nctref/src/cg.c
2025-02-27 20:10:02 +02:00

926 lines
31 KiB
C

#include"cg.h"
#include<stdlib.h>
#include<signal.h>
#include<string.h>
#include<assert.h>
#include"x86.h"
#define REGS 4
static const char *regs[][3] = {
[COLOR_EAX] = {"al", "ax", "eax"},
[COLOR_ECX] = {"cl", "cx", "ecx"},
[COLOR_EDX] = {"dl", "dx", "edx"},
[COLOR_EBX] = {"bl", "bx", "ebx"},
{"fu", "fk", "fck"}
};
static const char *BINOP_SIMPLE_INSTRS[] = {[BINOP_ADD] = "add", [BINOP_SUB] = "sub", [BINOP_BITWISE_AND] = "and", [BINOP_BITWISE_OR] = "or", [BINOP_BITWISE_XOR] = "xor"};
static size_t nextLocalLabel = 0;
typedef struct {
#define LOOPSTACKSIZE 96
size_t loopStackStart[LOOPSTACKSIZE];
size_t loopStackEnd[LOOPSTACKSIZE];
size_t loopStackIdx;
int isFunction;
AST *tlc;
} CGState;
static const char *direct(int size) {
switch(size) {
case 0:
case 1: return "db";
case 2: return "dw";
case 4: return "dd";
case 8: return "dq";
}
abort();
}
static const char *spec(int size) {
switch(size) {
case 0:
case 1: return "byte";
case 2: return "word";
case 4: return "dword";
case 8: return "qword";
}
abort();
}
static int log_size(int size) {
switch(size) {
case 0:
case 1: return 0;
case 2: return 1;
case 4: return 2;
case 8: return 3;
}
abort();
}
static const char *specexpr(AST *e) {
return spec(type_size(e->expression.type));
}
static const char *xv_sz(VarTableEntry *v, int sz) {
assert(v->kind == VARTABLEENTRY_VAR);
#define XVBUFS 8
#define XVBUFSZ 8
static char bufs[XVBUFS][XVBUFSZ];
static int bufidx = 0;
char *ret = bufs[bufidx];
#ifdef DEBUG
snprintf(ret, XVBUFSZ, "@%i", v->data.var.color);
#else
snprintf(ret, XVBUFSZ, "%s", regs[v->data.var.color][log_size(sz)]);
#endif
bufidx = (bufidx + 1) % XVBUFS;
return ret;
}
static const char *xv(VarTableEntry *v) {
return xv_sz(v, type_size(v->type));
}
static const char *xj(BinaryOp op) {
switch(op) {
case BINOP_EQUAL: return "e";
case BINOP_NEQUAL: return "ne";
case BINOP_LESS: return "b";
case BINOP_GREATER: return "a";
case BINOP_LEQUAL: return "be";
case BINOP_GEQUAL: return "ae";
default: abort(); return NULL;
}
}
static AST *is_field_access(AST *e) {
if(e->nodeKind != AST_EXPR_UNARY_OP || e->exprUnOp.operator != UNOP_DEREF) {
return NULL;
}
e = e->exprUnOp.operand;
if(e->nodeKind == AST_EXPR_CAST && e->exprCast.what->expression.type->type == TYPE_TYPE_POINTER && e->exprCast.to->type == TYPE_TYPE_POINTER) {
e = e->exprCast.what;
}
if(e->nodeKind == AST_EXPR_BINARY_OP && e->exprBinOp.operator == BINOP_ADD && e->exprBinOp.operands[0]->nodeKind == AST_EXPR_UNARY_OP && e->exprBinOp.operands[1]->nodeKind == AST_EXPR_PRIMITIVE && e->exprBinOp.operands[0]->exprUnOp.operator == UNOP_REF && e->exprBinOp.operands[0]->exprUnOp.operand->nodeKind == AST_EXPR_VAR && e->exprBinOp.operands[0]->exprUnOp.operand->exprVar.thing->kind == VARTABLEENTRY_SYMBOL) {
return e;
}
return NULL;
}
static const char *xop_sz(AST *tlc, AST *e, int sz) {
#define XOPBUFS 16
#define XOPBUFSZ 24
static char bufs[XOPBUFS][XOPBUFSZ];
static int bufidx = 0;
char *ret = bufs[bufidx];
if(e->nodeKind == AST_EXPR_CAST && e->exprCast.what->expression.type->type == TYPE_TYPE_POINTER && e->exprCast.to->type == TYPE_TYPE_POINTER) {
e = e->exprCast.what;
}
if(e->nodeKind == AST_EXPR_UNARY_OP && e->exprUnOp.operator == UNOP_DEREF) {
AST *p = e->exprUnOp.operand;
if(p->nodeKind == AST_EXPR_CAST && p->exprCast.to->type == TYPE_TYPE_POINTER) {
p = p->exprCast.what;
}
if(p->nodeKind == AST_EXPR_BINARY_OP && p->exprBinOp.operator == BINOP_ADD && p->exprBinOp.operands[0]->nodeKind == AST_EXPR_VAR && p->exprBinOp.operands[1]->nodeKind == AST_EXPR_VAR && p->exprBinOp.operands[0]->exprVar.thing->kind == VARTABLEENTRY_VAR && p->exprBinOp.operands[1]->exprVar.thing->kind == VARTABLEENTRY_VAR) {
