// Derived from Inferno utils/6c/reg.c
// http://code.google.com/p/inferno-os/source/browse/utils/6c/reg.c
//
// Copyright © 1994-1999 Lucent Technologies Inc. All rights reserved.
// Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net)
// Portions Copyright © 1997-1999 Vita Nuova Limited
// Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com)
// Portions Copyright © 2004,2006 Bruce Ellis
// Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net)
// Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others
// Portions Copyright © 2009 The Go Authors. All rights reserved.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
#include <u.h>
#include <libc.h>
#include "gg.h"
#include "opt.h"
#define NREGVAR 32 /* 16 general + 16 floating */
#define REGBITS ((uint32)0xffffffff)
static Reg* firstr;
static int first = 1;
int
rcmp(const void *a1, const void *a2)
{
Rgn *p1, *p2;
int c1, c2;
p1 = (Rgn*)a1;
p2 = (Rgn*)a2;
c1 = p2->cost;
c2 = p1->cost;
if(c1 -= c2)
return c1;
return p2->varno - p1->varno;
}
static void
setaddrs(Bits bit)
{
int i, n;
Var *v;
Node *node;
while(bany(&bit)) {
// convert each bit to a variable
i = bnum(bit);
node = var[i].node;
n = var[i].name;
bit.b[i/32] &= ~(1L<<(i%32));
// disable all pieces of that variable
for(i=0; i<nvar; i++) {
v = var+i;
if(v->node == node && v->name == n)
v->addr = 2;
}
}
}
static char* regname[] = {
".AX",
".CX",
".DX",
".BX",
".SP",
".BP",
".SI",
".DI",
".R8",
".R9",
".R10",
".R11",
".R12",
".R13",
".R14",
".R15",
".X0",
".X1",
".X2",
".X3",
".X4",
".X5",
".X6",
".X7",
".X8",
".X9",
".X10",
".X11",
".X12",
".X13",
".X14",
".X15",
};
static Node* regnodes[NREGVAR];
static void walkvardef(Node *n, Reg *r, int active);
void
regopt(Prog *firstp)
{
Reg *r, *r1;
Prog *p;
Graph *g;
ProgInfo info;
int i, z, active;
uint32 vreg;
Bits bit;
if(first) {
fmtinstall('Q', Qconv);
exregoffset = D_R15;
first = 0;
}
mergetemp(firstp);
/*
* control flow is more complicated in generated go code
* than in generated c code. define pseudo-variables for
* registers, so we have complete register usage information.
*/
nvar = NREGVAR;
memset(var, 0, NREGVAR*sizeof var[0]);
for(i=0; i<NREGVAR; i++) {
if(regnodes[i] == N)
regnodes[i] = newname(lookup(regname[i]));
var[i].node = regnodes[i];
}
regbits = RtoB(D_SP);
for(z=0; z<BITS; z++) {
externs.b[z] = 0;
params.b[z] = 0;
consts.b[z] = 0;
addrs.b[z] = 0;
ivar.b[z] = 0;
ovar.b[z] = 0;
}
/*
* pass 1
* build aux data structure
* allocate pcs
* find use and set of variables
*/
g = flowstart(firstp, sizeof(Reg));
if(g == nil) {
for(i=0; i<nvar; i++)
var[i].node->opt = nil;
return;
}
firstr = (Reg*)g->start;
for(r = firstr; r != R; r = (Reg*)r->f.link) {
p = r->f.prog;
if(p->as == AVARDEF || p->as == AVARKILL)
continue;
proginfo(&info, p);
// Avoid making variables for direct-called functions.
