| /* Example backend for vbcc, it models a generic 32bit RISC or CISC |
| CPU. |
| |
| Configurable at build-time are: |
| - number of (32bit) general-purpose-registers |
| - number of (64bit) floating-point-registers |
| - number of (8bit) condition-code-registers |
| - mechanism for stack-arguments (moving ot fixed sp) |
| |
| It allows to select as run-time-options: |
| - two- or three-address code |
| - memory operands or load-store-architecture |
| - number of register-arguments |
| - number of caller-save-registers |
| */ |
| |
| #include "supp.h" |
| |
| static char FILE_[]=__FILE__; |
| |
| /* Public data that MUST be there. */ |
| |
| /* Name and copyright. */ |
| char cg_copyright[]="vbcc bc16 code-generator V0.1 (c) in 2021 by Volker Barthelmann"; |
| |
| /* Commandline-flags the code-generator accepts: |
| 0: just a flag |
| VALFLAG: a value must be specified |
| STRINGFLAG: a string can be specified |
| FUNCFLAG: a function will be called |
| apart from FUNCFLAG, all other versions can only be specified once */ |
| int g_flags[MAXGF]={0,0, |
| VALFLAG,VALFLAG,VALFLAG, |
| 0,0, |
| VALFLAG,VALFLAG,0}; |
| |
| /* the flag-name, do not use names beginning with l, L, I, D or U, because |
| they collide with the frontend */ |
| char *g_flags_name[MAXGF]={"three-addr","load-store", |
| "volatile-gprs","volatile-fprs","volatile-ccrs", |
| "imm-ind","gpr-ind", |
| "gpr-args","fpr-args","use-commons"}; |
| |
| /* the results of parsing the command-line-flags will be stored here */ |
| union ppi g_flags_val[MAXGF]; |
| |
| /* Alignment-requirements for all types in bytes. */ |
| zmax align[MAX_TYPE+1]; |
| |
| /* Alignment that is sufficient for every object. */ |
| zmax maxalign; |
| |
| /* CHAR_BIT for the target machine. */ |
| zmax char_bit; |
| |
| /* sizes of the basic types (in bytes) */ |
| zmax sizetab[MAX_TYPE+1]; |
| |
| /* Minimum and Maximum values each type can have. */ |
| /* Must be initialized in init_cg(). */ |
| zmax t_min[MAX_TYPE+1]; |
| zumax t_max[MAX_TYPE+1]; |
| zumax tu_max[MAX_TYPE+1]; |
| |
| /* Names of all registers. will be initialized in init_cg(), |
| register number 0 is invalid, valid registers start at 1 */ |
| char *regnames[MAXR+1]; |
| |
| /* The Size of each register in bytes. */ |
| zmax regsize[MAXR+1]; |
| |
| /* a type which can store each register. */ |
| struct Typ *regtype[MAXR+1]; |
| |
| /* regsa[reg]!=0 if a certain register is allocated and should */ |
| /* not be used by the compiler pass. */ |
| int regsa[MAXR+1]; |
| |
| /* Specifies which registers may be scratched by functions. */ |
| int regscratch[MAXR+1]; |
| |
| /* specifies the priority for the register-allocator, if the same |
| estimated cost-saving can be obtained by several registers, the |
| one with the highest priority will be used */ |
| int reg_prio[MAXR+1]; |
| |
| /* an empty reg-handle representing initial state */ |
| struct reg_handle empty_reg_handle={0,0}; |
| |
| /* Names of target-specific variable attributes. */ |
| char *g_attr_name[]={"__interrupt",0}; |
| |
| |
| /****************************************/ |
| /* Private data and functions. */ |
| /****************************************/ |
| |
| #define THREE_ADDR (g_flags[0]&USEDFLAG) |
| #define LOAD_STORE (g_flags[1]&USEDFLAG) |
| #define VOL_GPRS ((g_flags[2]&USEDFLAG)?g_flags_val[2].l:NUM_GPRS/2) |
| #define VOL_FPRS ((g_flags[3]&USEDFLAG)?g_flags_val[3].l:NUM_FPRS/2) |
| #define VOL_CCRS ((g_flags[4]&USEDFLAG)?g_flags_val[4].l:NUM_CCRS/2) |
| #define IMM_IND ((g_flags[5]&USEDFLAG)?1:0) |
| #define GPR_IND ((g_flags[6]&USEDFLAG)?2:0) |
| #define GPR_ARGS ((g_flags[7]&USEDFLAG)?g_flags_val[7].l:0) |
| #define FPR_ARGS ((g_flags[8]&USEDFLAG)?g_flags_val[8].l:0) |
| #define USE_COMMONS (g_flags[9]&USEDFLAG) |
| |
| |
| /* alignment of basic data-types, used to initialize align[] */ |
| static long malign[MAX_TYPE+1]= {1,1,2,4,4,4,4,8,8,1,4,1,1,1,4,1}; |
| /* sizes of basic data-types, used to initialize sizetab[] */ |
| static long msizetab[MAX_TYPE+1]={1,1,2,4,4,8,4,8,8,0,4,0,0,0,4,0}; |
| |
| /* used to initialize regtyp[] */ |
| static struct Typ ltyp={LONG},ldbl={DOUBLE},lchar={CHAR}; |
| |
| /* macros defined by the backend */ |
