resource.c revision 132718
1218893Sdim/* Definitions for computing resource usage of specific insns. 2193326Sed Copyright (C) 1999, 2000, 2001, 2002, 2003 3193326Sed Free Software Foundation, Inc. 4193326Sed 5193326SedThis file is part of GCC. 6193326Sed 7193326SedGCC is free software; you can redistribute it and/or modify it under 8193326Sedthe terms of the GNU General Public License as published by the Free 9193326SedSoftware Foundation; either version 2, or (at your option) any later 10193326Sedversion. 11193326Sed 12193326SedGCC is distributed in the hope that it will be useful, but WITHOUT ANY 13193326SedWARRANTY; without even the implied warranty of MERCHANTABILITY or 14208600SrdivackyFITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 15193326Sedfor more details. 16193326Sed 17224145SdimYou should have received a copy of the GNU General Public License 18199512Srdivackyalong with GCC; see the file COPYING. If not, write to the Free 19193326SedSoftware Foundation, 59 Temple Place - Suite 330, Boston, MA 20199512Srdivacky02111-1307, USA. */ 21212904Sdim 22193326Sed#include "config.h" 23212904Sdim#include "system.h" 24193326Sed#include "coretypes.h" 25226633Sdim#include "tm.h" 26224145Sdim#include "toplev.h" 27198092Srdivacky#include "rtl.h" 28218893Sdim#include "tm_p.h" 29218893Sdim#include "hard-reg-set.h" 30193326Sed#include "basic-block.h" 31218893Sdim#include "function.h" 32218893Sdim#include "regs.h" 33193326Sed#include "flags.h" 34193326Sed#include "output.h" 35193326Sed#include "resource.h" 36234353Sdim#include "except.h" 37224145Sdim#include "insn-attr.h" 38193326Sed#include "params.h" 39193326Sed 40226633Sdim/* This structure is used to record liveness information at the targets or 41193326Sed fallthrough insns of branches. We will most likely need the information 42198092Srdivacky at targets again, so save them in a hash table rather than recomputing them 43193326Sed each time. */ 44234353Sdim 45234353Sdimstruct target_info 46226633Sdim{ 47226633Sdim int uid; /* INSN_UID of target. */ 48198092Srdivacky struct target_info *next; /* Next info for same hash bucket. */ 49234353Sdim HARD_REG_SET live_regs; /* Registers live at target. */ 50234353Sdim int block; /* Basic block number containing target. */ 51234353Sdim int bb_tick; /* Generation count of basic block info. */ 52234353Sdim}; 53234353Sdim 54234353Sdim#define TARGET_HASH_PRIME 257 55234353Sdim 56212904Sdim/* Indicates what resources are required at the beginning of the epilogue. */ 57234353Sdimstatic struct resources start_of_epilogue_needs; 58234353Sdim 59234353Sdim/* Indicates what resources are required at function end. */ 60234353Sdimstatic struct resources end_of_function_needs; 61234353Sdim 62198092Srdivacky/* Define the hash table itself. */ 63198092Srdivackystatic struct target_info **target_hash_table = NULL; 64212904Sdim 65212904Sdim/* For each basic block, we maintain a generation number of its basic 66212904Sdim block info, which is updated each time we move an insn from the 67212904Sdim target of a jump. This is the generation number indexed by block 68212904Sdim number. */ 69212904Sdim 70212904Sdimstatic int *bb_ticks; 71212904Sdim 72212904Sdim/* Marks registers possibly live at the current place being scanned by 73212904Sdim mark_target_live_regs. Also used by update_live_status. */ 74218893Sdim 75218893Sdimstatic HARD_REG_SET current_live_regs; 76218893Sdim 77218893Sdim/* Marks registers for which we have seen a REG_DEAD note but no assignment. 78224145Sdim Also only used by the next two functions. */ 79224145Sdim 80224145Sdimstatic HARD_REG_SET pending_dead_regs; 81224145Sdim 82224145Sdimstatic void update_live_status (rtx, rtx, void *); 83224145Sdimstatic int find_basic_block (rtx, int); 84224145Sdimstatic rtx next_insn_no_annul (rtx); 85224145Sdimstatic rtx find_dead_or_set_registers (rtx, struct resources*, 86224145Sdim rtx*, int, struct resources, 87224145Sdim struct resources); 88224145Sdim 89224145Sdim/* Utility function called from mark_target_live_regs via note_stores. 90224145Sdim It deadens any CLOBBERed registers and livens any SET registers. */ 91224145Sdim 92224145Sdimstatic void 93224145Sdimupdate_live_status (rtx dest, rtx x, void *data ATTRIBUTE_UNUSED) 94224145Sdim{ 95224145Sdim int first_regno, last_regno; 96234353Sdim int i; 97234353Sdim 98234353Sdim if (GET_CODE (dest) != REG 99234353Sdim && (GET_CODE (dest) != SUBREG || GET_CODE (SUBREG_REG (dest)) != REG)) 100224145Sdim return; 101224145Sdim 102224145Sdim if (GET_CODE (dest) == SUBREG) 103224145Sdim first_regno = subreg_regno (dest); 104224145Sdim else 105224145Sdim first_regno = REGNO (dest); 106234353Sdim 107224145Sdim last_regno = first_regno + HARD_REGNO_NREGS (first_regno, GET_MODE (dest)); 108224145Sdim 109224145Sdim if (GET_CODE (x) == CLOBBER) 110224145Sdim for (i = first_regno; i < last_regno; i++) 111224145Sdim CLEAR_HARD_REG_BIT (current_live_regs, i); 112224145Sdim else 113224145Sdim for (i = first_regno; i < last_regno; i++) 114224145Sdim { 115224145Sdim SET_HARD_REG_BIT (current_live_regs, i); 116226633Sdim CLEAR_HARD_REG_BIT (pending_dead_regs, i); 117226633Sdim } 118226633Sdim} 119226633Sdim 120226633Sdim/* Find the number of the basic block with correct live register 121226633Sdim information that starts closest to INSN. Return -1 if we couldn't 122226633Sdim find such a basic block or the beginning is more than 123202879Srdivacky SEARCH_LIMIT instructions before INSN. Use SEARCH_LIMIT = -1 for 124226633Sdim an unlimited search. 125226633Sdim 126226633Sdim The delay slot filling code destroys the control-flow graph so, 127226633Sdim instead of finding the basic block containing INSN, we search 128226633Sdim backwards toward a BARRIER where the live register information is 129226633Sdim correct. */ 130226633Sdim 131226633Sdimstatic int 132226633Sdimfind_basic_block (rtx insn, int search_limit) 133226633Sdim{ 134226633Sdim basic_block bb; 135202879Srdivacky 136202879Srdivacky /* Scan backwards to the previous BARRIER. Then see if we can find a 137226633Sdim label that starts a basic block. Return the basic block number. */ 138226633Sdim for (insn = prev_nonnote_insn (insn); 139226633Sdim insn && GET_CODE (insn) != BARRIER && search_limit != 0; 140226633Sdim insn = prev_nonnote_insn (insn), --search_limit) 141226633Sdim ; 142226633Sdim 143226633Sdim /* The closest BARRIER is too far away. */ 144226633Sdim if (search_limit == 0) 145226633Sdim return -1; 146226633Sdim 147202879Srdivacky /* The start of the function. */ 148202879Srdivacky else if (insn == 0) 149226633Sdim return ENTRY_BLOCK_PTR->next_bb->index; 150202879Srdivacky 151202879Srdivacky /* See if any of the upcoming CODE_LABELs start a basic block. If we reach 