if(p->as == ACALL && p->to.type == D_EXTERN)
continue;
r->use1.b[0] |= info.reguse | info.regindex;
r->set.b[0] |= info.regset;
bit = mkvar(r, &p->from);
if(bany(&bit)) {
if(info.flags & LeftAddr)
setaddrs(bit);
if(info.flags & LeftRead)
for(z=0; z<BITS; z++)
r->use1.b[z] |= bit.b[z];
if(info.flags & LeftWrite)
for(z=0; z<BITS; z++)
r->set.b[z] |= bit.b[z];
}
bit = mkvar(r, &p->to);
if(bany(&bit)) {
if(info.flags & RightAddr)
setaddrs(bit);
if(info.flags & RightRead)
for(z=0; z<BITS; z++)
r->use2.b[z] |= bit.b[z];
if(info.flags & RightWrite)
for(z=0; z<BITS; z++)
r->set.b[z] |= bit.b[z];
}
}
for(i=0; i<nvar; i++) {
Var *v = var+i;
if(v->addr) {
bit = blsh(i);
for(z=0; z<BITS; z++)
addrs.b[z] |= bit.b[z];
}
if(debug['R'] && debug['v'])
print("bit=%2d addr=%d et=%-6E w=%-2d s=%N + %lld\n",
i, v->addr, v->etype, v->width, v->node, v->offset);
}
if(debug['R'] && debug['v'])
dumpit("pass1", &firstr->f, 1);
/*
* pass 2
* find looping structure
*/
flowrpo(g);
if(debug['R'] && debug['v'])
dumpit("pass2", &firstr->f, 1);
/*
* pass 2.5
* iterate propagating fat vardef covering forward
* r->act records vars with a VARDEF since the last CALL.
* (r->act will be reused in pass 5 for something else,
* but we'll be done with it by then.)
*/
active = 0;
for(r = firstr; r != R; r = (Reg*)r->f.link) {
r->f.active = 0;
r->act = zbits;
}
for(r = firstr; r != R; r = (Reg*)r->f.link) {
p = r->f.prog;
if(p->as == AVARDEF && isfat(p->to.node->type) && p->to.node->opt != nil) {
active++;
walkvardef(p->to.node, r, active);
}
}
/*
* pass 3
* iterate propagating usage
* back until flow graph is complete
*/
loop1:
change = 0;
for(r = firstr; r != R; r = (Reg*)r->f.link)
r->f.active = 0;
for(r = firstr; r != R; r = (Reg*)r->f.link)
if(r->f.prog->as == ARET)
prop(r, zbits, zbits);
loop11:
/* pick up unreachable code */
i = 0;
for(r = firstr; r != R; r = r1) {
r1 = (Reg*)r->f.link;
if(r1 && r1->f.active && !r->f.active) {
prop(r, zbits, zbits);
i = 1;
}
}
if(i)
goto loop11;
if(change)
goto loop1;
if(debug['R'] && debug['v'])
dumpit("pass3", &firstr->f, 1);
/*
* pass 4
* iterate propagating register/variable synchrony
* forward until graph is complete
*/
loop2:
change = 0;
for(r = firstr; r != R; r = (Reg*)r->f.link)
r->f.active = 0;
synch(firstr, zbits);
if(change)
goto loop2;
if(debug['R'] && debug['v'])
dumpit("pass4", &firstr->f, 1);
/*
* pass 4.5
* move register pseudo-variables into regu.
*/
for(r = firstr; r != R; r = (Reg*)r->f.link) {
r->regu = (r->refbehind.b[0] | r->set.b[0]) & REGBITS;
r->set.b[0] &= ~REGBITS;
r->use1.b[0] &= ~REGBITS;
r->use2.b[0] &= ~REGBITS;
r->refbehind.b[0] &= ~REGBITS;
r->refahead.b[0] &= ~REGBITS;
r->calbehind.b[0] &= ~REGBITS;
r->calahead.b[0] &= ~REGBITS;
r->regdiff.b[0] &= ~REGBITS;
r->act.b[0] &= ~REGBITS;
}
/*
* pass 5
* isolate regions
* calculate costs (paint1)
*/
r = firstr;
if(r) {
for(z=0; z<BITS; z++)
bit.b[z] = (r->refahead.b[z] | r->calahead.b[z]) &
~(externs.b[z] | params.b[z] | addrs.b[z] | consts.b[z]);
if(bany(&bit) && !r->f.refset) {