| static char *marray[]={"__section(x)=__vattr(\"section(\"#x\")\")", |
| "__GENERIC__", |
| 0}; |
| |
| /* special registers */ |
| static int sp; /* Stackpointer */ |
| static int t1,t2,t3; /* temporary gprs */ |
| static int f1,f2,f3; /* temporary fprs */ |
| |
| #define dt(t) (((t)&UNSIGNED)?udt[(t)&NQ]:sdt[(t)&NQ]) |
| static char *sdt[MAX_TYPE+1]={"??","c","s","i","l","ll","f","d","ld","v","p"}; |
| static char *udt[MAX_TYPE+1]={"??","uc","us","ui","ul","ull","f","d","ld","v","p"}; |
| |
| /* sections */ |
| #define DATA 0 |
| #define BSS 1 |
| #define CODE 2 |
| #define RODATA 3 |
| #define SPECIAL 4 |
| |
| static long stack; |
| static int stack_valid; |
| static int section=-1,newobj; |
| static char *codename="\t.text\n", |
| *dataname="\t.data\n", |
| *bssname="", |
| *rodataname="\t.section\t.rodata\n"; |
| |
| /* return-instruction */ |
| static char *ret; |
| |
| /* label at the end of the function (if any) */ |
| static int exit_label; |
| |
| /* assembly-prefixes for labels and external identifiers */ |
| static char *labprefix="l",*idprefix="_"; |
| |
| #if FIXED_SP |
| /* variables to calculate the size and partitioning of the stack-frame |
| in the case of FIXED_SP */ |
| static long frameoffset,pushed,maxpushed,framesize; |
| #else |
| /* variables to keep track of the current stack-offset in the case of |
| a moving stack-pointer */ |
| static long notpopped,dontpop,pushed,stackoffset,maxpushed; |
| #endif |
| |
| static long localsize,rsavesize,argsize; |
| |
| static void emit_obj(FILE *f,struct obj *p,int t); |
| |
| /* calculate the actual current offset of an object relativ to the |
| stack-pointer; we use a layout like this: |
| ------------------------------------------------ |
| | arguments to this function | |
| ------------------------------------------------ |
| | return-address [size=4] | |
| ------------------------------------------------ |
| | caller-save registers [size=rsavesize] | |
| ------------------------------------------------ |
| | local variables [size=localsize] | |
| ------------------------------------------------ |
| | arguments to called functions [size=argsize] | |
| ------------------------------------------------ |
| All sizes will be aligned as necessary. |
| In the case of FIXED_SP, the stack-pointer will be adjusted at |
| function-entry to leave enough space for the arguments and have it |
| aligned to 16 bytes. Therefore, when calling a function, the |
| stack-pointer is always aligned to 16 bytes. |
| For a moving stack-pointer, the stack-pointer will usually point |
| to the bottom of the area for local variables, but will move while |
| arguments are put on the stack. |
| |
| This is just an example layout. Other layouts are also possible. |
| */ |
| |
| static void push(int i) |
| { |
| pushed-=i; |
| if(pushed<maxpushed) |
| maxpushed=pushed; |
| } |
| |
| static void pop(int i) |
| { |
| pushed+=i; |
| if(pushed>0) ierror(0); |
| } |
| |
| static long real_offset(struct obj *o) |
| { |
| long off=zm2l(o->v->offset); |
| if(off<0){ |
| /* function parameter */ |
| off=localsize+rsavesize+4-off-zm2l(maxalign); |
| } |
| |
| #if FIXED_SP |
| off+=argsize; |
| #else |
| off+=stackoffset; |
| #endif |
| off+=zm2l(o->val.vmax); |
| return off; |
| } |
| |
| /* Initializes an addressing-mode structure and returns a pointer to |
| that object. Will not survive a second call! */ |
| static struct obj *cam(int flags,int base,long offset) |
| { |
| static struct obj obj; |
| static struct AddressingMode am; |
| obj.am=&am; |
| am.flags=flags; |
| am.base=base; |
| am.offset=offset; |
| return &obj; |
| } |
| |
| /* changes to a special section, used for __section() */ |
| static int special_section(FILE *f,struct Var *v) |
| { |
| char *sec; |
| if(!v->vattr) return 0; |
| sec=strstr(v->vattr,"section("); |
| if(!sec) return 0; |
| sec+=strlen("section("); |
| emit(f,"\t.section\t"); |
| while(*sec&&*sec!=')') emit_char(f,*sec++); |
| emit(f,"\n"); |
| if(f) section=SPECIAL; |
| return 1; |
| } |
| |
| /* generate code to load the address of a variable into register r */ |
| static void load_address(FILE *f,int r,struct obj *o,int type) |
| /* Generates code to load the address of a variable into register r. */ |
| { |
