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mirror of https://github.com/golang/go synced 2024-11-12 03:00:22 -07:00

cmd/gc: move flow graph into portable opt

Now there's only one copy of the flow graph construction
and dominator computation, and different optimizations
can attach different annotations to the instructions.

R=ken2
CC=golang-dev
https://golang.org/cl/12797045
This commit is contained in:
Russ Cox 2013-08-12 22:02:10 -04:00
parent 954d14741d
commit dbf96addfb
11 changed files with 964 additions and 1501 deletions

View File

@ -55,6 +55,7 @@ typedef struct Rgn Rgn;
// r->prog->opt points back to r.
struct Reg
{
Flow f;
Bits set; // variables written by this instruction.
Bits use1; // variables read by prog->from.
@ -68,19 +69,6 @@ struct Reg
Bits act;
int32 regu; // register used bitmap
int32 rpo; // reverse post ordering
int32 active;
uint16 loop; // x5 for every loop
uchar refset; // diagnostic generated
Reg* p1; // predecessors of this instruction: p1,
Reg* p2; // and then p2 linked though p2link.
Reg* p2link;
Reg* s1; // successors of this instruction (at most two: s1 and s2).
Reg* s2;
Reg* link; // next instruction in function code
Prog* prog; // actual instruction
};
#define R ((Reg*)0)
@ -96,7 +84,6 @@ struct Rgn
EXTERN int32 exregoffset; // not set
EXTERN int32 exfregoffset; // not set
EXTERN Reg* firstr;
EXTERN Reg* lastr;
EXTERN Reg zreg;
EXTERN Reg* freer;
EXTERN Reg** rpo2r;
@ -134,34 +121,21 @@ void regopt(Prog*);
void addmove(Reg*, int, int, int);
Bits mkvar(Reg *r, Adr *a);
void prop(Reg*, Bits, Bits);
void loopit(Reg*, int32);
void synch(Reg*, Bits);
uint32 allreg(uint32, Rgn*);
void paint1(Reg*, int);
uint32 paint2(Reg*, int);
void paint3(Reg*, int, int32, int);
void addreg(Adr*, int);
void dumpit(char *str, Reg *r0);
void dumpit(char *str, Flow *r0, int);
/*
* peep.c
*/
void peep(void);
void excise(Reg*);
Reg* uniqp(Reg*);
Reg* uniqs(Reg*);
int regtyp(Adr*);
int anyvar(Adr*);
int subprop(Reg*);
int copyprop(Reg*);
int copy1(Adr*, Adr*, Reg*, int);
void peep(Prog*);
void excise(Flow*);
int copyu(Prog*, Adr*, Adr*);
int copyas(Adr*, Adr*);
int copyau(Adr*, Adr*);
int copysub(Adr*, Adr*, Adr*, int);
int copysub1(Prog*, Adr*, Adr*, int);
int32 RtoB(int);
int32 FtoB(int);
int BtoR(int32);

View File

@ -34,57 +34,43 @@
#include "gg.h"
#include "opt.h"
int xtramodes(Reg*, Adr*);
int shortprop(Reg *r);
int shiftprop(Reg *r);
void constprop(Adr *c1, Adr *v1, Reg *r);
static int xtramodes(Graph*, Flow*, Adr*);
static int shortprop(Flow *r);
static int regtyp(Adr*);
static int subprop(Flow*);
static int copyprop(Graph*, Flow*);
static int copy1(Adr*, Adr*, Flow*, int);
static int copyas(Adr*, Adr*);
static int copyau(Adr*, Adr*);
static int copysub(Adr*, Adr*, Adr*, int);
static int copysub1(Prog*, Adr*, Adr*, int);
static Flow* findpre(Flow *r, Adr *v);
static int copyau1(Prog *p, Adr *v);
static int isdconst(Addr *a);
Reg* findpre(Reg *r, Adr *v);
void predicate(void);
int copyau1(Prog *p, Adr *v);
int isdconst(Addr *a);
// UNUSED
int shiftprop(Flow *r);
void constprop(Adr *c1, Adr *v1, Flow *r);
void predicate(Graph*);
void
peep(void)
peep(Prog *firstp)
{
Reg *r, *r1, *r2;
Flow *r;
Graph *g;
Prog *p;
int t;
ProgInfo info;
/*
* complete R structure
*/
for(r=firstr; r!=R; r=r1) {
r1 = r->link;
if(r1 == R)
break;
for(p = r->prog->link; p != r1->prog; p = p->link) {
proginfo(&info, p);
if(info.flags & Skip)
continue;
r2 = rega();
r->link = r2;
r2->link = r1;
r2->prog = p;
p->opt = r2;
r2->p1 = r;
r->s1 = r2;
r2->s1 = r1;
r1->p1 = r2;
r = r2;
}
}
//dumpit("begin", firstr);
g = flowstart(firstp, sizeof(Flow));
if(g == nil)
return;
loop1:
if(debug['P'] && debug['v'])
dumpit("loop1", g->start, 0);
t = 0;
for(r=firstr; r!=R; r=r->link) {
for(r=g->start; r!=nil; r=r->link) {
p = r->prog;
switch(p->as) {
case ASLL:
@ -108,12 +94,12 @@ loop1:
if(regtyp(&p->from))
if(p->from.type == p->to.type)
if(p->scond == C_SCOND_NONE) {
if(copyprop(r)) {
if(copyprop(g, r)) {
excise(r);
t++;
break;
}
if(subprop(r) && copyprop(r)) {
if(subprop(r) && copyprop(g, r)) {
excise(r);
t++;
break;
@ -144,7 +130,7 @@ loop1:
if(t)
goto loop1;
for(r=firstr; r!=R; r=r->link) {
for(r=g->start; r!=nil; r=r->link) {
p = r->prog;
switch(p->as) {
case AEOR:
@ -164,7 +150,7 @@ loop1:
}
}
for(r=firstr; r!=R; r=r->link) {
for(r=g->start; r!=nil; r=r->link) {
p = r->prog;
switch(p->as) {
case AMOVW:
@ -172,10 +158,10 @@ loop1:
case AMOVBS:
case AMOVBU:
if(p->from.type == D_OREG && p->from.offset == 0)
xtramodes(r, &p->from);
xtramodes(g, r, &p->from);
else
if(p->to.type == D_OREG && p->to.offset == 0)
xtramodes(r, &p->to);
xtramodes(g, r, &p->to);
else
continue;
break;
@ -186,7 +172,7 @@ loop1:
// if(isdconst(&p->from) || p->from.offset != 0)
// continue;
// r2 = r->s1;
// if(r2 == R)
// if(r2 == nil)
// continue;
// t = r2->prog->as;
// switch(t) {
@ -213,8 +199,8 @@ loop1:
// r1 = r;
// do
// r1 = uniqp(r1);
// while (r1 != R && r1->prog->as == ANOP);
// if(r1 == R)
// while (r1 != nil && r1->prog->as == ANOP);
// if(r1 == nil)
// continue;
// p1 = r1->prog;
// if(p1->to.type != D_REG)
@ -249,47 +235,10 @@ loop1:
}
}
// predicate();
// predicate(g);
}
/*
* uniqp returns a "unique" predecessor to instruction r.
* If the instruction is the first one or has multiple
* predecessors due to jump, R is returned.
*/
Reg*
uniqp(Reg *r)
{
Reg *r1;
r1 = r->p1;
if(r1 == R) {
r1 = r->p2;
if(r1 == R || r1->p2link != R)
return R;
} else
if(r->p2 != R)
return R;
return r1;
}
Reg*
uniqs(Reg *r)
{
Reg *r1;
r1 = r->s1;
if(r1 == R) {
r1 = r->s2;
if(r1 == R)
return R;
} else
if(r->s2 != R)
return R;
return r1;
}
int
static int
regtyp(Adr *a)
{
@ -314,12 +263,12 @@ regtyp(Adr *a)
* hopefully, then the former or latter MOV
* will be eliminated by copy propagation.
*/
int
subprop(Reg *r0)
static int
subprop(Flow *r0)
{
Prog *p;
Adr *v1, *v2;
Reg *r;
Flow *r;
int t;
ProgInfo info;
@ -330,8 +279,8 @@ subprop(Reg *r0)
v2 = &p->to;
if(!regtyp(v2))
return 0;
for(r=uniqp(r0); r!=R; r=uniqp(r)) {
if(uniqs(r) == R)
for(r=uniqp(r0); r!=nil; r=uniqp(r)) {
if(uniqs(r) == nil)
break;
p = r->prog;
proginfo(&info, p);
@ -405,25 +354,25 @@ gotit:
* set v1 F=1
* set v2 return success
*/
int
copyprop(Reg *r0)
static int
copyprop(Graph *g, Flow *r0)
{
Prog *p;
Adr *v1, *v2;
Reg *r;
Flow *r;
p = r0->prog;
v1 = &p->from;
v2 = &p->to;
if(copyas(v1, v2))
return 1;
for(r=firstr; r!=R; r=r->link)
for(r=g->start; r!=nil; r=r->link)
r->active = 0;
return copy1(v1, v2, r0->s1, 0);
}
int
copy1(Adr *v1, Adr *v2, Reg *r, int f)
static int
copy1(Adr *v1, Adr *v2, Flow *r, int f)
{
int t;
Prog *p;
@ -436,11 +385,11 @@ copy1(Adr *v1, Adr *v2, Reg *r, int f)
r->active = 1;
if(debug['P'])
print("copy %D->%D f=%d\n", v1, v2, f);
for(; r != R; r = r->s1) {
for(; r != nil; r = r->s1) {
p = r->prog;
if(debug['P'])
print("%P", p);
if(!f && uniqp(r) == R) {
if(!f && uniqp(r) == nil) {
f = 1;
if(debug['P'])
print("; merge; f=%d", f);
@ -499,6 +448,7 @@ copy1(Adr *v1, Adr *v2, Reg *r, int f)
return 1;
}
// UNUSED
/*
* The idea is to remove redundant constants.
* $c1->v1
@ -507,17 +457,17 @@ copy1(Adr *v1, Adr *v2, Reg *r, int f)
* The v1->v2 should be eliminated by copy propagation.
*/
void
constprop(Adr *c1, Adr *v1, Reg *r)
