sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 1 | |
| 2 | /*---------------------------------------------------------------*/ |
sewardj | 752f906 | 2010-05-03 21:38:49 +0000 | [diff] [blame] | 3 | /*--- begin host_reg_alloc2.c ---*/ |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 4 | /*---------------------------------------------------------------*/ |
| 5 | |
sewardj | f8ed9d8 | 2004-11-12 17:40:23 +0000 | [diff] [blame] | 6 | /* |
sewardj | 752f906 | 2010-05-03 21:38:49 +0000 | [diff] [blame] | 7 | This file is part of Valgrind, a dynamic binary instrumentation |
| 8 | framework. |
sewardj | f8ed9d8 | 2004-11-12 17:40:23 +0000 | [diff] [blame] | 9 | |
sewardj | 89ae847 | 2013-10-18 14:12:58 +0000 | [diff] [blame] | 10 | Copyright (C) 2004-2013 OpenWorks LLP |
sewardj | 752f906 | 2010-05-03 21:38:49 +0000 | [diff] [blame] | 11 | info@open-works.net |
sewardj | f8ed9d8 | 2004-11-12 17:40:23 +0000 | [diff] [blame] | 12 | |
sewardj | 752f906 | 2010-05-03 21:38:49 +0000 | [diff] [blame] | 13 | This program is free software; you can redistribute it and/or |
| 14 | modify it under the terms of the GNU General Public License as |
| 15 | published by the Free Software Foundation; either version 2 of the |
| 16 | License, or (at your option) any later version. |
sewardj | f8ed9d8 | 2004-11-12 17:40:23 +0000 | [diff] [blame] | 17 | |
sewardj | 752f906 | 2010-05-03 21:38:49 +0000 | [diff] [blame] | 18 | This program is distributed in the hope that it will be useful, but |
| 19 | WITHOUT ANY WARRANTY; without even the implied warranty of |
| 20 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 21 | General Public License for more details. |
| 22 | |
| 23 | You should have received a copy of the GNU General Public License |
| 24 | along with this program; if not, write to the Free Software |
| 25 | Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
sewardj | 7bd6ffe | 2005-08-03 16:07:36 +0000 | [diff] [blame] | 26 | 02110-1301, USA. |
| 27 | |
sewardj | 752f906 | 2010-05-03 21:38:49 +0000 | [diff] [blame] | 28 | The GNU General Public License is contained in the file COPYING. |
sewardj | f8ed9d8 | 2004-11-12 17:40:23 +0000 | [diff] [blame] | 29 | |
| 30 | Neither the names of the U.S. Department of Energy nor the |
| 31 | University of California nor the names of its contributors may be |
| 32 | used to endorse or promote products derived from this software |
| 33 | without prior written permission. |
sewardj | f8ed9d8 | 2004-11-12 17:40:23 +0000 | [diff] [blame] | 34 | */ |
| 35 | |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 36 | #include "libvex_basictypes.h" |
| 37 | #include "libvex.h" |
| 38 | |
sewardj | cef7d3e | 2009-07-02 12:21:59 +0000 | [diff] [blame] | 39 | #include "main_util.h" |
| 40 | #include "host_generic_regs.h" |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 41 | |
| 42 | /* Set to 1 for lots of debugging output. */ |
| 43 | #define DEBUG_REGALLOC 0 |
| 44 | |
| 45 | |
| 46 | /* TODO 27 Oct 04: |
| 47 | |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 48 | Better consistency checking from what isMove tells us. |
| 49 | |
| 50 | We can possibly do V-V coalescing even when the src is spilled, |
| 51 | providing we can arrange for the dst to have the same spill slot. |
| 52 | |
| 53 | Note that state[].hreg is the same as the available real regs. |
| 54 | |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 55 | Generally rationalise data structures. */ |
| 56 | |
| 57 | |
| 58 | /* Records information on virtual register live ranges. Computed once |
| 59 | and remains unchanged after that. */ |
| 60 | typedef |
| 61 | struct { |
| 62 | /* Becomes live for the first time after this insn ... */ |
| 63 | Short live_after; |
| 64 | /* Becomes dead for the last time before this insn ... */ |
| 65 | Short dead_before; |
| 66 | /* The "home" spill slot, if needed. Never changes. */ |
| 67 | Short spill_offset; |
| 68 | Short spill_size; |
| 69 | /* What kind of register this is. */ |
| 70 | HRegClass reg_class; |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 71 | } |
sewardj | ad572dd | 2004-12-30 01:44:51 +0000 | [diff] [blame] | 72 | VRegLR; |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 73 | |
| 74 | |
| 75 | /* Records information on real-register live ranges. Computed once |
| 76 | and remains unchanged after that. */ |
| 77 | typedef |
| 78 | struct { |
| 79 | HReg rreg; |
| 80 | /* Becomes live after this insn ... */ |
| 81 | Short live_after; |
| 82 | /* Becomes dead before this insn ... */ |
| 83 | Short dead_before; |
| 84 | } |
sewardj | ad572dd | 2004-12-30 01:44:51 +0000 | [diff] [blame] | 85 | RRegLR; |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 86 | |
| 87 | |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 88 | /* An array of the following structs (rreg_state) comprises the |
| 89 | running state of the allocator. It indicates what the current |
| 90 | disposition of each allocatable real register is. The array gets |
| 91 | updated as the allocator processes instructions. */ |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 92 | typedef |
| 93 | struct { |
sewardj | 607ca2d | 2007-08-25 21:11:33 +0000 | [diff] [blame] | 94 | /* ------ FIELDS WHICH DO NOT CHANGE ------ */ |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 95 | /* Which rreg is this for? */ |
| 96 | HReg rreg; |
| 97 | /* Is this involved in any HLRs? (only an optimisation hint) */ |
| 98 | Bool has_hlrs; |
sewardj | 607ca2d | 2007-08-25 21:11:33 +0000 | [diff] [blame] | 99 | /* ------ FIELDS WHICH DO CHANGE ------ */ |
| 100 | /* 6 May 07: rearranged fields below so the whole struct fits |
| 101 | into 16 bytes on both x86 and amd64. */ |
| 102 | /* Used when .disp == Bound and we are looking for vregs to |
| 103 | spill. */ |
| 104 | Bool is_spill_cand; |
| 105 | /* Optimisation: used when .disp == Bound. Indicates when the |
| 106 | rreg has the same value as the spill slot for the associated |
| 107 | vreg. Is safely left at False, and becomes True after a |
| 108 | spill store or reload for this rreg. */ |
| 109 | Bool eq_spill_slot; |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 110 | /* What's it's current disposition? */ |
| 111 | enum { Free, /* available for use */ |
| 112 | Unavail, /* in a real-reg live range */ |
| 113 | Bound /* in use (holding value of some vreg) */ |
| 114 | } |
| 115 | disp; |
sewardj | 607ca2d | 2007-08-25 21:11:33 +0000 | [diff] [blame] | 116 | /* If .disp == Bound, what vreg is it bound to? */ |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 117 | HReg vreg; |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 118 | } |
| 119 | RRegState; |
| 120 | |
sewardj | c3bc60a | 2006-12-01 02:59:17 +0000 | [diff] [blame] | 121 | |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 122 | /* The allocator also maintains a redundant array of indexes |
| 123 | (vreg_state) from vreg numbers back to entries in rreg_state. It |
| 124 | is redundant because iff vreg_state[i] == j then |
| 125 | hregNumber(rreg_state[j].vreg) == i -- that is, the two entries |
| 126 | point at each other. The purpose of this is to speed up activities |
| 127 | which involve looking for a particular vreg: there is no need to |
| 128 | scan the rreg_state looking for it, just index directly into |
| 129 | vreg_state. The FAQ "does this vreg already have an associated |
| 130 | rreg" is the main beneficiary. |
| 131 | |
| 132 | To indicate, in vreg_state[i], that a given vreg is not currently |
| 133 | associated with any rreg, that entry can be set to INVALID_RREG_NO. |
| 134 | |
| 135 | Because the vreg_state entries are signed Shorts, the max number |
| 136 | of vregs that can be handed by regalloc is 32767. |
| 137 | */ |
| 138 | |
| 139 | #define INVALID_RREG_NO ((Short)(-1)) |
| 140 | |
| 141 | #define IS_VALID_VREGNO(_zz) ((_zz) >= 0 && (_zz) < n_vregs) |
| 142 | #define IS_VALID_RREGNO(_zz) ((_zz) >= 0 && (_zz) < n_rregs) |
| 143 | |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 144 | |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 145 | /* Does this instruction mention a particular reg? */ |
| 146 | static Bool instrMentionsReg ( |
florian | d8c64e0 | 2014-10-08 08:54:44 +0000 | [diff] [blame] | 147 | void (*getRegUsage) (HRegUsage*, const HInstr*, Bool), |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 148 | HInstr* instr, |
cerion | 92b6436 | 2005-12-13 12:02:26 +0000 | [diff] [blame] | 149 | HReg r, |
| 150 | Bool mode64 |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 151 | ) |
| 152 | { |
| 153 | Int i; |
| 154 | HRegUsage reg_usage; |
cerion | 92b6436 | 2005-12-13 12:02:26 +0000 | [diff] [blame] | 155 | (*getRegUsage)(®_usage, instr, mode64); |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 156 | for (i = 0; i < reg_usage.n_used; i++) |
florian | 79efdc6 | 2013-02-11 00:47:35 +0000 | [diff] [blame] | 157 | if (sameHReg(reg_usage.hreg[i], r)) |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 158 | return True; |
| 159 | return False; |
| 160 | } |
| 161 | |
| 162 | |
| 163 | /* Search forward from some given point in the incoming instruction |
| 164 | sequence. Point is to select a virtual register to spill, by |
| 165 | finding the vreg which is mentioned as far ahead as possible, in |
| 166 | the hope that this will minimise the number of consequent reloads. |
| 167 | |
| 168 | Only do the search for vregs which are Bound in the running state, |
| 169 | and for which the .is_spill_cand field is set. This allows the |
| 170 | caller to arbitrarily restrict the set of spill candidates to be |
| 171 | considered. |
| 172 | |
| 173 | Returns an index into the state array indicating the (v,r) pair to |
| 174 | spill, or -1 if none was found. */ |
| 175 | static |
| 176 | Int findMostDistantlyMentionedVReg ( |
florian | d8c64e0 | 2014-10-08 08:54:44 +0000 | [diff] [blame] | 177 | void (*getRegUsage) (HRegUsage*, const HInstr*, Bool), |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 178 | HInstrArray* instrs_in, |
| 179 | Int search_from_instr, |
| 180 | RRegState* state, |
cerion | 92b6436 | 2005-12-13 12:02:26 +0000 | [diff] [blame] | 181 | Int n_state, |
| 182 | Bool mode64 |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 183 | ) |
| 184 | { |
| 185 | Int k, m; |
| 186 | Int furthest_k = -1; |
| 187 | Int furthest = -1; |
| 188 | vassert(search_from_instr >= 0); |
| 189 | for (k = 0; k < n_state; k++) { |
| 190 | if (!state[k].is_spill_cand) |
| 191 | continue; |
| 192 | vassert(state[k].disp == Bound); |
| 193 | for (m = search_from_instr; m < instrs_in->arr_used; m++) { |