| if(!(o->flags&VAR)) ierror(0); |
| if(o->v->storage_class==AUTO||o->v->storage_class==REGISTER){ |
| long off=real_offset(o); |
| if(THREE_ADDR){ |
| emit(f,"\tadd.%s\t%s,%s,%ld\n",dt(POINTER),regnames[r],regnames[sp],off); |
| }else{ |
| emit(f,"\tmov.%s\t%s,%s\n",dt(POINTER),regnames[r],regnames[sp]); |
| if(off) |
| emit(f,"\tadd.%s\t%s,%ld\n",dt(POINTER),regnames[r],off); |
| } |
| }else{ |
| emit(f,"\tmov.%s\t%s,",dt(POINTER),regnames[r]); |
| emit_obj(f,o,type); |
| emit(f,"\n"); |
| } |
| } |
| /* Generates code to load a memory object into register r. tmp is a |
| general purpose register which may be used. tmp can be r. */ |
| static void load_reg(FILE *f,int r,struct obj *o,int type) |
| { |
| type&=NU; |
| if(o->flags&VARADR){ |
| load_address(f,r,o,POINTER); |
| }else{ |
| if((o->flags&(REG|DREFOBJ))==REG&&o->reg==r) |
| return; |
| emit(f,"\tmov.%s\t%s,",dt(type),regnames[r]); |
| emit_obj(f,o,type); |
| emit(f,"\n"); |
| } |
| } |
| |
| /* Generates code to store register r into memory object o. */ |
| static void store_reg(FILE *f,int r,struct obj *o,int type) |
| { |
| type&=NQ; |
| emit(f,"\tmov.%s\t",dt(type)); |
| emit_obj(f,o,type); |
| emit(f,",%s\n",regnames[r]); |
| } |
| |
| /* Yields log2(x)+1 or 0. */ |
| static long pof2(zumax x) |
| { |
| zumax p;int ln=1; |
| p=ul2zum(1L); |
| while(ln<=32&&zumleq(p,x)){ |
| if(zumeqto(x,p)) return ln; |
| ln++;p=zumadd(p,p); |
| } |
| return 0; |
| } |
| |
| static struct IC *preload(FILE *,struct IC *); |
| |
| static void function_top(FILE *,struct Var *,long); |
| static void function_bottom(FILE *f,struct Var *,long); |
| |
| #define isreg(x) ((p->x.flags&(REG|DREFOBJ))==REG) |
| #define isconst(x) ((p->x.flags&(KONST|DREFOBJ))==KONST) |
| |
| static int q1reg,q2reg,zreg; |
| |
| static char *ccs[]={"eq","ne","lt","ge","le","gt",""}; |
| static char *logicals[]={"or","xor","and"}; |
| static char *arithmetics[]={"slw","srw","add","sub","mullw","divw","mod"}; |
| |
| /* compare if two objects are the same */ |
| static int compare_objects(struct obj *o1,struct obj *o2) |
| { |
| if((o1->flags&(REG|DREFOBJ))==REG&&(o2->flags&(REG|DREFOBJ))==REG&&o1->reg==o2->reg) |
| return 1; |
| if(o1->flags==o2->flags&&o1->am==o2->am){ |
| if(!(o1->flags&VAR)||(o1->v==o2->v&&zmeqto(o1->val.vmax,o2->val.vmax))){ |
| if(!(o1->flags®)||o1->reg==o2->reg){ |
| return 1; |
| } |
| } |
| } |
| return 0; |
| } |
| |
| /* Does some pre-processing like fetching operands from memory to |
| registers etc. */ |
| static struct IC *preload(FILE *f,struct IC *p) |
| { |
| int r; |
| |
| if(isreg(q1)) |
| q1reg=p->q1.reg; |
| else |
| q1reg=0; |
| |
| if(isreg(q2)) |
| q2reg=p->q2.reg; |
| else |
| q2reg=0; |
| |
| if(isreg(z)&&(THREE_ADDR||!compare_objects(&p->q2,&p->z))){ |
| zreg=p->z.reg; |
| }else{ |
| if(ISFLOAT(ztyp(p))) |
| zreg=f1; |
| else |
| zreg=t1; |
| } |
| |
| if((p->q1.flags&(DREFOBJ|REG))==DREFOBJ&&!p->q1.am){ |
| p->q1.flags&=~DREFOBJ; |
| load_reg(f,t1,&p->q1,q1typ(p)); |
| p->q1.reg=t1; |
| p->q1.flags|=(REG|DREFOBJ); |
| } |
| if(p->q1.flags&&LOAD_STORE&&!isreg(q1)){ |
| if(p->code==ASSIGN&&isreg(z)) |
| q1reg=p->z.reg; |
| else if(ISFLOAT(q1typ(p))) |
| q1reg=f1; |
| else |
| q1reg=t1; |
| load_reg(f,q1reg,&p->q1,q1typ(p)); |
| p->q1.reg=q1reg; |
| p->q1.flags=REG; |
| } |
| |
| if((p->q2.flags&(DREFOBJ|REG))==DREFOBJ&&!p->q2.am){ |
| p->q2.flags&=~DREFOBJ; |
| load_reg(f,t1,&p->q2,q2typ(p)); |
| p->q2.reg=t1; |
| p->q2.flags|=(REG|DREFOBJ); |
| } |
| if(p->q2.flags&&LOAD_STORE&&!isreg(q2)){ |
| if(ISFLOAT(q2typ(p))) |
| q2reg=f2; |
| else |
| q2reg=t2; |
| load_reg(f,q2reg,&p->q2,q2typ(p)); |
| p->q2.reg=q2reg; |
| p->q2.flags=REG; |
| } |
| return p; |
| } |
| |
| /* save the result (in zreg) into p->z */ |
| void save_result(FILE *f,struct IC *p) |
| { |
| if((p->z.flags&(REG|DREFOBJ))==DREFOBJ&&!p->z.am){ |
| p->z.flags&=~DREFOBJ; |
| load_reg(f,t2,&p->z,POINTER); |
| p->z.reg=t2; |
| p->z.flags|=(REG|DREFOBJ); |
| } |
| if(isreg(z)){ |
| if(p->z.reg!=zreg) |
| emit(f,"\tmov.%s\t%s,%s\n",dt(ztyp(p)),regnames[p->z.reg],regnames[zreg]); |
| }else{ |
| store_reg(f,zreg,&p->z,ztyp(p)); |
| } |
| } |
| |
| /* prints an object */ |
| static void emit_obj(FILE *f,struct obj *p,int t) |
| { |
| if(p->am){ |