snprintf(ret, XOPBUFSZ, "%s [%s + %s]",
spec(sz),
xv_sz(p->exprBinOp.operands[0]->exprVar.thing, 4),
xv_sz(p->exprBinOp.operands[1]->exprVar.thing, 4));
} else if(p->nodeKind == AST_EXPR_BINARY_OP && p->exprBinOp.operator == BINOP_ADD && p->exprBinOp.operands[0]->nodeKind == AST_EXPR_UNARY_OP && p->exprBinOp.operands[1]->nodeKind == AST_EXPR_VAR && p->exprBinOp.operands[0]->exprUnOp.operator == UNOP_REF && p->exprBinOp.operands[0]->exprUnOp.operand->nodeKind == AST_EXPR_VAR && p->exprBinOp.operands[0]->exprUnOp.operand->exprVar.thing->kind == VARTABLEENTRY_SYMBOL && p->exprBinOp.operands[1]->exprVar.thing->kind == VARTABLEENTRY_VAR) {
snprintf(ret, XOPBUFSZ, "%s [%s + %s]",
spec(sz),
p->exprBinOp.operands[0]->exprUnOp.operand->exprVar.thing->data.symbol.name,
xv_sz(p->exprBinOp.operands[1]->exprVar.thing, 4));
} else if(is_field_access(e)) {
e = is_field_access(e);
snprintf(ret, XOPBUFSZ, "%s [%s + %i]",
spec(sz),
e->exprBinOp.operands[0]->exprUnOp.operand->exprVar.thing->data.symbol.name,
e->exprBinOp.operands[1]->exprPrim.val);
} else if(p->nodeKind == AST_EXPR_BINARY_OP && p->exprBinOp.operator == BINOP_ADD && p->exprBinOp.operands[0]->nodeKind == AST_EXPR_UNARY_OP && p->exprBinOp.operands[1]->nodeKind == AST_EXPR_BINARY_OP && p->exprBinOp.operands[0]->exprUnOp.operator == UNOP_REF && p->exprBinOp.operands[0]->exprUnOp.operand->nodeKind == AST_EXPR_VAR && p->exprBinOp.operands[0]->exprUnOp.operand->exprVar.thing->kind == VARTABLEENTRY_SYMBOL && p->exprBinOp.operands[1]->exprBinOp.operator == BINOP_MUL && p->exprBinOp.operands[1]->exprBinOp.operands[1]->nodeKind == AST_EXPR_VAR && p->exprBinOp.operands[1]->exprBinOp.operands[0]->nodeKind == AST_EXPR_PRIMITIVE && p->exprBinOp.operands[1]->exprBinOp.operands[1]->exprVar.thing->kind == VARTABLEENTRY_VAR) {
snprintf(ret, XOPBUFSZ, "%s [%s + %i * %s]",
spec(sz),
p->exprBinOp.operands[0]->exprUnOp.operand->exprVar.thing->data.symbol.name,
p->exprBinOp.operands[1]->exprBinOp.operands[0]->exprPrim.val,
xv_sz(p->exprBinOp.operands[1]->exprBinOp.operands[1]->exprVar.thing, 4));
} else if(p->nodeKind == AST_EXPR_VAR && p->exprVar.thing->kind == VARTABLEENTRY_VAR) {
snprintf(ret, XOPBUFSZ, "%s [%s]", spec(sz), xv_sz(p->exprVar.thing, 4));
} else if(p->nodeKind == AST_EXPR_BINARY_OP && p->exprBinOp.operator == BINOP_ADD && p->exprBinOp.operands[0]->nodeKind == AST_EXPR_STACK_POINTER && p->exprBinOp.operands[1]->nodeKind == AST_EXPR_PRIMITIVE) {
snprintf(ret, XOPBUFSZ, "[esp + %i]", p->exprBinOp.operands[1]->exprPrim.val);
} else {
return NULL;
}
} else if(e->nodeKind == AST_EXPR_STACK_POINTER) {
snprintf(ret, XOPBUFSZ, "esp", tlc->chunk.stackReservation);
} else if(e->nodeKind == AST_EXPR_VAR) {
VarTableEntry *v = e->exprVar.thing;
if(v->kind == VARTABLEENTRY_VAR) {
return xv_sz(v, sz);
} else if(v->kind == VARTABLEENTRY_SYMBOL) {
snprintf(ret, XOPBUFSZ, "%s [%s]", spec(sz), v->data.symbol.name);
} else abort();
} else if(e->nodeKind == AST_EXPR_PRIMITIVE) {
snprintf(ret, XOPBUFSZ, "%s %i", spec(type_size(e->exprPrim.type)), e->exprPrim.val);
} else if(e->nodeKind == AST_EXPR_UNARY_OP && e->exprUnOp.operator == UNOP_REF && e->exprUnOp.operand->nodeKind == AST_EXPR_VAR && e->exprUnOp.operand->exprVar.thing->kind == VARTABLEENTRY_SYMBOL) {
snprintf(ret, XOPBUFSZ, "%s", e->exprUnOp.operand->exprVar.thing->data.symbol.name);
} else {
return NULL;
}
bufidx = (bufidx + 1) % XOPBUFS;
return ret;
}
static const char *xop(AST *tlc, AST *e) {
return xop_sz(tlc, e, type_size(e->expression.type));
}
static int ud_empty(VarTableEntry *a) {
assert(a->kind == VARTABLEENTRY_VAR);
assert(!a->data.var.usedefFirst == !a->data.var.usedefLast);
