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use register classes (will allow better and simpler code gen - fixed long double handling

tcc-xref
bellard 2001-12-23 00:34:26 +00:00
parent 498551188e
commit 21c35b9443
2 changed files with 183 additions and 142 deletions
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212
i386-gen.c
View File

@ -21,11 +21,11 @@
/* number of available registers */
#define NB_REGS 4
#define NB_REG_CLASSES 2
/* a register can belong to several classes */
#define REG_CLASS_INT 0x0001
#define REG_CLASS_FLOAT 0x0002
#define RC_INT 0x0001 /* generic integer register */
#define RC_FLOAT 0x0002 /* generic float register */
#define RC_IRET 0x0004 /* function returned integer register */
#define RC_FRET 0x0008 /* function returned float register */
/* pretty names for the registers */
enum {
@ -36,16 +36,15 @@ enum {
};
int reg_classes[NB_REGS] = {
REG_CLASS_INT, /* eax */
REG_CLASS_INT, /* ecx */
REG_CLASS_INT, /* edx */
REG_CLASS_FLOAT, /* st0 */
/* eax */ RC_INT | RC_IRET,
/* ecx */ RC_INT,
/* edx */ RC_INT,
/* st0 */ RC_FLOAT | RC_FRET,
};
/* integer return register for functions */
#define FUNC_RET_REG 0
/* float return register for functions */
#define FUNC_RET_FREG 3
/* return registers for function */
#define REG_IRET REG_EAX
#define REG_FRET REG_ST0
/* defined if function parameters must be evaluated in reverse order */
#define INVERT_FUNC_PARAMS
@ -89,40 +88,17 @@ void gen_le32(int c)
g(c >> 24);
}
/* add a new relocation entry to symbol 's' */
void greloc(Sym *s, int addr, int type)
/* patch relocation entry with value 'val' */
void greloc_patch1(Reloc *p, int val)
{
Reloc *p;
p = malloc(sizeof(Reloc));
if (!p)
error("memory full");
p->type = type;
p->addr = addr;
p->next = (Reloc *)s->c;
s->c = (int)p;
}
/* patch each relocation entry with value 'val' */
void greloc_patch(Sym *s, int val)
{
Reloc *p, *p1;
p = (Reloc *)s->c;
while (p != NULL) {
p1 = p->next;
switch(p->type) {
case RELOC_ADDR32:
*(int *)p->addr = val;
break;
case RELOC_REL32:
*(int *)p->addr = val - p->addr - 4;
break;
}
free(p);
p = p1;
switch(p->type) {
case RELOC_ADDR32:
*(int *)p->addr = val;
break;
case RELOC_REL32:
*(int *)p->addr = val - p->addr - 4;
break;
}
s->c = val;
s->r &= ~VT_FORWARD;
}
/* output a symbol and patch all calls to it */
@ -166,6 +142,30 @@ void gen_addr32(int r, int c)
}
}
/* generate a modrm reference. 'op_reg' contains the addtionnal 3
opcode bits */
void gen_modrm(int op_reg, int r, int c)
{
op_reg = op_reg << 3;
if ((r & VT_VALMASK) == VT_CONST) {
/* constant memory reference */
o(0x05 | op_reg);
gen_addr32(r, c);
} else if ((r & VT_VALMASK) == VT_LOCAL) {
/* currently, we use only ebp as base */
if (c == (char)c) {
/* short reference */
o(0x45 | op_reg);
g(c);
} else {
oad(0x85 | op_reg, c);
}
} else {
g(0x00 | op_reg | (r & VT_VALMASK));
}
}
/* load 'r' from value 'sv' */