constprop(Adr *c1, Adr *v1, Flow *r)
{
Prog *p;
if(debug['P'])
print("constprop %D->%D\n", c1, v1);
for(; r != R; r = r->s1) {
for(; r != nil; r = r->s1) {
p = r->prog;
if(debug['P'])
print("%P", p);
if(uniqp(r) == R) {
if(uniqp(r) == nil) {
if(debug['P'])
print("; merge; return\n");
return;
@ -541,27 +491,27 @@ constprop(Adr *c1, Adr *v1, Reg *r)
/*
* shortprop eliminates redundant zero/sign extensions.
*
* MOVBS x, R
* <no use R>
* MOVBS R, R'
* MOVBS x, nil
* <no use nil>
* MOVBS nil, nil'
*
* changed to
*
* MOVBS x, R
* MOVBS x, nil
* ...
* MOVB R, R' (compiled to mov)
* MOVB nil, nil' (compiled to mov)
*
* MOVBS above can be a MOVBS, MOVBU, MOVHS or MOVHU.
*/
int
shortprop(Reg *r)
static int
shortprop(Flow *r)
{
Prog *p, *p1;
Reg *r1;
Flow *r1;
p = r->prog;
r1 = findpre(r, &p->from);
if(r1 == R)
if(r1 == nil)
return 0;
p1 = r1->prog;
@ -596,6 +546,7 @@ gotit:
return 1;
}
// UNUSED
/*
* ASLL x,y,w
* .. (not use w, not set x y w)
@ -609,9 +560,9 @@ gotit:
*/
#define FAIL(msg) { if(debug['P']) print("\t%s; FAILURE\n", msg); return 0; }
int
shiftprop(Reg *r)
shiftprop(Flow *r)
{
Reg *r1;
Flow *r1;
Prog *p, *p1, *p2;
int n, o;
Adr a;
@ -631,9 +582,9 @@ shiftprop(Reg *r)
for(;;) {
/* find first use of shift result; abort if shift operands or result are changed */
r1 = uniqs(r1);
if(r1 == R)
if(r1 == nil)
FAIL("branch");
if(uniqp(r1) == R)
if(uniqp(r1) == nil)
FAIL("merge");
p1 = r1->prog;
if(debug['P'])
@ -704,7 +655,7 @@ shiftprop(Reg *r)
if(p1->to.reg != n)
for (;;) {
r1 = uniqs(r1);
if(r1 == R)
if(r1 == nil)
FAIL("inconclusive");
p1 = r1->prog;
if(debug['P'])
@ -757,40 +708,40 @@ shiftprop(Reg *r)
* before r. It must be a set, and there must be
* a unique path from that instruction to r.
*/
Reg*
findpre(Reg *r, Adr *v)
static Flow*
findpre(Flow *r, Adr *v)
{
Reg *r1;
Flow *r1;
for(r1=uniqp(r); r1!=R; r=r1,r1=uniqp(r)) {
for(r1=uniqp(r); r1!=nil; r=r1,r1=uniqp(r)) {
if(uniqs(r1) != r)
return R;
return nil;
switch(copyu(r1->prog, v, A)) {
case 1: /* used */
case 2: /* read-alter-rewrite */
return R;
return nil;
case 3: /* set */
case 4: /* set and used */
return r1;
}
}
return R;
return nil;
}
/*
* findinc finds ADD instructions with a constant
* argument which falls within the immed_12 range.
*/
Reg*
findinc(Reg *r, Reg *r2, Adr *v)
static Flow*
findinc(Flow *r, Flow *r2, Adr *v)
{
Reg *r1;
Flow *r1;
Prog *p;
for(r1=uniqs(r); r1!=R && r1!=r2; r=r1,r1=uniqs(r)) {
for(r1=uniqs(r); r1!=nil && r1!=r2; r=r1,r1=uniqs(r)) {
if(uniqp(r1) != r)
return R;
return nil;
switch(copyu(r1->prog, v, A)) {
case 0: /* not touched */
continue;
@ -801,14 +752,14 @@ findinc(Reg *r, Reg *r2, Adr *v)
if(p->from.offset > -4096 && p->from.offset < 4096)
return r1;
default:
return R;
return nil;
}
}
return R;
return nil;
}
int
nochange(Reg *r, Reg *r2, Prog *p)
static int
nochange(Flow *r, Flow *r2, Prog *p)
{
Adr a[3];
int i, n;
@ -830,7 +781,7 @@ nochange(Reg *r, Reg *r2, Prog *p)
}
if(n == 0)
return 1;
for(; r!=R && r!=r2; r=uniqs(r)) {
for(; r!=nil && r!=r2; r=uniqs(r)) {
p = r->prog;
for(i=0; i<n; i++)
if(copyu(p, &a[i], A) > 1)
@ -839,10 +790,10 @@ nochange(Reg *r, Reg *r2, Prog *p)
return 1;
}
int
findu1(Reg *r, Adr *v)
static int
findu1(Flow *r, Adr *v)
{
for(; r != R; r = r->s1) {
for(; r != nil; r = r->s1) {
if(r->active)
return 0;
r->active = 1;
@ -861,12 +812,12 @@ findu1(Reg *r, Adr *v)
return 0;
}
int
finduse(Reg *r, Adr *v)
static int
finduse(Graph *g, Flow *r, Adr *v)
{
Reg *r1;
Flow *r1;
for(r1=firstr; r1!=R; r1=r1->link)
for(r1=g->start; r1!=nil; r1=r1->link)
r1->active = 0;
return findu1(r, v);
}
@ -884,10 +835,10 @@ finduse(Reg *r, Adr *v)
* into
* MOVBU R0<<0(R1),R0
*/
int
xtramodes(Reg *r, Adr *a)
static int
xtramodes(Graph *g, Flow *r, Adr *a)
{
Reg *r1, *r2, *r3;
Flow *r1, *r2, *r3;
Prog *p, *p1;
Adr v;
@ -895,7 +846,7 @@ xtramodes(Reg *r, Adr *a)
v = *a;
v.type = D_REG;
r1 = findpre(r, &v);
if(r1 != R) {
if(r1 != nil) {
p1 = r1->prog;
if(p1->to.type == D_REG && p1->to.reg == v.reg)
switch(p1->as) {
@ -910,7 +861,7 @@ xtramodes(Reg *r, Adr *a)
p1->from.offset > -4096 && p1->from.offset < 4096))
if(nochange(uniqs(r1), r, p1)) {
if(a != &p->from || v.reg != p->to.reg)
if (finduse(r->s1, &v)) {
if (finduse(g, r->s1, &v)) {
if(p1->reg == NREG || p1->reg == v.reg)
/* pre-indexing */
p->scond |= C_WBIT;
@ -938,7 +889,7 @@ xtramodes(Reg *r, Adr *a)
break;
case AMOVW:
if(p1->from.type == D_REG)
if((r2 = findinc(r1, r, &p1->from)) != R) {
if((r2 = findinc(r1, r, &p1->from)) != nil) {
for(r3=uniqs(r2); r3->prog->as==ANOP; r3=uniqs(r3))
;
if(r3 == r) {
@ -947,7 +898,7 @@ xtramodes(Reg *r, Adr *a)
a->reg = p1->to.reg;
a->offset = p1->from.offset;
p->scond |= C_PBIT;
if(!finduse(r, &r1->prog->to))
if(!finduse(g, r, &r1->prog->to))
excise(r1);
excise(r2);
return 1;
@ -957,7 +908,7 @@ xtramodes(Reg *r, Adr *a)
}
}
if(a != &p->from || a->reg != p->to.reg)
if((r1 = findinc(r, R, &v)) != R) {
if((r1 = findinc(r, nil, &v)) != nil) {
/* post-indexing */
p1 = r1->prog;
a->offset = p1->from.offset;
@ -1218,7 +1169,7 @@ copyu(Prog *p, Adr *v, Adr *s)
* could be set/use depending on
* semantics
*/
int
static int
copyas(Adr *a, Adr *v)
{
@ -1241,7 +1192,7 @@ copyas(Adr *a, Adr *v)
/*
* either direct or indirect
*/
int
static int
copyau(Adr *a, Adr *v)
{
@ -1282,7 +1233,7 @@ copyau(Adr *a, Adr *v)
* ADD r,r,r
* CMP r,r,
*/
int
static int
copyau1(Prog *p, Adr *v)
{
@ -1307,7 +1258,7 @@ copyau1(Prog *p, Adr *v)
* substitute s for v in a
* return failure to substitute
*/
int
static int
copysub(Adr *a, Adr *v, Adr *s, int f)
{
@ -1330,7 +1281,7 @@ copysub(Adr *a, Adr *v, Adr *s, int f)
return 0;
}
int
static int
copysub1(Prog *p1, Adr *v, Adr *s, int f)
{
@ -1365,9 +1316,9 @@ struct {
};
typedef struct {
Reg *start;
Reg *last;
Reg *end;
Flow *start;
Flow *last;
Flow *end;
int len;
} Joininfo;
@ -1387,13 +1338,13 @@ enum {
Keepbranch
};
int
static int
isbranch(Prog *p)
{
return (ABEQ <= p->as) && (p->as <= ABLE);
}
int
static int
predicable(Prog *p)
{
switch(p->as) {
@ -1423,7 +1374,7 @@ predicable(Prog *p)
*
* C_SBIT may also have been set explicitly in p->scond.
*/
int
static int
modifiescpsr(Prog *p)
{
switch(p->as) {
@ -1452,8 +1403,8 @@ modifiescpsr(Prog *p)
* Find the maximal chain of instructions starting with r which could
* be executed conditionally
*/
int
joinsplit(Reg *r, Joininfo *j)
static int
joinsplit(Flow *r, Joininfo *j)
{
j->start = r;
j->last = r;
@ -1488,8 +1439,8 @@ joinsplit(Reg *r, Joininfo *j)
return Toolong;
}
Reg*
successor(Reg *r)
static Flow*
successor(Flow *r)
{
if(r->s1)
return r->s1;
@ -1497,11 +1448,11 @@ successor(Reg *r)
return r->s2;
}
void
applypred(Reg *rstart, Joininfo *j, int cond, int branch)
static void
applypred(Flow *rstart, Joininfo *j, int cond, int branch)
{
int pred;
Reg *r;
Flow *r;
if(j->len == 0)
return;
@ -1534,13 +1485,13 @@ applypred(Reg *rstart, Joininfo *j, int cond, int branch)
}
void
predicate(void)
predicate(Graph *g)
{
Reg *r;
Flow *r;
int t1, t2;
Joininfo j1, j2;
for(r=firstr; r!=R; r=r->link) {
for(r=g->start; r!=nil; r=r->link) {
if (isbranch(r->prog)) {
t1 = joinsplit(r->s1, &j1);
t2 = joinsplit(r->s2, &j2);
@ -1563,7 +1514,7 @@ predicate(void)
}
}
int
static int
isdconst(Addr *a)
{
if(a->type == D_CONST && a->reg == NREG)