return !a->data.var.usedefFirst;
}
void cg_chunk(CGState *cg, AST *a) {
AST *s = a->chunk.statementFirst;
if(a->chunk.stackReservation) {
printf("sub esp, %lu\n", a->chunk.stackReservation);
}
// Potentially complex pattern matching
while(s) {
if(s->nodeKind == AST_STMT_EXT_SECTION) {
Token t = s->stmtExtSection.name;
printf("section %.*s\n", (int) t.length, t.content);
} else if(s->nodeKind == AST_STMT_EXT_ORG) {
printf("org %lu\n", s->stmtExtOrg.val);
} else if(s->nodeKind == AST_STMT_EXT_ALIGN) {
uint32_t val = s->stmtExtAlign.val;
if((val & (val - 1))) {
// nasm does not support non-PoT alignments, so pad manually
printf("times ($ - $$ + %u) / %u * %u - ($ - $$) db 0\n", val - 1, val, val);
} else {
printf("align %u\n", val);
}
} else if(s->nodeKind == AST_STMT_DECL && s->stmtDecl.thing->kind == VARTABLEENTRY_SYMBOL) {
VarTableEntry *v = s->stmtDecl.thing;
if(v->data.symbol.isExternal) {
printf("extern %s\n", v->data.symbol.name);
} else {
if(!v->data.symbol.isLocal) {
printf("global %s\n", v->data.symbol.name);
}
if(s->stmtDecl.expression) {
printf("%s:", v->data.symbol.name);
if(v->type->type == TYPE_TYPE_PRIMITIVE) {
assert(s->stmtDecl.expression->nodeKind == AST_EXPR_PRIMITIVE);
printf("%s %i", direct(type_size(v->type)), s->stmtDecl.expression->exprPrim.val);
} else if(v->type->type == TYPE_TYPE_ARRAY && v->type->array.of->type == TYPE_TYPE_PRIMITIVE) {
printf("%s ", direct(type_size(v->type->array.of)));
for(size_t i = 0; i < v->type->array.length; i++) {
printf("%i,", s->stmtDecl.expression->exprArray.items[i]->exprPrim.val);
}
} else if(v->type->type == TYPE_TYPE_FUNCTION) {
putchar('\n');
assert(s->stmtDecl.expression->nodeKind == AST_EXPR_FUNC);
dumben_go(s->stmtDecl.expression->exprFunc.chunk);
while(!cg_go(s->stmtDecl.expression->exprFunc.chunk)) {
dumben_go(s->stmtDecl.expression->exprFunc.chunk);
}
} else abort();
putchar('\n');
} else {
printf("%s resb %lu\n", v->data.symbol.name, type_size(s->stmtDecl.thing->type));
}
}
} else if(s->nodeKind == AST_STMT_ASSIGN && s->stmtAssign.to && s->stmtAssign.what->nodeKind == AST_EXPR_VAR && s->stmtAssign.what->exprVar.thing->kind == VARTABLEENTRY_VAR && s->stmtAssign.to->nodeKind == AST_EXPR_CALL) {
AST *e = s->stmtAssign.to;
puts("push ecx");
puts("push edx");
int argCount = e->exprCall.what->expression.type->function.argCount;
size_t argSize = 0;
for(int i = argCount - 1; i >= 0; i--) {
printf("push %s\n", xop_sz(cg->tlc, e->exprCall.args[i], 4));
argSize += (type_size(e->exprCall.args[i]->expression.type) + 3) & ~3;
}
assert(e->exprCall.what->nodeKind == AST_EXPR_VAR && e->exprCall.what->exprVar.thing->kind == VARTABLEENTRY_SYMBOL);
printf("call %s\n", e->exprCall.what->exprVar.thing->data.symbol.name);
if(argSize) printf("add esp, %lu\n", argSize);
puts("pop edx");
puts("pop ecx");
} else if(s->nodeKind == AST_STMT_ASSIGN) {
if(s->stmtAssign.to && is_xop(s->stmtAssign.what) == XOP_NOT_MEM && is_xop(s->stmtAssign.to) == XOP_NOT_MEM && !strcmp(xop(cg->tlc, s->stmtAssign.what), xop(cg->tlc, s->stmtAssign.to))) {
// It's a noop
} else if(s->stmtAssign.to) {
if(x86_imul_supported() && s->stmtAssign.to->nodeKind == AST_EXPR_BINARY_OP && s->stmtAssign.to->exprBinOp.operator == BINOP_MUL) {
assert(s->stmtAssign.what->nodeKind == AST_EXPR_VAR);
assert(s->stmtAssign.what->exprVar.thing->kind == VARTABLEENTRY_VAR);
if(!strcmp(xop(a, s->stmtAssign.what), xop(a, s->stmtAssign.to->exprBinOp.operands[0]))) {
printf("imul %s, %s\n", xop(a, s->stmtAssign.what), xop(a, s->stmtAssign.to->exprBinOp.operands[1]));
} else {
printf("imul %s, %s, %s\n", xop(a, s->stmtAssign.what), xop(a, s->stmtAssign.to->exprBinOp.operands[0]), xop(a, s->stmtAssign.to->exprBinOp.operands[1]));