void load(int r, SValue *sv)
{
@ -183,7 +183,7 @@ void load(int r, SValue *sv)
v1.r = VT_LOCAL | VT_LVAL;
v1.c.ul = fc;
load(r, &v1);
v = r;
fr = r;
}
if ((ft & VT_BTYPE) == VT_FLOAT) {
o(0xd9); /* flds */
@ -204,22 +204,14 @@ void load(int r, SValue *sv)
o(0xb70f); /* movzwl */
else
o(0x8b); /* movl */
if (v == VT_CONST) {
o(0x05 + r * 8); /* 0xXX, r */
gen_addr32(fr, fc);
} else if (v == VT_LOCAL) {
oad(0x85 + r * 8, fc); /* xx(%ebp), r */
} else {
g(0x00 + r * 8 + v); /* (v), r */
}
gen_modrm(r, fr, fc);
} else {
if (v == VT_CONST) {
o(0xb8 + r); /* mov $xx, r */
gen_addr32(fr, fc);
} else if (v == VT_LOCAL) {
o(0x8d);
oad(0x85 + r * 8, fc); /* lea xxx(%ebp), r */
o(0x8d); /* lea xxx(%ebp), r */
gen_modrm(r, VT_LOCAL, fc);
} else if (v == VT_CMP) {
oad(0xb8 + r, 0); /* mov $0, r */
o(0x0f); /* setxx %br */
@ -247,8 +239,7 @@ void store(int r, SValue *v)
fc = v->c.ul;
fr = v->r & VT_VALMASK;
bt = ft & VT_BTYPE;
/* XXX: incorrect if reg to reg */
/* XXX: should not flush float stack */
/* XXX: incorrect if float reg to reg */
if (bt == VT_FLOAT) {
o(0xd9); /* fsts */
r = 2;
@ -267,13 +258,10 @@ void store(int r, SValue *v)
else
o(0x89);
}
if (fr == VT_CONST) {
o(0x05 + r * 8); /* mov r,xxx */
gen_addr32(v->r, fc);
} else if (fr == VT_LOCAL) {
oad(0x85 + r * 8, fc); /* mov r,xxx(%ebp) */
} else if (v->r & VT_LVAL) {
g(fr + r * 8); /* mov r, (fr) */
if (fr == VT_CONST ||
fr == VT_LOCAL ||
(v->r & VT_LVAL)) {
gen_modrm(r, v->r, fc);
} else if (fr != r) {
o(0xc0 + fr + r * 8); /* mov r, fr */
}
@ -298,7 +286,7 @@ void gfunc_param(GFuncContext *c)
/* allocate the necessary size on stack */
oad(0xec81, size); /* sub $xxx, %esp */
/* generate structure store */
r = get_reg(REG_CLASS_INT);
r = get_reg(RC_INT);
o(0x89); /* mov %esp, r */
o(0xe0 + r);
vset(VT_INT, r, 0);
@ -306,7 +294,7 @@ void gfunc_param(GFuncContext *c)
vstore();
c->args_size += size;
} else if (is_float(vtop->t)) {
gv(); /* only one float register */
gv(RC_FLOAT); /* only one float register */
if ((vtop->t & VT_BTYPE) == VT_FLOAT)
size = 4;
else if ((vtop->t & VT_BTYPE) == VT_DOUBLE)
@ -324,7 +312,7 @@ void gfunc_param(GFuncContext *c)
} else {
/* simple type (currently always same size) */
/* XXX: implicit cast ? */
r = gv();
r = gv(RC_INT);
o(0x50 + r); /* push r */
c->args_size += 4;
}
@ -347,7 +335,7 @@ void gfunc_call(GFuncContext *c)
}
} else {
/* otherwise, indirect call */
r = gv();
r = gv(RC_INT);
o(0xff); /* call *r */
o(0xd0 + r);
}
@ -383,17 +371,22 @@ int gtst(int inv, int t)
t = gjmp(t);
gsym(vtop->c.i);
}
} else if ((vtop->r & (VT_VALMASK | VT_LVAL)) == VT_CONST) {
/* constant jmp optimization */
if ((vtop->c.i != 0) != inv)
t = gjmp(t);
} else {
/* XXX: floats */
v = gv();
o(0x85);
o(0xc0 + v * 9);
g(0x0f);
t = psym(0x85 ^ inv, t);
if (is_float(vtop->t)) {
vpushi(0);
gen_op(TOK_NE);
}