// should never happen - all variables are preset
if(debug['w'])
print("%L: used and not set: %Q\n", r->f.prog->lineno, bit);
r->f.refset = 1;
}
}
for(r = firstr; r != R; r = (Reg*)r->f.link)
r->act = zbits;
rgp = region;
nregion = 0;
for(r = firstr; r != R; r = (Reg*)r->f.link) {
for(z=0; z<BITS; z++)
bit.b[z] = r->set.b[z] &
~(r->refahead.b[z] | r->calahead.b[z] | addrs.b[z]);
if(bany(&bit) && !r->f.refset) {
if(debug['w'])
print("%L: set and not used: %Q\n", r->f.prog->lineno, bit);
r->f.refset = 1;
excise(&r->f);
}
for(z=0; z<BITS; z++)
bit.b[z] = LOAD(r) & ~(r->act.b[z] | addrs.b[z]);
while(bany(&bit)) {
i = bnum(bit);
rgp->enter = r;
rgp->varno = i;
change = 0;
paint1(r, i);
bit.b[i/32] &= ~(1L<<(i%32));
if(change <= 0)
continue;
rgp->cost = change;
nregion++;
if(nregion >= NRGN) {
if(debug['R'] && debug['v'])
print("too many regions\n");
goto brk;
}
rgp++;
}
}
brk:
qsort(region, nregion, sizeof(region[0]), rcmp);
if(debug['R'] && debug['v'])
dumpit("pass5", &firstr->f, 1);
/*
* pass 6
* determine used registers (paint2)
* replace code (paint3)
*/
rgp = region;
for(i=0; i<nregion; i++) {
bit = blsh(rgp->varno);
vreg = paint2(rgp->enter, rgp->varno);
vreg = allreg(vreg, rgp);
if(rgp->regno != 0) {
if(debug['R'] && debug['v']) {
Var *v;
v = var + rgp->varno;
print("registerize %N+%lld (bit=%2d et=%2E) in %R\n",
v->node, v->offset, rgp->varno, v->etype, rgp->regno);
}
paint3(rgp->enter, rgp->varno, vreg, rgp->regno);
}
rgp++;
}
if(debug['R'] && debug['v'])
dumpit("pass6", &firstr->f, 1);
/*
* free aux structures. peep allocates new ones.
*/
for(i=0; i<nvar; i++)
var[i].node->opt = nil;
flowend(g);
firstr = R;
/*
* pass 7
* peep-hole on basic block
*/
if(!debug['R'] || debug['P'])
peep(firstp);
/*
* eliminate nops
*/
for(p=firstp; p!=P; p=p->link) {
while(p->link != P && p->link->as == ANOP)
p->link = p->link->link;
if(p->to.type == D_BRANCH)
while(p->to.u.branch != P && p->to.u.branch->as == ANOP)
p->to.u.branch = p->to.u.branch->link;
}
if(debug['R']) {
if(ostats.ncvtreg ||
ostats.nspill ||
ostats.nreload ||
ostats.ndelmov ||
ostats.nvar ||
ostats.naddr ||
0)
print("\nstats\n");
if(ostats.ncvtreg)
print(" %4d cvtreg\n", ostats.ncvtreg);
if(ostats.nspill)
print(" %4d spill\n", ostats.nspill);
if(ostats.nreload)
print(" %4d reload\n", ostats.nreload);
if(ostats.ndelmov)
print(" %4d delmov\n", ostats.ndelmov);
if(ostats.nvar)
print(" %4d var\n", ostats.nvar);
if(ostats.naddr)
print(" %4d addr\n", ostats.naddr);
memset(&ostats, 0, sizeof(ostats));
}
}
static void
walkvardef(Node *n, Reg *r, int active)
{
Reg *r1, *r2;
int bn;
Var *v;
for(r1=r; r1!=R; r1=(Reg*)r1->f.s1) {
if(r1->f.active == active)
break;
r1->f.active = active;
if(r1->f.prog->as == AVARKILL && r1->f.prog->to.node == n)
break;
for(v=n->opt; v!=nil; v=v->nextinnode) {
bn = v - var;
r1->act.b[bn/32] |= 1L << (bn%32);
}
if(r1->f.prog->as == ACALL)
break;
}
for(r2=r; r2!=r1; r2=(Reg*)r2->f.s1)
if(r2->f.s2 != nil)
walkvardef(n, (Reg*)r2->f.s2, active);
}
/*
* add mov b,rn
* just after r
*/
void