}
} else if(s->stmtAssign.to->nodeKind == AST_EXPR_BINARY_OP && s->stmtAssign.to->exprBinOp.operator == BINOP_MULHI) {
assert(s->stmtAssign.what->nodeKind == AST_EXPR_VAR);
assert(s->stmtAssign.what->exprVar.thing->kind == VARTABLEENTRY_VAR);
assert(s->stmtAssign.what->exprVar.thing->data.var.color == COLOR_EDX);
assert(s->statement.next->nodeKind == AST_STMT_ASSIGN);
assert(s->statement.next->stmtAssign.to->nodeKind == AST_EXPR_BINARY_OP);
assert(s->statement.next->stmtAssign.to->exprBinOp.operator == BINOP_MUL);
AST *otherop = NULL;
if(ast_expression_equal(s->statement.next->stmtAssign.to->exprBinOp.operands[0], s->statement.next->stmtAssign.what)) {
otherop = s->statement.next->stmtAssign.to->exprBinOp.operands[1];
} else if(ast_expression_equal(s->statement.next->stmtAssign.to->exprBinOp.operands[1], s->statement.next->stmtAssign.what)) {
otherop = s->statement.next->stmtAssign.to->exprBinOp.operands[0];
} else abort();
printf("mul %s\n", xop(a, otherop));
// Skip next statement, because they come in a pair
s = s->statement.next;
} else if(s->stmtAssign.to->nodeKind == AST_EXPR_BINARY_OP && ast_expression_equal(s->stmtAssign.what, s->stmtAssign.to->exprBinOp.operands[0]) && (s->stmtAssign.to->exprBinOp.operator == BINOP_ADD || s->stmtAssign.to->exprBinOp.operator == BINOP_SUB) && s->stmtAssign.to->exprBinOp.operands[1]->nodeKind == AST_EXPR_PRIMITIVE && s->stmtAssign.to->exprBinOp.operands[1]->exprPrim.val == 1) {
// inc or dec
static const char *instrs[] = {"inc", "dec"};
printf("%s %s\n", instrs[s->stmtAssign.to->exprBinOp.operator == BINOP_SUB], xop(cg->tlc, s->stmtAssign.what));
} else if(s->stmtAssign.to->nodeKind == AST_EXPR_BINARY_OP && ast_expression_equal(s->stmtAssign.what, s->stmtAssign.to->exprBinOp.operands[0]) && s->stmtAssign.to->exprBinOp.operator < BINOP_SIMPLES) {
printf("%s %s, %s\n", BINOP_SIMPLE_INSTRS[s->stmtAssign.to->exprBinOp.operator], xop(cg->tlc, s->stmtAssign.what), xop(cg->tlc, s->stmtAssign.to->exprBinOp.operands[1]));
} else if(s->stmtAssign.what->nodeKind == AST_EXPR_VAR && s->stmtAssign.to->nodeKind == AST_EXPR_BINARY_OP && s->stmtAssign.to->exprBinOp.operator == BINOP_ADD && s->stmtAssign.to->exprBinOp.operands[0]->nodeKind == AST_EXPR_VAR && s->stmtAssign.to->exprBinOp.operands[1]->nodeKind == AST_EXPR_VAR && s->stmtAssign.to->exprBinOp.operands[0]->exprVar.thing->kind == VARTABLEENTRY_VAR && s->stmtAssign.to->exprBinOp.operands[1]->exprVar.thing->kind == VARTABLEENTRY_VAR) {
printf("lea %s, [%s + %s]\n",
xv(s->stmtAssign.what->exprVar.thing),
xv(s->stmtAssign.to->exprBinOp.operands[0]->exprVar.thing),
xv(s->stmtAssign.to->exprBinOp.operands[1]->exprVar.thing));
} else if(s->stmtAssign.what->nodeKind == AST_EXPR_VAR && s->stmtAssign.to->nodeKind == AST_EXPR_BINARY_OP && s->stmtAssign.to->exprBinOp.operator == BINOP_ADD && s->stmtAssign.to->exprBinOp.operands[0]->nodeKind == AST_EXPR_UNARY_OP && s->stmtAssign.to->exprBinOp.operands[0]->exprUnOp.operator == UNOP_REF && s->stmtAssign.to->exprBinOp.operands[0]->exprUnOp.operand->nodeKind == AST_EXPR_VAR && s->stmtAssign.to->exprBinOp.operands[1]->nodeKind == AST_EXPR_VAR && s->stmtAssign.to->exprBinOp.operands[0]->exprUnOp.operand->exprVar.thing->kind == VARTABLEENTRY_SYMBOL && s->stmtAssign.to->exprBinOp.operands[1]->exprVar.thing->kind == VARTABLEENTRY_VAR) {
printf("lea %s, [%s + %s]\n",
xv(s->stmtAssign.what->exprVar.thing),
s->stmtAssign.to->exprBinOp.operands[0]->exprUnOp.operand->exprVar.thing->data.symbol.name,
xv(s->stmtAssign.to->exprBinOp.operands[1]->exprVar.thing));