View File

@ -38,23 +38,7 @@
#define REGBITS ((uint32)0xffffffff)
void addsplits(void);
static int first = 0;
Reg*
rega(void)
{
Reg *r;
r = freer;
if(r == R) {
r = mal(sizeof(*r));
} else
freer = r->link;
*r = zreg;
return r;
}
static int first = 1;
int
rcmp(const void *a1, const void *a2)
@ -96,7 +80,7 @@ setoutvar(void)
}
void
excise(Reg *r)
excise(Flow *r)
{
Prog *p;
@ -173,40 +157,19 @@ regopt(Prog *firstp)
{
Reg *r, *r1;
Prog *p;
int i, z, nr;
Graph *g;
int i, z;
uint32 vreg;
Bits bit;
ProgInfo info, info2;
ProgInfo info;
if(first == 0) {
if(first) {
fmtinstall('Q', Qconv);
first = 0;
}
fixjmp(firstp);
first++;
if(debug['K']) {
if(first != 13)
return;
// debug['R'] = 2;
// debug['P'] = 2;
print("optimizing %S\n", curfn->nname->sym);
}
// count instructions
nr = 0;
for(p=firstp; p!=P; p=p->link)
nr++;
// if too big dont bother
if(nr >= 10000) {
// print("********** %S is too big (%d)\n", curfn->nname->sym, nr);
return;
}
firstr = R;
lastr = R;
/*
* control flow is more complicated in generated go code
* than in generated c code. define pseudo-variables for
@ -238,34 +201,14 @@ regopt(Prog *firstp)
* allocate pcs
* find use and set of variables
*/
nr = 0;
for(p=firstp; p != P; p = p->link) {
g = flowstart(firstp, sizeof(Reg));
if(g == nil)
return;
firstr = (Reg*)g->start;
for(r = firstr; r != R; r = (Reg*)r->f.link) {
p = r->f.prog;
proginfo(&info, p);
if(info.flags & Skip)
continue;
r = rega();
nr++;
if(firstr == R) {
firstr = r;
lastr = r;
} else {
lastr->link = r;
r->p1 = lastr;
lastr->s1 = r;
lastr = r;
}
r->prog = p;
p->opt = r;
r1 = r->p1;
if(r1 != R) {
proginfo(&info2, r1->prog);
if(info2.flags & Break) {
r->p1 = R;
r1->s1 = R;
}
}
// Avoid making variables for direct-called functions.
if(p->as == ABL && p->to.type == D_EXTERN)
@ -313,50 +256,19 @@ regopt(Prog *firstp)
}
if(debug['R'] && debug['v'])
dumpit("pass1", firstr);
dumpit("pass1", &firstr->f, 1);
/*
* pass 2
* turn branch references to pointers
* build back pointers
*/
for(r=firstr; r!=R; r=r->link) {
p = r->prog;
if(p->to.type == D_BRANCH) {
if(p->to.u.branch == P)
fatal("pnil %P", p);
r1 = p->to.u.branch->opt;
if(r1 == R)
fatal("rnil %P", p);
if(r1 == r) {
//fatal("ref to self %P", p);
continue;
}
r->s2 = r1;
r->p2link = r1->p2;
r1->p2 = r;
}
}
if(debug['R']) {
p = firstr->prog;
print("\n%L %D\n", p->lineno, &p->from);
print(" addr = %Q\n", addrs);
}
if(debug['R'] && debug['v'])
dumpit("pass2", firstr);
/*
* pass 2.5
* find looping structure
*/
for(r = firstr; r != R; r = r->link)
r->active = 0;
for(r = firstr; r != R; r = (Reg*)r->f.link)
r->f.active = 0;
change = 0;
loopit(firstr, nr);
flowrpo(g);
if(debug['R'] && debug['v'])
dumpit("pass2.5", firstr);
dumpit("pass2", &firstr->f, 1);
/*
* pass 3
@ -365,17 +277,17 @@ regopt(Prog *firstp)
*/
loop1:
change = 0;
for(r = firstr; r != R; r = r->link)
r->active = 0;
for(r = firstr; r != R; r = r->link)
if(r->prog->as == ARET)
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 = r->link;
if(r1 && r1->active && !r->active) {
r1 = (Reg*)r->f.link;
if(r1 && r1->f.active && !r->f.active) {
prop(r, zbits, zbits);
i = 1;
}
@ -386,7 +298,7 @@ loop11:
goto loop1;
if(debug['R'] && debug['v'])
dumpit("pass3", firstr);
dumpit("pass3", &firstr->f, 1);
/*
@ -396,8 +308,8 @@ loop11:
*/
loop2:
change = 0;
for(r = firstr; r != R; r = r->link)
r->active = 0;
for(r = firstr; r != R; r = (Reg*)r->f.link)
r->f.active = 0;
synch(firstr, zbits);
if(change)
goto loop2;
@ -405,12 +317,12 @@ loop2:
addsplits();
if(debug['R'] && debug['v'])
dumpit("pass4", firstr);
dumpit("pass4", &firstr->f, 1);
if(debug['R'] > 1) {
print("\nprop structure:\n");
for(r = firstr; r != R; r = r->link) {
print("%d:%P", r->loop, r->prog);
for(r = firstr; r != R; r = (Reg*)r->f.link) {
print("%d:%P", r->f.loop, r->f.prog);
for(z=0; z<BITS; z++) {
bit.b[z] = r->set.b[z] |
r->refahead.b[z] | r->calahead.b[z] |
@ -444,7 +356,7 @@ loop2:
* pass 4.5
* move register pseudo-variables into regu.
*/
for(r = firstr; r != R; r = r->link) {
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;
@ -459,7 +371,7 @@ loop2:
}
if(debug['R'] && debug['v'])
dumpit("pass4.5", firstr);
dumpit("pass4.5", &firstr->f, 1);
/*
* pass 5
@ -471,27 +383,27 @@ loop2:
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->refset) {
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->prog->lineno, bit);
r->refset = 1;
print("%L: used and not set: %Q\n", r->f.prog->lineno, bit);
r->f.refset = 1;
}
}
for(r = firstr; r != R; r = r->link)
for(r = firstr; r != R; r = (Reg*)r->f.link)
r->act = zbits;
rgp = region;
nregion = 0;
for(r = firstr; r != R; r = r->link) {
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->refset) {
if(bany(&bit) && !r->f.refset) {
if(debug['w'])
print("%L: set and not used: %Q\n", r->prog->lineno, bit);
r->refset = 1;
excise(r);
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]);
@ -507,7 +419,7 @@ loop2:
if(change <= 0) {
if(debug['R'])
print("%L $%d: %Q\n",
r->prog->lineno, change, blsh(i));
r->f.prog->lineno, change, blsh(i));
continue;
}
rgp->cost = change;
@ -524,7 +436,7 @@ brk:
qsort(region, nregion, sizeof(region[0]), rcmp);
if(debug['R'] && debug['v'])
dumpit("pass5", firstr);
dumpit("pass5", &firstr->f, 1);
/*
* pass 6
@ -539,13 +451,13 @@ brk:
if(debug['R']) {
if(rgp->regno >= NREG)
print("%L $%d F%d: %Q\n",
rgp->enter->prog->lineno,
rgp->enter->f.prog->lineno,
rgp->cost,
rgp->regno-NREG,
bit);
else
print("%L $%d R%d: %Q\n",
rgp->enter->prog->lineno,
rgp->enter->f.prog->lineno,
rgp->cost,
rgp->regno,
bit);
@ -556,18 +468,18 @@ brk:
}
if(debug['R'] && debug['v'])
dumpit("pass6", firstr);
dumpit("pass6", &firstr->f, 1);
/*
* pass 7
* peep-hole on basic block
*/
if(!debug['R'] || debug['P']) {
peep();
peep(firstp);
}
if(debug['R'] && debug['v'])
dumpit("pass7", firstr);
dumpit("pass7", &firstr->f, 1);
/*
* last pass
@ -623,11 +535,8 @@ brk:
}
}
}
if(lastr != R) {
lastr->link = freer;
freer = firstr;
}
flowend(g);
}
void
@ -637,13 +546,13 @@ addsplits(void)
int z, i;
Bits bit;
for(r = firstr; r != R; r = r->link) {
if(r->loop > 1)
for(r = firstr; r != R; r = (Reg*)r->f.link) {
if(r->f.loop > 1)
continue;
if(r->prog->as == ABL)
if(r->f.prog->as == ABL)
continue;
for(r1 = r->p2; r1 != R; r1 = r1->p2link) {
if(r1->loop <= 1)
for(r1 = (Reg*)r->f.p2; r1 != R; r1 = (Reg*)r1->f.p2link) {
if(r1->f.loop <= 1)
continue;
for(z=0; z<BITS; z++)
bit.b[z] = r1->calbehind.b[z] &
@ -670,7 +579,7 @@ addmove(Reg *r, int bn, int rn, int f)
p1 = mal(sizeof(*p1));
*p1 = zprog;
p = r->prog;
p = r->f.prog;
// If there's a stack fixup coming (after BL newproc or BL deferproc),
// delay the load until after the fixup.
@ -814,11 +723,11 @@ mkvar(Reg *r, Adr *a)
case D_OREG:
if(a->reg != NREG) {
if(a == &r->prog->from)
if(a == &r->f.prog->from)
r->use1.b[0] |= RtoB(a->reg);
else
r->use2.b[0] |= RtoB(a->reg);
if(r->prog->scond & (C_PBIT|C_WBIT))
if(r->f.prog->scond & (C_PBIT|C_WBIT))
r->set.b[0] |= RtoB(a->reg);
}
break;
@ -921,7 +830,7 @@ prop(Reg *r, Bits ref, Bits cal)
Reg *r1, *r2;
int z;
for(r1 = r; r1 != R; r1 = r1->p1) {
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]) {
@ -934,9 +843,9 @@ prop(Reg *r, Bits ref, Bits cal)
change++;
}
}
switch(r1->prog->as) {
switch(r1->f.prog->as) {
case ABL:
if(noreturn(r1->prog))
if(noreturn(r1->f.prog))
break;
for(z=0; z<BITS; z++) {
cal.b[z] |= ref.b[z] | externs.b[z];
@ -976,158 +885,22 @@ prop(Reg *r, Bits ref, Bits cal)
r1->refbehind.b[z] = ref.b[z];
r1->calbehind.b[z] = cal.b[z];
}
if(r1->active)
if(r1->f.active)
break;
r1->active = 1;
r1->f.active = 1;
}
for(; r != r1; r = r->p1)
for(r2 = r->p2; r2 != R; r2 = r2->p2link)
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);
}
/*
* find looping structure
*
* 1) find reverse postordering
* 2) find approximate dominators,
* the actual dominators if the flow graph is reducible
* otherwise, dominators plus some other non-dominators.
* See Matthew S. Hecht and Jeffrey D. Ullman,
* "Analysis of a Simple Algorithm for Global Data Flow Problems",
* Conf. Record of ACM Symp. on Principles of Prog. Langs, Boston, Massachusetts,
* Oct. 1-3, 1973, pp. 207-217.
* 3) find all nodes with a predecessor dominated by the current node.
* such a node is a loop head.
* recursively, all preds with a greater rpo number are in the loop
*/
int32
postorder(Reg *r, Reg **rpo2r, int32 n)
{
Reg *r1;
r->rpo = 1;
r1 = r->s1;
if(r1 && !r1->rpo)
n = postorder(r1, rpo2r, n);
r1 = r->s2;
if(r1 && !r1->rpo)
n = postorder(r1, rpo2r, n);
rpo2r[n] = r;
n++;
return n;
}
int32
rpolca(int32 *idom, int32 rpo1, int32 rpo2)
{
int32 t;
if(rpo1 == -1)
return rpo2;
while(rpo1 != rpo2){
if(rpo1 > rpo2){
t = rpo2;
rpo2 = rpo1;
rpo1 = t;
}
while(rpo1 < rpo2){
t = idom[rpo2];
if(t >= rpo2)
fatal("bad idom");
rpo2 = t;
}
}
return rpo1;
}
int
doms(int32 *idom, int32 r, int32 s)
{
while(s > r)
s = idom[s];
return s == r;
}
int
loophead(int32 *idom, Reg *r)
{
int32 src;
src = r->rpo;
if(r->p1 != R && doms(idom, src, r->p1->rpo))
return 1;
for(r = r->p2; r != R; r = r->p2link)
if(doms(idom, src, r->rpo))
return 1;
return 0;
}
void
loopmark(Reg **rpo2r, int32 head, Reg *r)
{
if(r->rpo < head || r->active == head)
return;
r->active = head;
r->loop += LOOP;
if(r->p1 != R)
loopmark(rpo2r, head, r->p1);
for(r = r->p2; r != R; r = r->p2link)
loopmark(rpo2r, head, r);
}
void
loopit(Reg *r, int32 nr)
{
Reg *r1;
int32 i, d, me;
if(nr > maxnr) {
rpo2r = mal(nr * sizeof(Reg*));
idom = mal(nr * sizeof(int32));
maxnr = nr;
}
d = postorder(r, rpo2r, 0);
if(d > nr)
fatal("too many reg nodes");
nr = d;
for(i = 0; i < nr / 2; i++){
r1 = rpo2r[i];
rpo2r[i] = rpo2r[nr - 1 - i];
rpo2r[nr - 1 - i] = r1;
}
for(i = 0; i < nr; i++)
rpo2r[i]->rpo = i;
idom[0] = 0;
for(i = 0; i < nr; i++){
r1 = rpo2r[i];
me = r1->rpo;
d = -1;
// rpo2r[r->rpo] == r protects against considering dead code,
// which has r->rpo == 0.
if(r1->p1 != R && rpo2r[r1->p1->rpo] == r1->p1 && r1->p1->rpo < me)
d = r1->p1->rpo;
for(r1 = r1->p2; r1 != nil; r1 = r1->p2link)
if(rpo2r[r1->rpo] == r1 && r1->rpo < me)
d = rpolca(idom, d, r1->rpo);
idom[i] = d;
}
for(i = 0; i < nr; i++){
r1 = rpo2r[i];
r1->loop++;
if(r1->p2 != R && loophead(idom, r1))
loopmark(rpo2r, i, r1);
}
}
void
synch(Reg *r, Bits dif)
{
Reg *r1;
int z;
for(r1 = r; r1 != R; r1 = r1->s1) {
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])) |
@ -1137,13 +910,13 @@ synch(Reg *r, Bits dif)
change++;
}
}
if(r1->active)
if(r1->f.active)
break;
r1->active = 1;
r1->f.active = 1;
for(z=0; z<BITS; z++)
dif.b[z] &= ~(~r1->calbehind.b[z] & r1->calahead.b[z]);
if(r1->s2 != R)
synch(r1->s2, dif);
if(r1->f.s2 != nil)
synch((Reg*)r1->f.s2, dif);
}
}
@ -1214,7 +987,7 @@ paint1(Reg *r, int bn)
for(;;) {
if(!(r->refbehind.b[z] & bb))
break;
r1 = r->p1;
r1 = (Reg*)r->f.p1;
if(r1 == R)
break;
if(!(r1->refahead.b[z] & bb))
@ -1225,48 +998,48 @@ paint1(Reg *r, int bn)
}
if(LOAD(r) & ~(r->set.b[z] & ~(r->use1.b[z]|r->use2.b[z])) & bb) {
change -= CLOAD * r->loop;
change -= CLOAD * r->f.loop;
if(debug['R'] > 1)
print("%d%P\td %Q $%d\n", r->loop,
r->prog, blsh(bn), change);
print("%d%P\td %Q $%d\n", r->f.loop,
r->f.prog, blsh(bn), change);
}
for(;;) {
r->act.b[z] |= bb;
p = r->prog;
p = r->f.prog;
if(r->use1.b[z] & bb) {
change += CREF * r->loop;
change += CREF * r->f.loop;
if(debug['R'] > 1)
print("%d%P\tu1 %Q $%d\n", r->loop,
print("%d%P\tu1 %Q $%d\n", r->f.loop,
p, blsh(bn), change);
}
if((r->use2.b[z]|r->set.b[z]) & bb) {
change += CREF * r->loop;
change += CREF * r->f.loop;
if(debug['R'] > 1)
print("%d%P\tu2 %Q $%d\n", r->loop,
print("%d%P\tu2 %Q $%d\n", r->f.loop,
p, blsh(bn), change);
}
if(STORE(r) & r->regdiff.b[z] & bb) {
change -= CLOAD * r->loop;
change -= CLOAD * r->f.loop;
if(debug['R'] > 1)
print("%d%P\tst %Q $%d\n", r->loop,
print("%d%P\tst %Q $%d\n", r->f.loop,
p, blsh(bn), change);
}
if(r->refbehind.b[z] & bb)
for(r1 = r->p2; r1 != R; r1 = r1->p2link)
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 = r->s2;
r1 = (Reg*)r->f.s2;
if(r1 != R)
if(r1->refbehind.b[z] & bb)
paint1(r1, bn);
r = r->s1;
r = (Reg*)r->f.s1;
if(r == R)
break;
if(r->act.b[z] & bb)
@ -1291,7 +1064,7 @@ paint2(Reg *r, int bn)
for(;;) {
if(!(r->refbehind.b[z] & bb))
break;
r1 = r->p1;
r1 = (Reg*)r->f.p1;
if(r1 == R)
break;
if(!(r1->refahead.b[z] & bb))
@ -1306,17 +1079,17 @@ paint2(Reg *r, int bn)
vreg |= r->regu;
if(r->refbehind.b[z] & bb)
for(r1 = r->p2; r1 != R; r1 = r1->p2link)
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 = r->s2;
r1 = (Reg*)r->f.s2;
if(r1 != R)
if(r1->refbehind.b[z] & bb)
vreg |= paint2(r1, bn);
r = r->s1;
r = (Reg*)r->f.s1;
if(r == R)
break;
if(!(r->act.b[z] & bb))
@ -1342,7 +1115,7 @@ paint3(Reg *r, int bn, int32 rb, int rn)
for(;;) {
if(!(r->refbehind.b[z] & bb))
break;
r1 = r->p1;
r1 = (Reg*)r->f.p1;
if(r1 == R)
break;
if(!(r1->refahead.b[z] & bb))
@ -1357,7 +1130,7 @@ paint3(Reg *r, int bn, int32 rb, int rn)
for(;;) {
r->act.b[z] |= bb;
p = r->prog;
p = r->f.prog;
if(r->use1.b[z] & bb) {
if(debug['R'])
@ -1379,17 +1152,17 @@ paint3(Reg *r, int bn, int32 rb, int rn)
r->regu |= rb;
if(r->refbehind.b[z] & bb)
for(r1 = r->p2; r1 != R; r1 = r1->p2link)
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 = r->s2;
r1 = (Reg*)r->f.s2;
if(r1 != R)
if(r1->refbehind.b[z] & bb)
paint3(r1, bn, rb, rn);
r = r->s1;
r = (Reg*)r->f.s1;
if(r == R)
break;
if(r->act.b[z] & bb)
@ -1464,65 +1237,69 @@ BtoF(int32 b)
}
void
dumpone(Reg *r)
dumpone(Flow *f, int isreg)
{
int z;
Bits bit;
Reg *r;
print("%d:%P", r->loop, r->prog);
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("%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, Reg *r0)
dumpit(char *str, Flow *r0, int isreg)
{
Reg *r, *r1;
Flow *r, *r1;
print("\n%s\n", str);
for(r = r0; r != R; r = r->link) {
dumpone(r);
for(r = r0; r != nil; r = r->link) {
dumpone(r, isreg);
r1 = r->p2;
if(r1 != R) {
if(r1 != nil) {
print(" pred:");
for(; r1 != R; r1 = r1->p2link)
for(; r1 != nil; r1 = r1->p2link)
print(" %.4ud", r1->prog->loc);
print("\n");
}
// r1 = r->s1;
// if(r1 != R) {
// if(r1 != nil) {
// print(" succ:");
// for(; r1 != R; r1 = r1->s1)
// print(" %.4ud", r1->prog->loc);