| 194 | if (instrMentionsReg(getRegUsage, |
cerion | 92b6436 | 2005-12-13 12:02:26 +0000 | [diff] [blame] | 195 | instrs_in->arr[m], state[k].vreg, mode64)) |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 196 | break; |
| 197 | } |
| 198 | if (m > furthest) { |
| 199 | furthest = m; |
| 200 | furthest_k = k; |
| 201 | } |
| 202 | } |
| 203 | return furthest_k; |
| 204 | } |
| 205 | |
| 206 | |
sewardj | 478646f | 2008-05-01 20:13:04 +0000 | [diff] [blame] | 207 | /* Check that this vreg has been assigned a sane spill offset. */ |
| 208 | static inline void sanity_check_spill_offset ( VRegLR* vreg ) |
| 209 | { |
sewardj | c4530ae | 2012-05-21 10:18:49 +0000 | [diff] [blame] | 210 | switch (vreg->reg_class) { |
sewardj | c4530ae | 2012-05-21 10:18:49 +0000 | [diff] [blame] | 211 | case HRcVec128: case HRcFlt64: |
| 212 | vassert(0 == ((UShort)vreg->spill_offset % 16)); break; |
| 213 | default: |
| 214 | vassert(0 == ((UShort)vreg->spill_offset % 8)); break; |
sewardj | 478646f | 2008-05-01 20:13:04 +0000 | [diff] [blame] | 215 | } |
| 216 | } |
| 217 | |
| 218 | |
sewardj | ad572dd | 2004-12-30 01:44:51 +0000 | [diff] [blame] | 219 | /* Double the size of the real-reg live-range array, if needed. */ |
| 220 | static void ensureRRLRspace ( RRegLR** info, Int* size, Int used ) |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 221 | { |
sewardj | ad572dd | 2004-12-30 01:44:51 +0000 | [diff] [blame] | 222 | Int k; |
| 223 | RRegLR* arr2; |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 224 | if (used < *size) return; |
| 225 | if (0) |
| 226 | vex_printf("ensureRRISpace: %d -> %d\n", *size, 2 * *size); |
| 227 | vassert(used == *size); |
sewardj | ad572dd | 2004-12-30 01:44:51 +0000 | [diff] [blame] | 228 | arr2 = LibVEX_Alloc(2 * *size * sizeof(RRegLR)); |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 229 | for (k = 0; k < *size; k++) |
| 230 | arr2[k] = (*info)[k]; |
| 231 | *size *= 2; |
| 232 | *info = arr2; |
| 233 | } |
| 234 | |
| 235 | |
sewardj | c3bc60a | 2006-12-01 02:59:17 +0000 | [diff] [blame] | 236 | /* Sort an array of RRegLR entries by either the .live_after or |
| 237 | .dead_before fields. This is performance-critical. */ |
| 238 | static void sortRRLRarray ( RRegLR* arr, |
| 239 | Int size, Bool by_live_after ) |
| 240 | { |
| 241 | Int incs[14] = { 1, 4, 13, 40, 121, 364, 1093, 3280, |
| 242 | 9841, 29524, 88573, 265720, |
| 243 | 797161, 2391484 }; |
| 244 | Int lo = 0; |
| 245 | Int hi = size-1; |
| 246 | Int i, j, h, bigN, hp; |
| 247 | RRegLR v; |
| 248 | |
| 249 | vassert(size >= 0); |
| 250 | if (size == 0) |
| 251 | return; |
| 252 | |
| 253 | bigN = hi - lo + 1; if (bigN < 2) return; |
| 254 | hp = 0; while (hp < 14 && incs[hp] < bigN) hp++; hp--; |
| 255 | |
| 256 | if (by_live_after) { |
| 257 | |
| 258 | for ( ; hp >= 0; hp--) { |
| 259 | h = incs[hp]; |
| 260 | for (i = lo + h; i <= hi; i++) { |
| 261 | v = arr[i]; |
| 262 | j = i; |
| 263 | while (arr[j-h].live_after > v.live_after) { |
| 264 | arr[j] = arr[j-h]; |
| 265 | j = j - h; |
| 266 | if (j <= (lo + h - 1)) break; |
| 267 | } |
| 268 | arr[j] = v; |
| 269 | } |
| 270 | } |
| 271 | |
| 272 | } else { |
| 273 | |
| 274 | for ( ; hp >= 0; hp--) { |
| 275 | h = incs[hp]; |
| 276 | for (i = lo + h; i <= hi; i++) { |
| 277 | v = arr[i]; |
| 278 | j = i; |
| 279 | while (arr[j-h].dead_before > v.dead_before) { |
| 280 | arr[j] = arr[j-h]; |
| 281 | j = j - h; |
| 282 | if (j <= (lo + h - 1)) break; |
| 283 | } |
| 284 | arr[j] = v; |
| 285 | } |
| 286 | } |
| 287 | |
| 288 | } |
| 289 | } |
| 290 | |
| 291 | |
sewardj | 17bbc21 | 2004-12-30 00:14:54 +0000 | [diff] [blame] | 292 | /* A target-independent register allocator. Requires various |
| 293 | functions which it uses to deal abstractly with instructions and |
| 294 | registers, since it cannot have any target-specific knowledge. |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 295 | |
| 296 | Returns a new list of instructions, which, as a result of the |
| 297 | behaviour of mapRegs, will be in-place modifications of the |
| 298 | original instructions. |
| 299 | |
| 300 | Requires that the incoming code has been generated using |
| 301 | vreg numbers 0, 1 .. n_vregs-1. Appearance of a vreg outside |
| 302 | that range is a checked run-time error. |
| 303 | |
| 304 | Takes an expandable array of pointers to unallocated insns. |
| 305 | Returns an expandable array of pointers to allocated insns. |
| 306 | */ |
| 307 | HInstrArray* doRegisterAllocation ( |
| 308 | |
| 309 | /* Incoming virtual-registerised code. */ |
| 310 | HInstrArray* instrs_in, |
| 311 | |
| 312 | /* An array listing all the real registers the allocator may use, |
| 313 | in no particular order. */ |
| 314 | HReg* available_real_regs, |
| 315 | Int n_available_real_regs, |
| 316 | |
| 317 | /* Return True iff the given insn is a reg-reg move, in which |
| 318 | case also return the src and dst regs. */ |
florian | d8c64e0 | 2014-10-08 08:54:44 +0000 | [diff] [blame] | 319 | Bool (*isMove) ( const HInstr*, HReg*, HReg* ), |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 320 | |
| 321 | /* Get info about register usage in this insn. */ |
florian | d8c64e0 | 2014-10-08 08:54:44 +0000 | [diff] [blame] | 322 | void (*getRegUsage) ( HRegUsage*, const HInstr*, Bool ), |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 323 | |
| 324 | /* Apply a reg-reg mapping to an insn. */ |
cerion | 92b6436 | 2005-12-13 12:02:26 +0000 | [diff] [blame] | 325 | void (*mapRegs) ( HRegRemap*, HInstr*, Bool ), |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 326 | |
sewardj | 6c299f3 | 2009-12-31 18:00:12 +0000 | [diff] [blame] | 327 | /* Return one, or, if we're unlucky, two insn(s) to spill/restore a |
| 328 | real reg to a spill slot byte offset. The two leading HInstr** |
| 329 | args are out parameters, through which the generated insns are |
| 330 | returned. Also (optionally) a 'directReload' function, which |
sewardj | fb7373a | 2007-08-25 21:29:03 +0000 | [diff] [blame] | 331 | attempts to replace a given instruction by one which reads |
| 332 | directly from a specified spill slot. May be NULL, in which |
| 333 | case the optimisation is not attempted. */ |
sewardj | 6c299f3 | 2009-12-31 18:00:12 +0000 | [diff] [blame] | 334 | void (*genSpill) ( HInstr**, HInstr**, HReg, Int, Bool ), |
| 335 | void (*genReload) ( HInstr**, HInstr**, HReg, Int, Bool ), |
sewardj | fb7373a | 2007-08-25 21:29:03 +0000 | [diff] [blame] | 336 | HInstr* (*directReload) ( HInstr*, HReg, Short ), |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 337 | Int guest_sizeB, |
| 338 | |
| 339 | /* For debug printing only. */ |
florian | d8c64e0 | 2014-10-08 08:54:44 +0000 | [diff] [blame] | 340 | void (*ppInstr) ( const HInstr*, Bool ), |
cerion | 92b6436 | 2005-12-13 12:02:26 +0000 | [diff] [blame] | 341 | void (*ppReg) ( HReg ), |
| 342 | |
| 343 | /* 32/64bit mode */ |
| 344 | Bool mode64 |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 345 | ) |
| 346 | { |
| 347 | # define N_SPILL64S (LibVEX_N_SPILL_BYTES / 8) |
| 348 | |
sewardj | 607ca2d | 2007-08-25 21:11:33 +0000 | [diff] [blame] | 349 | const Bool eq_spill_opt = True; |
| 350 | |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 351 | /* Iterators and temporaries. */ |
| 352 | Int ii, j, k, m, spillee, k_suboptimal; |
| 353 | HReg rreg, vreg, vregS, vregD; |
| 354 | HRegUsage reg_usage; |
| 355 | |
| 356 | /* Info on vregs and rregs. Computed once and remains |
| 357 | unchanged. */ |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 358 | Int n_vregs; |
| 359 | VRegLR* vreg_lrs; /* [0 .. n_vregs-1] */ |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 360 | |
sewardj | c3bc60a | 2006-12-01 02:59:17 +0000 | [diff] [blame] | 361 | /* We keep two copies of the real-reg live range info, one sorted |
| 362 | by .live_after and the other by .dead_before. First the |
| 363 | unsorted info is created in the _la variant is copied into the |
| 364 | _db variant. Once that's done both of them are sorted. |
| 365 | We also need two integer cursors which record the next |
| 366 | location in the two arrays to consider. */ |
| 367 | RRegLR* rreg_lrs_la; |
| 368 | RRegLR* rreg_lrs_db; |
sewardj | ad572dd | 2004-12-30 01:44:51 +0000 | [diff] [blame] | 369 | Int rreg_lrs_size; |
| 370 | Int rreg_lrs_used; |
sewardj | c3bc60a | 2006-12-01 02:59:17 +0000 | [diff] [blame] | 371 | Int rreg_lrs_la_next; |
| 372 | Int rreg_lrs_db_next; |
sewardj | ad572dd | 2004-12-30 01:44:51 +0000 | [diff] [blame] | 373 | |
| 374 | /* Used when constructing vreg_lrs (for allocating stack |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 375 | slots). */ |
| 376 | Int ss_busy_until_before[N_SPILL64S]; |
| 377 | |
sewardj | ad572dd | 2004-12-30 01:44:51 +0000 | [diff] [blame] | 378 | /* Used when constructing rreg_lrs. */ |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 379 | Int* rreg_live_after; |
| 380 | Int* rreg_dead_before; |
| 381 | |
| 382 | /* Running state of the core allocation algorithm. */ |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 383 | RRegState* rreg_state; /* [0 .. n_rregs-1] */ |
| 384 | Int n_rregs; |
| 385 | |
| 386 | /* .. and the redundant backward map */ |
| 387 | /* Each value is 0 .. n_rregs-1 or is INVALID_RREG_NO. |
| 388 | This inplies n_rregs must be <= 32768. */ |
| 389 | Short* vreg_state; /* [0 .. n_vregs-1] */ |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 390 | |
| 391 | /* The vreg -> rreg map constructed and then applied to each |
| 392 | instr. */ |
| 393 | HRegRemap remap; |
| 394 | |
| 395 | /* The output array of instructions. */ |
| 396 | HInstrArray* instrs_out; |
| 397 | |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 398 | /* Sanity checks are expensive. They are only done periodically, |
| 399 | not at each insn processed. */ |
| 400 | Bool do_sanity_check; |
| 401 | |
florian | 95a487b | 2014-02-14 08:55:32 +0000 | [diff] [blame] | 402 | vassert(0 == (guest_sizeB % 16)); |
| 403 | vassert(0 == (LibVEX_N_SPILL_BYTES % 16)); |
| 404 | vassert(0 == (N_SPILL64S % 2)); |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 405 | |
| 406 | /* The live range numbers are signed shorts, and so limiting the |
sewardj | 8c50d7d | 2012-07-14 09:18:02 +0000 | [diff] [blame] | 407 | number of insns to 15000 comfortably guards against them |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 408 | overflowing 32k. */ |
sewardj | 8c50d7d | 2012-07-14 09:18:02 +0000 | [diff] [blame] | 409 | vassert(instrs_in->arr_used <= 15000); |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 410 | |