} else if(s->stmtAssign.what->nodeKind == AST_EXPR_VAR && s->stmtAssign.to->nodeKind == AST_EXPR_BINARY_OP && s->stmtAssign.to->exprBinOp.operator == BINOP_ADD && s->stmtAssign.to->exprBinOp.operands[0]->nodeKind == AST_EXPR_VAR && s->stmtAssign.to->exprBinOp.operands[1]->nodeKind == AST_EXPR_PRIMITIVE && s->stmtAssign.to->exprBinOp.operands[0]->exprVar.thing->kind == VARTABLEENTRY_VAR) {
printf("lea %s, [%s + %i]\n",
xv_sz(s->stmtAssign.what->exprVar.thing, 4),
xv_sz(s->stmtAssign.to->exprBinOp.operands[0]->exprVar.thing, 4),
s->stmtAssign.to->exprBinOp.operands[1]->exprPrim.val);
} else if(is_xop(s->stmtAssign.what) != NULL && s->stmtAssign.to->nodeKind == AST_EXPR_UNARY_OP && s->stmtAssign.to->exprUnOp.operator == UNOP_NEGATE && ast_expression_equal(s->stmtAssign.what, s->stmtAssign.to->exprUnOp.operand)) {
printf("neg %s\n", xop(cg->tlc, s->stmtAssign.what));
} else if(is_xop(s->stmtAssign.what) && s->stmtAssign.to->nodeKind == AST_EXPR_CAST) {
printf("movzx %s, %s\n", xop(cg->tlc, s->stmtAssign.what), xop(cg->tlc, s->stmtAssign.to->exprCast.what));
} else {
if(is_xop(s->stmtAssign.to) == XOP_MEM && type_size(s->stmtAssign.what->expression.type) != type_size(s->stmtAssign.to->expression.type)) {
printf("movzx %s, %s\n", xop_sz(cg->tlc, s->stmtAssign.what, 4), xop_sz(cg->tlc, s->stmtAssign.to, type_size(s->stmtAssign.what->expression.type)));
} else {
printf("mov %s, %s\n", xop(cg->tlc, s->stmtAssign.what), xop_sz(cg->tlc, s->stmtAssign.to, type_size(s->stmtAssign.what->expression.type)));
}
}
}
} else if(s->nodeKind == AST_STMT_LOOP) {
size_t lbl0 = nextLocalLabel++;
size_t lbl1 = nextLocalLabel++;
cg->loopStackStart[cg->loopStackIdx] = lbl0;
cg->loopStackEnd[cg->loopStackIdx] = lbl1;
cg->loopStackIdx++;
printf(".L%lu:\n", lbl0);
cg_chunk(cg, s->stmtLoop.body);
printf("jmp .L%lu\n", lbl0);
printf(".L%lu:\n", lbl1);
cg->loopStackIdx--;
} else if(s->nodeKind == AST_STMT_BREAK) {
printf("jmp .L%lu\n", cg->loopStackEnd[cg->loopStackIdx - 1]);
} else if(s->nodeKind == AST_STMT_CONTINUE) {
printf("jmp .L%lu\n", cg->loopStackStart[cg->loopStackIdx - 1]);
} else if(s->nodeKind == AST_STMT_IF) {
assert(s->stmtIf.expression->nodeKind == AST_EXPR_BINARY_OP && binop_is_comparison(s->stmtIf.expression->exprBinOp.operator));
size_t lbl = nextLocalLabel++;
printf("cmp %s, %s\n", xop(cg->tlc, s->stmtIf.expression->exprBinOp.operands[0]), xop(cg->tlc, s->stmtIf.expression->exprBinOp.operands[1]));
printf("j%s .L%lu\n", xj(binop_comp_opposite(s->stmtIf.expression->exprBinOp.operator)), lbl);
cg_chunk(cg, s->stmtIf.then);
printf(".L%lu:\n", lbl);
} else if(s->nodeKind == AST_STMT_RETURN) {
if(s->stmtReturn.val) {
assert(s->stmtReturn.val->nodeKind == AST_EXPR_VAR);
assert(s->stmtReturn.val->exprVar.thing->kind == VARTABLEENTRY_VAR);
assert(s->stmtReturn.val->exprVar.thing->data.var.color == COLOR_EAX);
}
if(a->chunk.stackReservation) {
printf("add esp, %lu\n", a->chunk.stackReservation);
}
printf("ret\n");
} else if(s->nodeKind == AST_STMT_EXPR && s->stmtExpr.expr->nodeKind == AST_EXPR_VAR) {
/* Loop guard, probably. */
} else abort();
s = s->statement.next;
}
}
struct Spill2VarState {
VarTableEntry *target;
};
static void spill2var_visitor(AST **aptr, AST *stmt, AST *stmtPrev, AST *chunk, AST *tlc, void *ud) {
static size_t vidx = 0;
struct Spill2VarState *this = ud;
AST *a = *aptr;
if(a->nodeKind == AST_STMT_ASSIGN && a->stmtAssign.to->nodeKind == AST_EXPR_CALL) {
assert(a->stmtAssign.what->nodeKind == AST_EXPR_VAR && a->stmtAssign.what->exprVar.thing->kind == VARTABLEENTRY_VAR);
if(a->stmtAssign.what->exprVar.thing == this->target) {
VarTableEntry *new = calloc(1, sizeof(*new));
new->kind = VARTABLEENTRY_VAR;
new->type = a->stmtAssign.what->exprVar.thing->type;