152202879Srdivacky anything other than a CODE_LABEL or note, we can't find this code. */ 153223017Sdim for (insn = next_nonnote_insn (insn); 154221345Sdim insn && GET_CODE (insn) == CODE_LABEL; 155202879Srdivacky insn = next_nonnote_insn (insn)) 156202879Srdivacky { 157202879Srdivacky FOR_EACH_BB (bb) 158202879Srdivacky if (insn == BB_HEAD (bb)) 159202879Srdivacky return bb->index; 160202879Srdivacky } 161202879Srdivacky 162202879Srdivacky return -1; 163202879Srdivacky} 164202879Srdivacky 165202879Srdivacky/* Similar to next_insn, but ignores insns in the delay slots of 166202879Srdivacky an annulled branch. */ 167202879Srdivacky 168202879Srdivackystatic rtx 169198092Srdivackynext_insn_no_annul (rtx insn) 170193326Sed{ 171193326Sed if (insn) 172193326Sed { 173193326Sed /* If INSN is an annulled branch, skip any insns from the target 174193326Sed of the branch. */ 175193326Sed if ((GET_CODE (insn) == JUMP_INSN 176226633Sdim || GET_CODE (insn) == CALL_INSN 177226633Sdim || GET_CODE (insn) == INSN) 178226633Sdim && INSN_ANNULLED_BRANCH_P (insn) 179212904Sdim && NEXT_INSN (PREV_INSN (insn)) != insn) 180212904Sdim { 181212904Sdim rtx next = NEXT_INSN (insn); 182212904Sdim enum rtx_code code = GET_CODE (next); 183212904Sdim 184223017Sdim while ((code == INSN || code == JUMP_INSN || code == CALL_INSN) 185234353Sdim && INSN_FROM_TARGET_P (next)) 186234353Sdim { 187234353Sdim insn = next; 188234353Sdim next = NEXT_INSN (insn); 189223017Sdim code = GET_CODE (next); 190212904Sdim } 191212904Sdim } 192212904Sdim 193234353Sdim insn = NEXT_INSN (insn); 194234353Sdim if (insn && GET_CODE (insn) == INSN 195221345Sdim && GET_CODE (PATTERN (insn)) == SEQUENCE) 196221345Sdim insn = XVECEXP (PATTERN (insn), 0, 0); 197193326Sed } 198221345Sdim 199221345Sdim return insn; 200221345Sdim} 201221345Sdim 202221345Sdim/* Given X, some rtl, and RES, a pointer to a `struct resource', mark 203226633Sdim which resources are referenced by the insn. If INCLUDE_DELAYED_EFFECTS 204221345Sdim is TRUE, resources used by the called routine will be included for 205226633Sdim CALL_INSNs. */ 206226633Sdim 207221345Sdimvoid 208221345Sdimmark_referenced_resources (rtx x, struct resources *res, 209221345Sdim int include_delayed_effects) 210221345Sdim{ 211193326Sed enum rtx_code code = GET_CODE (x); 212193326Sed int i, j; 213208600Srdivacky unsigned int r; 214208600Srdivacky const char *format_ptr; 215234353Sdim 216208600Srdivacky /* Handle leaf items for which we set resource flags. Also, special-case 217193326Sed CALL, SET and CLOBBER operators. */ 218193326Sed switch (code) 219193326Sed { 220193326Sed case CONST: 221193326Sed case CONST_INT: 222226633Sdim case CONST_DOUBLE: 223193326Sed case CONST_VECTOR: 224193326Sed case PC: 225193326Sed case SYMBOL_REF: 226234353Sdim case LABEL_REF: 227193326Sed return; 228193326Sed 229193326Sed case SUBREG: 230193326Sed if (GET_CODE (SUBREG_REG (x)) != REG) 231208600Srdivacky mark_referenced_resources (SUBREG_REG (x), res, 0); 232208600Srdivacky else 233208600Srdivacky { 234208600Srdivacky unsigned int regno = subreg_regno (x); 235208600Srdivacky unsigned int last_regno 236208600Srdivacky = regno + HARD_REGNO_NREGS (regno, GET_MODE (x)); 237208600Srdivacky 238193326Sed if (last_regno > FIRST_PSEUDO_REGISTER) 239198092Srdivacky abort (); 240193326Sed for (r = regno; r < last_regno; r++) 241193326Sed SET_HARD_REG_BIT (res->regs, r); 242210299Sed } 243210299Sed return; 244226633Sdim 245226633Sdim case REG: 246193326Sed { 247193326Sed unsigned int regno = REGNO (x); 248193326Sed unsigned int last_regno 249193326Sed = regno + HARD_REGNO_NREGS (regno, GET_MODE (x)); 250193326Sed 251193326Sed if (last_regno > FIRST_PSEUDO_REGISTER) 252207619Srdivacky abort (); 253234353Sdim for (r = regno; r < last_regno; r++) 254234353Sdim SET_HARD_REG_BIT (res->regs, r); 255198092Srdivacky } 256218893Sdim return; 257218893Sdim 258218893Sdim case MEM: 259218893Sdim /* If this memory shouldn't change, it really isn't referencing 260198092Srdivacky memory. */ 261212904Sdim if (RTX_UNCHANGING_P (x)) 262212904Sdim res->unch_memory = 1; 263212904Sdim else 264218893Sdim res->memory = 1; 265218893Sdim res->volatil |= MEM_VOLATILE_P (x); 266221345Sdim 267221345Sdim /* Mark registers used to access memory. */ 268226633Sdim mark_referenced_resources (XEXP (x, 0), res, 0); 269226633Sdim return; 270226633Sdim 271226633Sdim case CC0: 272226633Sdim res->cc = 1; 273226633Sdim return; 274226633Sdim 275226633Sdim case UNSPEC_VOLATILE: 276218893Sdim case ASM_INPUT: 277226633Sdim /* Traditional asm's are always volatile. */ 278218893Sdim res->volatil = 1; 279218893Sdim return; 280218893Sdim 281226633Sdim case TRAP_IF: 282218893Sdim res->volatil = 1; 283218893Sdim break; 284218893Sdim 285226633Sdim case ASM_OPERANDS: 286218893Sdim res->volatil |= MEM_VOLATILE_P (x); 287218893Sdim 288198092Srdivacky /* For all ASM_OPERANDS, we must traverse the vector of input operands. 289198092Srdivacky We can not just fall through here since then we would be confused 290198092Srdivacky by the ASM_INPUT rtx inside ASM_OPERANDS, which do not indicate 291198092Srdivacky traditional asms unlike their normal usage. */ 292198092Srdivacky 293210299Sed for (i = 0; i < ASM_OPERANDS_INPUT_LENGTH (x); i++) 294210299Sed mark_referenced_resources (ASM_OPERANDS_INPUT (x, i), res, 0); 295210299Sed return; 296210299Sed 297234353Sdim case CALL: 298234353Sdim /* The first operand will be a (MEM (xxx)) but doesn't really reference 299210299Sed memory. The second operand may be referenced, though. */ 300210299Sed mark_referenced_resources (XEXP (XEXP (x, 0), 0), res, 0); 301234353Sdim mark_referenced_resources (XEXP (x, 1), res, 0); 302210299Sed return; 303210299Sed 304210299Sed case SET: 305210299Sed /* Usually, the first operand of SET is set, not referenced. But 306226633Sdim registers used to access memory are referenced. SET_DEST is 307210299Sed also referenced if it is a ZERO_EXTRACT or SIGN_EXTRACT. */ 308210299Sed 309210299Sed mark_referenced_resources (SET_SRC (x), res, 0); 310210299Sed 311210299Sed x = SET_DEST (x); 312210299Sed if (GET_CODE (x) == SIGN_EXTRACT 313210299Sed || GET_CODE (x) == ZERO_EXTRACT 314210299Sed || GET_CODE (x) == STRICT_LOW_PART) 315210299Sed mark_referenced_resources (x, res, 0); 316210299Sed else if (GET_CODE (x) == SUBREG) 317210299Sed x = SUBREG_REG (x); 318210299Sed if (GET_CODE (x) == MEM) 319210299Sed mark_referenced_resources (XEXP (x, 0), res, 0); 320210299Sed return; 321212904Sdim 322212904Sdim case CLOBBER: 323212904Sdim return; 324212904Sdim 325212904Sdim case CALL_INSN: 326212904Sdim if (include_delayed_effects) 327212904Sdim { 328212904Sdim /* A CALL references memory, the frame pointer if it exists, the 329212904Sdim stack