ref: c881e33e8ed668f4d5a2102c113e3edb1ea80d44
dir: /sys/src/cmd/dtracy/cgen.c/
#include <u.h>
#include <libc.h>
#include <dtracy.h>
#include <bio.h>
#include "dat.h"
#include "fns.h"
u16int regsused = 1;
u32int cbuf[256];
int ncbuf;
int labtab[256];
int nlab;
static void
emit(u32int x)
{
assert(ncbuf < nelem(cbuf));
cbuf[ncbuf++] = x;
}
static int
regalloc(void)
{
u16int v;
int n;
if(regsused == 0xffff){
error("out of registers");
return 0;
}
v = regsused + 1 & ~regsused;
regsused ^= v;
n = 0;
if((u8int)v == 0) {v >>= 8; n += 8;}
if((v & 0xf) == 0) {v >>= 4; n += 4;}
if((v & 3) == 0) {v >>= 2; n += 2;}
return n + (v >> 1);
}
static void
regfree(int n)
{
assert((regsused & 1<<n) != 0);
assert(n != 0);
regsused &= ~(1<<n);
}
static int
popcount(u64int s)
{
s = (s & 0x5555555555555555ULL) + (s >> 1 & 0x5555555555555555ULL);
s = (s & 0x3333333333333333ULL) + (s >> 2 & 0x3333333333333333ULL);
s = (s & 0x0F0F0F0F0F0F0F0FULL) + (s >> 4 & 0x0F0F0F0F0F0F0F0FULL);
s = (s & 0x00FF00FF00FF00FFULL) + (s >> 8 & 0x00FF00FF00FF00FFULL);
s = (s & 0x0000FFFF0000FFFFULL) + (s >> 16 & 0x0000FFFF0000FFFFULL);
return (u32int)s + (u32int)(s >> 32);
}
static int
constenc(s64int val)
{
int i, r;
s64int x;
r = 0;
do{
i = popcount(val ^ val - 1) - 1;
x = val << 54 - i >> 54;
if(r == 0){
r = regalloc();
emit(DTE_LDI << 24 | (x & 0x3ff) << 14 | i << 8 | r);
}else
emit(DTE_XORI << 24 | (x & 0x3ff) << 14 | i << 8 | r);
val ^= x << i;
}while(val != 0);
return r;
}
static int egen(Node *);
static void
condgen(Node *n, int invert, int truelab)
{
int r1, r2, l1, op;
if(n->type != OBIN) goto other;
switch(n->op){
case OPEQ: op = DTE_BEQ; goto cmp;
case OPNE: op = DTE_BNE; goto cmp;
case OPLT: op = DTE_BLT; goto cmp;
case OPLE: op = DTE_BLE;
cmp:
r1 = egen(n->n1);
r2 = egen(n->n2);
if(invert)
emit(DTE(op ^ 1, r2, r1, truelab));
else
emit(DTE(op, r1, r2, truelab));
regfree(r1);
regfree(r2);
break;
case OPLOR:
case OPLAND:
if(invert ^ n->op == OPLOR){
condgen(n->n1, invert, truelab);
condgen(n->n2, invert, truelab);
}else{
l1 = nlab++;
condgen(n->n1, !invert, l1);
condgen(n->n2, invert, truelab);
labtab[l1] = ncbuf;
}
break;
default:
other:
r1 = egen(n);
emit(DTE(DTE_BNE ^ invert, r1, 0, truelab));
regfree(r1);
break;
}
}
static int
condvgen(Node *n, int invert)
{
int r, l1, l2, op;
if(n->type == OLNOT)
return condvgen(n->n1, !invert);
if(n->type != OBIN) goto other;
switch(n->op){
case OPEQ: op = DTE_SEQ; goto cmp;
case OPNE: op = DTE_SNE; goto cmp;
case OPLT: op = DTE_SLT; goto cmp;
case OPLE: op = DTE_SLE;
cmp:
if(invert)
return egen(node(OBIN, op ^ 1, n->n2, n->n1));
return egen(n);
case OPLOR:
case OPLAND:
if(invert ^ n->op == OPLOR){
l1 = nlab++;
l2 = nlab++;
condgen(n->n1, invert, l1);
r = condvgen(n->n2, invert);
emit(DTE(DTE_BEQ, 0, 0, l2));
labtab[l1] = ncbuf;
emit(DTE(DTE_LDI, 0, 1<<6, r));
labtab[l2] = ncbuf;
return r;
}else{
l1 = nlab++;
l2 = nlab++;
condgen(n->n1, !invert, l1);
r = condvgen(n->n2, invert);
emit(DTE(DTE_BEQ, 0, 0, l2));
labtab[l1] = ncbuf;
emit(DTE(DTE_LDI, 0, 0<<6, r));
labtab[l2] = ncbuf;
return r;
}
default:
other:
r = egen(n);
emit(DTE(DTE_SNE ^ invert, r, 0, r));