new->data.var.name = malp("$s2v_%lu", vidx++);
tlc->chunk.vars = realloc(tlc->chunk.vars, sizeof(*tlc->chunk.vars) * (++tlc->chunk.varCount));
tlc->chunk.vars[tlc->chunk.varCount - 1] = new;
ASTExprVar *ev0 = calloc(1, sizeof(*ev0));
ev0->nodeKind = AST_EXPR_VAR;
ev0->type = new->type;
ev0->thing = a->stmtAssign.what->exprVar.thing;
ASTExprVar *ev1 = calloc(1, sizeof(*ev1));
ev1->nodeKind = AST_EXPR_VAR;
ev1->type = new->type;
ev1->thing = new;
ASTStmtAssign *ass = calloc(1, sizeof(*ass));
ass->nodeKind = AST_STMT_ASSIGN;
ass->what = (AST*) ev0;
ass->to = (AST*) ev1;
a->stmtAssign.what->exprVar.thing = new;
ass->next = a->statement.next;
a->statement.next = (AST*) ass;
if(!ass->next) {
chunk->chunk.statementLast = (AST*) ass;
}
}
}
if(a->nodeKind == AST_STMT_RETURN && a->stmtReturn.val && a->stmtReturn.val->nodeKind == AST_EXPR_VAR && a->stmtReturn.val->exprVar.thing == this->target) {
VarTableEntry *new = calloc(1, sizeof(*new));
new->kind = VARTABLEENTRY_VAR;
new->type = a->stmtReturn.val->exprVar.thing->type;
new->data.var.name = malp("$s2v_%lu", vidx++);
tlc->chunk.vars = realloc(tlc->chunk.vars, sizeof(*tlc->chunk.vars) * (++tlc->chunk.varCount));
tlc->chunk.vars[tlc->chunk.varCount - 1] = new;
ASTExprVar *ev0 = calloc(1, sizeof(*ev0));
ev0->nodeKind = AST_EXPR_VAR;
ev0->type = new->type;
ev0->thing = a->stmtReturn.val->exprVar.thing;
ASTExprVar *ev1 = calloc(1, sizeof(*ev1));
ev1->nodeKind = AST_EXPR_VAR;
ev1->type = new->type;
ev1->thing = new;
ASTStmtAssign *ass = calloc(1, sizeof(*ass));
ass->nodeKind = AST_STMT_ASSIGN;
ass->what = (AST*) ev1;
ass->to = (AST*) ev0;
stmt->stmtReturn.val->exprVar.thing = new;
ass->next = stmt;
if(stmtPrev) {
stmtPrev->statement.next = (AST*) ass;
} else {
chunk->chunk.statementFirst = (AST*) ass;
}
}
}
struct PrecolorState {
VarTableEntry *mustBeSpilled;
};
static void precolor_visitor(AST **nptr, AST *stmt, AST *stmtPrev, AST *chunk, AST *tlc, void *ud) {
struct PrecolorState *this = ud;
if(this->mustBeSpilled) {
/* Since something must be spilled first, we can't do anything else. Quit ASAP. */
return;
}
AST *n = *nptr;
if(n == tlc) {
for(size_t i = 0; i < n->chunk.varCount; i++) {
n->chunk.vars[i]->data.var.color = -1;
n->chunk.vars[i]->data.var.precolored = false;
}
}
if(n->nodeKind == AST_STMT_RETURN && n->stmtReturn.val) {
assert(n->stmtReturn.val->nodeKind == AST_EXPR_VAR && n->stmtReturn.val->exprVar.thing->kind == VARTABLEENTRY_VAR);
VarTableEntry *vte = n->stmtReturn.val->exprVar.thing;
const int requiredColor = COLOR_EAX;
if(vte->data.var.precolored && vte->data.var.color != requiredColor) {
// Precoloring collision!
this->mustBeSpilled = vte;
return;
}
vte->data.var.color = requiredColor;
vte->data.var.precolored = true;
} else if(n->nodeKind == AST_STMT_ASSIGN && n->stmtAssign.to->nodeKind == AST_EXPR_CALL) {
assert(n->stmtAssign.what->nodeKind == AST_EXPR_VAR && n->stmtAssign.what->exprVar.thing->kind == VARTABLEENTRY_VAR);
VarTableEntry *vte = n->stmtAssign.what->exprVar.thing;
const int requiredColor = COLOR_EAX;
if(vte->data.var.precolored && vte->data.var.color != requiredColor) {
// Precoloring collision!
this->mustBeSpilled = vte;
return;
}
vte->data.var.color = requiredColor;
vte->data.var.precolored = true;
} else if(n->nodeKind == AST_STMT_ASSIGN && n->stmtAssign.what->nodeKind == AST_EXPR_VAR && n->stmtAssign.what->exprVar.thing->kind == VARTABLEENTRY_VAR && n->stmtAssign.to->nodeKind == AST_EXPR_BINARY_OP && n->stmtAssign.to->exprBinOp.operator == BINOP_MUL) {
VarTableEntry *vte = n->stmtAssign.what->exprVar.thing;
const int requiredColor = COLOR_EAX;
if(vte->data.var.precolored && vte->data.var.color != requiredColor) {
// Precoloring collision!