View File

@ -55,6 +55,7 @@ typedef struct Rgn Rgn;
// r->prog->opt points back to r.
struct Reg
{
Flow f;
Bits set; // variables written by this instruction.
Bits use1; // variables read by prog->from.
@ -68,19 +69,6 @@ struct Reg
Bits act;
int32 regu; // register used bitmap
int32 rpo; // reverse post ordering
int32 active;
uint16 loop; // x5 for every loop
uchar refset; // diagnostic generated
Reg* p1; // predecessors of this instruction: p1,
Reg* p2; // and then p2 linked though p2link.
Reg* p2link;
Reg* s1; // successors of this instruction (at most two: s1 and s2).
Reg* s2;
Reg* link; // next instruction in function code
Prog* prog; // actual instruction
};
#define R ((Reg*)0)
@ -96,10 +84,7 @@ struct Rgn
EXTERN int32 exregoffset; // not set
EXTERN int32 exfregoffset; // not set
EXTERN Reg* firstr;
EXTERN Reg* lastr;
EXTERN Reg zreg;
EXTERN Reg* freer;
EXTERN Reg** rpo2r;
EXTERN Rgn region[NRGN];
EXTERN Rgn* rgp;
EXTERN int nregion;
@ -113,7 +98,6 @@ EXTERN Bits addrs;
EXTERN Bits ovar;
EXTERN int change;
EXTERN int32 maxnr;
EXTERN int32* idom;
EXTERN struct
{
@ -128,41 +112,27 @@ EXTERN struct
/*
* reg.c
*/
Reg* rega(void);
int rcmp(const void*, const void*);
void regopt(Prog*);
void addmove(Reg*, int, int, int);
Bits mkvar(Reg*, Adr*);
void prop(Reg*, Bits, Bits);
void loopit(Reg*, int32);
void synch(Reg*, Bits);
uint32 allreg(uint32, Rgn*);
void paint1(Reg*, int);
uint32 paint2(Reg*, int);
void paint3(Reg*, int, int32, int);
void addreg(Adr*, int);
void dumpone(Reg*);
void dumpit(char*, Reg*);
void dumpone(Flow*, int);
void dumpit(char*, Flow*, int);
/*
* peep.c
*/
void peep(void);
void excise(Reg*);
Reg* uniqp(Reg*);
Reg* uniqs(Reg*);
int regtyp(Adr*);
int anyvar(Adr*);
int subprop(Reg*);
int copyprop(Reg*);
int copy1(Adr*, Adr*, Reg*, int);
void peep(Prog*);
void excise(Flow*);
int copyu(Prog*, Adr*, Adr*);
int copyas(Adr*, Adr*);
int copyau(Adr*, Adr*);
int copysub(Adr*, Adr*, Adr*, int);
int copysub1(Prog*, Adr*, Adr*, int);
int32 RtoB(int);
int32 FtoB(int);
int BtoR(int32);

View File

@ -33,11 +33,18 @@
#include "gg.h"
#include "opt.h"
static void conprop(Reg *r);
static void elimshortmov(Reg *r);
static int prevl(Reg *r, int reg);
static void pushback(Reg *r);
static int regconsttyp(Adr*);
static void conprop(Flow *r);
static void elimshortmov(Graph *g);
static int prevl(Flow *r, int reg);
static void pushback(Flow *r);
static int regconsttyp(Adr*);
static int regtyp(Adr*);
static int subprop(Flow*);
static int copyprop(Graph*, Flow*);
static int copy1(Adr*, Adr*, Flow*, int);
static int copyas(Adr*, Adr*);
static int copyau(Adr*, Adr*);
static int copysub(Adr*, Adr*, Adr*, int);
// do we need the carry bit
static int
@ -56,19 +63,19 @@ needc(Prog *p)
return 0;
}
static Reg*
rnops(Reg *r)
static Flow*
rnops(Flow *r)
{
Prog *p;
Reg *r1;
Flow *r1;
if(r != R)
if(r != nil)
for(;;) {
p = r->prog;
if(p->as != ANOP || p->from.type != D_NONE || p->to.type != D_NONE)
break;
r1 = uniqs(r);
if(r1 == R)
if(r1 == nil)
break;
r = r1;
}
@ -76,52 +83,25 @@ rnops(Reg *r)
}
void
peep(void)
peep(Prog *firstp)
{
Reg *r, *r1, *r2;
Flow *r, *r1;
Graph *g;
Prog *p, *p1;
int t;
ProgInfo info;
/*
* complete R structure
*/
t = 0;
for(r=firstr; r!=R; r=r1) {
r1 = r->link;
if(r1 == R)
break;
p = r->prog->link;
for(p = r->prog->link; p != r1->prog; p = p->link) {
proginfo(&info, p);
if(info.flags & Skip)
continue;
g = flowstart(firstp, sizeof(Flow));
if(g == nil)
return;
r2 = rega();
r->link = r2;
r2->link = r1;
r2->prog = p;
p->opt = r2;
r2->p1 = r;
r->s1 = r2;
r2->s1 = r1;
r1->p1 = r2;
r = r2;
t++;
}
}
// byte, word arithmetic elimination.
elimshortmov(r);
elimshortmov(g);
// constant propagation
// find MOV $con,R followed by
// another MOV $con,R without
// setting R in the interim
for(r=firstr; r!=R; r=r->link) {
// find MOV $con,nil followed by
// another MOV $con,nil without
// setting nil in the interim
for(r=g->start; r!=nil; r=r->link) {
p = r->prog;
switch(p->as) {
case ALEAL:
@ -147,10 +127,10 @@ peep(void)
loop1:
if(debug['P'] && debug['v'])
dumpit("loop1", firstr);
dumpit("loop1", g->start, 0);
t = 0;
for(r=firstr; r!=R; r=r->link) {
for(r=g->start; r!=nil; r=r->link) {
p = r->prog;
switch(p->as) {
case AMOVL:
@ -159,11 +139,11 @@ loop1:
case AMOVSD:
if(regtyp(&p->to))
if(regtyp(&p->from)) {
if(copyprop(r)) {
if(copyprop(g, r)) {
excise(r);
t++;
} else
if(subprop(r) && copyprop(r)) {
if(subprop(r) && copyprop(g, r)) {
excise(r);
t++;
}
@ -176,7 +156,7 @@ loop1:
case AMOVWLSX:
if(regtyp(&p->to)) {
r1 = rnops(uniqs(r));
if(r1 != R) {
if(r1 != nil) {
p1 = r1->prog;
if(p->as == p1->as && p->to.type == p1->from.type){
p1->as = AMOVL;
@ -195,7 +175,7 @@ loop1:
case AMOVQL:
if(regtyp(&p->to)) {
r1 = rnops(uniqs(r));
if(r1 != R) {
if(r1 != nil) {
p1 = r1->prog;
if(p->as == p1->as && p->to.type == p1->from.type){
p1->as = AMOVQ;
@ -278,7 +258,7 @@ loop1:
// can be replaced by MOVAPD, which moves the pair of float64s
// instead of just the lower one. We only use the lower one, but
// the processor can do better if we do moves using both.
for(r=firstr; r!=R; r=r->link) {
for(r=g->start; r!=nil; r=r->link) {
p = r->prog;
if(p->as == AMOVLQZX)
if(regtyp(&p->from))
@ -295,7 +275,7 @@ loop1:
// load pipelining
// push any load from memory as early as possible
// to give it time to complete before use.
for(r=firstr; r!=R; r=r->link) {
for(r=g->start; r!=nil; r=r->link) {
p = r->prog;
switch(p->as) {
case AMOVB:
@ -307,17 +287,19 @@ loop1:
pushback(r);
}
}
flowend(g);
}
static void
pushback(Reg *r0)
pushback(Flow *r0)
{
Reg *r, *b;
Flow *r, *b;
Prog *p0, *p, t;
b = R;
b = nil;
p0 = r0->prog;
for(r=uniqp(r0); r!=R && uniqs(r)!=R; r=uniqp(r)) {
for(r=uniqp(r0); r!=nil && uniqs(r)!=nil; r=uniqp(r)) {
p = r->prog;
if(p->as != ANOP) {
if(!regconsttyp(&p->from) || !regtyp(&p->to))
@ -330,11 +312,11 @@ pushback(Reg *r0)
b = r;
}
if(b == R) {
if(b == nil) {
if(debug['v']) {
print("no pushback: %P\n", r0->prog);
if(r)
print("\t%P [%d]\n", r->prog, uniqs(r)!=R);
print("\t%P [%d]\n", r->prog, uniqs(r)!=nil);
}
return;
}
@ -377,7 +359,7 @@ pushback(Reg *r0)
}
void
excise(Reg *r)
excise(Flow *r)
{
Prog *p;
@ -392,39 +374,7 @@ excise(Reg *r)
ostats.ndelmov++;
}
Reg*
uniqp(Reg *r)
{
Reg *r1;
r1 = r->p1;
if(r1 == R) {
r1 = r->p2;
if(r1 == R || r1->p2link != R)
return R;
} else
if(r->p2 != R)
return R;
return r1;
}
Reg*
uniqs(Reg *r)
{
Reg *r1;
r1 = r->s1;
if(r1 == R) {
r1 = r->s2;
if(r1 == R)
return R;
} else
if(r->s2 != R)
return R;
return r1;
}
int
static int
regtyp(Adr *a)
{
int t;
@ -448,12 +398,12 @@ regtyp(Adr *a)
// TODO: Using the Q forms here instead of the L forms
// seems unnecessary, and it makes the instructions longer.
static void
elimshortmov(Reg *r)
elimshortmov(Graph *g)
{
Prog *p;
Flow *r;
USED(r);
for(r=firstr; r!=R; r=r->link) {
for(r=g->start; r!=nil; r=r->link) {
p = r->prog;
if(regtyp(&p->to)) {
switch(p->as) {
@ -554,13 +504,13 @@ regconsttyp(Adr *a)
// is reg guaranteed to be truncated by a previous L instruction?
static int
prevl(Reg *r0, int reg)
prevl(Flow *r0, int reg)
{
Prog *p;
Reg *r;
Flow *r;
ProgInfo info;
for(r=uniqp(r0); r!=R; r=uniqp(r)) {
for(r=uniqp(r0); r!=nil; r=uniqp(r)) {
p = r->prog;
if(p->to.type == reg) {
proginfo(&info, p);
@ -588,13 +538,13 @@ prevl(Reg *r0, int reg)
* hopefully, then the former or latter MOV
* will be eliminated by copy propagation.
*/
int
subprop(Reg *r0)
static int
subprop(Flow *r0)
{
Prog *p;
ProgInfo info;
Adr *v1, *v2;
Reg *r;
Flow *r;
int t;
if(debug['P'] && debug['v'])
@ -612,10 +562,10 @@ subprop(Reg *r0)
print("\tnot regtype %D; return 0\n", v2);
return 0;
}
for(r=uniqp(r0); r!=R; r=uniqp(r)) {
for(r=uniqp(r0); r!=nil; r=uniqp(r)) {
if(debug['P'] && debug['v'])
print("\t? %P\n", r->prog);
if(uniqs(r) == R) {
if(uniqs(r) == nil) {
if(debug['P'] && debug['v'])
print("\tno unique successor\n");
break;
@ -689,12 +639,12 @@ gotit:
* set v1 F=1
* set v2 return success
*/
int
copyprop(Reg *r0)
static int
copyprop(Graph *g, Flow *r0)
{
Prog *p;
Adr *v1, *v2;
Reg *r;
Flow *r;
if(debug['P'] && debug['v'])
print("copyprop %P\n", r0->prog);
@ -703,13 +653,13 @@ copyprop(Reg *r0)
v2 = &p->to;
if(copyas(v1, v2))
return 1;
for(r=firstr; r!=R; r=r->link)
for(r=g->start; r!=nil; r=r->link)
r->active = 0;
return copy1(v1, v2, r0->s1, 0);
}
int
copy1(Adr *v1, Adr *v2, Reg *r, int f)
static int
copy1(Adr *v1, Adr *v2, Flow *r, int f)
{
int t;
Prog *p;
@ -722,11 +672,11 @@ copy1(Adr *v1, Adr *v2, Reg *r, int f)
r->active = 1;
if(debug['P'])
print("copy %D->%D f=%d\n", v1, v2, f);
for(; r != R; r = r->s1) {
for(; r != nil; r = r->s1) {
p = r->prog;
if(debug['P'])
print("%P", p);
if(!f && uniqp(r) == R) {
if(!f && uniqp(r) == nil) {
f = 1;
if(debug['P'])
print("; merge; f=%d", f);
@ -880,7 +830,7 @@ copyu(Prog *p, Adr *v, Adr *s)
* could be set/use depending on
* semantics
*/
int
static int
copyas(Adr *a, Adr *v)
{
if(a->type != v->type)
@ -896,7 +846,7 @@ copyas(Adr *a, Adr *v)
/*
* either direct or indirect
*/
int
static int
copyau(Adr *a, Adr *v)
{
@ -924,7 +874,7 @@ copyau(Adr *a, Adr *v)
* substitute s for v in a
* return failure to substitute
*/
int
static int
copysub(Adr *a, Adr *v, Adr *s, int f)
{
int t;
@ -957,9 +907,9 @@ copysub(Adr *a, Adr *v, Adr *s, int f)
}
static void
conprop(Reg *r0)
conprop(Flow *r0)
{
Reg *r;
Flow *r;
Prog *p, *p0;
int t;
Adr *v0;
@ -970,9 +920,9 @@ conprop(Reg *r0)
loop:
r = uniqs(r);
if(r == R || r == r0)
if(r == nil || r == r0)
return;
if(uniqp(r) == R)
if(uniqp(r) == nil)
return;
p = r->prog;