| 411 | # define INVALID_INSTRNO (-2) |
| 412 | |
| 413 | # define EMIT_INSTR(_instr) \ |
| 414 | do { \ |
| 415 | HInstr* _tmp = (_instr); \ |
| 416 | if (DEBUG_REGALLOC) { \ |
| 417 | vex_printf("** "); \ |
cerion | 92b6436 | 2005-12-13 12:02:26 +0000 | [diff] [blame] | 418 | (*ppInstr)(_tmp, mode64); \ |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 419 | vex_printf("\n\n"); \ |
| 420 | } \ |
| 421 | addHInstr ( instrs_out, _tmp ); \ |
| 422 | } while (0) |
| 423 | |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 424 | # define PRINT_STATE \ |
| 425 | do { \ |
| 426 | Int z, q; \ |
| 427 | for (z = 0; z < n_rregs; z++) { \ |
| 428 | vex_printf(" rreg_state[%2d] = ", z); \ |
| 429 | (*ppReg)(rreg_state[z].rreg); \ |
| 430 | vex_printf(" \t"); \ |
| 431 | switch (rreg_state[z].disp) { \ |
| 432 | case Free: vex_printf("Free\n"); break; \ |
| 433 | case Unavail: vex_printf("Unavail\n"); break; \ |
| 434 | case Bound: vex_printf("BoundTo "); \ |
| 435 | (*ppReg)(rreg_state[z].vreg); \ |
| 436 | vex_printf("\n"); break; \ |
| 437 | } \ |
| 438 | } \ |
| 439 | vex_printf("\n vreg_state[0 .. %d]:\n ", n_vregs-1); \ |
| 440 | q = 0; \ |
| 441 | for (z = 0; z < n_vregs; z++) { \ |
| 442 | if (vreg_state[z] == INVALID_RREG_NO) \ |
| 443 | continue; \ |
| 444 | vex_printf("[%d] -> %d ", z, vreg_state[z]); \ |
| 445 | q++; \ |
| 446 | if (q > 0 && (q % 6) == 0) \ |
| 447 | vex_printf("\n "); \ |
| 448 | } \ |
| 449 | vex_printf("\n"); \ |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 450 | } while (0) |
| 451 | |
| 452 | |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 453 | /* --------- Stage 0: set up output array --------- */ |
| 454 | /* --------- and allocate/initialise running state. --------- */ |
| 455 | |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 456 | instrs_out = newHInstrArray(); |
| 457 | |
| 458 | /* ... and initialise running state. */ |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 459 | /* n_rregs is no more than a short name for n_available_real_regs. */ |
| 460 | n_rregs = n_available_real_regs; |
| 461 | n_vregs = instrs_in->n_vregs; |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 462 | |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 463 | /* If this is not so, vreg_state entries will overflow. */ |
| 464 | vassert(n_vregs < 32767); |
| 465 | |
| 466 | rreg_state = LibVEX_Alloc(n_rregs * sizeof(RRegState)); |
| 467 | vreg_state = LibVEX_Alloc(n_vregs * sizeof(Short)); |
| 468 | |
| 469 | for (j = 0; j < n_rregs; j++) { |
| 470 | rreg_state[j].rreg = available_real_regs[j]; |
| 471 | rreg_state[j].has_hlrs = False; |
| 472 | rreg_state[j].disp = Free; |
| 473 | rreg_state[j].vreg = INVALID_HREG; |
| 474 | rreg_state[j].is_spill_cand = False; |
sewardj | 607ca2d | 2007-08-25 21:11:33 +0000 | [diff] [blame] | 475 | rreg_state[j].eq_spill_slot = False; |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 476 | } |
| 477 | |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 478 | for (j = 0; j < n_vregs; j++) |
| 479 | vreg_state[j] = INVALID_RREG_NO; |
| 480 | |
| 481 | |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 482 | /* --------- Stage 1: compute vreg live ranges. --------- */ |
| 483 | /* --------- Stage 2: compute rreg live ranges. --------- */ |
| 484 | |
| 485 | /* ------ start of SET UP TO COMPUTE VREG LIVE RANGES ------ */ |
| 486 | |
| 487 | /* This is relatively simple, because (1) we only seek the complete |
| 488 | end-to-end live range of each vreg, and are not interested in |
| 489 | any holes in it, and (2) the vregs are conveniently numbered 0 |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 490 | .. n_vregs-1, so we can just dump the results in a |
sewardj | ad572dd | 2004-12-30 01:44:51 +0000 | [diff] [blame] | 491 | pre-allocated array. */ |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 492 | |
sewardj | ad572dd | 2004-12-30 01:44:51 +0000 | [diff] [blame] | 493 | vreg_lrs = NULL; |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 494 | if (n_vregs > 0) |
| 495 | vreg_lrs = LibVEX_Alloc(sizeof(VRegLR) * n_vregs); |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 496 | |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 497 | for (j = 0; j < n_vregs; j++) { |
sewardj | ad572dd | 2004-12-30 01:44:51 +0000 | [diff] [blame] | 498 | vreg_lrs[j].live_after = INVALID_INSTRNO; |
| 499 | vreg_lrs[j].dead_before = INVALID_INSTRNO; |
| 500 | vreg_lrs[j].spill_offset = 0; |
| 501 | vreg_lrs[j].spill_size = 0; |
| 502 | vreg_lrs[j].reg_class = HRcINVALID; |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 503 | } |
| 504 | |
| 505 | /* ------ end of SET UP TO COMPUTE VREG LIVE RANGES ------ */ |
| 506 | |
| 507 | /* ------ start of SET UP TO COMPUTE RREG LIVE RANGES ------ */ |
| 508 | |
| 509 | /* This is more complex than Stage 1, because we need to compute |
| 510 | exactly all the live ranges of all the allocatable real regs, |
| 511 | and we don't know in advance how many there will be. */ |
| 512 | |
sewardj | ad572dd | 2004-12-30 01:44:51 +0000 | [diff] [blame] | 513 | rreg_lrs_used = 0; |
| 514 | rreg_lrs_size = 4; |
sewardj | c3bc60a | 2006-12-01 02:59:17 +0000 | [diff] [blame] | 515 | rreg_lrs_la = LibVEX_Alloc(rreg_lrs_size * sizeof(RRegLR)); |
| 516 | rreg_lrs_db = NULL; /* we'll create this later */ |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 517 | |
| 518 | /* We'll need to track live range start/end points seperately for |
| 519 | each rreg. Sigh. */ |
| 520 | vassert(n_available_real_regs > 0); |
| 521 | rreg_live_after = LibVEX_Alloc(n_available_real_regs * sizeof(Int)); |
| 522 | rreg_dead_before = LibVEX_Alloc(n_available_real_regs * sizeof(Int)); |
| 523 | |
| 524 | for (j = 0; j < n_available_real_regs; j++) { |
| 525 | rreg_live_after[j] = |
| 526 | rreg_dead_before[j] = INVALID_INSTRNO; |
| 527 | } |
| 528 | |
| 529 | /* ------ end of SET UP TO COMPUTE RREG LIVE RANGES ------ */ |
| 530 | |
| 531 | /* ------ start of ITERATE OVER INSNS ------ */ |
| 532 | |
| 533 | for (ii = 0; ii < instrs_in->arr_used; ii++) { |
| 534 | |
cerion | 92b6436 | 2005-12-13 12:02:26 +0000 | [diff] [blame] | 535 | (*getRegUsage)( ®_usage, instrs_in->arr[ii], mode64 ); |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 536 | |
| 537 | # if 0 |
| 538 | vex_printf("\n%d stage1: ", ii); |
cerion | 92b6436 | 2005-12-13 12:02:26 +0000 | [diff] [blame] | 539 | (*ppInstr)(instrs_in->arr[ii], mode64); |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 540 | vex_printf("\n"); |
| 541 | ppHRegUsage(®_usage); |
| 542 | # endif |
| 543 | |
| 544 | /* ------ start of DEAL WITH VREG LIVE RANGES ------ */ |
| 545 | |
| 546 | /* for each reg mentioned in the insn ... */ |
| 547 | for (j = 0; j < reg_usage.n_used; j++) { |
| 548 | |
| 549 | vreg = reg_usage.hreg[j]; |
| 550 | /* only interested in virtual registers right now. */ |
| 551 | if (!hregIsVirtual(vreg)) |
| 552 | continue; |
| 553 | k = hregNumber(vreg); |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 554 | if (k < 0 || k >= n_vregs) { |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 555 | vex_printf("\n"); |
cerion | 92b6436 | 2005-12-13 12:02:26 +0000 | [diff] [blame] | 556 | (*ppInstr)(instrs_in->arr[ii], mode64); |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 557 | vex_printf("\n"); |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 558 | vex_printf("vreg %d, n_vregs %d\n", k, n_vregs); |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 559 | vpanic("doRegisterAllocation: out-of-range vreg"); |
| 560 | } |
| 561 | |
| 562 | /* Take the opportunity to note its regclass. We'll need |
| 563 | that when allocating spill slots. */ |
sewardj | ad572dd | 2004-12-30 01:44:51 +0000 | [diff] [blame] | 564 | if (vreg_lrs[k].reg_class == HRcINVALID) { |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 565 | /* First mention of this vreg. */ |
sewardj | ad572dd | 2004-12-30 01:44:51 +0000 | [diff] [blame] | 566 | vreg_lrs[k].reg_class = hregClass(vreg); |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 567 | } else { |
| 568 | /* Seen it before, so check for consistency. */ |
sewardj | ad572dd | 2004-12-30 01:44:51 +0000 | [diff] [blame] | 569 | vassert(vreg_lrs[k].reg_class == hregClass(vreg)); |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 570 | } |
| 571 | |
| 572 | /* Now consider live ranges. */ |
| 573 | switch (reg_usage.mode[j]) { |
| 574 | case HRmRead: |
sewardj | ad572dd | 2004-12-30 01:44:51 +0000 | [diff] [blame] | 575 | if (vreg_lrs[k].live_after == INVALID_INSTRNO) { |
sewardj | d08f2d7 | 2004-12-01 23:19:36 +0000 | [diff] [blame] | 576 | vex_printf("\n\nOFFENDING VREG = %d\n", k); |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 577 | vpanic("doRegisterAllocation: " |
| 578 | "first event for vreg is Read"); |
sewardj | d08f2d7 | 2004-12-01 23:19:36 +0000 | [diff] [blame] | 579 | } |
sewardj | 40e144d | 2005-03-28 00:46:27 +0000 | [diff] [blame] | 580 | vreg_lrs[k].dead_before = toShort(ii + 1); |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 581 | break; |
| 582 | case HRmWrite: |
sewardj | ad572dd | 2004-12-30 01:44:51 +0000 | [diff] [blame] | 583 | if (vreg_lrs[k].live_after == INVALID_INSTRNO) |
sewardj | 40e144d | 2005-03-28 00:46:27 +0000 | [diff] [blame] | 584 | vreg_lrs[k].live_after = toShort(ii); |
| 585 | vreg_lrs[k].dead_before = toShort(ii + 1); |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 586 | break; |
| 587 | case HRmModify: |
sewardj | ad572dd | 2004-12-30 01:44:51 +0000 | [diff] [blame] | 588 | if (vreg_lrs[k].live_after == INVALID_INSTRNO) { |
sewardj | 109ffdb | 2004-12-10 21:45:38 +0000 | [diff] [blame] | 589 | vex_printf("\n\nOFFENDING VREG = %d\n", k); |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 590 | vpanic("doRegisterAllocation: " |
| 591 | "first event for vreg is Modify"); |
sewardj | 109ffdb | 2004-12-10 21:45:38 +0000 | [diff] [blame] | 592 | } |
sewardj | 40e144d | 2005-03-28 00:46:27 +0000 | [diff] [blame] | 593 | vreg_lrs[k].dead_before = toShort(ii + 1); |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 594 | break; |
| 595 | default: |
| 596 | vpanic("doRegisterAllocation(1)"); |
| 597 | } /* switch */ |
| 598 | |
| 599 | } /* iterate over registers */ |
| 600 | |
| 601 | /* ------ end of DEAL WITH VREG LIVE RANGES ------ */ |
| 602 | |
| 603 | /* ------ start of DEAL WITH RREG LIVE RANGES ------ */ |
| 604 | |
| 605 | /* for each reg mentioned in the insn ... */ |
| 606 | for (j = 0; j < reg_usage.n_used; j++) { |
| 607 | |
| 608 | /* Dummy initialisations of flush_la and flush_db to avoid |