| if(p->am->flags&GPR_IND) emit(f,"(%s,%s)",regnames[p->am->offset],regnames[p->am->base]); |
| if(p->am->flags&IMM_IND) emit(f,"(%ld,%s)",p->am->offset,regnames[p->am->base]); |
| return; |
| } |
| if((p->flags&(KONST|DREFOBJ))==(KONST|DREFOBJ)){ |
| emitval(f,&p->val,p->dtyp&NU); |
| return; |
| } |
| if(p->flags&DREFOBJ) emit(f,"("); |
| if(p->flags®){ |
| emit(f,"%s",regnames[p->reg]); |
| }else if(p->flags&VAR) { |
| if(p->v->storage_class==AUTO||p->v->storage_class==REGISTER) |
| emit(f,"%ld(%s)",real_offset(p),regnames[sp]); |
| else{ |
| if(!zmeqto(l2zm(0L),p->val.vmax)){emitval(f,&p->val,LONG);emit(f,"+");} |
| if(p->v->storage_class==STATIC){ |
| emit(f,"%s%ld",labprefix,zm2l(p->v->offset)); |
| }else{ |
| emit(f,"%s%s",idprefix,p->v->identifier); |
| } |
| } |
| } |
| if(p->flags&KONST){ |
| emitval(f,&p->val,t&NU); |
| } |
| if(p->flags&DREFOBJ) emit(f,")"); |
| } |
| |
| /* Test if there is a sequence of FREEREGs containing FREEREG reg. |
| Used by peephole. */ |
| static int exists_freereg(struct IC *p,int reg) |
| { |
| while(p&&(p->code==FREEREG||p->code==ALLOCREG)){ |
| if(p->code==FREEREG&&p->q1.reg==reg) return 1; |
| p=p->next; |
| } |
| return 0; |
| } |
| |
| /* search for possible addressing-modes */ |
| static void peephole(struct IC *p) |
| { |
| int c,c2,r;struct IC *p2;struct AddressingMode *am; |
| |
| for(;p;p=p->next){ |
| c=p->code; |
| if(c!=FREEREG&&c!=ALLOCREG&&(c!=SETRETURN||!isreg(q1)||p->q1.reg!=p->z.reg)) exit_label=0; |
| if(c==LABEL) exit_label=p->typf; |
| |
| /* Try const(reg) */ |
| if(IMM_IND&&(c==ADDI2P||c==SUBIFP)&&isreg(z)&&(p->q2.flags&(KONST|DREFOBJ))==KONST){ |
| int base;zmax of;struct obj *o; |
| eval_const(&p->q2.val,p->typf); |
| if(c==SUBIFP) of=zmsub(l2zm(0L),vmax); else of=vmax; |
| if(1/*zmleq(l2zm(-32768L),vmax)&&zmleq(vmax,l2zm(32767L))*/){ |
| r=p->z.reg; |
| if(isreg(q1)) base=p->q1.reg; else base=r; |
| o=0; |
| for(p2=p->next;p2;p2=p2->next){ |
| c2=p2->code; |
| if(c2==CALL||c2==LABEL||(c2>=BEQ&&c2<=BRA)) break; |
| if(c2!=FREEREG&&(p2->q1.flags&(REG|DREFOBJ))==REG&&p2->q1.reg==r) break; |
| if(c2!=FREEREG&&(p2->q2.flags&(REG|DREFOBJ))==REG&&p2->q2.reg==r) break; |
| if(c2!=CALL&&(c2<LABEL||c2>BRA)/*&&c2!=ADDRESS*/){ |
| if(!p2->q1.am&&(p2->q1.flags&(REG|DREFOBJ))==(REG|DREFOBJ)&&p2->q1.reg==r){ |
| if(o) break; |
| o=&p2->q1; |
| } |
| if(!p2->q2.am&&(p2->q2.flags&(REG|DREFOBJ))==(REG|DREFOBJ)&&p2->q2.reg==r){ |
| if(o) break; |
| o=&p2->q2; |
| } |
| if(!p2->z.am&&(p2->z.flags&(REG|DREFOBJ))==(REG|DREFOBJ)&&p2->z.reg==r){ |
| if(o) break; |
| o=&p2->z; |
| } |
| } |
| if(c2==FREEREG||(p2->z.flags&(REG|DREFOBJ))==REG){ |
| int m; |
| if(c2==FREEREG) |
| m=p2->q1.reg; |
| else |
| m=p2->z.reg; |
| if(m==r){ |
| if(o){ |
| o->am=am=mymalloc(sizeof(*am)); |
| am->flags=IMM_IND; |
| am->base=base; |
| am->offset=zm2l(of); |
| if(isreg(q1)){ |
| p->code=c=NOP;p->q1.flags=p->q2.flags=p->z.flags=0; |
| }else{ |
| p->code=c=ASSIGN;p->q2.flags=0; |
| p->typf=p->typf2;p->q2.val.vmax=sizetab[p->typf2&NQ]; |
| } |
| } |
| break; |
| } |
| if(c2!=FREEREG&&m==base) break; |
| continue; |
| } |
| } |
| } |
| } |
| /* Try reg,reg */ |
| if(GPR_IND&&c==ADDI2P&&isreg(q2)&&isreg(z)&&(isreg(q1)||p->q2.reg!=p->z.reg)){ |
| int base,idx;struct obj *o; |
| r=p->z.reg;idx=p->q2.reg; |
| if(isreg(q1)) base=p->q1.reg; else base=r; |
| o=0; |
| for(p2=p->next;p2;p2=p2->next){ |
| c2=p2->code; |
| if(c2==CALL||c2==LABEL||(c2>=BEQ&&c2<=BRA)) break; |
| if(c2!=FREEREG&&(p2->q1.flags&(REG|DREFOBJ))==REG&&p2->q1.reg==r) break; |
| if(c2!=FREEREG&&(p2->q2.flags&(REG|DREFOBJ))==REG&&p2->q2.reg==r) break; |
| if((p2->z.flags&(REG|DREFOBJ))==REG&&p2->z.reg==idx&&idx!=r) break; |
| |
| if(c2!=CALL&&(c2<LABEL||c2>BRA)/*&&c2!=ADDRESS*/){ |
| if(!p2->q1.am&&(p2->q1.flags&(REG|DREFOBJ))==(REG|DREFOBJ)&&p2->q1.reg==r){ |
| if(o||(q1typ(p2)&NQ)==LLONG) break; |
| o=&p2->q1; |
| } |
| if(!p2->q2.am&&(p2->q2.flags&(REG|DREFOBJ))==(REG|DREFOBJ)&&p2->q2.reg==r){ |
| if(o||(q2typ(p2)&NQ)==LLONG) break; |
| o=&p2->q2; |
| } |
| if(!p2->z.am&&(p2->z.flags&(REG|DREFOBJ))==(REG|DREFOBJ)&&p2->z.reg==r){ |
| if(o||(ztyp(p2)&NQ)==LLONG) break; |
| o=&p2->z; |
| } |
| } |
| if(c2==FREEREG||(p2->z.flags&(REG|DREFOBJ))==REG){ |
| int m; |