pointer, any global registers and any registers given in 330226633Sdim USE insns immediately in front of the CALL. 331212904Sdim 332212904Sdim However, we may have moved some of the parameter loading insns 333212904Sdim into the delay slot of this CALL. If so, the USE's for them 334212904Sdim don't count and should be skipped. */ 335212904Sdim rtx insn = PREV_INSN (x); 336212904Sdim rtx sequence = 0; 337212904Sdim int seq_size = 0; 338212904Sdim int i; 339212904Sdim 340212904Sdim /* If we are part of a delay slot sequence, point at the SEQUENCE. */ 341212904Sdim if (NEXT_INSN (insn) != x) 342212904Sdim { 343212904Sdim sequence = PATTERN (NEXT_INSN (insn)); 344212904Sdim seq_size = XVECLEN (sequence, 0); 345212904Sdim if (GET_CODE (sequence) != SEQUENCE) 346212904Sdim abort (); 347212904Sdim } 348212904Sdim 349218893Sdim res->memory = 1; 350218893Sdim SET_HARD_REG_BIT (res->regs, STACK_POINTER_REGNUM); 351212904Sdim if (frame_pointer_needed) 352212904Sdim { 353212904Sdim SET_HARD_REG_BIT (res->regs, FRAME_POINTER_REGNUM); 354212904Sdim#if FRAME_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM 355218893Sdim SET_HARD_REG_BIT (res->regs, HARD_FRAME_POINTER_REGNUM); 356218893Sdim#endif 357210299Sed } 358198092Srdivacky 359198092Srdivacky for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) 360224145Sdim if (global_regs[i]) 361224145Sdim SET_HARD_REG_BIT (res->regs, i); 362226633Sdim 363226633Sdim /* Check for a REG_SETJMP. If it exists, then we must 364224145Sdim assume that this call can need any register. 365224145Sdim 366224145Sdim This is done to be more conservative about how we handle setjmp. 367224145Sdim We assume that they both use and set all registers. Using all 368224145Sdim registers ensures that a register will not be considered dead 369224145Sdim just because it crosses a setjmp call. A register should be 370224145Sdim considered dead only if the setjmp call returns nonzero. */ 371224145Sdim if (find_reg_note (x, REG_SETJMP, NULL)) 372234353Sdim SET_HARD_REG_SET (res->regs); 373234353Sdim 374234353Sdim { 375224145Sdim rtx link; 376234353Sdim 377224145Sdim for (link = CALL_INSN_FUNCTION_USAGE (x); 378224145Sdim link; 379224145Sdim link = XEXP (link, 1)) 380224145Sdim if (GET_CODE (XEXP (link, 0)) == USE) 381224145Sdim { 382224145Sdim for (i = 1; i < seq_size; i++) 383224145Sdim { 384224145Sdim rtx slot_pat = PATTERN (XVECEXP (sequence, 0, i)); 385224145Sdim if (GET_CODE (slot_pat) == SET 386224145Sdim && rtx_equal_p (SET_DEST (slot_pat), 387226633Sdim XEXP (XEXP (link, 0), 0))) 388224145Sdim break; 389224145Sdim } 390224145Sdim if (i >= seq_size) 391224145Sdim mark_referenced_resources (XEXP (XEXP (link, 0), 0), 392224145Sdim res, 0); 393226633Sdim } 394224145Sdim } 395224145Sdim } 396224145Sdim 397224145Sdim /* ... fall through to other INSN processing ... */ 398224145Sdim 399224145Sdim case INSN: 400224145Sdim case JUMP_INSN: 401198092Srdivacky 402198092Srdivacky#ifdef INSN_REFERENCES_ARE_DELAYED 403234353Sdim if (! include_delayed_effects 404234353Sdim && INSN_REFERENCES_ARE_DELAYED (x)) 405234353Sdim return; 406234353Sdim#endif 407234353Sdim 408234353Sdim /* No special processing, just speed up. */ 409234353Sdim mark_referenced_resources (PATTERN (x), res, include_delayed_effects); 410234353Sdim return; 411234353Sdim 412234353Sdim default: 413202879Srdivacky break; 414202879Srdivacky } 415202879Srdivacky 416198092Srdivacky /* Process each sub-expression and flag what it needs. */ 417198092Srdivacky format_ptr = GET_RTX_FORMAT (code); 418198092Srdivacky for (i = 0; i < GET_RTX_LENGTH (code); i++) 419198092Srdivacky switch (*format_ptr++) 420198092Srdivacky { 421198092Srdivacky case 'e': 422226633Sdim mark_referenced_resources (XEXP (x, i), res, include_delayed_effects); 423198092Srdivacky break; 424198092Srdivacky 425198092Srdivacky case 'E': 426198092Srdivacky for (j = 0; j < XVECLEN (x, i); j++) 427234353Sdim mark_referenced_resources (XVECEXP (x, i, j), res, 428234353Sdim include_delayed_effects); 429234353Sdim break; 430234353Sdim } 431234353Sdim} 432234353Sdim 433234353Sdim/* A subroutine of mark_target_live_regs. Search forward from TARGET 434234353Sdim looking for registers that are set before they are used. These are dead. 435234353Sdim Stop after passing a few conditional jumps, and/or a small 436234353Sdim number of unconditional branches. */ 437234353Sdim 438234353Sdimstatic rtx 439234353Sdimfind_dead_or_set_registers (rtx target, struct resources *res, 440234353Sdim rtx *jump_target, int jump_count, 441234353Sdim struct resources set, struct resources needed) 442234353Sdim{ 443234353Sdim HARD_REG_SET scratch; 444234353Sdim rtx insn, next; 445234353Sdim rtx jump_insn = 0; 446234353Sdim int i; 447234353Sdim 448234353Sdim for (insn = target; insn; insn = next) 449234353Sdim { 450234353Sdim rtx this_jump_insn = insn; 451234353Sdim 452234353Sdim next = NEXT_INSN (insn); 453234353Sdim 454234353Sdim /* If this instruction can throw an exception, then we don't 455234353Sdim know where we might end up next. That means that we have to 456234353Sdim assume that whatever we have already marked as live really is 457234353Sdim live. */ 458234353Sdim if (can_throw_internal (insn)) 459202879Srdivacky break; 460202879Srdivacky 461198092Srdivacky switch (GET_CODE (insn)) 462202879Srdivacky { 463202879Srdivacky case CODE_LABEL: 464203955Srdivacky /* After a label, any pending dead registers that weren't yet 465221345Sdim used can be made dead. */ 466221345Sdim AND_COMPL_HARD_REG_SET (pending_dead_regs, needed.regs); 467226633Sdim AND_COMPL_HARD_REG_SET (res->regs, pending_dead_regs); 468226633Sdim CLEAR_HARD_REG_SET (pending_dead_regs); 469226633Sdim 470202879Srdivacky continue; 471221345Sdim 472224145Sdim case BARRIER: 473202879Srdivacky case NOTE: 474202879Srdivacky continue; 475202879Srdivacky 476203955Srdivacky case INSN: 477202879Srdivacky if (GET_CODE (PATTERN (insn)) == USE) 478203955Srdivacky { 479202879Srdivacky /* If INSN is a USE made by update_block, we care about the 480202879Srdivacky underlying insn. Any registers set by the underlying insn 481218893Sdim are live since the insn is being done somewhere else. */ 482221345Sdim if (INSN_P (XEXP (PATTERN (insn), 0))) 483218893Sdim mark_set_resources (XEXP (PATTERN (insn), 0), res, 0, 484218893Sdim MARK_SRC_DEST_CALL); 485218893Sdim 486218893Sdim /* All other USE insns are to be ignored. */ 487218893Sdim continue; 488218893Sdim } 489218893Sdim else if (GET_CODE (PATTERN (insn)) == CLOBBER) 490224145Sdim continue; 491218893Sdim else if (GET_CODE (PATTERN (insn)) == SEQUENCE) 492218893Sdim { 493224145Sdim /* An unconditional jump can be used to fill the delay slot 494224145Sdim of a call, so search for a JUMP_INSN in any