| 609 | possible bogus uninit-var warnings from gcc. */ |
| 610 | Int flush_la = INVALID_INSTRNO, flush_db = INVALID_INSTRNO; |
| 611 | Bool flush; |
| 612 | |
| 613 | rreg = reg_usage.hreg[j]; |
| 614 | |
| 615 | /* only interested in real registers right now. */ |
| 616 | if (hregIsVirtual(rreg)) |
| 617 | continue; |
| 618 | |
| 619 | /* Furthermore, we're not interested in this rreg unless it's |
| 620 | one of the allocatable ones. For example, it could be a |
| 621 | stack pointer register, or some other register beyond our |
| 622 | control, in which case we should just ignore it. */ |
| 623 | for (k = 0; k < n_available_real_regs; k++) |
florian | 79efdc6 | 2013-02-11 00:47:35 +0000 | [diff] [blame] | 624 | if (sameHReg(available_real_regs[k], rreg)) |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 625 | break; |
| 626 | if (k == n_available_real_regs) |
| 627 | continue; /* not found -- ignore. */ |
| 628 | flush = False; |
| 629 | switch (reg_usage.mode[j]) { |
| 630 | case HRmWrite: |
| 631 | flush_la = rreg_live_after[k]; |
| 632 | flush_db = rreg_dead_before[k]; |
| 633 | if (flush_la != INVALID_INSTRNO |
| 634 | && flush_db != INVALID_INSTRNO) |
| 635 | flush = True; |
| 636 | rreg_live_after[k] = ii; |
| 637 | rreg_dead_before[k] = ii+1; |
| 638 | break; |
| 639 | case HRmRead: |
sewardj | 6447157 | 2005-02-09 19:13:29 +0000 | [diff] [blame] | 640 | if (rreg_live_after[k] == INVALID_INSTRNO) { |
| 641 | vex_printf("\nOFFENDING RREG = "); |
| 642 | (*ppReg)(available_real_regs[k]); |
| 643 | vex_printf("\n"); |
| 644 | vex_printf("\nOFFENDING instr = "); |
cerion | 92b6436 | 2005-12-13 12:02:26 +0000 | [diff] [blame] | 645 | (*ppInstr)(instrs_in->arr[ii], mode64); |
sewardj | 6447157 | 2005-02-09 19:13:29 +0000 | [diff] [blame] | 646 | vex_printf("\n"); |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 647 | vpanic("doRegisterAllocation: " |
| 648 | "first event for rreg is Read"); |
sewardj | 6447157 | 2005-02-09 19:13:29 +0000 | [diff] [blame] | 649 | } |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 650 | rreg_dead_before[k] = ii+1; |
| 651 | break; |
| 652 | case HRmModify: |
sewardj | 6447157 | 2005-02-09 19:13:29 +0000 | [diff] [blame] | 653 | if (rreg_live_after[k] == INVALID_INSTRNO) { |
| 654 | vex_printf("\nOFFENDING RREG = "); |
| 655 | (*ppReg)(available_real_regs[k]); |
| 656 | vex_printf("\n"); |
| 657 | vex_printf("\nOFFENDING instr = "); |
cerion | 92b6436 | 2005-12-13 12:02:26 +0000 | [diff] [blame] | 658 | (*ppInstr)(instrs_in->arr[ii], mode64); |
sewardj | 6447157 | 2005-02-09 19:13:29 +0000 | [diff] [blame] | 659 | vex_printf("\n"); |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 660 | vpanic("doRegisterAllocation: " |
| 661 | "first event for rreg is Modify"); |
sewardj | 6447157 | 2005-02-09 19:13:29 +0000 | [diff] [blame] | 662 | } |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 663 | rreg_dead_before[k] = ii+1; |
| 664 | break; |
| 665 | default: |
| 666 | vpanic("doRegisterAllocation(2)"); |
| 667 | } |
| 668 | |
| 669 | if (flush) { |
| 670 | vassert(flush_la != INVALID_INSTRNO); |
| 671 | vassert(flush_db != INVALID_INSTRNO); |
sewardj | c3bc60a | 2006-12-01 02:59:17 +0000 | [diff] [blame] | 672 | ensureRRLRspace(&rreg_lrs_la, &rreg_lrs_size, rreg_lrs_used); |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 673 | if (0) |
| 674 | vex_printf("FLUSH 1 (%d,%d)\n", flush_la, flush_db); |
sewardj | c3bc60a | 2006-12-01 02:59:17 +0000 | [diff] [blame] | 675 | rreg_lrs_la[rreg_lrs_used].rreg = rreg; |
| 676 | rreg_lrs_la[rreg_lrs_used].live_after = toShort(flush_la); |
| 677 | rreg_lrs_la[rreg_lrs_used].dead_before = toShort(flush_db); |
sewardj | ad572dd | 2004-12-30 01:44:51 +0000 | [diff] [blame] | 678 | rreg_lrs_used++; |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 679 | } |
| 680 | |
| 681 | } /* iterate over regs in the instr */ |
| 682 | |
| 683 | /* ------ end of DEAL WITH RREG LIVE RANGES ------ */ |
| 684 | |
| 685 | } /* iterate over insns */ |
| 686 | |
| 687 | /* ------ end of ITERATE OVER INSNS ------ */ |
| 688 | |
| 689 | /* ------ start of FINALISE RREG LIVE RANGES ------ */ |
| 690 | |
| 691 | /* Now finish up any live ranges left over. */ |
| 692 | for (j = 0; j < n_available_real_regs; j++) { |
| 693 | |
| 694 | # if 0 |
| 695 | vex_printf("residual %d: %d %d\n", j, rreg_live_after[j], |
| 696 | rreg_dead_before[j]); |
| 697 | # endif |
| 698 | vassert( (rreg_live_after[j] == INVALID_INSTRNO |
| 699 | && rreg_dead_before[j] == INVALID_INSTRNO) |
| 700 | || |
| 701 | (rreg_live_after[j] != INVALID_INSTRNO |
| 702 | && rreg_dead_before[j] != INVALID_INSTRNO) |
| 703 | ); |
| 704 | |
| 705 | if (rreg_live_after[j] == INVALID_INSTRNO) |
| 706 | continue; |
| 707 | |
sewardj | c3bc60a | 2006-12-01 02:59:17 +0000 | [diff] [blame] | 708 | ensureRRLRspace(&rreg_lrs_la, &rreg_lrs_size, rreg_lrs_used); |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 709 | if (0) |
| 710 | vex_printf("FLUSH 2 (%d,%d)\n", |
| 711 | rreg_live_after[j], rreg_dead_before[j]); |
sewardj | c3bc60a | 2006-12-01 02:59:17 +0000 | [diff] [blame] | 712 | rreg_lrs_la[rreg_lrs_used].rreg = available_real_regs[j]; |
| 713 | rreg_lrs_la[rreg_lrs_used].live_after = toShort(rreg_live_after[j]); |
| 714 | rreg_lrs_la[rreg_lrs_used].dead_before = toShort(rreg_dead_before[j]); |
sewardj | ad572dd | 2004-12-30 01:44:51 +0000 | [diff] [blame] | 715 | rreg_lrs_used++; |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 716 | } |
| 717 | |
| 718 | /* Compute summary hints for choosing real regs. If a real reg is |
| 719 | involved in a hard live range, record that fact in the fixed |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 720 | part of the running rreg_state. Later, when offered a choice between |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 721 | rregs, it's better to choose one which is not marked as having |
| 722 | any HLRs, since ones with HLRs may need to be spilled around |
| 723 | their HLRs. Correctness of final assignment is unaffected by |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 724 | this mechanism -- it is only an optimisation. */ |
florian | ee31366 | 2012-01-18 14:04:23 +0000 | [diff] [blame] | 725 | |
sewardj | ad572dd | 2004-12-30 01:44:51 +0000 | [diff] [blame] | 726 | for (j = 0; j < rreg_lrs_used; j++) { |
sewardj | c3bc60a | 2006-12-01 02:59:17 +0000 | [diff] [blame] | 727 | rreg = rreg_lrs_la[j].rreg; |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 728 | vassert(!hregIsVirtual(rreg)); |
| 729 | /* rreg is involved in a HLR. Record this info in the array, if |
| 730 | there is space. */ |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 731 | for (k = 0; k < n_rregs; k++) |
florian | 79efdc6 | 2013-02-11 00:47:35 +0000 | [diff] [blame] | 732 | if (sameHReg(rreg_state[k].rreg, rreg)) |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 733 | break; |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 734 | vassert(k < n_rregs); /* else rreg was not found in rreg_state?! */ |
| 735 | rreg_state[k].has_hlrs = True; |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 736 | } |
| 737 | if (0) { |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 738 | for (j = 0; j < n_rregs; j++) { |
| 739 | if (!rreg_state[j].has_hlrs) |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 740 | continue; |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 741 | ppReg(rreg_state[j].rreg); |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 742 | vex_printf(" hinted\n"); |
| 743 | } |
| 744 | } |
| 745 | |
sewardj | c3bc60a | 2006-12-01 02:59:17 +0000 | [diff] [blame] | 746 | /* Finally, copy the _la variant into the _db variant and |
| 747 | sort both by their respective fields. */ |
| 748 | rreg_lrs_db = LibVEX_Alloc(rreg_lrs_used * sizeof(RRegLR)); |
| 749 | for (j = 0; j < rreg_lrs_used; j++) |
| 750 | rreg_lrs_db[j] = rreg_lrs_la[j]; |
| 751 | |
| 752 | sortRRLRarray( rreg_lrs_la, rreg_lrs_used, True /* by .live_after*/ ); |
| 753 | sortRRLRarray( rreg_lrs_db, rreg_lrs_used, False/* by .dead_before*/ ); |
| 754 | |
| 755 | /* And set up the cursors. */ |
| 756 | rreg_lrs_la_next = 0; |
| 757 | rreg_lrs_db_next = 0; |
| 758 | |
| 759 | for (j = 1; j < rreg_lrs_used; j++) { |
| 760 | vassert(rreg_lrs_la[j-1].live_after <= rreg_lrs_la[j].live_after); |
| 761 | vassert(rreg_lrs_db[j-1].dead_before <= rreg_lrs_db[j].dead_before); |
| 762 | } |
| 763 | |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 764 | /* ------ end of FINALISE RREG LIVE RANGES ------ */ |
| 765 | |
| 766 | # if DEBUG_REGALLOC |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 767 | for (j = 0; j < n_vregs; j++) { |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 768 | vex_printf("vreg %d: la = %d, db = %d\n", |
sewardj | ad572dd | 2004-12-30 01:44:51 +0000 | [diff] [blame] | 769 | j, vreg_lrs[j].live_after, vreg_lrs[j].dead_before ); |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 770 | } |
| 771 | # endif |
| 772 | |
| 773 | # if DEBUG_REGALLOC |
sewardj | c3bc60a | 2006-12-01 02:59:17 +0000 | [diff] [blame] | 774 | vex_printf("RRegLRs by LA:\n"); |
sewardj | ad572dd | 2004-12-30 01:44:51 +0000 | [diff] [blame] | 775 | for (j = 0; j < rreg_lrs_used; j++) { |
sewardj | c3bc60a | 2006-12-01 02:59:17 +0000 | [diff] [blame] | 776 | vex_printf(" "); |
| 777 | (*ppReg)(rreg_lrs_la[j].rreg); |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 778 | vex_printf(" la = %d, db = %d\n", |
sewardj | c3bc60a | 2006-12-01 02:59:17 +0000 | [diff] [blame] | 779 | rreg_lrs_la[j].live_after, rreg_lrs_la[j].dead_before ); |
| 780 | } |
| 781 | vex_printf("RRegLRs by DB:\n"); |
| 782 | for (j = 0; j < rreg_lrs_used; j++) { |
| 783 | vex_printf(" "); |
| 784 | (*ppReg)(rreg_lrs_db[j].rreg); |
| 785 | vex_printf(" la = %d, db = %d\n", |
| 786 | rreg_lrs_db[j].live_after, rreg_lrs_db[j].dead_before ); |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 787 | } |
| 788 | # endif |
| 789 | |
| 790 | /* --------- Stage 3: allocate spill slots. --------- */ |
| 791 | |
sewardj | 7fb65eb | 2007-03-25 04:14:58 +0000 | [diff] [blame] | 792 | /* Each spill slot is 8 bytes long. For vregs which take more than |
| 793 | 64 bits to spill (classes Flt64 and Vec128), we have to allocate |
sewardj | c4530ae | 2012-05-21 10:18:49 +0000 | [diff] [blame] | 794 | two consecutive spill slots. For 256 bit registers (class |
| 795 | Vec256), we have to allocate four consecutive spill slots. |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 796 | |