if ((vtop->r & (VT_VALMASK | VT_LVAL | VT_FORWARD)) == VT_CONST) {
/* constant jmp optimization */
if ((vtop->c.i != 0) != inv)
t = gjmp(t);
} else {
v = gv(RC_INT);
o(0x85);
o(0xc0 + v * 9);
g(0x0f);
t = psym(0x85 ^ inv, t);
}
}
vtop--;
return t;
@ -405,9 +398,9 @@ void gen_opi(int op)
int t, r, fr;
vswap();
r = gv();
r = gv(RC_INT);
vswap();
fr = gv();
fr = gv(RC_INT);
vtop--;
if (op == '+') {
@ -460,9 +453,9 @@ void gen_opi(int op)
oad(0xbd, t);
}
if (op == '%' | op == TOK_UMOD)
r = 2;
r = REG_EDX;
else
r = 0;
r = REG_EAX;
vtop->r = r;
} else {
vtop--;
@ -477,22 +470,22 @@ void gen_opi(int op)
/* NOTE: currently floats can only be lvalues */
void gen_opf(int op)
{
int a, ft, fc, swapped, r;
int a, ft, fc, swapped;
/* convert constants to memory references */
if ((vtop[-1].r & (VT_CONST | VT_LVAL)) == VT_CONST) {
vswap();
gv();
gv(RC_FLOAT);
vswap();
}
if ((vtop[0].r & (VT_CONST | VT_LVAL)) == VT_CONST)
gv();
gv(RC_FLOAT);
/* must put at least one value in the floating point register */
if ((vtop[-1].r & VT_LVAL) &&
(vtop[0].r & VT_LVAL)) {
vswap();
gv();
gv(RC_FLOAT);
vswap();
}
if (op >= TOK_EQ && op <= TOK_GT) {
@ -520,13 +513,18 @@ void gen_opf(int op)
vtop->r = VT_CMP;
vtop->c.i = op;
} else {
swapped = 0;
/* swap the stack if needed so that t1 is the register and t2 is
the memory reference */
swapped = 0;
if (vtop[-1].r & VT_LVAL) {
vswap();
swapped = 1;
}
/* no memory reference possible for long double operations */
if ((vtop->t & VT_BTYPE) == VT_LDOUBLE) {
load(REG_ST0, vtop);
swapped = !swapped;
}
switch(op) {
default:
@ -534,34 +532,30 @@ void gen_opf(int op)
a = 0;
break;
case '-':
a = 0x20;
a = 4;
if (swapped)
a += 8;
a++;
break;
case '*':
a = 0x08;
a = 1;
break;
case '/':
a = 0x30;
a = 6;
if (swapped)
a += 8;
a++;
break;
}
ft = vtop->t;
fc = vtop->c.ul;
if ((ft & VT_BTYPE) == VT_DOUBLE)
o(0xdc);
else
o(0xd8);
r = vtop->r & VT_VALMASK;
if (r == VT_CONST) {
o(0x05 + a);
gen_addr32(vtop->r, fc);
} else if (r == VT_LOCAL) {
oad(0x85 + a, fc);
if ((ft & VT_BTYPE) == VT_LDOUBLE) {
o(0xde); /* fxxxp %st, %st(1) */
o(0xc1 + (a << 3));
} else {
g(0x00 + a + r);
if ((ft & VT_BTYPE) == VT_DOUBLE)
o(0xdc);
else
o(0xd8);
gen_modrm(a, vtop->r, fc);
}
vtop--;
}
@ -570,7 +564,7 @@ void gen_opf(int op)
/* convert integers to fp 't' type */
void gen_cvt_itof(int t)
{
gv();
gv(RC_INT);
if ((vtop->t & (VT_BTYPE | VT_UNSIGNED)) == (VT_INT | VT_UNSIGNED)) {
/* unsigned int to float/double/long double */
o(0x6a); /* push $0 */
@ -599,7 +593,7 @@ void gen_cvt_ftoi(int t)
{
int r, size;
gv();
gv(RC_FLOAT);
if (t == VT_INT | VT_UNSIGNED &&
t == VT_LLONG | VT_UNSIGNED &&
t == VT_LLONG)
@ -607,7 +601,7 @@ void gen_cvt_ftoi(int t)
else
size = 4;
r = get_reg(REG_CLASS_INT);
r = get_reg(RC_INT);
oad(0x2dd9, (int)&__tcc_int_fpu_control); /* ldcw xxx */
oad(0xec81, size); /* sub $xxx, %esp */
if (size == 4)
@ -626,7 +620,7 @@ void gen_cvt_ftoi(int t)