this->mustBeSpilled = vte;
return;
}
vte->data.var.color = requiredColor;
vte->data.var.precolored = true;
} else if(n->nodeKind == AST_STMT_ASSIGN && n->stmtAssign.what->nodeKind == AST_EXPR_VAR && n->stmtAssign.what->exprVar.thing->kind == VARTABLEENTRY_VAR && n->stmtAssign.to->nodeKind == AST_EXPR_BINARY_OP && n->stmtAssign.to->exprBinOp.operator == BINOP_MULHI) {
VarTableEntry *vte = n->stmtAssign.what->exprVar.thing;
const int requiredColor = COLOR_EDX;
if(vte->data.var.precolored && vte->data.var.color != requiredColor) {
// Precoloring collision!
this->mustBeSpilled = vte;
return;
}
vte->data.var.color = requiredColor;
vte->data.var.precolored = true;
}
}
typedef VarTableEntry *Adjacency[2];
static bool var_collision(AST *tlc, VarTableEntry *v1, VarTableEntry *v2) {
/* 1D intersection test */
return !ud_empty(v1) && !ud_empty(v2) && (
(ast_stmt_is_after(tlc, v1->data.var.usedefFirst->stmt, v2->data.var.usedefFirst->stmt) == 1
&& ast_stmt_is_after(tlc, v2->data.var.usedefLast->stmt, v1->data.var.usedefFirst->stmt) == 1)
||
(ast_stmt_is_after(tlc, v1->data.var.usedefLast->stmt, v2->data.var.usedefFirst->stmt) == 1
&& ast_stmt_is_after(tlc, v2->data.var.usedefLast->stmt, v1->data.var.usedefLast->stmt) == 1)
);
}
static VarTableEntry *get_precolor_spill_candidate(AST *tlc) {
Adjacency *adjs = NULL;
size_t adjCount = 0;
for(size_t i = 0; i < tlc->chunk.varCount; i++) {
tlc->chunk.vars[i]->data.var.degree = 0;
for(size_t j = 0; j < tlc->chunk.varCount; j++) {
if( tlc->chunk.vars[i]->data.var.precolored
&& tlc->chunk.vars[j]->data.var.precolored
&& tlc->chunk.vars[i]->data.var.color == tlc->chunk.vars[j]->data.var.color
&& var_collision(tlc, tlc->chunk.vars[i], tlc->chunk.vars[j])) {
adjs = realloc(adjs, sizeof(*adjs) * ++adjCount);
adjs[adjCount - 1][0] = tlc->chunk.vars[i];
adjs[adjCount - 1][1] = tlc->chunk.vars[j];
}
}
}
if(adjCount == 0) {
return NULL;
}
for(size_t a = 0; a < adjCount; a++) {
adjs[a][0]->data.var.degree++;
adjs[a][1]->data.var.degree++;
}
VarTableEntry *maxdeg = tlc->chunk.vars[0];
for(size_t v = 1; v < tlc->chunk.varCount; v++) {
if(maxdeg->data.var.degree < tlc->chunk.vars[v]->data.var.degree) {
maxdeg = tlc->chunk.vars[v];
}
}
free(adjs);
return maxdeg;
}
struct CalleeSavedState {
AST *targetTLC;
VarTableEntry *ebxuser;
// To make sure we don't process the same return statement to infinity
AST *lastProcessedReturn;
};
static void callee_saved_visitor(AST **nptr, AST *stmt, AST *stmtPrev, AST *chunk, AST *tlc, void *ud) {
struct CalleeSavedState *this = ud;
AST *n = *nptr;
if(tlc != this->targetTLC) {
// Don't do anything.
return;
}
if(n == tlc) {
// Function entry
ASTExprStackPointer *stk = calloc(1, sizeof(*stk));
stk->nodeKind = AST_EXPR_STACK_POINTER;
stk->type = primitive_parse("u32");
ASTExprPrimitive *offset = calloc(1, sizeof(*offset));
offset->nodeKind = AST_EXPR_PRIMITIVE;
offset->type = primitive_parse("u32");
offset->val = tlc->chunk.stackReservation;
ASTExprBinaryOp *sum = calloc(1, sizeof(*sum));
sum->nodeKind = AST_EXPR_BINARY_OP;
sum->type = offset->type;
sum->operator = BINOP_ADD;
sum->operands[0] = (AST*) stk;
sum->operands[1] = (AST*) offset;
ASTExprUnaryOp *deref = calloc(1, sizeof(*deref));
deref->nodeKind = AST_EXPR_UNARY_OP;
deref->type = offset->type;
deref->operator = UNOP_DEREF;
deref->operand = (AST*) sum;
ASTExprVar *ev = calloc(1, sizeof(*ev));
ev->nodeKind = AST_EXPR_VAR;
ev->type = this->ebxuser->type;
ev->thing = this->ebxuser;
ASTStmtAssign *assign = calloc(1, sizeof(*assign));
assign->nodeKind = AST_STMT_ASSIGN;
assign->what = (AST*) deref;
assign->to = (AST*) ev;
assign->next = tlc->chunk.statementFirst;
tlc->chunk.statementFirst = (AST*) assign;
assert(tlc->chunk.statementLast != NULL);
tlc->chunk.stackReservation += 4;
} else if(n->nodeKind == AST_STMT_RETURN && n != this->lastProcessedReturn) {