position. */ 495218893Sdim for (i = 0; i < XVECLEN (PATTERN (insn), 0); i++) 496202879Srdivacky { 497224145Sdim this_jump_insn = XVECEXP (PATTERN (insn), 0, i); 498202879Srdivacky if (GET_CODE (this_jump_insn) == JUMP_INSN) 499226633Sdim break; 500224145Sdim } 501224145Sdim } 502202879Srdivacky 503224145Sdim default: 504224145Sdim break; 505224145Sdim } 506224145Sdim 507224145Sdim if (GET_CODE (this_jump_insn) == JUMP_INSN) 508226633Sdim { 509224145Sdim if (jump_count++ < 10) 510224145Sdim { 511224145Sdim if (any_uncondjump_p (this_jump_insn) 512226633Sdim || GET_CODE (PATTERN (this_jump_insn)) == RETURN) 513224145Sdim { 514224145Sdim next = JUMP_LABEL (this_jump_insn); 515224145Sdim if (jump_insn == 0) 516224145Sdim { 517224145Sdim jump_insn = insn; 518224145Sdim if (jump_target) 519224145Sdim *jump_target = JUMP_LABEL (this_jump_insn); 520224145Sdim } 521224145Sdim } 522224145Sdim else if (any_condjump_p (this_jump_insn)) 523224145Sdim { 524224145Sdim struct resources target_set, target_res; 525224145Sdim struct resources fallthrough_res; 526198092Srdivacky 527198092Srdivacky /* We can handle conditional branches here by following 528212904Sdim both paths, and then IOR the results of the two paths 529201361Srdivacky together, which will give us registers that are dead 530193326Sed on both paths. Since this is expensive, we give it 531203955Srdivacky a much higher cost than unconditional branches. The 532221345Sdim cost was chosen so that we will follow at most 1 533221345Sdim conditional branch. */ 534221345Sdim 535224145Sdim jump_count += 4; 536224145Sdim if (jump_count >= 10) 537224145Sdim break; 538224145Sdim 539224145Sdim mark_referenced_resources (insn, &needed, 1); 540234353Sdim 541224145Sdim /* For an annulled branch, mark_set_resources ignores slots 542224145Sdim filled by instructions from the target. This is correct 543226633Sdim if the branch is not taken. Since we are following both 544224145Sdim paths from the branch, we must also compute correct info 545226633Sdim if the branch is taken. We do this by inverting all of 546224145Sdim the INSN_FROM_TARGET_P bits, calling mark_set_resources, 547224145Sdim and then inverting the INSN_FROM_TARGET_P bits again. */ 548224145Sdim 549224145Sdim if (GET_CODE (PATTERN (insn)) == SEQUENCE 550226633Sdim && INSN_ANNULLED_BRANCH_P (this_jump_insn)) 551226633Sdim { 552224145Sdim for (i = 1; i < XVECLEN (PATTERN (insn), 0); i++) 553224145Sdim INSN_FROM_TARGET_P (XVECEXP (PATTERN (insn), 0, i)) 554224145Sdim = ! INSN_FROM_TARGET_P (XVECEXP (PATTERN (insn), 0, i)); 555224145Sdim 556224145Sdim target_set = set; 557224145Sdim mark_set_resources (insn, &target_set, 0, 558221345Sdim MARK_SRC_DEST_CALL); 559226633Sdim 560193326Sed for (i = 1; i < XVECLEN (PATTERN (insn), 0); i++) 561221345Sdim INSN_FROM_TARGET_P (XVECEXP (PATTERN (insn), 0, i)) 562221345Sdim = ! INSN_FROM_TARGET_P (XVECEXP (PATTERN (insn), 0, i)); 563221345Sdim 564226633Sdim mark_set_resources (insn, &set, 0, MARK_SRC_DEST_CALL); 565221345Sdim } 566221345Sdim else 567221345Sdim { 568221345Sdim mark_set_resources (insn, &set, 0, MARK_SRC_DEST_CALL); 569226633Sdim target_set = set; 570203955Srdivacky } 571226633Sdim 572226633Sdim target_res = *res; 573226633Sdim COPY_HARD_REG_SET (scratch, target_set.regs); 574226633Sdim AND_COMPL_HARD_REG_SET (scratch, needed.regs); 575226633Sdim AND_COMPL_HARD_REG_SET (target_res.regs, scratch); 576226633Sdim 577226633Sdim fallthrough_res = *res; 578226633Sdim COPY_HARD_REG_SET (scratch, set.regs); 579226633Sdim AND_COMPL_HARD_REG_SET (scratch, needed.regs); 580203955Srdivacky AND_COMPL_HARD_REG_SET (fallthrough_res.regs, scratch); 581226633Sdim 582226633Sdim find_dead_or_set_registers (JUMP_LABEL (this_jump_insn), 583234982Sdim &target_res, 0, jump_count, 584226633Sdim target_set, needed); 585226633Sdim find_dead_or_set_registers (next, 586226633Sdim &fallthrough_res, 0, jump_count, 587226633Sdim set, needed); 588226633Sdim IOR_HARD_REG_SET (fallthrough_res.regs, target_res.regs); 589226633Sdim AND_HARD_REG_SET (res->regs, fallthrough_res.regs); 590226633Sdim break; 591226633Sdim } 592226633Sdim else 593203955Srdivacky break; 594226633Sdim } 595226633Sdim else 596226633Sdim { 597226633Sdim /* Don't try this optimization if we expired our jump count 598226633Sdim above, since that would mean there may be an infinite loop 599226633Sdim in the function being compiled. */ 600221345Sdim jump_insn = 0; 601193326Sed break; 602203955Srdivacky } 603221345Sdim } 604221345Sdim 605226633Sdim mark_referenced_resources (insn, &needed, 1); 606226633Sdim mark_set_resources (insn, &set, 0, MARK_SRC_DEST_CALL); 607221345Sdim 608226633Sdim COPY_HARD_REG_SET (scratch, set.regs); 609221345Sdim AND_COMPL_HARD_REG_SET (scratch, needed.regs); 610221345Sdim AND_COMPL_HARD_REG_SET (res->regs, scratch); 611221345Sdim } 612221345Sdim 613221345Sdim return jump_insn; 614226633Sdim} 615203955Srdivacky 616203955Srdivacky/* Given X, a part of an insn, and a pointer to a `struct resource', 617226633Sdim RES, indicate which resources are modified by the insn. If 618203955Srdivacky MARK_TYPE is MARK_SRC_DEST_CALL, also mark resources potentially 619226633Sdim set by the called routine. 620203955Srdivacky 621193326Sed If IN_DEST is nonzero, it means we are inside a SET. Otherwise, 622226633Sdim objects are being referenced instead of set. 623198092Srdivacky 624212904Sdim We never mark the insn as modifying the condition code unless it explicitly 625212904Sdim SETs CC0 even though this is not totally correct. The reason for this is 626226633Sdim that we require a SET of CC0 to immediately precede the reference to CC0. 627203955Srdivacky So if some other insn sets CC0 as a side-effect, we know it cannot affect 628221345Sdim our computation and thus may be placed in a delay slot. */ 629221345Sdim 630226633Sdimvoid 631221345Sdimmark_set_resources (rtx x, struct resources *res, int in_dest, 632221345Sdim enum mark_resource_type mark_type) 633221345Sdim{ 634221345Sdim enum rtx_code code; 635198092Srdivacky int i, j; 636210299Sed unsigned int r; 637210299Sed const char *format_ptr; 638212904Sdim 639212904Sdim restart: 640198092Srdivacky 641193326Sed code = GET_CODE (x); 642198092Srdivacky 643221345Sdim switch (code) 644221345Sdim { 645221345Sdim case NOTE: 646226633Sdim case BARRIER: 647221345Sdim case CODE_LABEL: 648221345Sdim case USE: 649221345Sdim case CONST_INT: 650203955Srdivacky case CONST_DOUBLE: 651203955Srdivacky case CONST_VECTOR: 652203955Srdivacky case LABEL_REF: 653203955Srdivacky case SYMBOL_REF: 654221345Sdim case CONST: 655203955Srdivacky case PC: 656203955Srdivacky /* These don't set any resources. */ 657221345Sdim return; 658226633Sdim 659203955Srdivacky case CC0: 660203955Srdivacky