| if(c2==FREEREG) |
| m=p2->q1.reg; |
| else |
| m=p2->z.reg; |
| if(m==r){ |
| if(o){ |
| o->am=am=mymalloc(sizeof(*am)); |
| am->flags=GPR_IND; |
| am->base=base; |
| am->offset=idx; |
| if(isreg(q1)){ |
| p->code=c=NOP;p->q1.flags=p->q2.flags=p->z.flags=0; |
| }else{ |
| p->code=c=ASSIGN;p->q2.flags=0; |
| p->typf=p->typf2;p->q2.val.vmax=sizetab[p->typf2&NQ]; |
| } |
| } |
| break; |
| } |
| if(c2!=FREEREG&&m==base) break; |
| continue; |
| } |
| } |
| } |
| } |
| } |
| |
| /* generates the function entry code */ |
| static void function_top(FILE *f,struct Var *v,long offset) |
| { |
| rsavesize=0; |
| if(!special_section(f,v)&§ion!=CODE){emit(f,codename);if(f) section=CODE;} |
| if(v->storage_class==EXTERN){ |
| if((v->flags&(INLINEFUNC|INLINEEXT))!=INLINEFUNC) |
| emit(f,"\t.global\t%s%s\n",idprefix,v->identifier); |
| emit(f,"%s%s:\n",idprefix,v->identifier); |
| }else |
| emit(f,"%s%ld:\n",labprefix,zm2l(v->offset)); |
| } |
| /* generates the function exit code */ |
| static void function_bottom(FILE *f,struct Var *v,long offset) |
| { |
| emit(f,ret); |
| } |
| |
| /****************************************/ |
| /* End of private data and functions. */ |
| /****************************************/ |
| |
| /* Does necessary initializations for the code-generator. Gets called */ |
| /* once at the beginning and should return 0 in case of problems. */ |
| int init_cg(void) |
| { |
| int i; |
| /* Initialize some values which cannot be statically initialized */ |
| /* because they are stored in the target's arithmetic. */ |
| maxalign=l2zm(8L); |
| char_bit=l2zm(8L); |
| stackalign=l2zm(4); |
| |
| for(i=0;i<=MAX_TYPE;i++){ |
| sizetab[i]=l2zm(msizetab[i]); |
| align[i]=l2zm(malign[i]); |
| } |
| |
| regnames[0]="noreg"; |
| for(i=FIRST_GPR;i<=LAST_GPR;i++){ |
| regnames[i]=mymalloc(10); |
| sprintf(regnames[i],"gpr%d",i-FIRST_GPR); |
| regsize[i]=l2zm(4L); |
| regtype[i]=<yp; |
| } |
| for(i=FIRST_FPR;i<=LAST_FPR;i++){ |
| regnames[i]=mymalloc(10); |
| sprintf(regnames[i],"fpr%d",i-FIRST_FPR); |
| regsize[i]=l2zm(8L); |
| regtype[i]=&ldbl; |
| } |
| for(i=FIRST_CCR;i<=LAST_CCR;i++){ |
| regnames[i]=mymalloc(10); |
| sprintf(regnames[i],"ccr%d",i-FIRST_CCR); |
| regsize[i]=l2zm(1L); |
| regtype[i]=&lchar; |
| } |
| |
| /* Use multiple ccs. */ |
| multiple_ccs=0; |
| |
| /* Initialize the min/max-settings. Note that the types of the */ |
| /* host system may be different from the target system and you may */ |
| /* only use the smallest maximum values ANSI guarantees if you */ |
| /* want to be portable. */ |
| /* That's the reason for the subtraction in t_min[INT]. Long could */ |
| /* be unable to represent -2147483648 on the host system. */ |
| t_min[CHAR]=l2zm(-128L); |
| t_min[SHORT]=l2zm(-32768L); |
| t_min[INT]=zmsub(l2zm(-2147483647L),l2zm(1L)); |
| t_min[LONG]=t_min(INT); |
| t_min[LLONG]=zmlshift(l2zm(1L),l2zm(63L)); |
| t_min[MAXINT]=t_min(LLONG); |
| t_max[CHAR]=ul2zum(127L); |
| t_max[SHORT]=ul2zum(32767UL); |
| t_max[INT]=ul2zum(2147483647UL); |
| t_max[LONG]=t_max(INT); |
| t_max[LLONG]=zumrshift(zumkompl(ul2zum(0UL)),ul2zum(1UL)); |
| t_max[MAXINT]=t_max(LLONG); |
| tu_max[CHAR]=ul2zum(255UL); |
| tu_max[SHORT]=ul2zum(65535UL); |
| tu_max[INT]=ul2zum(4294967295UL); |
| tu_max[LONG]=t_max(UNSIGNED|INT); |
| tu_max[LLONG]=zumkompl(ul2zum(0UL)); |
| tu_max[MAXINT]=t_max(UNSIGNED|LLONG); |
| |
| /* Reserve a few registers for use by the code-generator. */ |
| /* This is not optimal but simple. */ |
| sp=FIRST_GPR; |
| t1=FIRST_GPR+1; |
| t2=FIRST_GPR+2; |
| f1=FIRST_FPR; |
| f2=FIRST_FPR+1; |
| regsa[t1]=regsa[t2]=1; |
| regsa[f1]=regsa[f2]=1; |
| regsa[sp]=1; |
| regscratch[t1]=regscratch[t2]=0; |
| regscratch[f1]=regscratch[f2]=0; |
| regscratch[sp]=0; |
| |
| for(i=FIRST_GPR;i<=LAST_GPR-VOL_GPRS;i++) |
| regscratch[i]=1; |
| for(i=FIRST_FPR;i<=LAST_FPR-VOL_FPRS;i++) |
| regscratch[i]=1; |
| for(i=FIRST_CCR;i<=LAST_CCR-VOL_CCRS;i++) |
| regscratch[i]=1; |
| |
| target_macros=marray; |
| |
| |
| return 1; |
| } |
| |
| void init_db(FILE *f) |
| { |
| } |
| |
| int freturn(struct Typ *t) |
| /* Returns the register in which variables of type t are returned. */ |
| /* If the value cannot be returned in a register returns 0. */ |