sewardj | 478646f | 2008-05-01 20:13:04 +0000 | [diff] [blame] | 797 | For Vec128-class on PowerPC, the spill slot's actual address |
| 798 | must be 16-byte aligned. Since the spill slot's address is |
| 799 | computed as an offset from the guest state pointer, and since |
| 800 | the user of the generated code must set that pointer to a |
sewardj | c4530ae | 2012-05-21 10:18:49 +0000 | [diff] [blame] | 801 | 32-aligned value, we have the residual obligation here of |
sewardj | 478646f | 2008-05-01 20:13:04 +0000 | [diff] [blame] | 802 | choosing a 16-aligned spill slot offset for Vec128-class values. |
| 803 | Since each spill slot is 8 bytes long, that means for |
| 804 | Vec128-class values we must allocated a spill slot number which |
| 805 | is zero mod 2. |
| 806 | |
sewardj | c4530ae | 2012-05-21 10:18:49 +0000 | [diff] [blame] | 807 | Similarly, for Vec256 calss on amd64, find a spill slot number |
| 808 | which is zero mod 4. This guarantees it will be 32 byte |
| 809 | aligned, which isn't actually necessary on amd64 (we use movUpd |
| 810 | etc to spill), but seems like good practice. |
| 811 | |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 812 | Do a rank-based allocation of vregs to spill slot numbers. We |
sewardj | 607ca2d | 2007-08-25 21:11:33 +0000 | [diff] [blame] | 813 | put as few values as possible in spill slots, but nevertheless |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 814 | need to have a spill slot available for all vregs, just in case. |
| 815 | */ |
| 816 | /* max_ss_no = -1; */ |
| 817 | |
| 818 | for (j = 0; j < N_SPILL64S; j++) |
| 819 | ss_busy_until_before[j] = 0; |
| 820 | |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 821 | for (j = 0; j < n_vregs; j++) { |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 822 | |
| 823 | /* True iff this vreg is unused. In which case we also expect |
| 824 | that the reg_class field for it has not been set. */ |
sewardj | ad572dd | 2004-12-30 01:44:51 +0000 | [diff] [blame] | 825 | if (vreg_lrs[j].live_after == INVALID_INSTRNO) { |
| 826 | vassert(vreg_lrs[j].reg_class == HRcINVALID); |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 827 | continue; |
| 828 | } |
| 829 | |
sewardj | 7fb65eb | 2007-03-25 04:14:58 +0000 | [diff] [blame] | 830 | /* The spill slots are 64 bits in size. As per the comment on |
sewardj | c4530ae | 2012-05-21 10:18:49 +0000 | [diff] [blame] | 831 | definition of HRegClass in host_generic_regs.h, that means, |
| 832 | to spill a vreg of class Flt64 or Vec128, we'll need to find |
| 833 | two adjacent spill slots to use. For Vec256, we'll need to |
| 834 | find four adjacent slots to use. Note, this logic needs to |
| 835 | kept in sync with the size info on the definition of |
| 836 | HRegClass. */ |
| 837 | switch (vreg_lrs[j].reg_class) { |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 838 | |
sewardj | c4530ae | 2012-05-21 10:18:49 +0000 | [diff] [blame] | 839 | case HRcVec128: case HRcFlt64: |
| 840 | /* Find two adjacent free slots in which between them |
| 841 | provide up to 128 bits in which to spill the vreg. |
| 842 | Since we are trying to find an even:odd pair, move |
| 843 | along in steps of 2 (slots). */ |
| 844 | for (k = 0; k < N_SPILL64S-1; k += 2) |
| 845 | if (ss_busy_until_before[k+0] <= vreg_lrs[j].live_after |
| 846 | && ss_busy_until_before[k+1] <= vreg_lrs[j].live_after) |
| 847 | break; |
| 848 | if (k >= N_SPILL64S-1) { |
| 849 | vpanic("LibVEX_N_SPILL_BYTES is too low. " |
| 850 | "Increase and recompile."); |
| 851 | } |
| 852 | if (0) vex_printf("16-byte spill offset in spill slot %d\n", |
| 853 | (Int)k); |
| 854 | ss_busy_until_before[k+0] = vreg_lrs[j].dead_before; |
| 855 | ss_busy_until_before[k+1] = vreg_lrs[j].dead_before; |
| 856 | break; |
sewardj | 7fb65eb | 2007-03-25 04:14:58 +0000 | [diff] [blame] | 857 | |
sewardj | c4530ae | 2012-05-21 10:18:49 +0000 | [diff] [blame] | 858 | default: |
| 859 | /* The ordinary case -- just find a single spill slot. */ |
| 860 | /* Find the lowest-numbered spill slot which is available |
| 861 | at the start point of this interval, and assign the |
| 862 | interval to it. */ |
| 863 | for (k = 0; k < N_SPILL64S; k++) |
| 864 | if (ss_busy_until_before[k] <= vreg_lrs[j].live_after) |
| 865 | break; |
| 866 | if (k == N_SPILL64S) { |
| 867 | vpanic("LibVEX_N_SPILL_BYTES is too low. " |
| 868 | "Increase and recompile."); |
| 869 | } |
| 870 | ss_busy_until_before[k] = vreg_lrs[j].dead_before; |
| 871 | break; |
sewardj | 7fb65eb | 2007-03-25 04:14:58 +0000 | [diff] [blame] | 872 | |
sewardj | c4530ae | 2012-05-21 10:18:49 +0000 | [diff] [blame] | 873 | } /* switch (vreg_lrs[j].reg_class) { */ |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 874 | |
| 875 | /* This reflects LibVEX's hard-wired knowledge of the baseBlock |
sewardj | 478646f | 2008-05-01 20:13:04 +0000 | [diff] [blame] | 876 | layout: the guest state, then two equal sized areas following |
| 877 | it for two sets of shadow state, and then the spill area. */ |
| 878 | vreg_lrs[j].spill_offset = toShort(guest_sizeB * 3 + k * 8); |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 879 | |
sewardj | 478646f | 2008-05-01 20:13:04 +0000 | [diff] [blame] | 880 | /* Independent check that we've made a sane choice of slot */ |
| 881 | sanity_check_spill_offset( &vreg_lrs[j] ); |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 882 | /* if (j > max_ss_no) */ |
| 883 | /* max_ss_no = j; */ |
| 884 | } |
| 885 | |
| 886 | # if 0 |
| 887 | vex_printf("\n\n"); |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 888 | for (j = 0; j < n_vregs; j++) |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 889 | vex_printf("vreg %d --> spill offset %d\n", |
sewardj | ad572dd | 2004-12-30 01:44:51 +0000 | [diff] [blame] | 890 | j, vreg_lrs[j].spill_offset); |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 891 | # endif |
| 892 | |
| 893 | /* --------- Stage 4: establish rreg preferences --------- */ |
| 894 | |
| 895 | /* It may be advantageous to allocating certain vregs to specific |
| 896 | rregs, as a way of avoiding reg-reg moves later. Here we |
| 897 | establish which, if any, rreg each vreg would prefer to be in. |
| 898 | Note that this constrains the allocator -- ideally we end up |
sewardj | 2fa60a3 | 2004-10-30 22:23:53 +0000 | [diff] [blame] | 899 | with as few as possible vregs expressing a preference. |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 900 | |
sewardj | 2fa60a3 | 2004-10-30 22:23:53 +0000 | [diff] [blame] | 901 | This is an optimisation: if the .preferred_rreg field is never |
| 902 | set to anything different from INVALID_HREG, the allocator still |
| 903 | works. */ |
sewardj | 17bbc21 | 2004-12-30 00:14:54 +0000 | [diff] [blame] | 904 | |
| 905 | /* 30 Dec 04: removed this mechanism as it does not seem to |
| 906 | help. */ |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 907 | |
| 908 | /* --------- Stage 5: process instructions --------- */ |
| 909 | |
| 910 | /* This is the main loop of the allocator. First, we need to |
| 911 | correctly set up our running state, which tracks the status of |
| 912 | each real register. */ |
| 913 | |
| 914 | /* ------ BEGIN: Process each insn in turn. ------ */ |
| 915 | |
| 916 | for (ii = 0; ii < instrs_in->arr_used; ii++) { |
| 917 | |
| 918 | # if DEBUG_REGALLOC |
| 919 | vex_printf("\n====----====---- Insn %d ----====----====\n", ii); |
| 920 | vex_printf("---- "); |
cerion | 92b6436 | 2005-12-13 12:02:26 +0000 | [diff] [blame] | 921 | (*ppInstr)(instrs_in->arr[ii], mode64); |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 922 | vex_printf("\n\nInitial state:\n"); |
| 923 | PRINT_STATE; |
| 924 | vex_printf("\n"); |
| 925 | # endif |
| 926 | |
| 927 | /* ------------ Sanity checks ------------ */ |
| 928 | |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 929 | /* Sanity checks are expensive. So they are done only once |
| 930 | every 7 instructions, and just before the last |
| 931 | instruction. */ |
| 932 | do_sanity_check |
| 933 | = toBool( |
| 934 | False /* Set to True for sanity checking of all insns. */ |
| 935 | || ii == instrs_in->arr_used-1 |
| 936 | || (ii > 0 && (ii % 7) == 0) |
| 937 | ); |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 938 | |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 939 | if (do_sanity_check) { |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 940 | |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 941 | /* Sanity check 1: all rregs with a hard live range crossing |
| 942 | this insn must be marked as unavailable in the running |
| 943 | state. */ |
| 944 | for (j = 0; j < rreg_lrs_used; j++) { |
sewardj | c3bc60a | 2006-12-01 02:59:17 +0000 | [diff] [blame] | 945 | if (rreg_lrs_la[j].live_after < ii |
| 946 | && ii < rreg_lrs_la[j].dead_before) { |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 947 | /* ii is the middle of a hard live range for some real |
| 948 | reg. Check it's marked as such in the running |
| 949 | state. */ |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 950 | |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 951 | # if 0 |
| 952 | vex_printf("considering la %d .. db %d reg = ", |
| 953 | rreg_lrs[j].live_after, |
| 954 | rreg_lrs[j].dead_before); |
| 955 | (*ppReg)(rreg_lrs[j].rreg); |
| 956 | vex_printf("\n"); |
| 957 | # endif |
| 958 | |
| 959 | /* find the state entry for this rreg */ |
| 960 | for (k = 0; k < n_rregs; k++) |
florian | 79efdc6 | 2013-02-11 00:47:35 +0000 | [diff] [blame] | 961 | if (sameHReg(rreg_state[k].rreg, rreg_lrs_la[j].rreg)) |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 962 | break; |
| 963 | |
| 964 | /* and assert that this rreg is marked as unavailable */ |
| 965 | vassert(rreg_state[k].disp == Unavail); |
| 966 | } |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 967 | } |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 968 | |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 969 | /* Sanity check 2: conversely, all rregs marked as |
| 970 | unavailable in the running rreg_state must have a |
| 971 | corresponding hard live range entry in the rreg_lrs |
| 972 | array. */ |
| 973 | for (j = 0; j < n_available_real_regs; j++) { |
| 974 | vassert(rreg_state[j].disp == Bound |
| 975 | || rreg_state[j].disp == Free |
| 976 | || rreg_state[j].disp == Unavail); |
| 977 | if (rreg_state[j].disp != Unavail) |
| 978 | continue; |
| 979 | for (k = 0; k < rreg_lrs_used; k++) |
florian | 79efdc6 | 2013-02-11 00:47:35 +0000 | [diff] [blame] | 980 | if (sameHReg(rreg_lrs_la[k].rreg, rreg_state[j].rreg) |