return r;
}
}
static int
egen(Node *n)
{
int r1, r2, rt, l1, l2, op;
switch(/*nodetype*/n->type){
case ONUM:
return constenc(n->num);
case OSYM:
switch(n->sym->type){
case SYMVAR:
rt = regalloc();
emit(DTE(DTE_LDV, n->sym->idx, rt, 0));
return rt;
default: sysfatal("egen: unknown symbol type %d", n->sym->type); return 0;
}
case OBIN:
switch(/*oper*/n->op){
case OPLAND:
case OPLOR:
return condvgen(n, 0);
case OPADD: op = DTE_ADD; break;
case OPSUB: op = DTE_SUB; break;
case OPMUL: op = DTE_MUL; break;
case OPDIV: op = n->typ->sign ? DTE_SDIV : DTE_UDIV; break;
case OPMOD: op = n->typ->sign ? DTE_SMOD : DTE_UMOD; break;
case OPAND: op = DTE_AND; break;
case OPOR: op = DTE_OR; break;
case OPXOR: op = DTE_XOR; break;
case OPLSH: op = DTE_LSL; break;
case OPRSH: op = n->typ->sign ? DTE_ASR : DTE_LSR; break;
case OPEQ: op = DTE_SEQ; break;
case OPNE: op = DTE_SNE; break;
case OPLT: op = DTE_SLT; break;
case OPLE: op = DTE_SLE; break;
case OPXNOR: op = DTE_XNOR; break;
default: sysfatal("egen: unknown op %d", n->op); return 0;
}
r1 = egen(n->n1);
r2 = egen(n->n2);
regfree(r1);
regfree(r2);
rt = regalloc();
emit(DTE(op, r1, r2, rt));
return rt;
case OTERN:
l1 = nlab++;
l2 = nlab++;
condgen(n->n1, 1, l1);
r1 = egen(n->n2);
emit(DTE(DTE_BEQ, 0, 0, l2));
labtab[l1] = ncbuf;
r2 = egen(n->n3);
if(r1 != r2)
emit(DTE(DTE_OR, 0, r2, r1));
labtab[l2] = ncbuf;
return r1;
case OLNOT:
return condvgen(n, 0);
case OCAST:
switch(n->typ->type){
case TYPINT:
r1 = egen(n->n1);
emit(DTE(n->typ->sign ? DTE_SXT : DTE_ZXT, r1, n->typ->size * 8, r1));
return r1;
case TYPSTRING:
return egen(n->n1);
default:
sysfatal("egen: don't know how to cast %τ to %τ", n->n1->typ, n->typ);
}
case ORECORD:
case OSTR:
default: sysfatal("egen: unknown type %α", n->type); return 0;
}
}
DTExpr *
codegen(Node *n)
{
int r, i, t;
DTExpr *ep;
regsused = 1;
ncbuf = 0;
nlab = 0;
r = egen(n);
emit(DTE(DTE_RET, r, 0, 0));
for(i = 0; i < ncbuf; i++)
if((cbuf[i] >> 24 & 0xf0) == 0x30){
t = labtab[cbuf[i] & 0xff];
assert((uint)(t - i - 1) < 0x100);
cbuf[i] = cbuf[i] & 0xffffff00 | t - i - 1;
}
ep = emalloc(sizeof(DTExpr) + ncbuf * sizeof(u32int));
ep->n = ncbuf;
ep->b = (void *)(ep + 1);
memcpy(ep->b, cbuf, ncbuf * sizeof(u32int));
return ep;
}
Node *
tracegen(Node *n, DTActGr *g, int *recoff)
{
switch(/*nodetype*/n->type){
case OSYM:
case ONUM:
case OSTR:
break;
case OBIN:
n->n1 = tracegen(n->n1, g, recoff);
n->n2 = tracegen(n->n2, g, recoff);
break;
case OLNOT:
n->n1 = tracegen(n->n1, g, recoff);
break;
case OTERN:
n->n1 = tracegen(n->n1, g, recoff);
n->n2 = tracegen(n->n2, g, recoff);
n->n3 = tracegen(n->n3, g, recoff);
break;
case OCAST:
n->n1 = tracegen(n->n1, g, recoff);
break;
case ORECORD:
switch(n->typ->type){
case TYPINT:
actgradd(g, (DTAct){ACTTRACE, codegen(n->n1), n->typ->size, noagg});
break;
case TYPSTRING:
actgradd(g, (DTAct){ACTTRACESTR, codegen(n->n1), n->typ->size, noagg});
break;
default:
sysfatal("tracegen: don't know how to record %τ", n->typ);
}
n->num = *recoff;
*recoff += n->typ->size;
return n;
default: sysfatal("tracegen: unknown type %α", n->type); return nil;
}
return n;
}