if (in_dest) 661221345Sdim res->cc = 1; 662221345Sdim return; 663221345Sdim 664203955Srdivacky case CALL_INSN: 665203955Srdivacky /* Called routine modifies the condition code, memory, any registers 666226633Sdim that aren't saved across calls, global registers and anything 667221345Sdim explicitly CLOBBERed immediately after the CALL_INSN. */ 668203955Srdivacky 669221345Sdim if (mark_type == MARK_SRC_DEST_CALL) 670221345Sdim { 671221345Sdim rtx link; 672221345Sdim 673221345Sdim res->cc = res->memory = 1; 674221345Sdim for (r = 0; r < FIRST_PSEUDO_REGISTER; r++) 675221345Sdim if (call_used_regs[r] || global_regs[r]) 676221345Sdim SET_HARD_REG_BIT (res->regs, r); 677221345Sdim 678221345Sdim for (link = CALL_INSN_FUNCTION_USAGE (x); 679221345Sdim link; link = XEXP (link, 1)) 680221345Sdim if (GET_CODE (XEXP (link, 0)) == CLOBBER) 681212904Sdim mark_set_resources (SET_DEST (XEXP (link, 0)), res, 1, 682203955Srdivacky MARK_SRC_DEST); 683218893Sdim 684218893Sdim /* Check for a REG_SETJMP. If it exists, then we must 685218893Sdim assume that this call can clobber any register. */ 686218893Sdim if (find_reg_note (x, REG_SETJMP, NULL)) 687218893Sdim SET_HARD_REG_SET (res->regs); 688218893Sdim } 689218893Sdim 690218893Sdim /* ... and also what its RTL says it modifies, if anything. */ 691218893Sdim 692218893Sdim case JUMP_INSN: 693218893Sdim case INSN: 694218893Sdim 695218893Sdim /* An insn consisting of just a CLOBBER (or USE) is just for flow 696218893Sdim and doesn't actually do anything, so we ignore it. */ 697218893Sdim 698218893Sdim#ifdef INSN_SETS_ARE_DELAYED 699218893Sdim if (mark_type != MARK_SRC_DEST_CALL 700218893Sdim && INSN_SETS_ARE_DELAYED (x)) 701218893Sdim return; 702218893Sdim#endif 703218893Sdim 704218893Sdim x = PATTERN (x); 705218893Sdim if (GET_CODE (x) != USE && GET_CODE (x) != CLOBBER) 706218893Sdim goto restart; 707218893Sdim return; 708218893Sdim 709218893Sdim case SET: 710218893Sdim /* If the source of a SET is a CALL, this is actually done by 711218893Sdim the called routine. So only include it if we are to include the 712218893Sdim effects of the calling routine. */ 713218893Sdim 714218893Sdim mark_set_resources (SET_DEST (x), res, 715218893Sdim (mark_type == MARK_SRC_DEST_CALL 716218893Sdim || GET_CODE (SET_SRC (x)) != CALL), 717234353Sdim mark_type); 718234353Sdim 719218893Sdim mark_set_resources (SET_SRC (x), res, 0, MARK_SRC_DEST); 720218893Sdim return; 721218893Sdim 722218893Sdim case CLOBBER: 723218893Sdim mark_set_resources (XEXP (x, 0), res, 1, MARK_SRC_DEST); 724218893Sdim return; 725218893Sdim 726218893Sdim case SEQUENCE: 727218893Sdim for (i = 0; i < XVECLEN (x, 0); i++) 728218893Sdim if (! (INSN_ANNULLED_BRANCH_P (XVECEXP (x, 0, 0)) 729218893Sdim && INSN_FROM_TARGET_P (XVECEXP (x, 0, i)))) 730218893Sdim mark_set_resources (XVECEXP (x, 0, i), res, 0, mark_type); 731218893Sdim return; 732218893Sdim 733218893Sdim case POST_INC: 734218893Sdim case PRE_INC: 735218893Sdim case POST_DEC: 736218893Sdim case PRE_DEC: 737218893Sdim mark_set_resources (XEXP (x, 0), res, 1, MARK_SRC_DEST); 738218893Sdim return; 739218893Sdim 740218893Sdim case PRE_MODIFY: 741218893Sdim case POST_MODIFY: 742218893Sdim mark_set_resources (XEXP (x, 0), res, 1, MARK_SRC_DEST); 743223017Sdim mark_set_resources (XEXP (XEXP (x, 1), 0), res, 0, MARK_SRC_DEST); 744218893Sdim mark_set_resources (XEXP (XEXP (x, 1), 1), res, 0, MARK_SRC_DEST); 745218893Sdim return; 746218893Sdim 747218893Sdim case SIGN_EXTRACT: 748218893Sdim case ZERO_EXTRACT: 749218893Sdim mark_set_resources (XEXP (x, 0), res, in_dest, MARK_SRC_DEST); 750218893Sdim mark_set_resources (XEXP (x, 1), res, 0, MARK_SRC_DEST); 751212904Sdim mark_set_resources (XEXP (x, 2), res, 0, MARK_SRC_DEST); 752212904Sdim return; 753212904Sdim 754212904Sdim case MEM: 755212904Sdim if (in_dest) 756212904Sdim { 757212904Sdim res->memory = 1; 758212904Sdim res->unch_memory |= RTX_UNCHANGING_P (x); 759212904Sdim res->volatil |= MEM_VOLATILE_P (x); 760212904Sdim } 761212904Sdim 762212904Sdim mark_set_resources (XEXP (x, 0), res, 0, MARK_SRC_DEST); 763210299Sed return; 764210299Sed 765193326Sed case SUBREG: 766193326Sed if (in_dest) 767193326Sed { 768224145Sdim if (GET_CODE (SUBREG_REG (x)) != REG) 769224145Sdim mark_set_resources (SUBREG_REG (x), res, in_dest, mark_type); 770224145Sdim else 771193326Sed { 772226633Sdim unsigned int regno = subreg_regno (x); 773224145Sdim unsigned int last_regno 774224145Sdim = regno + HARD_REGNO_NREGS (regno, GET_MODE (x)); 775193326Sed 776193326Sed if (last_regno > FIRST_PSEUDO_REGISTER) 777218893Sdim abort (); 778210299Sed for (r = regno; r < last_regno; r++) 779210299Sed SET_HARD_REG_BIT (res->regs, r); 780193326Sed } 781198092Srdivacky } 782193326Sed return; 783193326Sed 784193326Sed case REG: 785193326Sed if (in_dest) 786193326Sed { 787193326Sed unsigned int regno = REGNO (x); 788193326Sed unsigned int last_regno 789193326Sed = regno + HARD_REGNO_NREGS (regno, GET_MODE (x)); 790221345Sdim 791226633Sdim if (last_regno > FIRST_PSEUDO_REGISTER) 792193326Sed abort (); 793193326Sed for (r = regno; r < last_regno; r++) 794221345Sdim SET_HARD_REG_BIT (res->regs, r); 795226633Sdim } 796221345Sdim return; 797221345Sdim 798193326Sed case UNSPEC_VOLATILE: 799193326Sed case ASM_INPUT: 800193326Sed /* Traditional asm's are always volatile. */ 801193326Sed res->volatil = 1; 802210299Sed return; 803210299Sed 804218893Sdim case TRAP_IF: 805218893Sdim res->volatil = 1; 806218893Sdim break; 807218893Sdim 808218893Sdim case ASM_OPERANDS: 809218893Sdim res->volatil |= MEM_VOLATILE_P (x); 810218893Sdim 811218893Sdim /* For all ASM_OPERANDS, we must traverse the vector of input operands. 812218893Sdim We can not just fall through here since then we would be confused 813218893Sdim by the ASM_INPUT rtx inside ASM_OPERANDS, which do not indicate 814223017Sdim traditional asms unlike their normal usage. */ 815218893Sdim 816218893Sdim for (i = 0; i < ASM_OPERANDS_INPUT_LENGTH (x); i++) 817218893Sdim mark_set_resources (ASM_OPERANDS_INPUT (x, i), res, in_dest, 818198092Srdivacky MARK_SRC_DEST); 819193326Sed return; 820193326Sed 821193326Sed default: 822193326Sed break; 823199512Srdivacky } 824193326Sed 825193326Sed /* Process each sub-expression and flag what it needs. */ 826193326Sed format_ptr = GET_RTX_FORMAT (code); 827193326Sed for (i = 0; i < GET_RTX_LENGTH (code); i++) 828193326Sed switch (*format_ptr++) 829193326Sed { 830193326Sed case 'e': 831210299Sed mark_set_resources (XEXP (x, i), res, in_dest, mark_type); 832193326Sed break; 833198092Srdivacky 834193326Sed case 'E': 835210299Sed for (j = 0; j < XVECLEN (x, i); j++) 836210299Sed mark_set_resources (XVECEXP (x, i, j), res, in_dest, mark_type); 837193326Sed break; 838193326Sed } 839193326Sed} 840210299Sed 841210299Sed/* Set the resources that are live at TARGET. 