View File

@ -38,21 +38,6 @@
static int first = 1;
Reg*
rega(void)
{
Reg *r;
r = freer;
if(r == R) {
r = mal(sizeof(*r));
} else
freer = r->link;
*r = zreg;
return r;
}
int
rcmp(const void *a1, const void *a2)
{
@ -157,8 +142,9 @@ regopt(Prog *firstp)
{
Reg *r, *r1;
Prog *p;
ProgInfo info, info2;
int i, z, nr;
Graph *g;
ProgInfo info;
int i, z;
uint32 vreg;
Bits bit;
@ -169,20 +155,7 @@ regopt(Prog *firstp)
}
fixjmp(firstp);
// count instructions
nr = 0;
for(p=firstp; p!=P; p=p->link)
nr++;
// if too big dont bother
if(nr >= 10000) {
// print("********** %S is too big (%d)\n", curfn->nname->sym, nr);
return;
}
firstr = R;
lastr = R;
/*
* control flow is more complicated in generated go code
* than in generated c code. define pseudo-variables for
@ -214,33 +187,14 @@ regopt(Prog *firstp)
* allocate pcs
* find use and set of variables
*/
nr = 0;
for(p=firstp; p!=P; p=p->link) {
proginfo(&info, p);
if(info.flags & Skip)
continue;
r = rega();
nr++;
if(firstr == R) {
firstr = r;
lastr = r;
} else {
lastr->link = r;
r->p1 = lastr;
lastr->s1 = r;
lastr = r;
}
r->prog = p;
p->opt = r;
g = flowstart(firstp, sizeof(Reg));
if(g == nil)
return;
firstr = (Reg*)g->start;
r1 = r->p1;
if(r1 != R) {
proginfo(&info2, r1->prog);
if(info2.flags & Break) {
r->p1 = R;
r1->s1 = R;
}
}
for(r = firstr; r != R; r = (Reg*)r->f.link) {
p = r->f.prog;
proginfo(&info, p);
// Avoid making variables for direct-called functions.
if(p->as == ACALL && p->to.type == D_EXTERN)
@ -273,8 +227,6 @@ regopt(Prog *firstp)
r->set.b[z] |= bit.b[z];
}
}
if(firstr == R)
return;
for(i=0; i<nvar; i++) {
Var *v = var+i;
@ -290,45 +242,19 @@ regopt(Prog *firstp)
}
if(debug['R'] && debug['v'])
dumpit("pass1", firstr);
dumpit("pass1", &firstr->f, 1);
/*
* pass 2
* turn branch references to pointers
* build back pointers
*/
for(r=firstr; r!=R; r=r->link) {
p = r->prog;
if(p->to.type == D_BRANCH) {
if(p->to.u.branch == P)
fatal("pnil %P", p);
r1 = p->to.u.branch->opt;
if(r1 == R)
fatal("rnil %P", p);
if(r1 == r) {
//fatal("ref to self %P", p);
continue;
}
r->s2 = r1;
r->p2link = r1->p2;
r1->p2 = r;
}
}
if(debug['R'] && debug['v'])
dumpit("pass2", firstr);
/*
* pass 2.5
* find looping structure
*/
for(r = firstr; r != R; r = r->link)
r->active = 0;
for(r = firstr; r != R; r = (Reg*)r->f.link)
r->f.active = 0;
change = 0;
loopit(firstr, nr);
flowrpo(g);
if(debug['R'] && debug['v'])
dumpit("pass2.5", firstr);
dumpit("pass2", &firstr->f, 1);
/*
* pass 3
@ -337,17 +263,17 @@ regopt(Prog *firstp)
*/
loop1:
change = 0;
for(r = firstr; r != R; r = r->link)
r->active = 0;
for(r = firstr; r != R; r = r->link)
if(r->prog->as == ARET)
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 = r->link;
if(r1 && r1->active && !r->active) {
r1 = (Reg*)r->f.link;
if(r1 && r1->f.active && !r->f.active) {
prop(r, zbits, zbits);
i = 1;
}
@ -358,7 +284,7 @@ loop11:
goto loop1;
if(debug['R'] && debug['v'])
dumpit("pass3", firstr);
dumpit("pass3", &firstr->f, 1);
/*
* pass 4
@ -367,20 +293,20 @@ loop11:
*/
loop2:
change = 0;
for(r = firstr; r != R; r = r->link)
r->active = 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);
dumpit("pass4", &firstr->f, 1);
/*
* pass 4.5
* move register pseudo-variables into regu.
*/
for(r = firstr; r != R; r = r->link) {
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;
@ -404,26 +330,26 @@ loop2:
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->refset) {
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->prog->lineno, bit);
r->refset = 1;
print("%L: used and not set: %Q\n", r->f.prog->lineno, bit);
r->f.refset = 1;
}
}
for(r = firstr; r != R; r = r->link)
for(r = firstr; r != R; r = (Reg*)r->f.link)
r->act = zbits;
rgp = region;
nregion = 0;
for(r = firstr; r != R; r = r->link) {
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->refset) {
if(bany(&bit) && !r->f.refset) {
if(debug['w'])
print("%L: set and not used: %Q\n", r->prog->lineno, bit);
r->refset = 1;
excise(r);
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]);
@ -450,7 +376,7 @@ brk:
qsort(region, nregion, sizeof(region[0]), rcmp);
if(debug['R'] && debug['v'])
dumpit("pass5", firstr);
dumpit("pass5", &firstr->f, 1);
/*
* pass 6
@ -476,19 +402,23 @@ brk:
}
if(debug['R'] && debug['v'])
dumpit("pass6", firstr);
dumpit("pass6", &firstr->f, 1);
/*
* free aux structures. peep allocates new ones.
*/
flowend(g);
firstr = R;
/*
* pass 7
* peep-hole on basic block
*/
if(!debug['R'] || debug['P']) {
peep();
}
if(!debug['R'] || debug['P'])
peep(firstp);
/*
* eliminate nops
* free aux structures
*/
for(p=firstp; p!=P; p=p->link) {
while(p->link != P && p->link->as == ANOP)
@ -498,11 +428,6 @@ brk:
p->to.u.branch = p->to.u.branch->link;
}
if(lastr != R) {
lastr->link = freer;
freer = firstr;
}
if(debug['R']) {
if(ostats.ncvtreg ||
ostats.nspill ||
@ -545,7 +470,7 @@ addmove(Reg *r, int bn, int rn, int f)
clearp(p1);
p1->loc = 9999;
p = r->prog;
p = r->f.prog;
p1->link = p->link;
p->link = p1;
p1->lineno = p->lineno;
@ -769,7 +694,7 @@ prop(Reg *r, Bits ref, Bits cal)
Reg *r1, *r2;
int z;
for(r1 = r; r1 != R; r1 = r1->p1) {
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]) {
@ -782,9 +707,9 @@ prop(Reg *r, Bits ref, Bits cal)
change++;
}
}
switch(r1->prog->as) {
switch(r1->f.prog->as) {
case ACALL:
if(noreturn(r1->prog))
if(noreturn(r1->f.prog))
break;
for(z=0; z<BITS; z++) {
cal.b[z] |= ref.b[z] | externs.b[z];
@ -824,159 +749,22 @@ prop(Reg *r, Bits ref, Bits cal)
r1->refbehind.b[z] = ref.b[z];
r1->calbehind.b[z] = cal.b[z];
}
if(r1->active)
if(r1->f.active)
break;
r1->active = 1;
r1->f.active = 1;
}
for(; r != r1; r = r->p1)
for(r2 = r->p2; r2 != R; r2 = r2->p2link)
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);
}
/*
* find looping structure
*
* 1) find reverse postordering
* 2) find approximate dominators,
* the actual dominators if the flow graph is reducible
* otherwise, dominators plus some other non-dominators.
* See Matthew S. Hecht and Jeffrey D. Ullman,
* "Analysis of a Simple Algorithm for Global Data Flow Problems",
* Conf. Record of ACM Symp. on Principles of Prog. Langs, Boston, Massachusetts,
* Oct. 1-3, 1973, pp. 207-217.
* 3) find all nodes with a predecessor dominated by the current node.
* such a node is a loop head.
* recursively, all preds with a greater rpo number are in the loop
*/
int32
postorder(Reg *r, Reg **rpo2r, int32 n)
{
Reg *r1;
r->rpo = 1;
r1 = r->s1;
if(r1 && !r1->rpo)
n = postorder(r1, rpo2r, n);
r1 = r->s2;
if(r1 && !r1->rpo)
n = postorder(r1, rpo2r, n);
rpo2r[n] = r;
n++;
return n;
}
int32
rpolca(int32 *idom, int32 rpo1, int32 rpo2)
{
int32 t;
if(rpo1 == -1)
return rpo2;
while(rpo1 != rpo2){
if(rpo1 > rpo2){
t = rpo2;
rpo2 = rpo1;
rpo1 = t;
}
while(rpo1 < rpo2){
t = idom[rpo2];
if(t >= rpo2)
fatal("bad idom");
rpo2 = t;
}
}
return rpo1;
}
int
doms(int32 *idom, int32 r, int32 s)
{
while(s > r)
s = idom[s];
return s == r;
}
int
loophead(int32 *idom, Reg *r)
{
int32 src;
src = r->rpo;
if(r->p1 != R && doms(idom, src, r->p1->rpo))
return 1;
for(r = r->p2; r != R; r = r->p2link)
if(doms(idom, src, r->rpo))
return 1;
return 0;
}
void
loopmark(Reg **rpo2r, int32 head, Reg *r)
{
if(r->rpo < head || r->active == head)
return;
r->active = head;
r->loop += LOOP;
if(r->p1 != R)
loopmark(rpo2r, head, r->p1);
for(r = r->p2; r != R; r = r->p2link)
loopmark(rpo2r, head, r);
}
void
loopit(Reg *r, int32 nr)
{
Reg *r1;
int32 i, d, me;
if(nr > maxnr) {
rpo2r = mal(nr * sizeof(Reg*));
idom = mal(nr * sizeof(int32));
maxnr = nr;
}
d = postorder(r, rpo2r, 0);
if(d > nr)
fatal("too many reg nodes %d %d", d, nr);
nr = d;
for(i = 0; i < nr / 2; i++) {
r1 = rpo2r[i];
rpo2r[i] = rpo2r[nr - 1 - i];
rpo2r[nr - 1 - i] = r1;
}
for(i = 0; i < nr; i++)
rpo2r[i]->rpo = i;
idom[0] = 0;
for(i = 0; i < nr; i++) {
r1 = rpo2r[i];
me = r1->rpo;
d = -1;
// rpo2r[r->rpo] == r protects against considering dead code,
// which has r->rpo == 0.
if(r1->p1 != R && rpo2r[r1->p1->rpo] == r1->p1 && r1->p1->rpo < me)
d = r1->p1->rpo;
for(r1 = r1->p2; r1 != nil; r1 = r1->p2link)
if(rpo2r[r1->rpo] == r1 && r1->rpo < me)
d = rpolca(idom, d, r1->rpo);
idom[i] = d;
}
for(i = 0; i < nr; i++) {
r1 = rpo2r[i];
r1->loop++;
if(r1->p2 != R && loophead(idom, r1))
loopmark(rpo2r, i, r1);
}
}
void
synch(Reg *r, Bits dif)
{
Reg *r1;
int z;
for(r1 = r; r1 != R; r1 = r1->s1) {
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])) |
@ -986,13 +774,13 @@ synch(Reg *r, Bits dif)
change++;
}
}
if(r1->active)
if(r1->f.active)
break;
r1->active = 1;
r1->f.active = 1;
for(z=0; z<BITS; z++)
dif.b[z] &= ~(~r1->calbehind.b[z] & r1->calahead.b[z]);
if(r1->s2 != R)
synch(r1->s2, dif);
if(r1->f.s2 != nil)
synch((Reg*)r1->f.s2, dif);
}
}
@ -1057,7 +845,7 @@ paint1(Reg *r, int bn)
for(;;) {
if(!(r->refbehind.b[z] & bb))
break;
r1 = r->p1;
r1 = (Reg*)r->f.p1;
if(r1 == R)
break;
if(!(r1->refahead.b[z] & bb))
@ -1068,35 +856,35 @@ paint1(Reg *r, int bn)
}
if(LOAD(r) & ~(r->set.b[z]&~(r->use1.b[z]|r->use2.b[z])) & bb) {
change -= CLOAD * r->loop;
change -= CLOAD * r->f.loop;
}
for(;;) {
r->act.b[z] |= bb;
if(r->use1.b[z] & bb) {
change += CREF * r->loop;
change += CREF * r->f.loop;
}
if((r->use2.b[z]|r->set.b[z]) & bb) {
change += CREF * r->loop;
change += CREF * r->f.loop;
}
if(STORE(r) & r->regdiff.b[z] & bb) {
change -= CLOAD * r->loop;
change -= CLOAD * r->f.loop;
}
if(r->refbehind.b[z] & bb)
for(r1 = r->p2; r1 != R; r1 = r1->p2link)
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 = r->s2;
r1 = (Reg*)r->f.s2;
if(r1 != R)
if(r1->refbehind.b[z] & bb)
paint1(r1, bn);
r = r->s1;
r = (Reg*)r->f.s1;
if(r == R)
break;
if(r->act.b[z] & bb)
@ -1119,7 +907,7 @@ regset(Reg *r, uint32 bb)
v.type = b & 0xFFFF? BtoR(b): BtoF(b);
if(v.type == 0)
fatal("zero v.type for %#ux", b);
c = copyu(r->prog, &v, A);
c = copyu(r->f.prog, &v, A);
if(c == 3)
set |= b;
bb &= ~b;
@ -1138,7 +926,7 @@ reguse(Reg *r, uint32 bb)
v = zprog.from;
while(b = bb & ~(bb-1)) {
v.type = b & 0xFFFF? BtoR(b): BtoF(b);
c = copyu(r->prog, &v, A);
c = copyu(r->f.prog, &v, A);
if(c == 1 || c == 2 || c == 4)
set |= b;
bb &= ~b;
@ -1161,7 +949,7 @@ paint2(Reg *r, int bn)
for(;;) {
if(!(r->refbehind.b[z] & bb))
break;
r1 = r->p1;
r1 = (Reg*)r->f.p1;
if(r1 == R)
break;
if(!(r1->refahead.b[z] & bb))
@ -1176,17 +964,17 @@ paint2(Reg *r, int bn)
vreg |= r->regu;
if(r->refbehind.b[z] & bb)
for(r1 = r->p2; r1 != R; r1 = r1->p2link)
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 = r->s2;
r1 = (Reg*)r->f.s2;
if(r1 != R)
if(r1->refbehind.b[z] & bb)
vreg |= paint2(r1, bn);
r = r->s1;
r = (Reg*)r->f.s1;
if(r == R)
break;
if(!(r->act.b[z] & bb))
@ -1196,7 +984,7 @@ paint2(Reg *r, int bn)
}
bb = vreg;
for(; r; r=r->s1) {
for(; r; r=(Reg*)r->f.s1) {
x = r->regu & ~bb;
if(x) {
vreg |= reguse(r, x);
@ -1221,7 +1009,7 @@ paint3(Reg *r, int bn, int32 rb, int rn)
for(;;) {
if(!(r->refbehind.b[z] & bb))
break;
r1 = r->p1;
r1 = (Reg*)r->f.p1;
if(r1 == R)
break;
if(!(r1->refahead.b[z] & bb))
@ -1235,7 +1023,7 @@ paint3(Reg *r, int bn, int32 rb, int rn)
addmove(r, bn, rn, 0);
for(;;) {
r->act.b[z] |= bb;
p = r->prog;
p = r->f.prog;
if(r->use1.b[z] & bb) {
if(debug['R'] && debug['v'])
@ -1257,17 +1045,17 @@ paint3(Reg *r, int bn, int32 rb, int rn)
r->regu |= rb;
if(r->refbehind.b[z] & bb)
for(r1 = r->p2; r1 != R; r1 = r1->p2link)
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 = r->s2;
r1 = (Reg*)r->f.s2;
if(r1 != R)
if(r1->refbehind.b[z] & bb)
paint3(r1, bn, rb, rn);
r = r->s1;
r = (Reg*)r->f.s1;
if(r == R)
break;
if(r->act.b[z] & bb)
@ -1331,60 +1119,64 @@ BtoF(int32 b)
}
void
dumpone(Reg *r)
dumpone(Flow *f, int isreg)
{
int z;
Bits bit;
Reg *r;
print("%d:%P", r->loop, r->prog);
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("%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, Reg *r0)
dumpit(char *str, Flow *r0, int isreg)
{
Reg *r, *r1;
Flow *r, *r1;
print("\n%s\n", str);
for(r = r0; r != R; r = r->link) {
dumpone(r);
for(r = r0; r != nil; r = r->link) {
dumpone(r, isreg);
r1 = r->p2;
if(r1 != R) {
if(r1 != nil) {
print(" pred:");
for(; r1 != R; r1 = r1->p2link)
for(; r1 != nil; r1 = r1->p2link)
print(" %.4ud", r1->prog->loc);
print("\n");
}

