ref: 03aaebc565cf8b99b2babb03120998ab3f5a6d31
dir: /6/asm.h/
#define Maxarg 4 /* maximum number of args an insn can have */
#define Maxuse (2*Maxarg) /* maximum number of registers an insn can use or def */
#define Maxdef (2*Maxarg) /* maximum number of registers an insn can use or def */
#define Wordsz 4 /* the size of a "natural int" */
#define Ptrsz 8 /* the size of a machine word (ie, pointer size) */
#define Nsaved 13 /* number of registers saved in the ABI */
typedef size_t regid;
typedef struct Insn Insn;
typedef struct Loc Loc;
typedef struct Func Func;
typedef struct Blob Blob;
typedef struct Isel Isel;
typedef struct Asmbb Asmbb;
typedef enum {
#define Insn(val, fmt, use, def) val,
#include "insns.def"
#undef Insn
} AsmOp;
typedef enum {
#define Reg(r, name, mode) r,
#include "regs.def"
#undef Reg
Nreg
} Reg;
typedef enum {
Locnone,
Loclbl, /* label */
Locreg, /* register */
Locmem, /* reg offset mem */
Locmeml, /* label offset mem */
Loclit, /* literal value */
Loclitl /* label address */
} Loctype;
typedef enum {
ModeNone,
ModeB, /* byte */
ModeW, /* short */
ModeL, /* long */
ModeQ, /* quad */
ModeF, /* float32 */
ModeD, /* float64 */
Nmode,
} Mode;
typedef enum {
Classbad,
Classint,
Classflt,
Nclass,
} Rclass;
/* a register, label, or memory location */
struct Loc {
Loctype type; /* the type of loc */
Mode mode; /* the mode of this location */
void *list;
union {
char *lbl; /* for Loclbl, Loclitl */
struct { /* for Locreg */
regid id;
Reg colour;
} reg;
long lit; /* for Loclit */
/*
* for Locmem, Locmeml.
* address format is
* disp(base + index)
*/
struct {
/* only one of lbldisp and constdisp may be used */
char *lbldisp;
long constdisp;
int scale; /* 0,1,2,4, or 8 */
Loc *base; /* needed */
Loc *idx; /* optional */
} mem;
};
};
struct Insn {
size_t uid;
AsmOp op;
Loc *args[Maxarg];
size_t nargs;
};
struct Func {
char *name; /* function name */
int isexport; /* is this exported from the asm? */
size_t stksz; /* stack size */
Type *type; /* type of function */
Htab *stkoff; /* Loc* -> int stackoff map */
Node *ret; /* return value */
Cfg *cfg; /* flow graph */
};
struct Asmbb {
int id; /* unique identifier */
char **lbls; /* list of BB labels */
size_t nlbls; /* number of labels */
Insn **il; /* instructions */
size_t ni; /* number of instructions */
Bitset *pred; /* set of predecessor BB ids */
Bitset *succ; /* set of successor BB ids */
Bitset *use; /* registers used by this BB */
Bitset *def; /* registers defined by this BB */
Bitset *livein; /* variables live on entrance to BB */
Bitset *liveout; /* variables live on exit from BB */
};
/* instruction selection state */
struct Isel {
Cfg *cfg; /* cfg built with nodes */
Asmbb **bb; /* 1:1 mappings with the Node bbs in the CFG */
size_t nbb;
Asmbb *curbb;
Node *ret; /* we store the return into here */
Htab *spillslots; /* reg id => int stkoff */
Htab *reglocs; /* decl id => Loc *reg */
Htab *stkoff; /* decl id => int stkoff */
Htab *globls; /* decl id => char *globlname */
/* increased when we spill */
Loc *stksz;
Loc *calleesave[Nsaved];
/* register allocator state */
size_t *gbits; /* igraph matrix repr */
regid **gadj; /* igraph adj set repr */
size_t *ngadj;
int *degree; /* degree of nodes */
Loc **aliasmap; /* mapping of aliases */
Bitset *shouldspill; /* the first registers we should try to spill */
Bitset *neverspill; /* registers we should never spill */
Insn ***rmoves;
size_t *nrmoves;
/* move sets */
Insn **mcoalesced;
size_t nmcoalesced;
Insn **mconstrained;
size_t nmconstrained;
Insn **mfrozen;
size_t nmfrozen;
Bitset *mactiveset;
Insn **mactive;
size_t nmactive;
/* worklists */
Bitset *wlmoveset;
Insn **wlmove;
size_t nwlmove;
Loc **wlspill;
size_t nwlspill;
Loc **wlfreeze;
size_t nwlfreeze;
Loc **wlsimp;
size_t nwlsimp;
Loc **selstk;
size_t nselstk;
Bitset *coalesced;
Bitset *spilled;
Bitset *prepainted; /* locations that need to be a specific colour */
Bitset *initial; /* initial set of locations used by this fn */
};
/* entry points */
void genblob(FILE *fd, Node *blob, Htab *globls, Htab *strtab);
void genasm(FILE *fd, Func *fn, Htab *globls, Htab *strtab);
void genstrings(FILE *fd, Htab *strtab);
void gen(Node *file, char *out);
/* location generation */
extern size_t maxregid;
extern Loc **locmap; /* mapping from reg id => Loc * */
char *genlblstr(char *buf, size_t sz);
Node *genlbl(void);
Loc *loclbl(Node *lbl);
Loc *locstrlbl(char *lbl);
Loc *locreg(Mode m);
Loc *locphysreg(Reg r);
Loc *locmem(long disp, Loc *base, Loc *idx, Mode mode);
Loc *locmeml(char *disp, Loc *base, Loc *idx, Mode mode);
Loc *locmems(long disp, Loc *base, Loc *idx, int scale, Mode mode);
Loc *locmemls(char *disp, Loc *base, Loc *idx, int scale, Mode mode);
Loc *loclit(long val, Mode m);
Loc *loclitl(char *lbl);
Loc *coreg(Reg r, Mode m);
void locprint(FILE *fd, Loc *l, char spec);
void iprintf(FILE *fd, Insn *insn);
/* emitting instructions */
Insn *mkinsn(AsmOp op, ...);
/* register allocation */
extern char *regnames[]; /* name table */
extern Mode regmodes[]; /* mode table */
extern size_t modesize[]; /* mode size table */
void regalloc(Isel *s);
Rclass rclass(Loc *l);
/* useful functions */
size_t tysize(Type *t);
size_t size(Node *n);
int stacktype(Type *t);
int floattype(Type *t);
int stacknode(Node *n);
int floatnode(Node *n);
void breakhere();
void dumpasm(Isel *s, FILE *fd);
size_t alignto(size_t sz, Type *t);