138 lines
4.5 KiB
C
138 lines
4.5 KiB
C
/*
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* R E G I S T E R A L L O C A T I O N
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*
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*/
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/* TEMPORARY: should be put in ../../../h/em_mes.h: */
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#define ms_liv 9
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#define ms_ded 10
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#define INFINITE 10000
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#define NRREGTYPES (reg_float+1)
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int nrinstrs; /* number of instructions of current procedure */
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line_p *instrmap; /* Dynamic array: instrmap[i] points to i'th instruction */
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extern cond_p alocaltab[NRREGTYPES][NRREGTYPES],
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alocaddrtab[NRREGTYPES][NRREGTYPES], aconsttab,
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adconsttab,aglobaltab,aproctab;
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extern cond_p olocaltab[NRREGTYPES],olocaddrtab[NRREGTYPES],
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oconsttab,odconsttab,oglobaltab,oproctab;
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extern cond_p regsav_cost;
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/* Register Allocation */
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typedef struct item *item_p;
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typedef struct allocation *alloc_p;
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typedef struct interval *interv_p;
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typedef struct time *time_p;
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extern short regs_available[]; /* contains #registers of every type */
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/* A thing that can be put in a register is called an "item". The are several
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* types of items: a local variable, the address of a local variable,
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* the address of a global variable, the address of a procedure,
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* a word-size constant and a doubleword- size constant.
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*/
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#define LOCALVAR 0
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#define LOCAL_ADDR 1
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#define GLOBL_ADDR 2
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#define PROC_ADDR 3
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#define CONST 4
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#define DCONST 5
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#define NO_ITEM 6
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#define NRITEMTYPES 6
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struct item {
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item_p it_next; /* link to next item is list */
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short it_type; /* its type; see above */
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short it_regtype; /* preferred type of register */
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short it_size; /* its size (in bytes) */
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short it_lastlive; /* temporary, used to build livetime */
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lset it_usage; /* all points in text where item is used*/
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interv_p it_lives; /* intervals during which item is live */
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bool it_desirable; /* should this item be put in reg.? */
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union {
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obj_p it_obj; /* for GLOBL_ADDR */
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proc_p it_proc; /* for PROC_ADDR */
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offset it_off; /* for others */
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} i_t;
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};
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/* A 'point in time' is defined by a (line,basic block) pair */
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struct time {
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line_p t_line; /* point in EM text */
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bblock_p t_bblock; /* its basic block */
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};
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struct interval {
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short i_start; /* number of first instruction */
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short i_stop; /* number of last instruction */
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interv_p i_next;
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};
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/* An item may be put in a register for the duration of a whole procedure
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* or part of a procedure (e.g. a loop). So a possible "allocation" looks
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* like: put item X in a register during the timespan T (which is a subset
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* of the timespan of the entire procedure). The packing process deals
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* with allocations, rather than items. One item may be part of several
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* possible allocations.
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*/
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struct allocation {
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item_p al_item; /* the item to be put in a register */
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short al_id; /* unique identifying number */
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short al_regtype; /* the register type to be used */
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interv_p al_timespan; /* timespan during which item is in reg. */
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short al_profits; /* gains of putting item in register */
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cset al_rivals; /* set of allocations competing with it */
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short al_susecount; /* #usages during timespan (statically) */
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short al_dusecount; /* #usages (dynamically, estimate) */
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lset al_inits; /* points where reg. must be initialized */
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interv_p al_busy; /* used to compute rivals */
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short al_regnr; /* register nr.,if it is granted a reg. */
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offset al_dummy; /* dummy local variable,if granted a reg */
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alloc_p al_mates; /* link to allocations packed in same reg */
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alloc_p al_wholeproc; /* alloc. for whole proc as timespan */
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short al_cntrivals; /* # unpacked rivals ; used for cost estim. */
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bool al_isloop; /* true if timespan consists of loop */
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bool al_iswholeproc;/*true if timespan consists of whole proc*/
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alloc_p al_next; /* link to next one in a list */
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};
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extern short alloc_id; /* last al_id used for current procedure */
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#define LP_BLOCKS lp_extend->lpx_ra.lpx_blocks
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#define LP_HEADER lp_extend->lpx_ra.lpx_header
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#define B_BEGIN b_extend->bx_ra.bx_begin
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#define B_END b_extend->bx_ra.bx_end
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#define B_DIST b_extend->bx_ra.bx_dist
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#define B_USECNT b_extend->bx_ra.bx_usecnt
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#define B_MARK b_extend->bx_ra.bx_mark
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#define DLINK(l1,l2) l1->l_next=l2; l2->l_prev=l1
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struct item_descr {
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int id_type;
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int id_replindex;
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} ;
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extern struct item_descr itemtab[];
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#define newalloc() (alloc_p) newstruct(allocation)
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#define oldalloc(a) oldstruct(allocation,a)
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#define newitem() (item_p) newstruct(item)
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#define olditem(i) oldstruct(item,i)
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#define newtime() (time_p) newstruct(time)
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#define oldtime(t) oldstruct(time,t)
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#define newinterval() (interv_p) newstruct(interval)
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#define oldinterval(i) oldstruct(interval,i)
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