View File

@ -55,6 +55,7 @@ typedef struct Rgn Rgn;
// r->prog->opt points back to r.
struct Reg
{
Flow f;
Bits set; // variables written by this instruction.
Bits use1; // variables read by prog->from.
@ -96,7 +97,6 @@ struct Rgn
EXTERN int32 exregoffset; // not set
EXTERN int32 exfregoffset; // not set
EXTERN Reg* firstr;
EXTERN Reg* lastr;
EXTERN Reg zreg;
EXTERN Reg* freer;
EXTERN Reg** rpo2r;
@ -141,28 +141,16 @@ void paint1(Reg*, int);
uint32 paint2(Reg*, int);
void paint3(Reg*, int, int32, int);
void addreg(Adr*, int);
void dumpone(Reg*);
void dumpit(char*, Reg*);
void dumpone(Flow*, int);
void dumpit(char*, Flow*, int);
/*
* peep.c
*/
void peep(void);
void excise(Reg*);
Reg* uniqp(Reg*);
Reg* uniqs(Reg*);
int regtyp(Adr*);
int anyvar(Adr*);
int subprop(Reg*);
int copyprop(Reg*);
int copy1(Adr*, Adr*, Reg*, int);
void peep(Prog*);
void excise(Flow*);
int copyu(Prog*, Adr*, Adr*);
int copyas(Adr*, Adr*);
int copyau(Adr*, Adr*);
int copysub(Adr*, Adr*, Adr*, int);
int copysub1(Prog*, Adr*, Adr*, int);
int32 RtoB(int);
int32 FtoB(int);
int BtoR(int32);

View File

@ -35,8 +35,15 @@
#define REGEXT 0
static void conprop(Reg *r);
static void elimshortmov(Reg *r);
static void conprop(Flow *r);
static void elimshortmov(Graph*);
static int regtyp(Adr*);
static int subprop(Flow*);
static int copyprop(Graph*, Flow*);
static int copy1(Adr*, Adr*, Flow*, int);
static int copyas(Adr*, Adr*);
static int copyau(Adr*, Adr*);
static int copysub(Adr*, Adr*, Adr*, int);
// do we need the carry bit
static int
@ -55,19 +62,19 @@ needc(Prog *p)
return 0;
}
static Reg*
rnops(Reg *r)
static Flow*
rnops(Flow *r)
{
Prog *p;
Reg *r1;
Flow *r1;
if(r != R)
if(r != nil)
for(;;) {
p = r->prog;
if(p->as != ANOP || p->from.type != D_NONE || p->to.type != D_NONE)
break;
r1 = uniqs(r);
if(r1 == R)
if(r1 == nil)
break;
r = r1;
}
@ -75,49 +82,25 @@ rnops(Reg *r)
}
void
peep(void)
peep(Prog *firstp)
{
Reg *r, *r1, *r2;
Flow *r, *r1;
Graph *g;
Prog *p, *p1;
int t;
ProgInfo info;
/*
* complete R structure
*/
for(r=firstr; r!=R; r=r1) {
r1 = r->link;
if(r1 == R)
break;
for(p = r->prog->link; p != r1->prog; p = p->link) {
proginfo(&info, p);
if(info.flags & Skip)
continue;
r2 = rega();
r->link = r2;
r2->link = r1;
r2->prog = p;
p->opt = r2;
r2->p1 = r;
r->s1 = r2;
r2->s1 = r1;
r1->p1 = r2;
r = r2;
}
}
g = flowstart(firstp, sizeof(Flow));
if(g == nil)
return;
// byte, word arithmetic elimination.
elimshortmov(r);
elimshortmov(g);
// constant propagation
// find MOV $con,R followed by
// another MOV $con,R without
// setting R in the interim
for(r=firstr; r!=R; r=r->link) {
// find MOV $con,nil followed by
// another MOV $con,nil without
// setting nil in the interim
for(r=g->start; r!=nil; r=r->link) {
p = r->prog;
switch(p->as) {
case ALEAL:
@ -141,10 +124,10 @@ peep(void)
loop1:
if(debug['P'] && debug['v'])
dumpit("loop1", firstr);
dumpit("loop1", g->start, 0);
t = 0;
for(r=firstr; r!=R; r=r->link) {
for(r=g->start; r!=nil; r=r->link) {
p = r->prog;
switch(p->as) {
case AMOVL:
@ -152,11 +135,11 @@ loop1:
case AMOVSD:
if(regtyp(&p->to))
if(regtyp(&p->from)) {
if(copyprop(r)) {
if(copyprop(g, r)) {
excise(r);
t++;
} else
if(subprop(r) && copyprop(r)) {
if(subprop(r) && copyprop(g, r)) {
excise(r);
t++;
}
@ -169,7 +152,7 @@ loop1:
case AMOVWLSX:
if(regtyp(&p->to)) {
r1 = rnops(uniqs(r));
if(r1 != R) {
if(r1 != nil) {
p1 = r1->prog;
if(p->as == p1->as && p->to.type == p1->from.type){
p1->as = AMOVL;
@ -232,7 +215,7 @@ loop1:
// can be replaced by MOVAPD, which moves the pair of float64s
// instead of just the lower one. We only use the lower one, but
// the processor can do better if we do moves using both.
for(r=firstr; r!=R; r=r->link) {
for(r=g->start; r!=nil; r=r->link) {
p = r->prog;
if(p->as == AMOVSD)
if(regtyp(&p->from))
@ -242,7 +225,7 @@ loop1:
}
void
excise(Reg *r)
excise(Flow *r)
{
Prog *p;
@ -257,39 +240,7 @@ excise(Reg *r)
ostats.ndelmov++;
}
Reg*
uniqp(Reg *r)
{
Reg *r1;
r1 = r->p1;
if(r1 == R) {
r1 = r->p2;
if(r1 == R || r1->p2link != R)
return R;
} else
if(r->p2 != R)
return R;
return r1;
}
Reg*
uniqs(Reg *r)
{
Reg *r1;
r1 = r->s1;
if(r1 == R) {
r1 = r->s2;
if(r1 == R)
return R;
} else
if(r->s2 != R)
return R;
return r1;
}
int
static int
regtyp(Adr *a)
{
int t;
@ -310,11 +261,12 @@ regtyp(Adr *a)
// can smash the entire 64-bit register without
// causing any trouble.
static void
elimshortmov(Reg *r)
elimshortmov(Graph *g)
{
Prog *p;
Flow *r;
for(r=firstr; r!=R; r=r->link) {
for(r=g->start; r!=nil; r=r->link) {
p = r->prog;
if(regtyp(&p->to)) {
switch(p->as) {
@ -409,12 +361,12 @@ elimshortmov(Reg *r)
* hopefully, then the former or latter MOV
* will be eliminated by copy propagation.
*/
int
subprop(Reg *r0)
static int
subprop(Flow *r0)
{
Prog *p;
Adr *v1, *v2;
Reg *r;
Flow *r;
int t;
ProgInfo info;
@ -425,10 +377,10 @@ subprop(Reg *r0)
v2 = &p->to;
if(!regtyp(v2))
return 0;
for(r=uniqp(r0); r!=R; r=uniqp(r)) {
for(r=uniqp(r0); r!=nil; r=uniqp(r)) {
if(debug['P'] && debug['v'])
print("\t? %P\n", r->prog);
if(uniqs(r) == R)
if(uniqs(r) == nil)
break;
p = r->prog;
proginfo(&info, p);
@ -483,25 +435,25 @@ gotit:
* set v1 F=1
* set v2 return success
*/
int
copyprop(Reg *r0)
static int
copyprop(Graph *g, Flow *r0)
{
Prog *p;
Adr *v1, *v2;
Reg *r;
Flow *r;
p = r0->prog;
v1 = &p->from;
v2 = &p->to;
if(copyas(v1, v2))
return 1;
for(r=firstr; r!=R; r=r->link)
for(r=g->start; r!=nil; r=r->link)
r->active = 0;
return copy1(v1, v2, r0->s1, 0);
}
int
copy1(Adr *v1, Adr *v2, Reg *r, int f)
static int
copy1(Adr *v1, Adr *v2, Flow *r, int f)
{
int t;
Prog *p;
@ -514,11 +466,11 @@ copy1(Adr *v1, Adr *v2, Reg *r, int f)
r->active = 1;
if(debug['P'])
print("copy %D->%D f=%d\n", v1, v2, f);
for(; r != R; r = r->s1) {
for(; r != nil; r = r->s1) {
p = r->prog;
if(debug['P'])
print("%P", p);
if(!f && uniqp(r) == R) {
if(!f && uniqp(r) == nil) {
f = 1;
if(debug['P'])
print("; merge; f=%d", f);
@ -672,7 +624,7 @@ copyu(Prog *p, Adr *v, Adr *s)
* could be set/use depending on
* semantics
*/
int
static int
copyas(Adr *a, Adr *v)
{
if(a->type != v->type)
@ -688,7 +640,7 @@ copyas(Adr *a, Adr *v)
/*
* either direct or indirect
*/
int
static int
copyau(Adr *a, Adr *v)
{
@ -707,7 +659,7 @@ copyau(Adr *a, Adr *v)
* substitute s for v in a
* return failure to substitute
*/
int
static int
copysub(Adr *a, Adr *v, Adr *s, int f)
{
int t;
@ -740,9 +692,9 @@ copysub(Adr *a, Adr *v, Adr *s, int f)
}
static void
conprop(Reg *r0)
conprop(Flow *r0)
{
Reg *r;
Flow *r;
Prog *p, *p0;
int t;
Adr *v0;
@ -753,9 +705,9 @@ conprop(Reg *r0)
loop:
r = uniqs(r);
if(r == R || r == r0)
if(r == nil || r == r0)
return;
if(uniqp(r) == R)
if(uniqp(r) == nil)
return;
p = r->prog;