| /* A pointer MUST be returned in a register. The code-generator */ |
| /* has to simulate a pseudo register if necessary. */ |
| { |
| if(ISFLOAT(t->flags)) |
| return FIRST_FPR+2; |
| if(ISSTRUCT(t->flags)||ISUNION(t->flags)) |
| return 0; |
| if(zmleq(szof(t),l2zm(4L))) |
| return FIRST_GPR+3; |
| else |
| return 0; |
| } |
| |
| int reg_pair(int r,struct rpair *p) |
| /* Returns 0 if the register is no register pair. If r */ |
| /* is a register pair non-zero will be returned and the */ |
| /* structure pointed to p will be filled with the two */ |
| /* elements. */ |
| { |
| return 0; |
| } |
| |
| /* estimate the cost-saving if object o from IC p is placed in |
| register r */ |
| int cost_savings(struct IC *p,int r,struct obj *o) |
| { |
| int c=p->code; |
| if(o->flags&VKONST){ |
| if(!LOAD_STORE) |
| return 0; |
| if(o==&p->q1&&p->code==ASSIGN&&(p->z.flags&DREFOBJ)) |
| return 4; |
| else |
| return 2; |
| } |
| if(o->flags&DREFOBJ) |
| return 4; |
| if(c==SETRETURN&&r==p->z.reg&&!(o->flags&DREFOBJ)) return 3; |
| if(c==GETRETURN&&r==p->q1.reg&&!(o->flags&DREFOBJ)) return 3; |
| return 2; |
| } |
| |
| int regok(int r,int t,int mode) |
| /* Returns 0 if register r cannot store variables of */ |
| /* type t. If t==POINTER and mode!=0 then it returns */ |
| /* non-zero only if the register can store a pointer */ |
| /* and dereference a pointer to mode. */ |
| { |
| if(r==0) |
| return 0; |
| t&=NQ; |
| if(t==0&&r>=FIRST_CCR&&r<=LAST_CCR) |
| return 1; |
| if(ISFLOAT(t)&&r>=FIRST_FPR&&r<=LAST_FPR) |
| return 1; |
| if(t==POINTER&&r>=FIRST_GPR&&r<=LAST_GPR) |
| return 1; |
| if(t>=CHAR&&t<=LONG&&r>=FIRST_GPR&&r<=LAST_GPR) |
| return 1; |
| return 0; |
| } |
| |
| int dangerous_IC(struct IC *p) |
| /* Returns zero if the IC p can be safely executed */ |
| /* without danger of exceptions or similar things. */ |
| /* vbcc may generate code in which non-dangerous ICs */ |
| /* are sometimes executed although control-flow may */ |
| /* never reach them (mainly when moving computations */ |
| /* out of loops). */ |
| /* Typical ICs that generate exceptions on some */ |
| /* machines are: */ |
| /* - accesses via pointers */ |
| /* - division/modulo */ |
| /* - overflow on signed integer/floats */ |
| { |
| int c=p->code; |
| if((p->q1.flags&DREFOBJ)||(p->q2.flags&DREFOBJ)||(p->z.flags&DREFOBJ)) |
| return 1; |
| if((c==DIV||c==MOD)&&!isconst(q2)) |
| return 1; |
| return 0; |
| } |
| |
| int must_convert(int o,int t,int const_expr) |
| /* Returns zero if code for converting np to type t */ |
| /* can be omitted. */ |
| /* On the PowerPC cpu pointers and 32bit */ |
| /* integers have the same representation and can use */ |
| /* the same registers. */ |
| { |
| int op=o&NQ,tp=t&NQ; |
| if((op==INT||op==LONG||op==POINTER)&&(tp==INT||tp==LONG||tp==POINTER)) |
| return 0; |
| if(op==DOUBLE&&tp==LDOUBLE) return 0; |
| if(op==LDOUBLE&&tp==DOUBLE) return 0; |
| return 1; |
| } |
| |
| void gen_ds(FILE *f,zmax size,struct Typ *t) |
| /* This function has to create <size> bytes of storage */ |
| /* initialized with zero. */ |
| { |
| if(newobj&§ion!=SPECIAL) |
| emit(f,"%ld\n",zm2l(size)); |
| else |
| emit(f,"\t.space\t%ld\n",zm2l(size)); |
| newobj=0; |
| } |
| |
| void gen_align(FILE *f,zmax align) |
| /* This function has to make sure the next data is */ |
| /* aligned to multiples of <align> bytes. */ |
| { |
| if(zm2l(align)>1) emit(f,"\t.align\t2\n"); |
| } |
| |
| void gen_var_head(FILE *f,struct Var *v) |
| /* This function has to create the head of a variable */ |
| /* definition, i.e. the label and information for */ |
| /* linkage etc. */ |
| { |
| int constflag;char *sec; |
| if(v->clist) constflag=is_const(v->vtyp); |
| if(v->storage_class==STATIC){ |
| if(ISFUNC(v->vtyp->flags)) return; |
| if(!special_section(f,v)){ |
| if(v->clist&&(!constflag||(g_flags[2]&USEDFLAG))&§ion!=DATA){emit(f,dataname);if(f) section=DATA;} |
| if(v->clist&&constflag&&!(g_flags[2]&USEDFLAG)&§ion!=RODATA){emit(f,rodataname);if(f) section=RODATA;} |
| if(!v->clist&§ion!=BSS){emit(f,bssname);if(f) section=BSS;} |
| } |
| if(v->clist||section==SPECIAL){ |
| gen_align(f,falign(v->vtyp)); |
| emit(f,"%s%ld:\n",labprefix,zm2l(v->offset)); |
| }else |
| emit(f,"\t.lcomm\t%s%ld,",labprefix,zm2l(v->offset)); |