addmove(Reg *r, int bn, int rn, int f)
{
Prog *p, *p1;
Adr *a;
Var *v;
p1 = mal(sizeof(*p1));
clearp(p1);
p1->pc = 9999;
p = r->f.prog;
p1->link = p->link;
p->link = p1;
p1->lineno = p->lineno;
v = var + bn;
a = &p1->to;
a->offset = v->offset;
a->etype = v->etype;
a->type = v->name;
a->node = v->node;
a->sym = linksym(v->node->sym);
// need to clean this up with wptr and
// some of the defaults
p1->as = AMOVL;
switch(simtype[(uchar)v->etype]) {
default:
fatal("unknown type %E", v->etype);
case TINT8:
case TUINT8:
case TBOOL:
p1->as = AMOVB;
break;
case TINT16:
case TUINT16:
p1->as = AMOVW;
break;
case TINT64:
case TUINT64:
case TPTR64:
p1->as = AMOVQ;
break;
case TFLOAT32:
p1->as = AMOVSS;
break;
case TFLOAT64:
p1->as = AMOVSD;
break;
case TINT32:
case TUINT32:
case TPTR32:
break;
}
p1->from.type = rn;
if(!f) {
p1->from = *a;
*a = zprog.from;
a->type = rn;
if(v->etype == TUINT8)
p1->as = AMOVB;
if(v->etype == TUINT16)
p1->as = AMOVW;
}
if(debug['R'] && debug['v'])
print("%P ===add=== %P\n", p, p1);
ostats.nspill++;
}
uint32
doregbits(int r)
{
uint32 b;
b = 0;
if(r >= D_INDIR)
r -= D_INDIR;
if(r >= D_AX && r <= D_R15)
b |= RtoB(r);
else
if(r >= D_AL && r <= D_R15B)
b |= RtoB(r-D_AL+D_AX);
else
if(r >= D_AH && r <= D_BH)
b |= RtoB(r-D_AH+D_AX);
else
if(r >= D_X0 && r <= D_X0+15)
b |= FtoB(r);
return b;
}
static int
overlap(int64 o1, int w1, int64 o2, int w2)
{
int64 t1, t2;
t1 = o1+w1;
t2 = o2+w2;
if(!(t1 > o2 && t2 > o1))
return 0;
return 1;
}
Bits
mkvar(Reg *r, Adr *a)
{
Var *v;
int i, t, n, et, z, flag;
int64 w;
uint32 regu;
int64 o;
Bits bit;
Node *node;
/*
* mark registers used
*/
t = a->type;
if(t == D_NONE)
goto none;
if(r != R)
r->use1.b[0] |= doregbits(a->index);
switch(t) {
default:
regu = doregbits(t);
if(regu == 0)
goto none;
bit = zbits;
bit.b[0] = regu;
return bit;
case D_ADDR:
a->type = a->index;
bit = mkvar(r, a);
setaddrs(bit);
a->type = t;
ostats.naddr++;
goto none;
case D_EXTERN:
case D_STATIC:
case D_PARAM:
case D_AUTO:
n = t;
break;
}
node = a->node;
if(node == N || node->op != ONAME || node->orig == N)
goto none;
node = node->orig;
if(node->orig != node)
fatal("%D: bad node", a);
if(node->sym == S || node->sym->name[0] == '.')
goto none;
et = a->etype;
o = a->offset;
w = a->width;
if(w < 0)
fatal("bad width %lld for %D", w, a);
flag = 0;
for(i=0; i<nvar; i++) {
v = var+i;
if(v->node == node && v->name == n) {
if(v->offset == o)
if(v->etype == et)
if(v->width == w)
return blsh(i);
// if they overlaps, disable both
if(overlap(v->offset, v->width, o, w)) {
// print("disable overlap %s %d %d %d %d, %E != %E\n", s->name, v->offset, v->width, o, w, v->etype, et);
v->addr = 1;
flag = 1;
}
}
}
switch(et) {
case 0:
case TFUNC:
goto none;
}
if(nvar >= NVAR) {
if(debug['w'] > 1 && node != N)
fatal("variable not optimized: %#N", node);
// If we're not tracking a word in a variable, mark the rest as
// having its address taken, so that we keep the whole thing
// live at all calls. otherwise we might optimize away part of
// a variable but not all of it.