View File

@ -40,21 +40,6 @@ static int first = 1;
static void fixtemp(Prog*);
Reg*
rega(void)
{
Reg *r;
r = freer;
if(r == R) {
r = mal(sizeof(*r));
} else
freer = r->link;
*r = zreg;
return r;
}
int
rcmp(const void *a1, const void *a2)
{
@ -129,8 +114,9 @@ regopt(Prog *firstp)
{
Reg *r, *r1;
Prog *p;
ProgInfo info, info2;
int i, z, nr;
Graph *g;
ProgInfo info;
int i, z;
uint32 vreg;
Bits bit;
@ -143,19 +129,6 @@ regopt(Prog *firstp)
fixtemp(firstp);
fixjmp(firstp);
// count instructions
nr = 0;
for(p=firstp; p!=P; p=p->link)
nr++;
// if too big dont bother
if(nr >= 10000) {
// print("********** %S is too big (%d)\n", curfn->nname->sym, nr);
return;
}
firstr = R;
lastr = R;
/*
* control flow is more complicated in generated go code
* than in generated c code. define pseudo-variables for
@ -187,33 +160,14 @@ regopt(Prog *firstp)
* allocate pcs
* find use and set of variables
*/
nr = 0;
for(p=firstp; p!=P; p=p->link) {
proginfo(&info, p);
if(info.flags & Skip)
continue;
r = rega();
nr++;
if(firstr == R) {
firstr = r;
lastr = r;
} else {
lastr->link = r;
r->p1 = lastr;
lastr->s1 = r;
lastr = r;
}
r->prog = p;
p->opt = r;
g = flowstart(firstp, sizeof(Reg));
if(g == nil)
return;
firstr = (Reg*)g->start;
r1 = r->p1;
if(r1 != R) {
proginfo(&info2, r1->prog);
if(info2.flags & Break) {
r->p1 = R;
r1->s1 = R;
}
}
for(r = firstr; r != R; r = (Reg*)r->f.link) {
p = r->f.prog;
proginfo(&info, p);
// Avoid making variables for direct-called functions.
if(p->as == ACALL && p->to.type == D_EXTERN)
@ -263,45 +217,19 @@ regopt(Prog *firstp)
}
if(debug['R'] && debug['v'])
dumpit("pass1", firstr);
dumpit("pass1", &firstr->f, 1);
/*
* pass 2
* turn branch references to pointers
* build back pointers
*/
for(r=firstr; r!=R; r=r->link) {
p = r->prog;
if(p->to.type == D_BRANCH) {
if(p->to.u.branch == P)
fatal("pnil %P", p);
r1 = p->to.u.branch->opt;
if(r1 == R)
fatal("rnil %P", p);
if(r1 == r) {
//fatal("ref to self %P", p);
continue;
}
r->s2 = r1;
r->p2link = r1->p2;
r1->p2 = r;
}
}
if(debug['R'] && debug['v'])
dumpit("pass2", firstr);
/*
* pass 2.5
* find looping structure
*/
for(r = firstr; r != R; r = r->link)
r->active = 0;
for(r = firstr; r != R; r = (Reg*)r->f.link)
r->f.active = 0;
change = 0;
loopit(firstr, nr);
flowrpo(g);
if(debug['R'] && debug['v'])
dumpit("pass2.5", firstr);
dumpit("pass2", &firstr->f, 1);
/*
* pass 3
@ -310,17 +238,17 @@ regopt(Prog *firstp)
*/
loop1:
change = 0;
for(r = firstr; r != R; r = r->link)
r->active = 0;
for(r = firstr; r != R; r = r->link)
if(r->prog->as == ARET)
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 = r->link;
if(r1 && r1->active && !r->active) {
r1 = (Reg*)r->f.link;
if(r1 && r1->f.active && !r->f.active) {
prop(r, zbits, zbits);
i = 1;
}
@ -331,7 +259,7 @@ loop11:
goto loop1;
if(debug['R'] && debug['v'])
dumpit("pass3", firstr);
dumpit("pass3", &firstr->f, 1);
/*
* pass 4
@ -340,20 +268,20 @@ loop11:
*/
loop2:
change = 0;
for(r = firstr; r != R; r = r->link)
r->active = 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);
dumpit("pass4", &firstr->f, 1);
/*
* pass 4.5
* move register pseudo-variables into regu.
*/
for(r = firstr; r != R; r = r->link) {
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;
@ -377,26 +305,26 @@ loop2:
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->refset) {
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->prog->lineno, bit);
r->refset = 1;
print("%L: used and not set: %Q\n", r->f.prog->lineno, bit);
r->f.refset = 1;
}
}
for(r = firstr; r != R; r = r->link)
for(r = firstr; r != R; r = (Reg*)r->f.link)
r->act = zbits;
rgp = region;
nregion = 0;
for(r = firstr; r != R; r = r->link) {
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->refset) {
if(bany(&bit) && !r->f.refset) {
if(debug['w'])
print("%L: set and not used: %Q\n", r->prog->lineno, bit);
r->refset = 1;
excise(r);
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]);
@ -438,19 +366,23 @@ brk:
}
if(debug['R'] && debug['v'])
dumpit("pass6", firstr);
dumpit("pass6", &firstr->f, 1);
/*
* free aux structures. peep allocates new ones.
*/
flowend(g);
firstr = R;
/*
* pass 7
* peep-hole on basic block
*/
if(!debug['R'] || debug['P']) {
peep();
}
if(!debug['R'] || debug['P'])
peep(firstp);
/*
* eliminate nops
* free aux structures
*/
for(p=firstp; p!=P; p=p->link) {
while(p->link != P && p->link->as == ANOP)
@ -468,11 +400,6 @@ brk:
fatal("invalid use of %R with GO386=387: %P", p->to.type, p);
}
if(lastr != R) {
lastr->link = freer;
freer = firstr;
}
if(debug['R']) {
if(ostats.ncvtreg ||
ostats.nspill ||
@ -515,7 +442,7 @@ addmove(Reg *r, int bn, int rn, int f)
clearp(p1);
p1->loc = 9999;
p = r->prog;
p = r->f.prog;
p1->link = p->link;
p->link = p1;
p1->lineno = p->lineno;
@ -732,7 +659,7 @@ prop(Reg *r, Bits ref, Bits cal)
Reg *r1, *r2;
int z;
for(r1 = r; r1 != R; r1 = r1->p1) {
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]) {
@ -745,9 +672,9 @@ prop(Reg *r, Bits ref, Bits cal)
change++;
}
}
switch(r1->prog->as) {
switch(r1->f.prog->as) {
case ACALL:
if(noreturn(r1->prog))
if(noreturn(r1->f.prog))
break;
for(z=0; z<BITS; z++) {
cal.b[z] |= ref.b[z] | externs.b[z];
@ -787,159 +714,22 @@ prop(Reg *r, Bits ref, Bits cal)
r1->refbehind.b[z] = ref.b[z];
r1->calbehind.b[z] = cal.b[z];
}
if(r1->active)
if(r1->f.active)
break;
r1->active = 1;
r1->f.active = 1;
}
for(; r != r1; r = r->p1)
for(r2 = r->p2; r2 != R; r2 = r2->p2link)
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);
}
/*
* find looping structure
*
* 1) find reverse postordering
* 2) find approximate dominators,
* the actual dominators if the flow graph is reducible
* otherwise, dominators plus some other non-dominators.
* See Matthew S. Hecht and Jeffrey D. Ullman,
* "Analysis of a Simple Algorithm for Global Data Flow Problems",
* Conf. Record of ACM Symp. on Principles of Prog. Langs, Boston, Massachusetts,
* Oct. 1-3, 1973, pp. 207-217.
* 3) find all nodes with a predecessor dominated by the current node.
* such a node is a loop head.
* recursively, all preds with a greater rpo number are in the loop
*/
int32
postorder(Reg *r, Reg **rpo2r, int32 n)
{
Reg *r1;
r->rpo = 1;
r1 = r->s1;
if(r1 && !r1->rpo)
n = postorder(r1, rpo2r, n);
r1 = r->s2;
if(r1 && !r1->rpo)
n = postorder(r1, rpo2r, n);
rpo2r[n] = r;
n++;
return n;
}
int32
rpolca(int32 *idom, int32 rpo1, int32 rpo2)
{
int32 t;
if(rpo1 == -1)
return rpo2;
while(rpo1 != rpo2){
if(rpo1 > rpo2){
t = rpo2;
rpo2 = rpo1;
rpo1 = t;
}
while(rpo1 < rpo2){
t = idom[rpo2];
if(t >= rpo2)
fatal("bad idom");
rpo2 = t;
}
}
return rpo1;
}
int
doms(int32 *idom, int32 r, int32 s)
{
while(s > r)
s = idom[s];
return s == r;
}
int
loophead(int32 *idom, Reg *r)
{
int32 src;
src = r->rpo;
if(r->p1 != R && doms(idom, src, r->p1->rpo))
return 1;
for(r = r->p2; r != R; r = r->p2link)
if(doms(idom, src, r->rpo))
return 1;
return 0;
}
void
loopmark(Reg **rpo2r, int32 head, Reg *r)
{
if(r->rpo < head || r->active == head)
return;
r->active = head;
r->loop += LOOP;
if(r->p1 != R)
loopmark(rpo2r, head, r->p1);
for(r = r->p2; r != R; r = r->p2link)
loopmark(rpo2r, head, r);
}
void
loopit(Reg *r, int32 nr)
{
Reg *r1;
int32 i, d, me;
if(nr > maxnr) {
rpo2r = mal(nr * sizeof(Reg*));
idom = mal(nr * sizeof(int32));
maxnr = nr;
}
d = postorder(r, rpo2r, 0);
if(d > nr)
fatal("too many reg nodes %d %d", d, nr);
nr = d;
for(i = 0; i < nr / 2; i++) {
r1 = rpo2r[i];
rpo2r[i] = rpo2r[nr - 1 - i];
rpo2r[nr - 1 - i] = r1;
}
for(i = 0; i < nr; i++)
rpo2r[i]->rpo = i;
idom[0] = 0;
for(i = 0; i < nr; i++) {
r1 = rpo2r[i];
me = r1->rpo;
d = -1;
// rpo2r[r->rpo] == r protects against considering dead code,
// which has r->rpo == 0.
if(r1->p1 != R && rpo2r[r1->p1->rpo] == r1->p1 && r1->p1->rpo < me)
d = r1->p1->rpo;
for(r1 = r1->p2; r1 != nil; r1 = r1->p2link)
if(rpo2r[r1->rpo] == r1 && r1->rpo < me)
d = rpolca(idom, d, r1->rpo);
idom[i] = d;
}
for(i = 0; i < nr; i++) {
r1 = rpo2r[i];
r1->loop++;
if(r1->p2 != R && loophead(idom, r1))
loopmark(rpo2r, i, r1);
}
}
void
synch(Reg *r, Bits dif)
{
Reg *r1;
int z;
for(r1 = r; r1 != R; r1 = r1->s1) {
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])) |
@ -949,13 +739,13 @@ synch(Reg *r, Bits dif)
change++;
}
}
if(r1->active)
if(r1->f.active)
break;
r1->active = 1;
r1->f.active = 1;
for(z=0; z<BITS; z++)
dif.b[z] &= ~(~r1->calbehind.b[z] & r1->calahead.b[z]);
if(r1->s2 != R)
synch(r1->s2, dif);
if((Reg*)r1->f.s2 != R)
synch((Reg*)r1->f.s2, dif);
}
}
@ -1021,7 +811,7 @@ paint1(Reg *r, int bn)
for(;;) {
if(!(r->refbehind.b[z] & bb))
break;
r1 = r->p1;
r1 = (Reg*)r->f.p1;
if(r1 == R)
break;
if(!(r1->refahead.b[z] & bb))
@ -1032,45 +822,45 @@ paint1(Reg *r, int bn)
}
if(LOAD(r) & ~(r->set.b[z]&~(r->use1.b[z]|r->use2.b[z])) & bb) {
change -= CLOAD * r->loop;
change -= CLOAD * r->f.loop;
}
for(;;) {
r->act.b[z] |= bb;
p = r->prog;
p = r->f.prog;
if(r->use1.b[z] & bb) {
change += CREF * r->loop;
change += CREF * r->f.loop;
if(p->as == AFMOVL || p->as == AFMOVW)
if(BtoR(bb) != D_F0)
change = -CINF;
}
if((r->use2.b[z]|r->set.b[z]) & bb) {
change += CREF * r->loop;
change += CREF * r->f.loop;
if(p->as == AFMOVL || p->as == AFMOVW)
if(BtoR(bb) != D_F0)
change = -CINF;
}
if(STORE(r) & r->regdiff.b[z] & bb) {
change -= CLOAD * r->loop;
change -= CLOAD * r->f.loop;
if(p->as == AFMOVL || p->as == AFMOVW)
if(BtoR(bb) != D_F0)
change = -CINF;
}
if(r->refbehind.b[z] & bb)
for(r1 = r->p2; r1 != R; r1 = r1->p2link)
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 = r->s2;
r1 = (Reg*)r->f.s2;
if(r1 != R)
if(r1->refbehind.b[z] & bb)
paint1(r1, bn);
r = r->s1;
r = (Reg*)r->f.s1;
if(r == R)
break;
if(r->act.b[z] & bb)
@ -1091,7 +881,7 @@ regset(Reg *r, uint32 bb)
v = zprog.from;
while(b = bb & ~(bb-1)) {
v.type = b & 0xFF ? BtoR(b): BtoF(b);
c = copyu(r->prog, &v, A);
c = copyu(r->f.prog, &v, A);
if(c == 3)
set |= b;
bb &= ~b;
@ -1110,7 +900,7 @@ reguse(Reg *r, uint32 bb)
v = zprog.from;
while(b = bb & ~(bb-1)) {
v.type = b & 0xFF ? BtoR(b): BtoF(b);
c = copyu(r->prog, &v, A);
c = copyu(r->f.prog, &v, A);
if(c == 1 || c == 2 || c == 4)
set |= b;
bb &= ~b;
@ -1133,7 +923,7 @@ paint2(Reg *r, int bn)
for(;;) {
if(!(r->refbehind.b[z] & bb))
break;
r1 = r->p1;
r1 = (Reg*)r->f.p1;
if(r1 == R)
break;
if(!(r1->refahead.b[z] & bb))
@ -1148,17 +938,17 @@ paint2(Reg *r, int bn)
vreg |= r->regu;
if(r->refbehind.b[z] & bb)
for(r1 = r->p2; r1 != R; r1 = r1->p2link)
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 = r->s2;
r1 = (Reg*)r->f.s2;
if(r1 != R)
if(r1->refbehind.b[z] & bb)
vreg |= paint2(r1, bn);
r = r->s1;
r = (Reg*)r->f.s1;
if(r == R)
break;
if(!(r->act.b[z] & bb))
@ -1168,7 +958,7 @@ paint2(Reg *r, int bn)
}
bb = vreg;
for(; r; r=r->s1) {
for(; r; r=(Reg*)r->f.s1) {
x = r->regu & ~bb;
if(x) {
vreg |= reguse(r, x);
@ -1193,7 +983,7 @@ paint3(Reg *r, int bn, int32 rb, int rn)
for(;;) {
if(!(r->refbehind.b[z] & bb))
break;
r1 = r->p1;
r1 = (Reg*)r->f.p1;
if(r1 == R)
break;
if(!(r1->refahead.b[z] & bb))
@ -1207,7 +997,7 @@ paint3(Reg *r, int bn, int32 rb, int rn)
addmove(r, bn, rn, 0);
for(;;) {
r->act.b[z] |= bb;
p = r->prog;
p = r->f.prog;
if(r->use1.b[z] & bb) {
if(debug['R'] && debug['v'])
@ -1229,17 +1019,17 @@ paint3(Reg *r, int bn, int32 rb, int rn)
r->regu |= rb;
if(r->refbehind.b[z] & bb)
for(r1 = r->p2; r1 != R; r1 = r1->p2link)
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 = r->s2;
r1 = (Reg*)r->f.s2;
if(r1 != R)
if(r1->refbehind.b[z] & bb)
paint3(r1, bn, rb, rn);
r = r->s1;
r = (Reg*)r->f.s1;
if(r == R)
break;
if(r->act.b[z] & bb)
@ -1297,65 +1087,69 @@ BtoF(int32 b)
}
void
dumpone(Reg *r)
dumpone(Flow *f, int isreg)
{
int z;
Bits bit;
Reg *r;
print("%d:%P", r->loop, r->prog);
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("%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, Reg *r0)
dumpit(char *str, Flow *r0, int isreg)
{
Reg *r, *r1;
Flow *r, *r1;
print("\n%s\n", str);
for(r = r0; r != R; r = r->link) {
dumpone(r);
for(r = r0; r != nil; r = r->link) {
dumpone(r, isreg);
r1 = r->p2;
if(r1 != R) {
if(r1 != nil) {
print(" pred:");
for(; r1 != R; r1 = r1->p2link)
for(; r1 != nil; r1 = r->p2link)
print(" %.4ud", r1->prog->loc);
print("\n");
}
// r1 = r->s1;
// if(r1 != R) {
// if(r1 != nil) {
// print(" succ:");
// for(; r1 != R; r1 = r1->s1)
// print(" %.4ud", r1->prog->loc);