| newobj=1; |
| } |
| if(v->storage_class==EXTERN){ |
| emit(f,"\t.globl\t%s%s\n",idprefix,v->identifier); |
| if(v->flags&(DEFINED|TENTATIVE)){ |
| if(!special_section(f,v)){ |
| if(v->clist&&(!constflag||(g_flags[2]&USEDFLAG))&§ion!=DATA){emit(f,dataname);if(f) section=DATA;} |
| if(v->clist&&constflag&&!(g_flags[2]&USEDFLAG)&§ion!=RODATA){emit(f,rodataname);if(f) section=RODATA;} |
| if(!v->clist&§ion!=BSS){emit(f,bssname);if(f) section=BSS;} |
| } |
| if(v->clist||section==SPECIAL){ |
| gen_align(f,falign(v->vtyp)); |
| emit(f,"%s%s:\n",idprefix,v->identifier); |
| }else |
| emit(f,"\t.global\t%s%s\n\t.%scomm\t%s%s,",idprefix,v->identifier,(USE_COMMONS?"":"l"),idprefix,v->identifier); |
| newobj=1; |
| } |
| } |
| } |
| |
| void gen_dc(FILE *f,int t,struct const_list *p) |
| /* This function has to create static storage */ |
| /* initialized with const-list p. */ |
| { |
| emit(f,"\tdc.%s\t",dt(t&NQ)); |
| if(!p->tree){ |
| if(ISFLOAT(t)){ |
| /* auch wieder nicht sehr schoen und IEEE noetig */ |
| unsigned char *ip; |
| ip=(unsigned char *)&p->val.vdouble; |
| emit(f,"0x%02x%02x%02x%02x",ip[0],ip[1],ip[2],ip[3]); |
| if((t&NQ)!=FLOAT){ |
| emit(f,",0x%02x%02x%02x%02x",ip[4],ip[5],ip[6],ip[7]); |
| } |
| }else{ |
| emitval(f,&p->val,t&NU); |
| } |
| }else{ |
| emit_obj(f,&p->tree->o,t&NU); |
| } |
| emit(f,"\n");newobj=0; |
| } |
| |
| |
| /* The main code-generation routine. */ |
| /* f is the stream the code should be written to. */ |
| /* p is a pointer to a doubly linked list of ICs */ |
| /* containing the function body to generate code for. */ |
| /* v is a pointer to the function. */ |
| /* offset is the size of the stackframe the function */ |
| /* needs for local variables. */ |
| |
| void gen_code(FILE *f,struct IC *p,struct Var *v,zmax offset) |
| /* The main code-generation. */ |
| { |
| int c,t,i; |
| struct IC *m; |
| argsize=0; |
| if(DEBUG&1) printf("gen_code()\n"); |
| for(c=1;c<=MAXR;c++) regs[c]=regsa[c]; |
| maxpushed=0; |
| |
| /*FIXME*/ |
| ret="\trts\n"; |
| |
| for(m=p;m;m=m->next){ |
| c=m->code;t=m->typf&NU; |
| if(c==ALLOCREG) {regs[m->q1.reg]=1;continue;} |
| if(c==FREEREG) {regs[m->q1.reg]=0;continue;} |
| |
| /* convert MULT/DIV/MOD with powers of two */ |
| if((t&NQ)<=LONG&&(m->q2.flags&(KONST|DREFOBJ))==KONST&&(t&NQ)<=LONG&&(c==MULT||((c==DIV||c==MOD)&&(t&UNSIGNED)))){ |
| eval_const(&m->q2.val,t); |
| i=pof2(vmax); |
| if(i){ |
| if(c==MOD){ |
| vmax=zmsub(vmax,l2zm(1L)); |
| m->code=AND; |
| }else{ |
| vmax=l2zm(i-1); |
| if(c==DIV) m->code=RSHIFT; else m->code=LSHIFT; |
| } |
| c=m->code; |
| gval.vmax=vmax; |
| eval_const(&gval,MAXINT); |
| if(c==AND){ |
| insert_const(&m->q2.val,t); |
| }else{ |
| insert_const(&m->q2.val,INT); |
| p->typf2=INT; |
| } |
| } |
| } |
| #if FIXED_SP |
| if(c==CALL&&argsize<zm2l(m->q2.val.vmax)) argsize=zm2l(m->q2.val.vmax); |
| #endif |
| } |
| peephole(p); |
| |
| for(c=1;c<=MAXR;c++){ |
| if(regsa[c]||regused[c]){ |
| BSET(regs_modified,c); |
| } |
| } |
| |
| localsize=(zm2l(offset)+3)/4*4; |
| #if FIXED_SP |
| /*FIXME: adjust localsize to get an aligned stack-frame */ |
| #endif |
| |
| function_top(f,v,localsize); |
| |
| #if FIXED_SP |
| pushed=0; |
| #endif |
| |
| for(;p;p=p->next){ |
| c=p->code;t=p->typf; |
| if(c==NOP) {p->z.flags=0;continue;} |
| if(c==ALLOCREG) {regs[p->q1.reg]=1;continue;} |
| if(c==FREEREG) {regs[p->q1.reg]=0;continue;} |
| if(c==LABEL) {emit(f,"%s%d:\n",labprefix,t);continue;} |
| if(c==BRA){ |
| if(0/*t==exit_label&&framesize==0*/) |
| emit(f,ret); |
| else |
| emit(f,"\tb\t%s%d\n",labprefix,t); |
| continue; |
| } |
| if(c>=BEQ&&c<BRA){ |
| emit(f,"\tb%s\t",ccs[c-BEQ]); |
| if(isreg(q1)){ |
| emit_obj(f,&p->q1,0); |
| emit(f,","); |
| } |
| emit(f,"%s%d\n",labprefix,t); |
| continue; |
| } |
| if(c==MOVETOREG){ |
| load_reg(f,p->z.reg,&p->q1,regtype[p->z.reg]->flags); |
| continue; |
| } |
| if(c==MOVEFROMREG){ |
| store_reg(f,p->z.reg,&p->q1,regtype[p->z.reg]->flags); |
| continue; |
| } |
| if((c==ASSIGN||c==PUSH)&&((t&NQ)>POINTER||((t&NQ)==CHAR&&zm2l(p->q2.val.vmax)!=1))){ |
| ierror(0); |
| } |
| /* switch commutative operands if suitable */ |
| if(c==ADD||c==MULT||c==AND||c==XOR||c==OR){ |
| if(compare_objects(&p->q2,&p->z)){ |