sewardj | c3bc60a | 2006-12-01 02:59:17 +0000 | [diff] [blame] | 981 | && rreg_lrs_la[k].live_after < ii |
| 982 | && ii < rreg_lrs_la[k].dead_before) |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 983 | break; |
| 984 | /* If this vassertion fails, we couldn't find a |
| 985 | corresponding HLR. */ |
| 986 | vassert(k < rreg_lrs_used); |
| 987 | } |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 988 | |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 989 | /* Sanity check 3: all vreg-rreg bindings must bind registers |
| 990 | of the same class. */ |
| 991 | for (j = 0; j < n_rregs; j++) { |
sewardj | 607ca2d | 2007-08-25 21:11:33 +0000 | [diff] [blame] | 992 | if (rreg_state[j].disp != Bound) { |
| 993 | vassert(rreg_state[j].eq_spill_slot == False); |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 994 | continue; |
sewardj | 607ca2d | 2007-08-25 21:11:33 +0000 | [diff] [blame] | 995 | } |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 996 | vassert(hregClass(rreg_state[j].rreg) |
| 997 | == hregClass(rreg_state[j].vreg)); |
| 998 | vassert( hregIsVirtual(rreg_state[j].vreg)); |
| 999 | vassert(!hregIsVirtual(rreg_state[j].rreg)); |
| 1000 | } |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 1001 | |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 1002 | /* Sanity check 4: the vreg_state and rreg_state |
| 1003 | mutually-redundant mappings are consistent. If |
| 1004 | rreg_state[j].vreg points at some vreg_state entry then |
| 1005 | that vreg_state entry should point back at |
| 1006 | rreg_state[j]. */ |
| 1007 | for (j = 0; j < n_rregs; j++) { |
| 1008 | if (rreg_state[j].disp != Bound) |
| 1009 | continue; |
| 1010 | k = hregNumber(rreg_state[j].vreg); |
| 1011 | vassert(IS_VALID_VREGNO(k)); |
| 1012 | vassert(vreg_state[k] == j); |
| 1013 | } |
| 1014 | for (j = 0; j < n_vregs; j++) { |
| 1015 | k = vreg_state[j]; |
| 1016 | if (k == INVALID_RREG_NO) |
| 1017 | continue; |
| 1018 | vassert(IS_VALID_RREGNO(k)); |
| 1019 | vassert(rreg_state[k].disp == Bound); |
| 1020 | vassert(hregNumber(rreg_state[k].vreg) == j); |
| 1021 | } |
| 1022 | |
| 1023 | } /* if (do_sanity_check) */ |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 1024 | |
| 1025 | /* ------------ end of Sanity checks ------------ */ |
| 1026 | |
| 1027 | /* Do various optimisations pertaining to register coalescing |
| 1028 | and preferencing: |
| 1029 | MOV v <-> v coalescing (done here). |
| 1030 | MOV v <-> r coalescing (not yet, if ever) |
| 1031 | */ |
| 1032 | /* If doing a reg-reg move between two vregs, and the src's live |
| 1033 | range ends here and the dst's live range starts here, bind |
| 1034 | the dst to the src's rreg, and that's all. */ |
| 1035 | if ( (*isMove)( instrs_in->arr[ii], &vregS, &vregD ) ) { |
| 1036 | if (!hregIsVirtual(vregS)) goto cannot_coalesce; |
| 1037 | if (!hregIsVirtual(vregD)) goto cannot_coalesce; |
| 1038 | /* Check that *isMove is not telling us a bunch of lies ... */ |
| 1039 | vassert(hregClass(vregS) == hregClass(vregD)); |
| 1040 | k = hregNumber(vregS); |
| 1041 | m = hregNumber(vregD); |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 1042 | vassert(IS_VALID_VREGNO(k)); |
| 1043 | vassert(IS_VALID_VREGNO(m)); |
sewardj | ad572dd | 2004-12-30 01:44:51 +0000 | [diff] [blame] | 1044 | if (vreg_lrs[k].dead_before != ii + 1) goto cannot_coalesce; |
| 1045 | if (vreg_lrs[m].live_after != ii) goto cannot_coalesce; |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 1046 | # if DEBUG_REGALLOC |
| 1047 | vex_printf("COALESCE "); |
| 1048 | (*ppReg)(vregS); |
| 1049 | vex_printf(" -> "); |
| 1050 | (*ppReg)(vregD); |
| 1051 | vex_printf("\n\n"); |
| 1052 | # endif |
| 1053 | /* Find the state entry for vregS. */ |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 1054 | for (m = 0; m < n_rregs; m++) |
florian | 79efdc6 | 2013-02-11 00:47:35 +0000 | [diff] [blame] | 1055 | if (rreg_state[m].disp == Bound |
| 1056 | && sameHReg(rreg_state[m].vreg, vregS)) |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 1057 | break; |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 1058 | if (m == n_rregs) |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 1059 | /* We failed to find a binding for vregS, which means it's |
| 1060 | currently not in a register. So we can't do the |
| 1061 | coalescing. Give up. */ |
| 1062 | goto cannot_coalesce; |
| 1063 | |
| 1064 | /* Finally, we can do the coalescing. It's trivial -- merely |
| 1065 | claim vregS's register for vregD. */ |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 1066 | rreg_state[m].vreg = vregD; |
| 1067 | vassert(IS_VALID_VREGNO(hregNumber(vregD))); |
| 1068 | vassert(IS_VALID_VREGNO(hregNumber(vregS))); |
sewardj | d4d3dd6 | 2005-07-04 10:08:24 +0000 | [diff] [blame] | 1069 | vreg_state[hregNumber(vregD)] = toShort(m); |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 1070 | vreg_state[hregNumber(vregS)] = INVALID_RREG_NO; |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 1071 | |
sewardj | 607ca2d | 2007-08-25 21:11:33 +0000 | [diff] [blame] | 1072 | /* This rreg has become associated with a different vreg and |
| 1073 | hence with a different spill slot. Play safe. */ |
| 1074 | rreg_state[m].eq_spill_slot = False; |
| 1075 | |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 1076 | /* Move on to the next insn. We skip the post-insn stuff for |
| 1077 | fixed registers, since this move should not interact with |
| 1078 | them in any way. */ |
| 1079 | continue; |
| 1080 | } |
| 1081 | cannot_coalesce: |
| 1082 | |
| 1083 | /* ------ Free up rregs bound to dead vregs ------ */ |
| 1084 | |
| 1085 | /* Look for vregs whose live range has just ended, and |
| 1086 | mark the associated rreg as free. */ |
| 1087 | |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 1088 | for (j = 0; j < n_rregs; j++) { |
| 1089 | if (rreg_state[j].disp != Bound) |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 1090 | continue; |
florian | c17ce02 | 2013-01-24 16:18:48 +0000 | [diff] [blame] | 1091 | UInt vregno = hregNumber(rreg_state[j].vreg); |
| 1092 | vassert(IS_VALID_VREGNO(vregno)); |
| 1093 | if (vreg_lrs[vregno].dead_before <= ii) { |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 1094 | rreg_state[j].disp = Free; |
sewardj | 607ca2d | 2007-08-25 21:11:33 +0000 | [diff] [blame] | 1095 | rreg_state[j].eq_spill_slot = False; |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 1096 | m = hregNumber(rreg_state[j].vreg); |
| 1097 | vassert(IS_VALID_VREGNO(m)); |
| 1098 | vreg_state[m] = INVALID_RREG_NO; |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 1099 | if (DEBUG_REGALLOC) { |
| 1100 | vex_printf("free up "); |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 1101 | (*ppReg)(rreg_state[j].rreg); |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 1102 | vex_printf("\n"); |
| 1103 | } |
| 1104 | } |
| 1105 | } |
| 1106 | |
| 1107 | /* ------ Pre-instruction actions for fixed rreg uses ------ */ |
| 1108 | |
| 1109 | /* Now we have to deal with rregs which are about to be made |
| 1110 | live by this instruction -- in other words, are entering into |
| 1111 | one of their live ranges. If any such rreg holds a vreg, we |
| 1112 | will have to free up the rreg. The simplest solution which |
| 1113 | is correct is to spill the rreg. |
| 1114 | |
| 1115 | Note we could do better: |
| 1116 | * Could move it into some other free rreg, if one is available |
| 1117 | |
sewardj | c3bc60a | 2006-12-01 02:59:17 +0000 | [diff] [blame] | 1118 | Do this efficiently, by incrementally stepping along an array |
| 1119 | of rreg HLRs that are known to be sorted by start point |
| 1120 | (their .live_after field). |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 1121 | */ |
sewardj | c3bc60a | 2006-12-01 02:59:17 +0000 | [diff] [blame] | 1122 | while (True) { |
| 1123 | vassert(rreg_lrs_la_next >= 0); |
| 1124 | vassert(rreg_lrs_la_next <= rreg_lrs_used); |
| 1125 | if (rreg_lrs_la_next == rreg_lrs_used) |
| 1126 | break; /* no more real reg live ranges to consider */ |
| 1127 | if (ii < rreg_lrs_la[rreg_lrs_la_next].live_after) |
| 1128 | break; /* next live range does not yet start */ |
| 1129 | vassert(ii == rreg_lrs_la[rreg_lrs_la_next].live_after); |
| 1130 | /* rreg_lrs_la[rreg_lrs_la_next].rreg needs to be freed up. |
| 1131 | Find the associated rreg_state entry. */ |
| 1132 | /* Note, re ii == rreg_lrs_la[rreg_lrs_la_next].live_after. |
| 1133 | Real register live ranges are guaranteed to be well-formed |
| 1134 | in that they start with a write to the register -- Stage 2 |
| 1135 | rejects any code not satisfying this. So the correct |
| 1136 | question to ask is whether |
| 1137 | rreg_lrs_la[rreg_lrs_la_next].live_after == ii, that is, |
| 1138 | whether the reg becomes live after this insn -- rather |
| 1139 | than before it. */ |
| 1140 | # if DEBUG_REGALLOC |
| 1141 | vex_printf("need to free up rreg: "); |
| 1142 | (*ppReg)(rreg_lrs_la[rreg_lrs_la_next].rreg); |
| 1143 | vex_printf("\n\n"); |
| 1144 | # endif |
| 1145 | for (k = 0; k < n_rregs; k++) |
florian | 79efdc6 | 2013-02-11 00:47:35 +0000 | [diff] [blame] | 1146 | if (sameHReg(rreg_state[k].rreg, rreg_lrs_la[rreg_lrs_la_next].rreg)) |
sewardj | c3bc60a | 2006-12-01 02:59:17 +0000 | [diff] [blame] | 1147 | break; |
| 1148 | /* If this fails, we don't have an entry for this rreg. |
| 1149 | Which we should. */ |
| 1150 | vassert(IS_VALID_RREGNO(k)); |
| 1151 | m = hregNumber(rreg_state[k].vreg); |
| 1152 | if (rreg_state[k].disp == Bound) { |
| 1153 | /* Yes, there is an associated vreg. Spill it if it's |
| 1154 | still live. */ |
| 1155 | vassert(IS_VALID_VREGNO(m)); |
| 1156 | vreg_state[m] = INVALID_RREG_NO; |
| 1157 | if (vreg_lrs[m].dead_before > ii) { |
| 1158 | vassert(vreg_lrs[m].reg_class != HRcINVALID); |
sewardj | 607ca2d | 2007-08-25 21:11:33 +0000 | [diff] [blame] | 1159 | if ((!eq_spill_opt) || !rreg_state[k].eq_spill_slot) { |
sewardj | 6c299f3 | 2009-12-31 18:00:12 +0000 | [diff] [blame] | 1160 | HInstr* spill1 = NULL; |
| 1161 | HInstr* spill2 = NULL; |
| 1162 | (*genSpill)( &spill1, &spill2, rreg_state[k].rreg, |
| 1163 | vreg_lrs[m].spill_offset, mode64 ); |
| 1164 | vassert(spill1 || spill2); /* can't both be NULL */ |
| 1165 | if (spill1) |
| 1166 | EMIT_INSTR(spill1); |
| 1167 | if (spill2) |
| 1168 | EMIT_INSTR(spill2); |
sewardj | 607ca2d | 2007-08-25 21:11:33 +0000 | [diff] [blame] | 1169 | } |
| 1170 | rreg_state[k].eq_spill_slot = True; |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 1171 | } |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 1172 | } |