for(i=0; i<nvar; i++) {
v = var+i;
if(v->node == node)
v->addr = 1;
}
goto none;
}
i = nvar;
nvar++;
v = var+i;
v->offset = o;
v->name = n;
v->etype = et;
v->width = w;
v->addr = flag; // funny punning
v->node = node;
// node->opt is the head of a linked list
// of Vars within the given Node, so that
// we can start at a Var and find all the other
// Vars in the same Go variable.
v->nextinnode = node->opt;
node->opt = v;
bit = blsh(i);
if(n == D_EXTERN || n == D_STATIC)
for(z=0; z<BITS; z++)
externs.b[z] |= bit.b[z];
if(n == D_PARAM)
for(z=0; z<BITS; z++)
params.b[z] |= bit.b[z];
if(node->class == PPARAM)
for(z=0; z<BITS; z++)
ivar.b[z] |= bit.b[z];
if(node->class == PPARAMOUT)
for(z=0; z<BITS; z++)
ovar.b[z] |= bit.b[z];
// Treat values with their address taken as live at calls,
// because the garbage collector's liveness analysis in ../gc/plive.c does.
// These must be consistent or else we will elide stores and the garbage
// collector will see uninitialized data.
// The typical case where our own analysis is out of sync is when the
// node appears to have its address taken but that code doesn't actually
// get generated and therefore doesn't show up as an address being
// taken when we analyze the instruction stream.
// One instance of this case is when a closure uses the same name as
// an outer variable for one of its own variables declared with :=.
// The parser flags the outer variable as possibly shared, and therefore
// sets addrtaken, even though it ends up not being actually shared.
// If we were better about _ elision, _ = &x would suffice too.
// The broader := in a closure problem is mentioned in a comment in
// closure.c:/^typecheckclosure and dcl.c:/^oldname.
if(node->addrtaken)
v->addr = 1;
// Disable registerization for globals, because:
// (1) we might panic at any time and we want the recovery code
// to see the latest values (issue 1304).
// (2) we don't know what pointers might point at them and we want
// loads via those pointers to see updated values and vice versa (issue 7995).
//
// Disable registerization for results if using defer, because the deferred func
// might recover and return, causing the current values to be used.
if(node->class == PEXTERN || (hasdefer && node->class == PPARAMOUT))
v->addr = 1;
if(debug['R'])
print("bit=%2d et=%2E w=%lld+%lld %#N %D flag=%d\n", i, et, o, w, node, a, v->addr);
ostats.nvar++;
return bit;
none:
return zbits;
}
void
prop(Reg *r, Bits ref, Bits cal)
{
Reg *r1, *r2;
int z, i, j;
Var *v, *v1;
for(r1 = r; r1 != R; r1 = (Reg*)r1->f.p1) {
for(z=0; z<BITS; z++) {
ref.b[z] |= r1->refahead.b[z];
if(ref.b[z] != r1->refahead.b[z]) {
r1->refahead.b[z] = ref.b[z];
change++;
}
cal.b[z] |= r1->calahead.b[z];
if(cal.b[z] != r1->calahead.b[z]) {
r1->calahead.b[z] = cal.b[z];
change++;
}
}
switch(r1->f.prog->as) {
case ACALL:
if(noreturn(r1->f.prog))
break;
// Mark all input variables (ivar) as used, because that's what the
// liveness bitmaps say. The liveness bitmaps say that so that a
// panic will not show stale values in the parameter dump.
// Mark variables with a recent VARDEF (r1->act) as used,
// so that the optimizer flushes initializations to memory,
// so that if a garbage collection happens during this CALL,
// the collector will see initialized memory. Again this is to
// match what the liveness bitmaps say.
for(z=0; z<BITS; z++) {
cal.b[z] |= ref.b[z] | externs.b[z] | ivar.b[z] | r1->act.b[z];
ref.b[z] = 0;
}
// cal.b is the current approximation of what's live across the call.
// Every bit in cal.b is a single stack word. For each such word,
// find all the other tracked stack words in the same Go variable
// (struct/slice/string/interface) and mark them live too.
// This is necessary because the liveness analysis for the garbage
// collector works at variable granularity, not at word granularity.