842210299Sed 843193326Sed If TARGET is zero, we refer to the end of the current function and can 844193326Sed return our precomputed value. 845193326Sed 846210299Sed Otherwise, we try to find out what is live by consulting the basic block 847210299Sed information. This is tricky, because we must consider the actions of 848210299Sed reload and jump optimization, which occur after the basic block information 849193326Sed has been computed. 850193326Sed 851193326Sed Accordingly, we proceed as follows:: 852210299Sed 853193326Sed We find the previous BARRIER and look at all immediately following labels 854193326Sed (with no intervening active insns) to see if any of them start a basic 855193326Sed block. If we hit the start of the function first, we use block 0. 856210299Sed 857193326Sed Once we have found a basic block and a corresponding first insns, we can 858193326Sed accurately compute the live status from basic_block_live_regs and 859193326Sed reg_renumber. (By starting at a label following a BARRIER, we are immune 860210299Sed to actions taken by reload and jump.) Then we scan all insns between 861193326Sed that point and our target. For each CLOBBER (or for call-clobbered regs 862193326Sed when we pass a CALL_INSN), mark the appropriate registers are dead. For 863193326Sed a SET, mark them as live. 864210299Sed 865210299Sed We have to be careful when using REG_DEAD notes because they are not 866193326Sed updated by such things as find_equiv_reg. So keep track of registers 867193326Sed marked as dead that haven't been assigned to, and mark them dead at the 868193326Sed next CODE_LABEL since reload and jump won't propagate values across labels. 869210299Sed 870210299Sed If we cannot find the start of a basic block (should be a very rare 871193326Sed case, if it can happen at all), mark everything as potentially live. 872193326Sed 873193326Sed Next, scan forward from TARGET looking for things set or clobbered 874210299Sed before they are used. These are not live. 875193326Sed 876193326Sed Because we can be called many times on the same target, save our results 877193326Sed in a hash table indexed by INSN_UID. This is only done if the function 878210299Sed init_resource_info () was invoked before we are called. */ 879193326Sed 880193326Sedvoid 881193326Sedmark_target_live_regs (rtx insns, rtx target, struct resources *res) 882193326Sed{ 883198092Srdivacky int b = -1; 884198092Srdivacky unsigned int i; 885199512Srdivacky struct target_info *tinfo = NULL; 886210299Sed rtx insn; 887198092Srdivacky rtx jump_insn = 0; 888198092Srdivacky rtx jump_target; 889198092Srdivacky HARD_REG_SET scratch; 890198092Srdivacky struct resources set, needed; 891226633Sdim 892198092Srdivacky /* Handle end of function. */ 893198092Srdivacky if (target == 0) 894198092Srdivacky { 895198092Srdivacky *res = end_of_function_needs; 896198092Srdivacky return; 897198092Srdivacky } 898198092Srdivacky 899198092Srdivacky /* We have to assume memory is needed, but the CC isn't. */ 900210299Sed res->memory = 1; 901198092Srdivacky res->volatil = res->unch_memory = 0; 902210299Sed res->cc = 0; 903198092Srdivacky 904210299Sed /* See if we have computed this value already. */ 905198092Srdivacky if (target_hash_table != NULL) 906210299Sed { 907198092Srdivacky for (tinfo = target_hash_table[INSN_UID (target) % TARGET_HASH_PRIME]; 908210299Sed tinfo; tinfo = tinfo->next) 909198092Srdivacky if (tinfo->uid == INSN_UID (target)) 910210299Sed break; 911198092Srdivacky 912210299Sed /* Start by getting the basic block number. If we have saved 913198092Srdivacky information, we can get it from there unless the insn at the 914210299Sed start of the basic block has been deleted. */ 915198092Srdivacky if (tinfo && tinfo->block != -1 916198092Srdivacky && ! INSN_DELETED_P (BB_HEAD (BASIC_BLOCK (tinfo->block)))) 917210299Sed b = tinfo->block; 918193326Sed } 919198092Srdivacky 920198092Srdivacky if (b == -1) 921198092Srdivacky b = find_basic_block (target, MAX_DELAY_SLOT_LIVE_SEARCH); 922210299Sed 923198092Srdivacky if (target_hash_table != NULL) 924210299Sed { 925198092Srdivacky if (tinfo) 926210299Sed { 927198092Srdivacky /* If the information is up-to-date, use it. Otherwise, we will 928210299Sed update it below. */ 929198092Srdivacky if (b == tinfo->block && b != -1 && tinfo->bb_tick == bb_ticks[b]) 930210299Sed { 931198092Srdivacky COPY_HARD_REG_SET (res->regs, tinfo->live_regs); 932210299Sed return; 933198092Srdivacky } 934210299Sed } 935193326Sed else 936198092Srdivacky { 937210299Sed /* Allocate a place to put our results and chain it into the 938198092Srdivacky hash table. */ 939198092Srdivacky tinfo = xmalloc (sizeof (struct target_info)); 940210299Sed tinfo->uid = INSN_UID (target); 941198092Srdivacky tinfo->block = b; 942210299Sed tinfo->next 943198092Srdivacky = target_hash_table[INSN_UID (target) % TARGET_HASH_PRIME]; 944210299Sed target_hash_table[INSN_UID (target) % TARGET_HASH_PRIME] = tinfo; 945198092Srdivacky } 946210299Sed } 947198092Srdivacky 948210299Sed CLEAR_HARD_REG_SET (pending_dead_regs); 949198092Srdivacky 950210299Sed /* If we found a basic block, get the live registers from it and update 951198092Srdivacky them with anything set or killed between its start and the insn before 952198092Srdivacky TARGET. Otherwise, we must assume everything is live. */ 953200583Srdivacky if (b != -1) 954198092Srdivacky { 955198092Srdivacky regset regs_live = BASIC_BLOCK (b)->global_live_at_start; 956212904Sdim unsigned int j; 957212904Sdim unsigned int regno; 958212904Sdim rtx start_insn, stop_insn; 959212904Sdim 960212904Sdim /* Compute hard regs live at start of block -- this is the real hard regs 961226633Sdim marked live, plus live pseudo regs that have been renumbered to 962226633Sdim hard regs. */ 963226633Sdim 964226633Sdim REG_SET_TO_HARD_REG_SET (current_live_regs, regs_live); 965226633Sdim 966226633Sdim EXECUTE_IF_SET_IN_REG_SET 967226633Sdim (regs_live, FIRST_PSEUDO_REGISTER, i, 968226633Sdim { 969226633Sdim if (reg_renumber[i] >= 0) 970226633Sdim { 971226633Sdim regno = reg_renumber[i]; 972226633Sdim for (j = regno; 973226633Sdim j < regno + HARD_REGNO_NREGS (regno, 974226633Sdim PSEUDO_REGNO_MODE (i)); 975226633Sdim j++) 976226633Sdim SET_HARD_REG_BIT (current_live_regs, j); 977226633Sdim } 978226633Sdim }); 979226633Sdim 980226633Sdim /* Get starting and ending insn, handling the case where each might 981226633Sdim be a SEQUENCE. */ 982226633Sdim start_insn = (b == 0 ? insns : BB_HEAD (BASIC_BLOCK (b))); 983193326Sed stop_insn = target; 984198092Srdivacky 985193326Sed if (GET_CODE (start_insn) == INSN 986198092Srdivacky && GET_CODE (PATTERN (start_insn)) == SEQUENCE) 987193326Sed start_insn = XVECEXP (PATTERN (start_insn), 0, 0); 988193326Sed 989193326Sed if (GET_CODE (stop_insn) == INSN 990193326Sed && GET_CODE (PATTERN (stop_insn)) == SEQUENCE) 991193326Sed stop_insn = next_insn (PREV_INSN (stop_insn)); 992201361Srdivacky 993201361Srdivacky for (insn = start_insn; insn != stop_insn; 994201361Srdivacky insn = next_insn_no_annul (insn)) 995201361Srdivacky { 996201361Srdivacky rtx link; 997201361Srdivacky rtx real_insn = insn; 998203955Srdivacky enum rtx_code code = GET_CODE (insn); 999203955Srdivacky 1000203955Srdivacky /* If this insn is from the target of a branch, it isn't going to 1001203955Srdivacky be used in the sequel. If it is used in both cases, this 1002203955Srdivacky test will not be true. */ 1003203955Srdivacky if ((code == INSN || code == JUMP_INSN || code == CALL_INSN) 1004198092Srdivacky && INSN_FROM_TARGET_P (insn)) 1005193326Sed continue; 1006193326Sed 1007193326Sed /* If this insn is a USE made by update_block, we care about the 1008198092Srdivacky underlying insn. */ 1009193326Sed if (code == INSN && GET_CODE (PATTERN (insn)) == USE 1010193326Sed && INSN_P (XEXP (PATTERN (insn), 0))) 1011193326Sed real_insn = XEXP (PATTERN (insn), 0); 1012193326Sed 1013193326Sed if (GET_CODE (real_insn) == CALL_INSN) 1014221345Sdim { 1015221345Sdim /* CALL clobbers all call-used regs that aren't fixed except 1016221345Sdim sp, ap, and fp. Do this before setting the result of the 1017221345Sdim call live. */ 1018221345Sdim AND_COMPL_HARD_REG_SET (current_live_regs, 1019207619Srdivacky regs_invalidated_by_call); 1020207619Srdivacky 1021207619Srdivacky /* A CALL_INSN sets any global register live, since it may 1022207619Srdivacky have been modified by the call. */ 1023207619Srdivacky for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) 1024234353Sdim if (global_regs[i]) 1025234353Sdim SET_HARD_REG_BIT (current_live_regs, i); 1026234353Sdim } 1027234353Sdim 1028212904Sdim /* Mark anything killed in an insn to be deadened at the next 1029226633Sdim label. Ignore USE insns; the only REG_DEAD notes will be for 1030226633Sdim parameters. But they might be early. A CALL_INSN will usually 1031226633Sdim clobber registers used for parameters. It isn't worth bothering 1032212904Sdim with the unlikely case when it won't. */ 1033212904Sdim if ((GET_CODE (real_insn) == INSN 1034193326Sed && GET_CODE (PATTERN (real_insn)) != USE 1035193326Sed && GET_CODE (PATTERN (real_insn)) != CLOBBER) 1036193326Sed || GET_CODE (real_insn) == JUMP_INSN 1037193326Sed || GET_CODE (real_insn) == CALL_INSN) 1038234353Sdim { 1039234353Sdim for (link = REG_NOTES (real_insn); link; link = XEXP (link, 1)) 1040234353Sdim if (REG_NOTE_KIND (link) == REG_DEAD 1041234353Sdim && GET_CODE (XEXP (link, 0)) == REG 1042234353Sdim && REGNO (XEXP (link, 0)) < FIRST_PSEUDO_REGISTER) 1043234353Sdim { 1044234353Sdim unsigned int first_regno = REGNO (XEXP (link, 0)); 1045234353Sdim unsigned int last_regno 1046234353Sdim = (first_regno 1047234353Sdim + HARD_REGNO_NREGS (first_regno, 1048234353Sdim GET_MODE (XEXP (link, 0)))); 1049234353Sdim 1050234353Sdim for (i = first_regno; i < last_regno; i++) 1051234353Sdim SET_HARD_REG_BIT (pending_dead_regs, i); 1052234353Sdim } 1053234353Sdim 1054234353Sdim note_stores (PATTERN (real_insn), update_live_status, NULL); 1055234353Sdim 1056234353Sdim /* If any registers were unused after this insn, kill them. 1057234353Sdim These notes will always be accurate. */ 1058234353Sdim for (link = REG_NOTES (real_insn); link; link = XEXP (link, 1)) 1059234353Sdim if (REG_NOTE_KIND (link) == REG_UNUSED 1060234353Sdim && GET_CODE (XEXP (link, 0)) == REG 1061234353Sdim && REGNO (XEXP (link, 0)) < FIRST_PSEUDO_REGISTER) 1062234353Sdim { 1063234353Sdim unsigned int first_regno = REGNO (XEXP (link, 0)); 1064234353Sdim unsigned int last_regno 1065234353Sdim = (first_regno 1066234353Sdim + HARD_REGNO_NREGS (first_regno, 1067234353Sdim GET_MODE (XEXP (link, 0)))); 1068234353Sdim 1069234353Sdim for (i = first_regno; i < last_regno; i++) 1070234353Sdim CLEAR_HARD_REG_BIT (current_live_regs, i); 1071234353Sdim } 1072234353Sdim } 1073234353Sdim 1074234353Sdim else if (GET_CODE (real_insn) == CODE_LABEL) 1075234353Sdim { 1076234353Sdim /* A label clobbers the pending dead registers since neither 1077234353Sdim reload nor jump will propagate a value across a label. */ 1078234353Sdim AND_COMPL_HARD_REG_SET (current_live_regs, pending_dead_regs); 1079234353Sdim CLEAR_HARD_REG_SET (pending_dead_regs); 1080234353Sdim } 1081234353Sdim 1082234353Sdim /* The beginning of the epilogue corresponds to the end of the 1083234353Sdim RTL chain when there are no epilogue insns. Certain resources 1084234353Sdim are implicitly required at that point. */ 1085234353Sdim else if (GET_CODE (real_insn) == NOTE 1086234353Sdim && NOTE_LINE_NUMBER (real_insn) == NOTE_INSN_EPILOGUE_BEG) 1087234353Sdim IOR_HARD_REG_SET (current_live_regs, start_of_epilogue_needs.regs); 1088234353Sdim } 1089234982Sdim 1090234353Sdim COPY_HARD_REG_SET (res->regs, current_live_regs); 1091234353Sdim if (tinfo != NULL) 1092234353Sdim { 1093234353Sdim tinfo->block = b; 1094234353Sdim tinfo->bb_tick = bb_ticks[b]; 1095234353Sdim } 1096234353Sdim } 1097234353Sdim else 1098234353Sdim /* We didn't find the start of a basic block. Assume everything 1099234353Sdim in use. This should happen only extremely rarely. */ 1100234353Sdim SET_HARD_REG_SET (res->regs); 1101234353Sdim 1102234353Sdim CLEAR_RESOURCE (&set); 1103234353Sdim CLEAR_RESOURCE (&needed); 1104234353Sdim 1105234353Sdim jump_insn = find_dead_or_set_registers (target, res, &jump_target, 0, 1106234353Sdim set, needed); 1107234982Sdim 1108234353Sdim /* If we hit an unconditional branch, we have another way of finding out 1109234353Sdim what is live: we can see what is live at the branch target and include 1110234353Sdim anything used but not set before the branch. We add the live 1111234353Sdim resources found using the test below to those found until now. */ 1112234353Sdim 1113234353Sdim if (jump_insn) 1114234353Sdim { 1115234353Sdim struct resources new_resources; 1116234353Sdim rtx stop_insn = next_active_insn (jump_insn); 1117234353Sdim 1118234353Sdim mark_target_live_regs (insns, next_active_insn (jump_target), 1119234353Sdim &new_resources); 1120234353Sdim CLEAR_RESOURCE (&set); 1121234353Sdim CLEAR_RESOURCE (&needed); 1122234353Sdim 1123234353Sdim /* Include JUMP_INSN in the needed registers. */ 1124234353Sdim for (insn = target; insn != stop_insn; insn = next_active_insn (insn)) 1125234353Sdim { 1126234353Sdim mark_referenced_resources (insn, &needed, 1); 1127234353Sdim 1128234353Sdim COPY_HARD_REG_SET (scratch, needed.regs); 1129234353Sdim AND_COMPL_HARD_REG_SET (scratch, set.regs); 1130234353Sdim IOR_HARD_REG_SET (new_resources.regs, scratch); 1131234353Sdim 1132234353Sdim mark_set_resources (insn, &set, 0, MARK_SRC_DEST_CALL); 1133234353Sdim } 1134234353Sdim 1135234353Sdim IOR_HARD_REG_SET (res->regs, new_resources.regs); 1136234353Sdim } 1137234353Sdim 1138234353Sdim if (tinfo != NULL) 1139234353Sdim { 1140234353Sdim COPY_HARD_REG_SET (tinfo->live_regs, res->regs); 1141234353Sdim } 1142234353Sdim} 1143234353Sdim 1144234353Sdim/* Initialize the resources required by mark_target_live_regs (). 