ref: 0bfac109a491e61d7cd585060b88e1251da1e928
parent: 340d83d49d659b53e711ab59d6e819be39a0ad16
author: cinap_lenrek <[email protected]>
date: Mon Feb 1 14:27:57 EST 2016
mpc: constant expression folding
--- a/sys/src/cmd/mpc.y
+++ b/sys/src/cmd/mpc.y
@@ -28,6 +28,7 @@
Node* l;
Node* r;
Sym* s;
+ mpint* m;
int n;
};
@@ -238,11 +239,11 @@
{ $$ = new('e', $1, $2);}
-| expr LSH num
+| expr LSH expr
{$$ = new(LSH, $1, $3);
}
-| expr RSH num
+| expr RSH expr
{$$ = new(RSH, $1, $3);
}
@@ -390,6 +391,7 @@
n->l = l;
n->r = r;
n->s = nil;
+ n->m = nil;
n->n = lineno;
return n;
}
@@ -561,7 +563,7 @@
{if(n->c == NAME)
return 0;
- if(n->c == NUM && strlen(n->s->n) == 1 && atoi(n->s->n) < 3)
+ if(n->c == NUM && n->m->sign > 0 && mpcmp(n->m, mptwo) <= 0)
return 0;
return 1;
}
@@ -570,37 +572,131 @@
bcom(Node *n, Node *t);
Node*
+ccom(Node *f)
+{+ Node *l, *r;
+
+ if(f == nil)
+ return nil;
+
+ if(f->m != nil)
+ return f;
+ f->m = (void*)~0;
+
+ switch(f->c){+ case NUM:
+ f->m = strtomp(f->s->n, nil, 0, nil);
+ if(f->m == nil)
+ diag(f, "bad constant");
+ goto out;
+
+ case LSH:
+ case RSH:
+ break;
+
+ case '+':
+ case '-':
+ case '*':
+ case '/':
+ case '%':
+ case '^':
+ if(modulo == nil || modulo->c == NUM)
+ break;
+
+ /* wet floor */
+ default:
+ return f;
+ }
+
+ f->l = l = ccom(f->l);
+ f->r = r = ccom(f->r);
+ if(l == nil || r == nil || l->c != NUM || r->c != NUM)
+ return f;
+
+ f->m = mpnew(0);
+ switch(f->c){+ case LSH:
+ case RSH:
+ if(mpsignif(r->m) > 32)
+ diag(f, "bad shift");
+ if(f->c == LSH)
+ mpleft(l->m, mptoi(r->m), f->m);
+ else
+ mpright(l->m, mptoi(r->m), f->m);
+ goto out;
+
+ case '+':
+ mpadd(l->m, r->m, f->m);
+ break;
+ case '-':
+ mpsub(l->m, r->m, f->m);
+ break;
+ case '*':
+ mpmul(l->m, r->m, f->m);
+ break;
+ case '/':
+ if(modulo != nil){+ mpinvert(r->m, modulo->m, f->m);
+ mpmul(f->m, l->m, f->m);
+ } else {+ mpdiv(l->m, r->m, f->m, nil);
+ }
+ break;
+ case '%':
+ mpmod(l->m, r->m, f->m);
+ break;
+ case '^':
+ mpexp(l->m, r->m, modulo != nil ? modulo->m : nil, f->m);
+ goto out;
+ }
+ if(modulo != nil)
+ mpmod(f->m, modulo->m, f->m);
+
+out:
+ f->l = nil;
+ f->r = nil;
+ f->s = nil;
+ f->c = NUM;
+ return f;
+}
+
+Node*
ecom(Node *f, Node *t)
{Node *l, *r, *t2;
- mpint *m;
if(f == nil)
return nil;
+ f = ccom(f);
if(f->c == NUM){- m = strtomp(f->s->n, nil, 0, nil);
- if(m == nil)
- diag(f, "bad constant");
- if(mpcmp(m, mpzero) == 0){+ if(f->m->sign < 0){+ f->m->sign = 1;
+ t = ecom(f, t);
+ f->m->sign = -1;
+ if(isconst(t))
+ t = ecom(t, alloctmp());
+ cprint("%N->sign = -1;\n", t);+ return t;
+ }
+ if(mpcmp(f->m, mpzero) == 0){f->c = NAME;
f->s = sym("mpzero");f->s->f = FSET;
return ecom(f, t);
}
- if(mpcmp(m, mpone) == 0){+ if(mpcmp(f->m, mpone) == 0){f->c = NAME;
f->s = sym("mpone");f->s->f = FSET;
return ecom(f, t);
}
- if(mpcmp(m, mptwo) == 0){+ if(mpcmp(f->m, mptwo) == 0){f->c = NAME;
f->s = sym("mptwo");f->s->f = FSET;
return ecom(f, t);
}
- mpfree(m);
}
if(f->c == ','){@@ -645,24 +741,23 @@
switch(f->c){case NUM:
- m = strtomp(f->s->n, nil, 0, nil);
- if(m == nil)
- diag(f, "bad constant");
- if(mpsignif(m) <= 32)
- cprint("uitomp(%udUL, %N);\n", mptoui(m), t);- else if(mpsignif(m) <= 64)
- cprint("uvtomp(%lludULL, %N);\n", mptouv(m), t);+ if(mpsignif(f->m) <= 32)
+ cprint("uitomp(%udUL, %N);\n", mptoui(f->m), t);+ else if(mpsignif(f->m) <= 64)
+ cprint("uvtomp(%lludULL, %N);\n", mptouv(f->m), t);else
- cprint("strtomp(\"%.16B\", nil, 16, %N);\n", m, t);- mpfree(m);
+ cprint("strtomp(\"%.16B\", nil, 16, %N);\n", f->m, t);goto out;
case LSH:
- l = f->l->c == NAME ? f->l : ecom(f->l, t);
- cprint("mpleft(%N, %N, %N);\n", l, f->r, t);- goto out;
case RSH:
+ r = ccom(f->r);
+ if(r == nil || r->c != NUM || mpsignif(r->m) > 32)
+ diag(f, "bad shift");
l = f->l->c == NAME ? f->l : ecom(f->l, t);
- cprint("mpright(%N, %N, %N);\n", l, f->r, t);+ if(f->c == LSH)
+ cprint("mpleft(%N, %d, %N);\n", l, mptoi(r->m), t);+ else
+ cprint("mpright(%N, %d, %N);\n", l, mptoi(r->m), t);goto out;
case '*':
case '/':
@@ -670,8 +765,10 @@
r = ecom(f->r, nil);
break;
default:
- l = ecom(f->l, complex(f->l) && !symref(f->r, t->s) ? t : nil);
- r = ecom(f->r, complex(f->r) && l->s != t->s ? t : nil);
+ l = ccom(f->l);
+ r = ccom(f->r);
+ l = ecom(l, complex(l) && !symref(r, t->s) ? t : nil);
+ r = ecom(r, complex(r) && l->s != t->s ? t : nil);
break;
}
@@ -975,8 +1072,11 @@
return fmtprint(f, "%N, %N", n->l, n->r);
switch(n->c){- case NAME:
case NUM:
+ if(n->m != nil)
+ return fmtprint(f, "%B", n->m);
+ /* wet floor */
+ case NAME:
return fmtprint(f, "%s", n->s->n);
case EQ:
return fmtprint(f, "==");