void gen_cvt_ftof(int t)
{
/* all we have to do on i386 is to put the float in a register */
gv();
gv(RC_FLOAT);
}
/* pop stack value */

113
tcc.c
View File

@ -340,7 +340,7 @@ void gexpr(void);
void decl(int l);
void decl_initializer(int t, int r, int c, int first, int size_only);
int decl_initializer_alloc(int t, int sec, int has_init);
int gv(void);
int gv(int rc);
void move_reg(int r, int s);
void save_reg(int r);
void vpop(void);
@ -360,7 +360,9 @@ int pointed_size(int t);
int parse_btype(int *type_ptr);
int type_decl(int *v, int t, int td);
void error(const char *fmt, ...);
void vpushi(int v);
void vset(int t, int r, int v);
void greloc(Sym *s, int addr, int type);
/* true if float/double/long double type */
static inline int is_float(int t)
@ -419,6 +421,36 @@ void *dlsym(void *handle, char *symbol)
#endif
/* add a new relocation entry to symbol 's' */
void greloc(Sym *s, int addr, int type)
{
Reloc *p;
p = malloc(sizeof(Reloc));
if (!p)
error("memory full");
p->type = type;
p->addr = addr;
p->next = (Reloc *)s->c;
s->c = (int)p;
}
/* patch each relocation entry with value 'val' */
void greloc_patch(Sym *s, int val)
{
Reloc *p, *p1;
p = (Reloc *)s->c;
while (p != NULL) {
p1 = p->next;
greloc_patch1(p, val);
free(p);
p = p1;
}
s->c = val;
s->r &= ~VT_FORWARD;
}
static inline int isid(int c)
{
return (c >= 'a' && c <= 'z') ||
@ -1884,7 +1916,7 @@ void vsetc(int t, int r, CValue *vc)
/* cannot let cpu flags if other instruction are generated */
/* XXX: VT_JMP test too ? */
if ((vtop->r & VT_VALMASK) == VT_CMP)
gv();
gv(RC_INT);
vtop++;
vtop->t = t;
vtop->r = r;
@ -2028,12 +2060,12 @@ void move_reg(int r, int s)
}
}
/* convert a (vtop->t, vtop->c) in register. lvalues are converted as
values. Cannot be used if cannot be converted to register value
(such as structures). */
int gv(void)
/* store vtop a register belonging to class 'rc'. lvalues are
converted as values. Cannot be used if cannot be converted to
register value (such as structures). */
int gv(int rc)
{
int r, bit_pos, bit_size, rc, size, align, i;
int r, bit_pos, bit_size, size, align, i;
/* NOTE: get_reg can modify vstack[] */
if (vtop->t & VT_BITFIELD) {
@ -2047,7 +2079,7 @@ int gv(void)
vpushi(32 - bit_size);
/* NOTE: transformed to SHR if unsigned */
gen_op(TOK_SAR);
r = gv();
r = gv(rc);
} else {
if (is_float(vtop->t) &&
(vtop->r & (VT_VALMASK | VT_LVAL)) == VT_CONST) {
@ -2064,14 +2096,16 @@ int gv(void)
glo += size << 2;
}
r = vtop->r & VT_VALMASK;
if (r >= VT_CONST || (vtop->r & VT_LVAL)) {
if (is_float(vtop->t))
rc = REG_CLASS_FLOAT;
else
rc = REG_CLASS_INT;
/* need to reload if:
- constant
- lvalue (need to dereference pointer)
- already a register, but not in the right class */
if (r >= VT_CONST ||
(vtop->r & VT_LVAL) ||
!(reg_classes[r] & rc)) {
r = get_reg(rc);
load(r, vtop);
}
load(r, vtop);
vtop->r = r;
}
return r;