// It is fundamental for slice/string/interface: the garbage collector
// needs the whole value, not just some of the words, in order to
// interpret the other bits correctly. Specifically, slice needs a consistent
// ptr and cap, string needs a consistent ptr and len, and interface
// needs a consistent type word and data word.
for(z=0; z<BITS; z++) {
if(cal.b[z] == 0)
continue;
for(i=0; i<32; i++) {
if(z*32+i >= nvar || ((cal.b[z]>>i)&1) == 0)
continue;
v = var+z*32+i;
if(v->node->opt == nil) // v represents fixed register, not Go variable
continue;
// v->node->opt is the head of a linked list of Vars
// corresponding to tracked words from the Go variable v->node.
// Walk the list and set all the bits.
// For a large struct this could end up being quadratic:
// after the first setting, the outer loop (for z, i) would see a 1 bit
// for all of the remaining words in the struct, and for each such
// word would go through and turn on all the bits again.
// To avoid the quadratic behavior, we only turn on the bits if
// v is the head of the list or if the head's bit is not yet turned on.
// This will set the bits at most twice, keeping the overall loop linear.
v1 = v->node->opt;
j = v1 - var;
if(v == v1 || ((cal.b[j/32]>>(j&31))&1) == 0) {
for(; v1 != nil; v1 = v1->nextinnode) {
j = v1 - var;
cal.b[j/32] |= 1<<(j&31);
}
}
}
}
break;
case ATEXT:
for(z=0; z<BITS; z++) {
cal.b[z] = 0;
ref.b[z] = 0;
}
break;
case ARET:
for(z=0; z<BITS; z++) {
cal.b[z] = externs.b[z] | ovar.b[z];
ref.b[z] = 0;
}
break;
}
for(z=0; z<BITS; z++) {
ref.b[z] = (ref.b[z] & ~r1->set.b[z]) |
r1->use1.b[z] | r1->use2.b[z];
cal.b[z] &= ~(r1->set.b[z] | r1->use1.b[z] | r1->use2.b[z]);
r1->refbehind.b[z] = ref.b[z];
r1->calbehind.b[z] = cal.b[z];
}
if(r1->f.active)
break;
r1->f.active = 1;
}
for(; r != r1; r = (Reg*)r->f.p1)
for(r2 = (Reg*)r->f.p2; r2 != R; r2 = (Reg*)r2->f.p2link)
prop(r2, r->refbehind, r->calbehind);
}
void
synch(Reg *r, Bits dif)
{
Reg *r1;
int z;
for(r1 = r; r1 != R; r1 = (Reg*)r1->f.s1) {
for(z=0; z<BITS; z++) {
dif.b[z] = (dif.b[z] &
~(~r1->refbehind.b[z] & r1->refahead.b[z])) |
r1->set.b[z] | r1->regdiff.b[z];
if(dif.b[z] != r1->regdiff.b[z]) {
r1->regdiff.b[z] = dif.b[z];
change++;
}
}
if(r1->f.active)
break;
r1->f.active = 1;
for(z=0; z<BITS; z++)
dif.b[z] &= ~(~r1->calbehind.b[z] & r1->calahead.b[z]);
if(r1->f.s2 != nil)
synch((Reg*)r1->f.s2, dif);
}
}
uint32
allreg(uint32 b, Rgn *r)
{
Var *v;
int i;
v = var + r->varno;
r->regno = 0;
switch(v->etype) {
default:
fatal("unknown etype %d/%E", bitno(b), v->etype);
break;
case TINT8:
case TUINT8:
case TINT16:
case TUINT16:
case TINT32:
case TUINT32:
case TINT64:
case TUINT64:
case TINT:
case TUINT:
case TUINTPTR:
case TBOOL:
case TPTR32:
case TPTR64:
i = BtoR(~b);