sewardj | c3bc60a | 2006-12-01 02:59:17 +0000 | [diff] [blame] | 1173 | rreg_state[k].disp = Unavail; |
| 1174 | rreg_state[k].vreg = INVALID_HREG; |
sewardj | 607ca2d | 2007-08-25 21:11:33 +0000 | [diff] [blame] | 1175 | rreg_state[k].eq_spill_slot = False; |
sewardj | c3bc60a | 2006-12-01 02:59:17 +0000 | [diff] [blame] | 1176 | |
| 1177 | /* check for further rregs entering HLRs at this point */ |
| 1178 | rreg_lrs_la_next++; |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 1179 | } |
| 1180 | |
sewardj | c3bc60a | 2006-12-01 02:59:17 +0000 | [diff] [blame] | 1181 | |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 1182 | # if DEBUG_REGALLOC |
| 1183 | vex_printf("After pre-insn actions for fixed regs:\n"); |
| 1184 | PRINT_STATE; |
| 1185 | vex_printf("\n"); |
| 1186 | # endif |
| 1187 | |
| 1188 | |
| 1189 | /* ------ Deal with the current instruction. ------ */ |
| 1190 | |
| 1191 | /* Finally we can begin the processing of this instruction |
| 1192 | itself. The aim is to free up enough rregs for this insn. |
| 1193 | This may generate spill stores since we may have to evict |
| 1194 | some vregs currently in rregs. Also generates spill loads. |
| 1195 | We also build up the final vreg->rreg mapping to be applied |
| 1196 | to the insn. */ |
| 1197 | |
cerion | 92b6436 | 2005-12-13 12:02:26 +0000 | [diff] [blame] | 1198 | (*getRegUsage)( ®_usage, instrs_in->arr[ii], mode64 ); |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 1199 | |
| 1200 | initHRegRemap(&remap); |
| 1201 | |
sewardj | fb7373a | 2007-08-25 21:29:03 +0000 | [diff] [blame] | 1202 | /* ------------ BEGIN directReload optimisation ----------- */ |
| 1203 | |
| 1204 | /* If the instruction reads exactly one vreg which is currently |
| 1205 | in a spill slot, and this is last use of that vreg, see if we |
| 1206 | can convert the instruction into one reads directly from the |
| 1207 | spill slot. This is clearly only possible for x86 and amd64 |
sewardj | 6c299f3 | 2009-12-31 18:00:12 +0000 | [diff] [blame] | 1208 | targets, since ppc and arm load-store architectures. If |
sewardj | fb7373a | 2007-08-25 21:29:03 +0000 | [diff] [blame] | 1209 | successful, replace instrs_in->arr[ii] with this new |
| 1210 | instruction, and recompute its reg usage, so that the change |
| 1211 | is invisible to the standard-case handling that follows. */ |
| 1212 | |
| 1213 | if (directReload && reg_usage.n_used <= 2) { |
| 1214 | Bool debug_direct_reload = True && False; |
| 1215 | HReg cand = INVALID_HREG; |
| 1216 | Bool nreads = 0; |
| 1217 | Short spilloff = 0; |
| 1218 | |
| 1219 | for (j = 0; j < reg_usage.n_used; j++) { |
| 1220 | |
| 1221 | vreg = reg_usage.hreg[j]; |
| 1222 | |
| 1223 | if (!hregIsVirtual(vreg)) |
| 1224 | continue; |
| 1225 | |
| 1226 | if (reg_usage.mode[j] == HRmRead) { |
| 1227 | nreads++; |
| 1228 | m = hregNumber(vreg); |
| 1229 | vassert(IS_VALID_VREGNO(m)); |
| 1230 | k = vreg_state[m]; |
| 1231 | if (!IS_VALID_RREGNO(k)) { |
| 1232 | /* ok, it is spilled. Now, is this its last use? */ |
| 1233 | vassert(vreg_lrs[m].dead_before >= ii+1); |
| 1234 | if (vreg_lrs[m].dead_before == ii+1 |
florian | 79efdc6 | 2013-02-11 00:47:35 +0000 | [diff] [blame] | 1235 | && hregIsInvalid(cand)) { |
sewardj | fb7373a | 2007-08-25 21:29:03 +0000 | [diff] [blame] | 1236 | spilloff = vreg_lrs[m].spill_offset; |
| 1237 | cand = vreg; |
| 1238 | } |
| 1239 | } |
| 1240 | } |
| 1241 | } |
| 1242 | |
florian | 79efdc6 | 2013-02-11 00:47:35 +0000 | [diff] [blame] | 1243 | if (nreads == 1 && ! hregIsInvalid(cand)) { |
sewardj | fb7373a | 2007-08-25 21:29:03 +0000 | [diff] [blame] | 1244 | HInstr* reloaded; |
| 1245 | if (reg_usage.n_used == 2) |
florian | 79efdc6 | 2013-02-11 00:47:35 +0000 | [diff] [blame] | 1246 | vassert(! sameHReg(reg_usage.hreg[0], reg_usage.hreg[1])); |
sewardj | fb7373a | 2007-08-25 21:29:03 +0000 | [diff] [blame] | 1247 | |
| 1248 | reloaded = directReload ( instrs_in->arr[ii], cand, spilloff ); |
| 1249 | if (debug_direct_reload && !reloaded) { |
| 1250 | vex_printf("[%3d] ", spilloff); ppHReg(cand); vex_printf(" "); |
| 1251 | ppInstr(instrs_in->arr[ii], mode64); |
| 1252 | } |
| 1253 | if (reloaded) { |
| 1254 | /* Update info about the insn, so it looks as if it had |
| 1255 | been in this form all along. */ |
| 1256 | instrs_in->arr[ii] = reloaded; |
| 1257 | (*getRegUsage)( ®_usage, instrs_in->arr[ii], mode64 ); |
| 1258 | if (debug_direct_reload && !reloaded) { |
| 1259 | vex_printf(" --> "); |
| 1260 | ppInstr(reloaded, mode64); |
| 1261 | } |
| 1262 | } |
| 1263 | |
| 1264 | if (debug_direct_reload && !reloaded) |
| 1265 | vex_printf("\n"); |
| 1266 | } |
| 1267 | |
| 1268 | } |
| 1269 | |
| 1270 | /* ------------ END directReload optimisation ------------ */ |
| 1271 | |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 1272 | /* for each reg mentioned in the insn ... */ |
| 1273 | for (j = 0; j < reg_usage.n_used; j++) { |
| 1274 | |
| 1275 | vreg = reg_usage.hreg[j]; |
| 1276 | |
| 1277 | /* only interested in virtual registers right now. */ |
| 1278 | if (!hregIsVirtual(vreg)) |
| 1279 | continue; |
| 1280 | |
| 1281 | # if 0 |
| 1282 | vex_printf("considering "); (*ppReg)(vreg); vex_printf("\n"); |
| 1283 | # endif |
| 1284 | |
| 1285 | /* Now we're trying to find a rreg for "vreg". First of all, |
| 1286 | if it already has an rreg assigned, we don't need to do |
| 1287 | anything more. Search the current state to find out. */ |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 1288 | m = hregNumber(vreg); |
| 1289 | vassert(IS_VALID_VREGNO(m)); |
| 1290 | k = vreg_state[m]; |
| 1291 | if (IS_VALID_RREGNO(k)) { |
| 1292 | vassert(rreg_state[k].disp == Bound); |
| 1293 | addToHRegRemap(&remap, vreg, rreg_state[k].rreg); |
sewardj | 607ca2d | 2007-08-25 21:11:33 +0000 | [diff] [blame] | 1294 | /* If this rreg is written or modified, mark it as different |
| 1295 | from any spill slot value. */ |
| 1296 | if (reg_usage.mode[j] != HRmRead) |
| 1297 | rreg_state[k].eq_spill_slot = False; |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 1298 | continue; |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 1299 | } else { |
| 1300 | vassert(k == INVALID_RREG_NO); |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 1301 | } |
| 1302 | |
| 1303 | /* No luck. The next thing to do is see if there is a |
| 1304 | currently free rreg available, of the correct class. If |
| 1305 | so, bag it. NOTE, we could improve this by selecting an |
| 1306 | rreg for which the next live-range event is as far ahead |
| 1307 | as possible. */ |
| 1308 | k_suboptimal = -1; |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 1309 | for (k = 0; k < n_rregs; k++) { |
| 1310 | if (rreg_state[k].disp != Free |
| 1311 | || hregClass(rreg_state[k].rreg) != hregClass(vreg)) |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 1312 | continue; |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 1313 | if (rreg_state[k].has_hlrs) { |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 1314 | /* Well, at least we can use k_suboptimal if we really |
| 1315 | have to. Keep on looking for a better candidate. */ |
| 1316 | k_suboptimal = k; |
| 1317 | } else { |
| 1318 | /* Found a preferable reg. Use it. */ |
| 1319 | k_suboptimal = -1; |
| 1320 | break; |
| 1321 | } |
| 1322 | } |
| 1323 | if (k_suboptimal >= 0) |
| 1324 | k = k_suboptimal; |
| 1325 | |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 1326 | if (k < n_rregs) { |
| 1327 | rreg_state[k].disp = Bound; |
| 1328 | rreg_state[k].vreg = vreg; |
| 1329 | m = hregNumber(vreg); |
| 1330 | vassert(IS_VALID_VREGNO(m)); |
sewardj | d4d3dd6 | 2005-07-04 10:08:24 +0000 | [diff] [blame] | 1331 | vreg_state[m] = toShort(k); |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 1332 | addToHRegRemap(&remap, vreg, rreg_state[k].rreg); |
sewardj | 607ca2d | 2007-08-25 21:11:33 +0000 | [diff] [blame] | 1333 | /* Generate a reload if needed. This only creates needed |
| 1334 | reloads because the live range builder for vregs will |
| 1335 | guarantee that the first event for a vreg is a write. |
| 1336 | Hence, if this reference is not a write, it cannot be |
| 1337 | the first reference for this vreg, and so a reload is |
| 1338 | indeed needed. */ |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 1339 | if (reg_usage.mode[j] != HRmWrite) { |
sewardj | ad572dd | 2004-12-30 01:44:51 +0000 | [diff] [blame] | 1340 | vassert(vreg_lrs[m].reg_class != HRcINVALID); |
sewardj | 6c299f3 | 2009-12-31 18:00:12 +0000 | [diff] [blame] | 1341 | HInstr* reload1 = NULL; |
| 1342 | HInstr* reload2 = NULL; |
| 1343 | (*genReload)( &reload1, &reload2, rreg_state[k].rreg, |
| 1344 | vreg_lrs[m].spill_offset, mode64 ); |
| 1345 | vassert(reload1 || reload2); /* can't both be NULL */ |
| 1346 | if (reload1) |
| 1347 | EMIT_INSTR(reload1); |
| 1348 | if (reload2) |
| 1349 | EMIT_INSTR(reload2); |
sewardj | 7342b1b | 2008-05-30 22:58:07 +0000 | [diff] [blame] | 1350 | /* This rreg is read or modified by the instruction. |
| 1351 | If it's merely read we can claim it now equals the |
| 1352 | spill slot, but not so if it is modified. */ |
| 1353 | if (reg_usage.mode[j] == HRmRead) { |
| 1354 | rreg_state[k].eq_spill_slot = True; |
| 1355 | } else { |
| 1356 | vassert(reg_usage.mode[j] == HRmModify); |
| 1357 | rreg_state[k].eq_spill_slot = False; |
| 1358 | } |
sewardj | 607ca2d | 2007-08-25 21:11:33 +0000 | [diff] [blame] | 1359 | } else { |
| 1360 | rreg_state[k].eq_spill_slot = False; |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 1361 | } |
sewardj | 607ca2d | 2007-08-25 21:11:33 +0000 | [diff] [blame] | 1362 | |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 1363 | continue; |
| 1364 | } |
| 1365 | |
| 1366 | /* Well, now we have no option but to spill a vreg. It's |
| 1367 | important to make a good choice of vreg to spill, and of |
| 1368 | course we need to be careful not to spill a vreg which is |
| 1369 | needed by this insn. */ |
| 1370 | |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 1371 | /* First, mark in the rreg_state, those rregs which are not spill |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 1372 | candidates, due to holding a vreg mentioned by this |
| 1373 | instruction. Or being of the wrong class. */ |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 1374 | for (k = 0; k < n_rregs; k++) { |
| 1375 | rreg_state[k].is_spill_cand = False; |