1145234353Sdim This should be invoked before the first call to mark_target_live_regs. */ 1146234353Sdim 1147234353Sdimvoid 1148234353Sdiminit_resource_info (rtx epilogue_insn) 1149234353Sdim{ 1150234353Sdim int i; 1151234353Sdim 1152234353Sdim /* Indicate what resources are required to be valid at the end of the current 1153234353Sdim function. The condition code never is and memory always is. If the 1154234353Sdim frame pointer is needed, it is and so is the stack pointer unless 1155234353Sdim EXIT_IGNORE_STACK is nonzero. If the frame pointer is not needed, the 1156234353Sdim stack pointer is. Registers used to return the function value are 1157234353Sdim needed. Registers holding global variables are needed. */ 1158234353Sdim 1159234353Sdim end_of_function_needs.cc = 0; 1160234353Sdim end_of_function_needs.memory = 1; 1161234353Sdim end_of_function_needs.unch_memory = 0; 1162234353Sdim CLEAR_HARD_REG_SET (end_of_function_needs.regs); 1163234353Sdim 1164234353Sdim if (frame_pointer_needed) 1165234353Sdim { 1166234353Sdim SET_HARD_REG_BIT (end_of_function_needs.regs, FRAME_POINTER_REGNUM); 1167234353Sdim#if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM 1168234353Sdim SET_HARD_REG_BIT (end_of_function_needs.regs, HARD_FRAME_POINTER_REGNUM); 1169234353Sdim#endif 1170234353Sdim if (! EXIT_IGNORE_STACK 1171234353Sdim || current_function_sp_is_unchanging) 1172234353Sdim SET_HARD_REG_BIT (end_of_function_needs.regs, STACK_POINTER_REGNUM); 1173234353Sdim } 1174234353Sdim else 1175234353Sdim SET_HARD_REG_BIT (end_of_function_needs.regs, STACK_POINTER_REGNUM); 1176234353Sdim 1177234353Sdim if (current_function_return_rtx != 0) 1178234353Sdim mark_referenced_resources (current_function_return_rtx, 1179234353Sdim &end_of_function_needs, 1); 1180234353Sdim 1181234353Sdim for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) 1182234353Sdim if (global_regs[i] 1183234353Sdim#ifdef EPILOGUE_USES 1184234353Sdim || EPILOGUE_USES (i) 1185234353Sdim#endif 1186234353Sdim ) 1187234353Sdim SET_HARD_REG_BIT (end_of_function_needs.regs, i); 1188234353Sdim 1189234353Sdim /* The registers required to be live at the end of the function are 1190234353Sdim represented in the flow information as being dead just prior to 1191234353Sdim reaching the end of the function. For example, the return of a value 1192234353Sdim might be represented by a USE of the return register immediately 1193234353Sdim followed by an unconditional jump to the return label where the 1194234353Sdim return label is the end of the RTL chain. The end of the RTL chain 1195234353Sdim is then taken to mean that the return register is live. 1196234353Sdim 1197234353Sdim This sequence is no longer maintained when epilogue instructions are 1198234353Sdim added to the RTL chain. To reconstruct the original meaning, the 1199234353Sdim start of the epilogue (NOTE_INSN_EPILOGUE_BEG) is regarded as the 1200234353Sdim point where these registers become live (start_of_epilogue_needs). 1201234353Sdim If epilogue instructions are present, the registers set by those 1202234353Sdim instructions won't have been processed by flow. Thus, those 1203234353Sdim registers are additionally required at the end of the RTL chain 1204234353Sdim (end_of_function_needs). */ 1205234353Sdim 1206234353Sdim start_of_epilogue_needs = end_of_function_needs; 1207234353Sdim 1208234353Sdim while ((epilogue_insn = next_nonnote_insn (epilogue_insn))) 1209234353Sdim mark_set_resources (epilogue_insn, &end_of_function_needs, 0, 1210234353Sdim MARK_SRC_DEST_CALL); 1211234353Sdim 1212234353Sdim /* Allocate and initialize the tables used by mark_target_live_regs. */ 1213234353Sdim target_hash_table = xcalloc (TARGET_HASH_PRIME, sizeof (struct target_info *)); 1214234353Sdim bb_ticks = xcalloc (last_basic_block, sizeof (int)); 1215234353Sdim} 1216234353Sdim 1217234353Sdim/* Free up the resources allocated to mark_target_live_regs (). This 1218234353Sdim should be invoked after the last call to mark_target_live_regs (). */ 1219234353Sdim 1220234353Sdimvoid 1221234353Sdimfree_resource_info (void) 1222234353Sdim{ 1223234353Sdim if (target_hash_table != NULL) 1224234353Sdim { 1225234353Sdim int i; 1226234353Sdim 1227234353Sdim for (i = 0; i < TARGET_HASH_PRIME; ++i) 1228234353Sdim { 1229234353Sdim struct target_info *ti = target_hash_table[i]; 1230234353Sdim 1231234353Sdim while (ti) 1232234353Sdim { 1233234353Sdim struct target_info *next = ti->next; 1234234353Sdim free (ti); 1235234353Sdim ti = next; 1236234353Sdim } 1237234353Sdim } 1238234353Sdim 1239234353Sdim free (target_hash_table); 1240234353Sdim target_hash_table = NULL; 1241234353Sdim } 1242234353Sdim 1243234353Sdim if (bb_ticks != NULL) 1244234353Sdim { 1245234353Sdim free (bb_ticks); 1246234353Sdim bb_ticks = NULL; 1247234353Sdim } 1248234353Sdim} 1249234353Sdim 1250234353Sdim/* Clear any hashed information that we have stored for INSN. */ 1251234353Sdim 1252234353Sdimvoid 1253234353Sdimclear_hashed_info_for_insn (rtx insn) 1254234353Sdim{ 1255234353Sdim struct target_info *tinfo; 1256234353Sdim 1257234353Sdim if (target_hash_table != NULL) 1258234353Sdim { 1259234353Sdim for (tinfo = target_hash_table[INSN_UID (insn) % TARGET_HASH_PRIME]; 1260234353Sdim tinfo; tinfo = tinfo->next) 1261234353Sdim if (tinfo->uid == INSN_UID (insn)) 1262234353Sdim break; 1263234353Sdim 1264234353Sdim if (tinfo) 1265234353Sdim tinfo->block = -1; 1266234353Sdim } 1267234353Sdim} 1268234353Sdim 1269234353Sdim/* Increment the tick count for the basic block that contains INSN. */ 1270234353Sdim 1271234353Sdimvoid 1272234353Sdimincr_ticks_for_insn (rtx insn) 1273234353Sdim{ 1274234353Sdim int b = find_basic_block (insn, MAX_DELAY_SLOT_LIVE_SEARCH); 1275234353Sdim 1276234353Sdim if (b != -1) 1277234353Sdim bb_ticks[b]++; 1278234353Sdim} 1279234353Sdim 1280234353Sdim/* Add TRIAL to the set of resources used at the end of the current 1281234353Sdim function. */ 1282234353Sdimvoid 1283234353Sdimmark_end_of_function_resources (rtx trial, int include_delayed_effects) 1284234353Sdim{ 1285234353Sdim mark_referenced_resources (trial, &end_of_function_needs, 1286234353Sdim include_delayed_effects); 1287234353Sdim} 1288234353Sdim