// Function exit
this->lastProcessedReturn = n;
ASTExprStackPointer *stk = calloc(1, sizeof(*stk));
stk->nodeKind = AST_EXPR_STACK_POINTER;
stk->type = primitive_parse("u32");
ASTExprPrimitive *offset = calloc(1, sizeof(*offset));
offset->nodeKind = AST_EXPR_PRIMITIVE;
offset->type = primitive_parse("u32");
offset->val = tlc->chunk.stackReservation;
ASTExprBinaryOp *sum = calloc(1, sizeof(*sum));
sum->nodeKind = AST_EXPR_BINARY_OP;
sum->type = offset->type;
sum->operator = BINOP_ADD;
sum->operands[0] = (AST*) stk;
sum->operands[1] = (AST*) offset;
ASTExprUnaryOp *deref = calloc(1, sizeof(*deref));
deref->nodeKind = AST_EXPR_UNARY_OP;
deref->type = offset->type;
deref->operator = UNOP_DEREF;
deref->operand = (AST*) sum;
ASTExprVar *ev = calloc(1, sizeof(*ev));
ev->nodeKind = AST_EXPR_VAR;
ev->type = this->ebxuser->type;
ev->thing = this->ebxuser;
ASTStmtAssign *assign = calloc(1, sizeof(*assign));
assign->nodeKind = AST_STMT_ASSIGN;
assign->what = (AST*) ev;
assign->to = (AST*) deref;
assign->next = stmt;
if(stmtPrev) {
stmtPrev->statement.next = (AST*) assign;
} else {
tlc->chunk.statementFirst = (AST*) assign;
}
}
}
static void callee_saved(AST *tlc) {
VarTableEntry *ebxuser = NULL;
for(size_t v = 0; v < tlc->chunk.varCount; v++) {
if(tlc->chunk.vars[v]->data.var.color == COLOR_EBX) {
ebxuser = tlc->chunk.vars[v];
break;
}
}
if(ebxuser) {
struct CalleeSavedState state;
state.targetTLC = tlc;
state.ebxuser = ebxuser;
generic_visitor(&tlc, NULL, NULL, tlc, tlc, &state, callee_saved_visitor);
}
}
/* Welsh-Powell graph coloring */
static int comparator(const void *A, const void *B) {
VarTableEntry *const *a = A;
VarTableEntry *const *b = B;
return ((*a)->data.var.degree * (*a)->data.var.priority) - ((*b)->data.var.degree * (*b)->data.var.priority);
}
int cg_go(AST *a) {
ast_usedef_reset(a);
size_t adjCount = 0;
Adjacency *adjs = calloc(adjCount, sizeof(*adjs));
VarTableEntry **vars = a->chunk.vars;
for(size_t vi = 0; vi < a->chunk.varCount; vi++) {
vars[vi]->data.var.priority = 1;
vars[vi]->data.var.degree = 0;
if(!vars[vi]->data.var.precolored) {
vars[vi]->data.var.color = -1;
}
}
for(size_t v1i = 0; v1i < a->chunk.varCount; v1i++) {
for(size_t v2i = 0; v2i < a->chunk.varCount; v2i++) {
if(v1i == v2i) continue;
VarTableEntry *v1 = vars[v1i];
VarTableEntry *v2 = vars[v2i];
if(var_collision(a, v1, v2)) {
VarTableEntry *min = v1 < v2 ? v1 : v2;
VarTableEntry *max = v1 < v2 ? v2 : v1;
for(size_t a = 0; a < adjCount; a++) {
if(adjs[a][0] == min && adjs[a][1] == max) {
goto cont;
}
}
adjs = realloc(adjs, sizeof(*adjs) * ++adjCount);
adjs[adjCount - 1][0] = min;
adjs[adjCount - 1][1] = max;
cont:;
}
}
}
for(size_t a = 0; a < adjCount; a++) {
adjs[a][0]->data.var.degree++;
adjs[a][1]->data.var.degree++;
}
qsort(vars, a->chunk.varCount, sizeof(*vars), comparator);
int lastColor = 0;
/* Welsh plow my ass */
for(int v = 0; v < a->chunk.varCount; v++) {
if(vars[v]->data.var.color != -1) {
// Already assigned.
continue;
}
for(int c = 0;; c++) {
for(int a = 0; a < adjCount; a++) {
if(adjs[a][0] == vars[v] && adjs[a][1]->data.var.color != -1 && adjs[a][1]->data.var.color == c) {
goto nextColor;
} else if(adjs[a][1] == vars[v] && adjs[a][0]->data.var.color != -1 && adjs[a][0]->data.var.color == c) {
goto nextColor;
}
}
vars[v]->data.var.color = c;
lastColor = lastColor < c ? c : lastColor;
break;
nextColor:;
}
}
free(adjs);
if(lastColor >= 4) {
// Spill node with highest degree
VarTableEntry *chosen = NULL;
for(ssize_t i = a->chunk.varCount - 1; i >= 0; i--) {
if(!vars[i]->data.var.precolored) {
chosen = vars[i];
break;
}
}
assert(chosen != NULL);
ast_spill_to_stack(a, chosen);
return 0;
}
if(a->chunk.functionType) {
callee_saved(a);
}
CGState cg;
memset(&cg, 0, sizeof(cg));
cg.tlc = a;
cg.isFunction = !!a->chunk.functionType;
cg_chunk(&cg, a);
return 1;
}