| 1376 | if (rreg_state[k].disp != Bound) |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 1377 | continue; |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 1378 | if (hregClass(rreg_state[k].rreg) != hregClass(vreg)) |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 1379 | continue; |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 1380 | rreg_state[k].is_spill_cand = True; |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 1381 | for (m = 0; m < reg_usage.n_used; m++) { |
florian | 79efdc6 | 2013-02-11 00:47:35 +0000 | [diff] [blame] | 1382 | if (sameHReg(rreg_state[k].vreg, reg_usage.hreg[m])) { |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 1383 | rreg_state[k].is_spill_cand = False; |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 1384 | break; |
| 1385 | } |
| 1386 | } |
| 1387 | } |
| 1388 | |
| 1389 | /* We can choose to spill any rreg satisfying |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 1390 | rreg_state[r].is_spill_cand (so to speak). Choose r so that |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 1391 | the next use of its associated vreg is as far ahead as |
| 1392 | possible, in the hope that this will minimise the number |
| 1393 | of consequent reloads required. */ |
| 1394 | spillee |
| 1395 | = findMostDistantlyMentionedVReg ( |
cerion | 92b6436 | 2005-12-13 12:02:26 +0000 | [diff] [blame] | 1396 | getRegUsage, instrs_in, ii+1, rreg_state, n_rregs, mode64 ); |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 1397 | |
| 1398 | if (spillee == -1) { |
| 1399 | /* Hmmmmm. There don't appear to be any spill candidates. |
| 1400 | We're hosed. */ |
| 1401 | vex_printf("reg_alloc: can't find a register in class: "); |
| 1402 | ppHRegClass(hregClass(vreg)); |
| 1403 | vex_printf("\n"); |
| 1404 | vpanic("reg_alloc: can't create a free register."); |
| 1405 | } |
| 1406 | |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 1407 | /* Right. So we're going to spill rreg_state[spillee]. */ |
| 1408 | vassert(IS_VALID_RREGNO(spillee)); |
| 1409 | vassert(rreg_state[spillee].disp == Bound); |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 1410 | /* check it's the right class */ |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 1411 | vassert(hregClass(rreg_state[spillee].rreg) == hregClass(vreg)); |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 1412 | /* check we're not ejecting the vreg for which we are trying |
| 1413 | to free up a register. */ |
florian | 79efdc6 | 2013-02-11 00:47:35 +0000 | [diff] [blame] | 1414 | vassert(! sameHReg(rreg_state[spillee].vreg, vreg)); |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 1415 | |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 1416 | m = hregNumber(rreg_state[spillee].vreg); |
| 1417 | vassert(IS_VALID_VREGNO(m)); |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 1418 | |
| 1419 | /* So here's the spill store. Assert that we're spilling a |
| 1420 | live vreg. */ |
sewardj | ad572dd | 2004-12-30 01:44:51 +0000 | [diff] [blame] | 1421 | vassert(vreg_lrs[m].dead_before > ii); |
| 1422 | vassert(vreg_lrs[m].reg_class != HRcINVALID); |
sewardj | 607ca2d | 2007-08-25 21:11:33 +0000 | [diff] [blame] | 1423 | if ((!eq_spill_opt) || !rreg_state[spillee].eq_spill_slot) { |
sewardj | 6c299f3 | 2009-12-31 18:00:12 +0000 | [diff] [blame] | 1424 | HInstr* spill1 = NULL; |
| 1425 | HInstr* spill2 = NULL; |
| 1426 | (*genSpill)( &spill1, &spill2, rreg_state[spillee].rreg, |
| 1427 | vreg_lrs[m].spill_offset, mode64 ); |
| 1428 | vassert(spill1 || spill2); /* can't both be NULL */ |
| 1429 | if (spill1) |
| 1430 | EMIT_INSTR(spill1); |
| 1431 | if (spill2) |
| 1432 | EMIT_INSTR(spill2); |
sewardj | 607ca2d | 2007-08-25 21:11:33 +0000 | [diff] [blame] | 1433 | } |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 1434 | |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 1435 | /* Update the rreg_state to reflect the new assignment for this |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 1436 | rreg. */ |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 1437 | rreg_state[spillee].vreg = vreg; |
| 1438 | vreg_state[m] = INVALID_RREG_NO; |
| 1439 | |
sewardj | 607ca2d | 2007-08-25 21:11:33 +0000 | [diff] [blame] | 1440 | rreg_state[spillee].eq_spill_slot = False; /* be safe */ |
| 1441 | |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 1442 | m = hregNumber(vreg); |
| 1443 | vassert(IS_VALID_VREGNO(m)); |
sewardj | d4d3dd6 | 2005-07-04 10:08:24 +0000 | [diff] [blame] | 1444 | vreg_state[m] = toShort(spillee); |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 1445 | |
| 1446 | /* Now, if this vreg is being read or modified (as opposed to |
| 1447 | written), we have to generate a reload for it. */ |
| 1448 | if (reg_usage.mode[j] != HRmWrite) { |
sewardj | ad572dd | 2004-12-30 01:44:51 +0000 | [diff] [blame] | 1449 | vassert(vreg_lrs[m].reg_class != HRcINVALID); |
sewardj | 6c299f3 | 2009-12-31 18:00:12 +0000 | [diff] [blame] | 1450 | HInstr* reload1 = NULL; |
| 1451 | HInstr* reload2 = NULL; |
| 1452 | (*genReload)( &reload1, &reload2, rreg_state[spillee].rreg, |
| 1453 | vreg_lrs[m].spill_offset, mode64 ); |
| 1454 | vassert(reload1 || reload2); /* can't both be NULL */ |
| 1455 | if (reload1) |
| 1456 | EMIT_INSTR(reload1); |
| 1457 | if (reload2) |
| 1458 | EMIT_INSTR(reload2); |
sewardj | 7342b1b | 2008-05-30 22:58:07 +0000 | [diff] [blame] | 1459 | /* This rreg is read or modified by the instruction. |
| 1460 | If it's merely read we can claim it now equals the |
| 1461 | spill slot, but not so if it is modified. */ |
| 1462 | if (reg_usage.mode[j] == HRmRead) { |
| 1463 | rreg_state[spillee].eq_spill_slot = True; |
| 1464 | } else { |
| 1465 | vassert(reg_usage.mode[j] == HRmModify); |
| 1466 | rreg_state[spillee].eq_spill_slot = False; |
| 1467 | } |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 1468 | } |
| 1469 | |
| 1470 | /* So after much twisting and turning, we have vreg mapped to |
sewardj | 7342b1b | 2008-05-30 22:58:07 +0000 | [diff] [blame] | 1471 | rreg_state[spillee].rreg. Note that in the map. */ |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 1472 | addToHRegRemap(&remap, vreg, rreg_state[spillee].rreg); |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 1473 | |
| 1474 | } /* iterate over registers in this instruction. */ |
| 1475 | |
| 1476 | /* We've finished clowning around with registers in this instruction. |
| 1477 | Three results: |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 1478 | - the running rreg_state[] has been updated |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 1479 | - a suitable vreg->rreg mapping for this instruction has been |
| 1480 | constructed |
| 1481 | - spill and reload instructions may have been emitted. |
| 1482 | |
| 1483 | The final step is to apply the mapping to the instruction, |
| 1484 | and emit that. |
| 1485 | */ |
| 1486 | |
| 1487 | /* NOTE, DESTRUCTIVELY MODIFIES instrs_in->arr[ii]. */ |
cerion | 92b6436 | 2005-12-13 12:02:26 +0000 | [diff] [blame] | 1488 | (*mapRegs)( &remap, instrs_in->arr[ii], mode64 ); |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 1489 | EMIT_INSTR( instrs_in->arr[ii] ); |
| 1490 | |
| 1491 | # if DEBUG_REGALLOC |
| 1492 | vex_printf("After dealing with current insn:\n"); |
| 1493 | PRINT_STATE; |
| 1494 | vex_printf("\n"); |
| 1495 | # endif |
| 1496 | |
| 1497 | /* ------ Post-instruction actions for fixed rreg uses ------ */ |
| 1498 | |
| 1499 | /* Now we need to check for rregs exiting fixed live ranges |
| 1500 | after this instruction, and if so mark them as free. */ |
sewardj | c3bc60a | 2006-12-01 02:59:17 +0000 | [diff] [blame] | 1501 | while (True) { |
| 1502 | vassert(rreg_lrs_db_next >= 0); |
| 1503 | vassert(rreg_lrs_db_next <= rreg_lrs_used); |
| 1504 | if (rreg_lrs_db_next == rreg_lrs_used) |
| 1505 | break; /* no more real reg live ranges to consider */ |
| 1506 | if (ii+1 < rreg_lrs_db[rreg_lrs_db_next].dead_before) |
| 1507 | break; /* next live range does not yet start */ |
| 1508 | vassert(ii+1 == rreg_lrs_db[rreg_lrs_db_next].dead_before); |
| 1509 | /* rreg_lrs_db[[rreg_lrs_db_next].rreg is exiting a hard live |
| 1510 | range. Mark it as such in the main rreg_state array. */ |
| 1511 | for (k = 0; k < n_rregs; k++) |
florian | 79efdc6 | 2013-02-11 00:47:35 +0000 | [diff] [blame] | 1512 | if (sameHReg(rreg_state[k].rreg, rreg_lrs_db[rreg_lrs_db_next].rreg)) |
sewardj | c3bc60a | 2006-12-01 02:59:17 +0000 | [diff] [blame] | 1513 | break; |
| 1514 | /* If this vassertion fails, we don't have an entry for |
| 1515 | this rreg. Which we should. */ |
| 1516 | vassert(k < n_rregs); |
| 1517 | vassert(rreg_state[k].disp == Unavail); |
| 1518 | rreg_state[k].disp = Free; |
| 1519 | rreg_state[k].vreg = INVALID_HREG; |
sewardj | 607ca2d | 2007-08-25 21:11:33 +0000 | [diff] [blame] | 1520 | rreg_state[k].eq_spill_slot = False; |
sewardj | c3bc60a | 2006-12-01 02:59:17 +0000 | [diff] [blame] | 1521 | |
| 1522 | /* check for further rregs leaving HLRs at this point */ |
| 1523 | rreg_lrs_db_next++; |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 1524 | } |
| 1525 | |
| 1526 | # if DEBUG_REGALLOC |
| 1527 | vex_printf("After post-insn actions for fixed regs:\n"); |
| 1528 | PRINT_STATE; |
| 1529 | vex_printf("\n"); |
| 1530 | # endif |
| 1531 | |
| 1532 | } /* iterate over insns */ |
| 1533 | |
| 1534 | /* ------ END: Process each insn in turn. ------ */ |
| 1535 | |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 1536 | /* free(rreg_state); */ |
sewardj | ad572dd | 2004-12-30 01:44:51 +0000 | [diff] [blame] | 1537 | /* free(rreg_lrs); */ |
| 1538 | /* if (vreg_lrs) free(vreg_lrs); */ |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 1539 | |
| 1540 | /* Paranoia */ |
sewardj | ee7d228 | 2005-07-04 09:38:58 +0000 | [diff] [blame] | 1541 | for (j = 0; j < n_rregs; j++) |
florian | 79efdc6 | 2013-02-11 00:47:35 +0000 | [diff] [blame] | 1542 | vassert(sameHReg(rreg_state[j].rreg, available_real_regs[j])); |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 1543 | |
sewardj | c3bc60a | 2006-12-01 02:59:17 +0000 | [diff] [blame] | 1544 | vassert(rreg_lrs_la_next == rreg_lrs_used); |
| 1545 | vassert(rreg_lrs_db_next == rreg_lrs_used); |
| 1546 | |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 1547 | return instrs_out; |
| 1548 | |
| 1549 | # undef INVALID_INSTRNO |
| 1550 | # undef EMIT_INSTR |
| 1551 | # undef PRINT_STATE |
| 1552 | } |
| 1553 | |
| 1554 | |
| 1555 | |
| 1556 | /*---------------------------------------------------------------*/ |
sewardj | cef7d3e | 2009-07-02 12:21:59 +0000 | [diff] [blame] | 1557 | /*--- host_reg_alloc2.c ---*/ |
sewardj | 432b1c9 | 2004-10-30 13:00:55 +0000 | [diff] [blame] | 1558 | /*---------------------------------------------------------------*/ |