if(i && r->cost > 0) {
r->regno = i;
return RtoB(i);
}
break;
case TFLOAT32:
case TFLOAT64:
i = BtoF(~b);
if(i && r->cost > 0) {
r->regno = i;
return FtoB(i);
}
break;
}
return 0;
}
void
paint1(Reg *r, int bn)
{
Reg *r1;
int z;
uint32 bb;
z = bn/32;
bb = 1L<<(bn%32);
if(r->act.b[z] & bb)
return;
for(;;) {
if(!(r->refbehind.b[z] & bb))
break;
r1 = (Reg*)r->f.p1;
if(r1 == R)
break;
if(!(r1->refahead.b[z] & bb))
break;
if(r1->act.b[z] & bb)
break;
r = r1;
}
if(LOAD(r) & ~(r->set.b[z]&~(r->use1.b[z]|r->use2.b[z])) & bb) {
change -= CLOAD * r->f.loop;
}
for(;;) {
r->act.b[z] |= bb;
if(r->f.prog->as != ANOP) { // don't give credit for NOPs
if(r->use1.b[z] & bb)
change += CREF * r->f.loop;
if((r->use2.b[z]|r->set.b[z]) & bb)
change += CREF * r->f.loop;
}
if(STORE(r) & r->regdiff.b[z] & bb) {
change -= CLOAD * r->f.loop;
}
if(r->refbehind.b[z] & bb)
for(r1 = (Reg*)r->f.p2; r1 != R; r1 = (Reg*)r1->f.p2link)
if(r1->refahead.b[z] & bb)
paint1(r1, bn);
if(!(r->refahead.b[z] & bb))
break;
r1 = (Reg*)r->f.s2;
if(r1 != R)
if(r1->refbehind.b[z] & bb)
paint1(r1, bn);
r = (Reg*)r->f.s1;
if(r == R)
break;
if(r->act.b[z] & bb)
break;
if(!(r->refbehind.b[z] & bb))
break;
}
}
uint32
regset(Reg *r, uint32 bb)
{
uint32 b, set;
Adr v;
int c;
set = 0;
v = zprog.from;
while(b = bb & ~(bb-1)) {
v.type = b & 0xFFFF? BtoR(b): BtoF(b);
if(v.type == 0)
fatal("zero v.type for %#ux", b);
c = copyu(r->f.prog, &v, nil);
if(c == 3)
set |= b;
bb &= ~b;
}
return set;
}
uint32
reguse(Reg *r, uint32 bb)
{
uint32 b, set;
Adr v;
int c;
set = 0;
v = zprog.from;
while(b = bb & ~(bb-1)) {
v.type = b & 0xFFFF? BtoR(b): BtoF(b);
c = copyu(r->f.prog, &v, nil);
if(c == 1 || c == 2 || c == 4)
set |= b;
bb &= ~b;
}
return set;
}
uint32
paint2(Reg *r, int bn)
{
Reg *r1;
int z;
uint32 bb, vreg, x;
z = bn/32;
bb = 1L << (bn%32);
vreg = regbits;
if(!(r->act.b[z] & bb))
return vreg;
for(;;) {
if(!(r->refbehind.b[z] & bb))
break;
r1 = (Reg*)r->f.p1;
if(r1 == R)
break;
if(!(r1->refahead.b[z] & bb))
break;
if(!(r1->act.b[z] & bb))
break;
r = r1;
}
for(;;) {
r->act.b[z] &= ~bb;
vreg |= r->regu;
if(r->refbehind.b[z] & bb)
for(r1 = (Reg*)r->f.p2; r1 != R; r1 = (Reg*)r1->f.p2link)
if(r1->refahead.b[z] & bb)
vreg |= paint2(r1, bn);
if(!(r->refahead.b[z] & bb))
break;
r1 = (Reg*)r->f.s2;
if(r1 != R)
if(r1->refbehind.b[z] & bb)
vreg |= paint2(r1, bn);
r = (Reg*)r->f.s1;
if(r == R)
break;
if(!(r->act.b[z] & bb))
break;
if(!(r->refbehind.b[z] & bb))
break;
}
bb = vreg;
for(; r; r=(Reg*)r->f.s1) {
x = r->regu & ~bb;
if(x) {
vreg |= reguse(r, x);
bb |= regset(r, x);
}
}
return vreg;
}
void
paint3(Reg *r, int bn, int32 rb, int rn)
{
Reg *r1;
Prog *p;
int z;
uint32 bb;
z = bn/32;
bb = 1L << (bn%32);
if(r->act.b[z] & bb)
return;
for(;;) {
if(!(r->refbehind.b[z] & bb))
break;
