
+ */
+
+#endif // ifndef DECODE_H