@ -2620,7 +2654,7 @@ void gen_assign_cast(int dt)
/* store vtop in lvalue pushed on stack */
void vstore(void)
{
int ft, r, t, size, align, bit_size, bit_pos;
int ft, r, t, size, align, bit_size, bit_pos, rc;
GFuncContext gf;
ft = vtop[-1].t;
@ -2675,11 +2709,14 @@ void vstore(void)
/* store result */
vstore();
} else {
r = gv(); /* generate value */
rc = RC_INT;
if (is_float(ft))
rc = RC_FLOAT;
r = gv(rc); /* generate value (XXX: move that to store code) */
/* if lvalue was saved on stack, must read it */
if ((vtop[-1].r & VT_VALMASK) == VT_LLOCAL) {
SValue sv;
t = get_reg(REG_CLASS_INT);
t = get_reg(RC_INT);
sv.t = VT_INT;
sv.r = VT_LOCAL | VT_LVAL;
sv.c.ul = vtop[-1].c.ul;
@ -2696,19 +2733,24 @@ void vstore(void)
/* post defines POST/PRE add. c is the token ++ or -- */
void inc(int post, int c)
{
int r, r1;
int r, r1, rc, t;
SValue sv;
test_lvalue();
if (post)
vdup(); /* room for returned value */
vdup(); /* save lvalue */
r = gv();
if (post) {
/* duplicate value */
/* XXX: handle floats */
r1 = get_reg(REG_CLASS_INT);
rc = RC_INT;
sv.t = VT_INT;
t = vtop->t & VT_TYPE;
if (is_float(t)) {
rc = RC_FLOAT;
sv.t = t;
}
r = gv(rc);
r1 = get_reg(rc);
sv.r = r;
sv.c.ul = 0;
load(r1, &sv); /* move r to r1 */
@ -3137,10 +3179,10 @@ Sym *external_sym(int v, int u, int r)
void indir(void)
{
if (vtop->r & VT_LVAL)
gv();
if ((vtop->t & VT_BTYPE) != VT_PTR)
expect("pointer");
if (vtop->r & VT_LVAL)
gv(RC_INT);
vtop->t = pointed_type(vtop->t);
if (!(vtop->t & VT_ARRAY)) /* an array is never an lvalue */
vtop->r |= VT_LVAL;
@ -3442,7 +3484,11 @@ void unary(void)
gfunc_param(&gf);
} else {
ret.t = s->t;
ret.r = FUNC_RET_REG; /* return in register */
/* return in register */
if (is_float(ret.t))
ret.r = REG_FRET;
else
ret.r = REG_IRET;
ret.c.i = 0;
}
#ifndef INVERT_FUNC_PARAMS
@ -3561,7 +3607,7 @@ void eor(void)
/* XXX: better constant handling */
void expr_eq(void)
{
int t, u, c, r1, r2;
int t, u, c, r1, r2, rc;
if (const_wanted) {
sum(10);
@ -3582,16 +3628,19 @@ void expr_eq(void)
if (tok == '?') {
next();
t = gtst(1, 0);
gexpr();
r1 = gv();
/* XXX: float handling ? */
rc = RC_INT;
if (is_float(vtop->t))
rc = RC_FLOAT;
r1 = gv(rc);
vpop();
skip(':');
u = gjmp(0);
gsym(t);
expr_eq();
r2 = gv();
r2 = gv(rc);
move_reg(r1, r2);
vtop->r = r1;
gsym(u);
@ -3718,11 +3767,9 @@ void block(int *bsym, int *csym, int *case_sym, int *def_sym, int case_reg)
/* copy structure value to pointer */
vstore();
} else if (is_float(func_vt)) {
/* move return value to float return register */
move_reg(FUNC_RET_FREG, gv());
gv(RC_FRET);
} else {
/* move return value to standard return register */
move_reg(FUNC_RET_REG, gv());
gv(RC_IRET);
}
vpop();
}
@ -3794,7 +3841,7 @@ void block(int *bsym, int *csym, int *case_sym, int *def_sym, int case_reg)
next();
skip('(');
gexpr();
case_reg = gv();
case_reg = gv(RC_INT);
vpop();
skip(')');
a = 0;