r1 = (Reg*)r->f.p1;
if(r1 == R)
break;
if(!(r1->refahead.b[z] & bb))
break;
if(r1->act.b[z] & bb)
break;
r = r1;
}
if(LOAD(r) & ~(r->set.b[z] & ~(r->use1.b[z]|r->use2.b[z])) & bb)
addmove(r, bn, rn, 0);
for(;;) {
r->act.b[z] |= bb;
p = r->f.prog;
if(r->use1.b[z] & bb) {
if(debug['R'] && debug['v'])
print("%P", p);
addreg(&p->from, rn);
if(debug['R'] && debug['v'])
print(" ===change== %P\n", p);
}
if((r->use2.b[z]|r->set.b[z]) & bb) {
if(debug['R'] && debug['v'])
print("%P", p);
addreg(&p->to, rn);
if(debug['R'] && debug['v'])
print(" ===change== %P\n", p);
}
if(STORE(r) & r->regdiff.b[z] & bb)
addmove(r, bn, rn, 1);
r->regu |= rb;
if(r->refbehind.b[z] & bb)
for(r1 = (Reg*)r->f.p2; r1 != R; r1 = (Reg*)r1->f.p2link)
if(r1->refahead.b[z] & bb)
paint3(r1, bn, rb, rn);
if(!(r->refahead.b[z] & bb))
break;
r1 = (Reg*)r->f.s2;
if(r1 != R)
if(r1->refbehind.b[z] & bb)
paint3(r1, bn, rb, rn);
r = (Reg*)r->f.s1;
if(r == R)
break;
if(r->act.b[z] & bb)
break;
if(!(r->refbehind.b[z] & bb))
break;
}
}
void
addreg(Adr *a, int rn)
{
a->sym = nil;
a->offset = 0;
a->type = rn;
ostats.ncvtreg++;
}
int32
RtoB(int r)
{
if(r < D_AX || r > D_R15)
return 0;
return 1L << (r-D_AX);
}
int
BtoR(int32 b)
{
b &= 0xffffL;
if(nacl)
b &= ~((1<<(D_BP-D_AX)) | (1<<(D_R15-D_AX)));
if(b == 0)
return 0;
return bitno(b) + D_AX;
}
/*
* bit reg
* 16 X0
* ...
* 31 X15
*/
int32
FtoB(int f)
{
if(f < D_X0 || f > D_X15)
return 0;
return 1L << (f - D_X0 + 16);
}
int
BtoF(int32 b)
{
b &= 0xFFFF0000L;
if(b == 0)
return 0;
return bitno(b) - 16 + D_X0;
}
void
dumpone(Flow *f, int isreg)
{
int z;
Bits bit;
Reg *r;
print("%d:%P", f->loop, f->prog);
if(isreg) {
r = (Reg*)f;
for(z=0; z<BITS; z++)
bit.b[z] =
r->set.b[z] |
r->use1.b[z] |
r->use2.b[z] |
r->refbehind.b[z] |
r->refahead.b[z] |
r->calbehind.b[z] |
r->calahead.b[z] |
r->regdiff.b[z] |
r->act.b[z] |
0;
if(bany(&bit)) {
print("\t");
if(bany(&r->set))
print(" s:%Q", r->set);
if(bany(&r->use1))
print(" u1:%Q", r->use1);
if(bany(&r->use2))
print(" u2:%Q", r->use2);
if(bany(&r->refbehind))
print(" rb:%Q ", r->refbehind);
if(bany(&r->refahead))
print(" ra:%Q ", r->refahead);
if(bany(&r->calbehind))
print(" cb:%Q ", r->calbehind);
if(bany(&r->calahead))
print(" ca:%Q ", r->calahead);
if(bany(&r->regdiff))
print(" d:%Q ", r->regdiff);
if(bany(&r->act))
print(" a:%Q ", r->act);
}
}
print("\n");
}
void
dumpit(char *str, Flow *r0, int isreg)
{
Flow *r, *r1;
print("\n%s\n", str);
for(r = r0; r != nil; r = r->link) {
dumpone(r, isreg);
r1 = r->p2;
if(r1 != nil) {
print(" pred:");
for(; r1 != nil; r1 = r1->p2link)
print(" %.4ud", (int)r1->prog->pc);
print("\n");
}
// r1 = r->s1;
// if(r1 != R) {
// print(" succ:");
// for(; r1 != R; r1 = r1->s1)
// print(" %.4ud", (int)r1->prog->pc);
// print("\n");
// }
}
}