| struct obj tmp; |
| tmp=p->q1; |
| p->q1=p->q2; |
| p->q2=tmp; |
| } |
| } |
| |
| p=preload(f,p); |
| c=p->code; |
| if(c==SUBPFP) c=SUB; |
| if(c==ADDI2P) c=ADD; |
| if(c==SUBIFP) c=SUB; |
| if(c==CONVERT){ |
| if(ISFLOAT(q1typ(p))||ISFLOAT(ztyp(p))) ierror(0); |
| if(sizetab[q1typ(p)&NQ]<sizetab[ztyp(p)&NQ]){ |
| if(q1typ(p)&UNSIGNED) |
| emit(f,"\tzext.%s\t%s\n",dt(q1typ(p)),regnames[zreg]); |
| else |
| emit(f,"\tsext.%s\t%s\n",dt(q1typ(p)),regnames[zreg]); |
| } |
| save_result(f,p); |
| continue; |
| } |
| if(c==KOMPLEMENT){ |
| load_reg(f,zreg,&p->q1,t); |
| emit(f,"\tcpl.%s\t%s\n",dt(t),regnames[zreg]); |
| save_result(f,p); |
| continue; |
| } |
| if(c==SETRETURN){ |
| load_reg(f,p->z.reg,&p->q1,t); |
| BSET(regs_modified,p->z.reg); |
| continue; |
| } |
| if(c==GETRETURN){ |
| if(p->q1.reg){ |
| zreg=p->q1.reg; |
| save_result(f,p); |
| }else |
| p->z.flags=0; |
| continue; |
| } |
| if(c==CALL){ |
| int reg; |
| /*FIXME*/ |
| #if 0 |
| if(stack_valid&&(p->q1.flags&(VAR|DREFOBJ))==VAR&&p->q1.v->fi&&(p->q1.v->fi->flags&ALL_STACK)){ |
| if(framesize+zum2ul(p->q1.v->fi->stack1)>stack) |
| stack=framesize+zum2ul(p->q1.v->fi->stack1); |
| }else |
| stack_valid=0; |
| #endif |
| if((p->q1.flags&(VAR|DREFOBJ))==VAR&&p->q1.v->fi&&p->q1.v->fi->inline_asm){ |
| emit_inline_asm(f,p->q1.v->fi->inline_asm); |
| }else{ |
| emit(f,"\tcall\t"); |
| emit_obj(f,&p->q1,t); |
| emit(f,"\n"); |
| } |
| /*FIXME*/ |
| #if FIXED_SP |
| pushed-=zm2l(p->q2.val.vmax); |
| #endif |
| if((p->q1.flags&(VAR|DREFOBJ))==VAR&&p->q1.v->fi&&(p->q1.v->fi->flags&ALL_REGS)){ |
| bvunite(regs_modified,p->q1.v->fi->regs_modified,RSIZE); |
| }else{ |
| int i; |
| for(i=1;i<=MAXR;i++){ |
| if(regscratch[i]) BSET(regs_modified,i); |
| } |
| } |
| continue; |
| } |
| if(c==ASSIGN||c==PUSH){ |
| if(t==0) ierror(0); |
| if(c==PUSH){ |
| #if FIXED_SP |
| emit(f,"\tmov.%s\t%ld(%s),",dt(t),pushed,regnames[sp]); |
| emit_obj(f,&p->q1,t); |
| emit(f,"\n"); |
| pushed+=zm2l(p->q2.val.vmax); |
| #else |
| emit(f,"\tpush.%s\t",dt(t)); |
| emit_obj(f,&p->q1,t); |
| emit(f,"\n"); |
| push(zm2l(p->q2.val.vmax)); |
| #endif |
| continue; |
| } |
| if(c==ASSIGN){ |
| load_reg(f,zreg,&p->q1,t); |
| save_result(f,p); |
| } |
| continue; |
| } |
| if(c==ADDRESS){ |
| load_address(f,zreg,&p->q1,POINTER); |
| save_result(f,p); |
| continue; |
| } |
| if(c==MINUS){ |
| load_reg(f,zreg,&p->q1,t); |
| emit(f,"\tneg.%s\t%s\n",dt(t),regnames[zreg]); |
| save_result(f,p); |
| continue; |
| } |
| if(c==TEST){ |
| emit(f,"\ttst.%s\t",dt(t)); |
| if(multiple_ccs) |
| emit(f,"%s,",regnames[zreg]); |
| emit_obj(f,&p->q1,t); |
| emit(f,"\n"); |
| if(multiple_ccs) |
| save_result(f,p); |
| continue; |
| } |
| if(c==COMPARE){ |
| emit(f,"\tcmp.%s\t",dt(t)); |
| if(multiple_ccs) |
| emit(f,"%s,",regnames[zreg]); |
| emit_obj(f,&p->q1,t); |
| emit(f,","); |
| emit_obj(f,&p->q2,t); |
| emit(f,"\n"); |
| if(multiple_ccs) |
| save_result(f,p); |
| continue; |
| } |
| if((c>=OR&&c<=AND)||(c>=LSHIFT&&c<=MOD)){ |
| if(!THREE_ADDR) |
| load_reg(f,zreg,&p->q1,t); |
| if(c>=OR&&c<=AND) |
| emit(f,"\t%s.%s\t%s,",logicals[c-OR],dt(t),regnames[zreg]); |
| else |
| emit(f,"\t%s.%s\t%s,",arithmetics[c-LSHIFT],dt(t),regnames[zreg]); |
| if(THREE_ADDR){ |
| emit_obj(f,&p->q1,t); |
| emit(f,","); |
| } |
| emit_obj(f,&p->q2,t); |
| emit(f,"\n"); |
| save_result(f,p); |
| continue; |
| } |
| pric2(stdout,p); |
| ierror(0); |
| } |
| function_bottom(f,v,localsize); |
| if(stack_valid){ |
| if(!v->fi) v->fi=new_fi(); |
| v->fi->flags|=ALL_STACK; |
| v->fi->stack1=stack; |
| } |
| emit(f,"# stacksize=%lu%s\n",zum2ul(stack),stack_valid?"":"+??"); |
| } |
| |
| int shortcut(int code,int typ) |
| { |
| return 0; |
| } |
| |
| int reg_parm(struct reg_handle *m, struct Typ *t,int vararg,struct Typ *d) |
| { |
| int f; |
| f=t->flags&NQ; |
| if(f<=LONG||f==POINTER){ |
| if(m->gregs>=GPR_ARGS) |
| return 0; |
| else |
| return FIRST_GPR+3+m->gregs++; |
| } |
| if(ISFLOAT(f)){ |
| if(m->fregs>=FPR_ARGS) |
| return 0; |
| else |
| return FIRST_FPR+2+m->fregs++; |
| } |
| return 0; |
| } |
| |
| int handle_pragma(const char *s) |
| { |
| } |
| void cleanup_cg(FILE *f) |
| { |
| } |
| void cleanup_db(FILE *f) |
| { |
| if(f) section=-1; |
| } |
| |