View File

@ -181,3 +181,284 @@ fixjmp(Prog *firstp)
print("\n");
}
}
// Control flow analysis. The Flow structures hold predecessor and successor
// information as well as basic loop analysis.
//
// graph = flowstart(firstp, sizeof(Flow));
// ... use flow graph ...
// flowend(graph); // free graph
//
// Typical uses of the flow graph are to iterate over all the flow-relevant instructions:
//
// for(f = graph->start; f != nil; f = f->link)
//
// or, given an instruction f, to iterate over all the predecessors, which is
// f->p1 and this list:
//
// for(f2 = f->p2; f2 != nil; f2 = f2->p2link)
//
// Often the Flow struct is embedded as the first field inside a larger struct S.
// In that case casts are needed to convert Flow* to S* in many places but the
// idea is the same. Pass sizeof(S) instead of sizeof(Flow) to flowstart.
Graph*
flowstart(Prog *firstp, int size)
{
int nf;
Flow *f, *f1, *start, *last;
Graph *graph;
Prog *p;
ProgInfo info;
// Count and mark instructions to annotate.
nf = 0;
for(p = firstp; p != P; p = p->link) {
p->opt = nil; // should be already, but just in case
proginfo(&info, p);
if(info.flags & Skip)
continue;
p->opt = (void*)1;
nf++;
}
if(nf == 0)
return nil;
if(nf >= 20000) {
// fatal("%S is too big (%d instructions)", curfn->nname->sym, nf);
return nil;
}
// Allocate annotations and assign to instructions.
graph = calloc(sizeof *graph + size*nf, 1);
if(graph == nil)
fatal("out of memory");
start = (Flow*)(graph+1);
last = nil;
f = start;
for(p = firstp; p != P; p = p->link) {
if(p->opt == nil)
continue;
p->opt = f;
f->prog = p;
if(last)
last->link = f;
last = f;
f = (Flow*)((uchar*)f + size);
}
// Fill in pred/succ information.
for(f = start; f != nil; f = f->link) {
p = f->prog;
proginfo(&info, p);
if(!(info.flags & Break)) {
f1 = f->link;
f->s1 = f1;
f1->p1 = f;
}
if(p->to.type == D_BRANCH) {
if(p->to.u.branch == P)
fatal("pnil %P", p);
f1 = p->to.u.branch->opt;
if(f1 == nil)
fatal("fnil %P / %P", p, p->to.u.branch);
if(f1 == f) {
//fatal("self loop %P", p);
continue;
}
f->s2 = f1;
f->p2link = f1->p2;
f1->p2 = f;
}
}
graph->start = start;
graph->num = nf;
return graph;
}
void
flowend(Graph *graph)
{
Flow *f;
for(f = graph->start; f != nil; f = f->link)
f->prog->opt = nil;
free(graph);
}
/*
* find looping structure
*
* 1) find reverse postordering
* 2) find approximate dominators,
* the actual dominators if the flow graph is reducible
* otherwise, dominators plus some other non-dominators.
* See Matthew S. Hecht and Jeffrey D. Ullman,
* "Analysis of a Simple Algorithm for Global Data Flow Problems",
* Conf. Record of ACM Symp. on Principles of Prog. Langs, Boston, Massachusetts,
* Oct. 1-3, 1973, pp. 207-217.
* 3) find all nodes with a predecessor dominated by the current node.
* such a node is a loop head.
* recursively, all preds with a greater rpo number are in the loop
*/
static int32
postorder(Flow *r, Flow **rpo2r, int32 n)
{
Flow *r1;
r->rpo = 1;
r1 = r->s1;
if(r1 && !r1->rpo)
n = postorder(r1, rpo2r, n);
r1 = r->s2;
if(r1 && !r1->rpo)
n = postorder(r1, rpo2r, n);
rpo2r[n] = r;
n++;
return n;
}
static int32
rpolca(int32 *idom, int32 rpo1, int32 rpo2)
{
int32 t;
if(rpo1 == -1)
return rpo2;
while(rpo1 != rpo2){
if(rpo1 > rpo2){
t = rpo2;
rpo2 = rpo1;
rpo1 = t;
}
while(rpo1 < rpo2){
t = idom[rpo2];
if(t >= rpo2)
fatal("bad idom");
rpo2 = t;
}
}
return rpo1;
}
static int
doms(int32 *idom, int32 r, int32 s)
{
while(s > r)
s = idom[s];
return s == r;
}
static int
loophead(int32 *idom, Flow *r)
{
int32 src;
src = r->rpo;
if(r->p1 != nil && doms(idom, src, r->p1->rpo))
return 1;
for(r = r->p2; r != nil; r = r->p2link)
if(doms(idom, src, r->rpo))
return 1;
return 0;
}
static void
loopmark(Flow **rpo2r, int32 head, Flow *r)
{
if(r->rpo < head || r->active == head)
return;
r->active = head;
r->loop += LOOP;
if(r->p1 != nil)
loopmark(rpo2r, head, r->p1);
for(r = r->p2; r != nil; r = r->p2link)
loopmark(rpo2r, head, r);
}
void
flowrpo(Graph *g)
{
Flow *r1;
int32 i, d, me, nr, *idom;
Flow **rpo2r;
free(g->rpo);
g->rpo = calloc(g->num*sizeof g->rpo[0], 1);
idom = calloc(g->num*sizeof idom[0], 1);
if(g->rpo == nil || idom == nil)
fatal("out of memory");
rpo2r = g->rpo;
d = postorder(g->start, rpo2r, 0);
nr = g->num;
if(d > nr)
fatal("too many reg nodes %d %d", d, nr);
nr = d;
for(i = 0; i < nr / 2; i++) {
r1 = rpo2r[i];
rpo2r[i] = rpo2r[nr - 1 - i];
rpo2r[nr - 1 - i] = r1;
}
for(i = 0; i < nr; i++)
rpo2r[i]->rpo = i;
idom[0] = 0;
for(i = 0; i < nr; i++) {
r1 = rpo2r[i];
me = r1->rpo;
d = -1;
// rpo2r[r->rpo] == r protects against considering dead code,
// which has r->rpo == 0.
if(r1->p1 != nil && rpo2r[r1->p1->rpo] == r1->p1 && r1->p1->rpo < me)
d = r1->p1->rpo;
for(r1 = r1->p2; r1 != nil; r1 = r1->p2link)
if(rpo2r[r1->rpo] == r1 && r1->rpo < me)
d = rpolca(idom, d, r1->rpo);
idom[i] = d;
}
for(i = 0; i < nr; i++) {
r1 = rpo2r[i];
r1->loop++;
if(r1->p2 != nil && loophead(idom, r1))
loopmark(rpo2r, i, r1);
}
free(idom);
}
Flow*
uniqp(Flow *r)
{
Flow *r1;
r1 = r->p1;
if(r1 == nil) {
r1 = r->p2;
if(r1 == nil || r1->p2link != nil)
return nil;
} else
if(r->p2 != nil)
return nil;
return r1;
}
Flow*
uniqs(Flow *r)
{
Flow *r1;
r1 = r->s1;
if(r1 == nil) {
r1 = r->s2;
if(r1 == nil)
return nil;
} else
if(r->s2 != nil)
return nil;
return r1;
}

View File

@ -2,5 +2,39 @@
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
typedef struct Flow Flow;
typedef struct Graph Graph;
struct Flow {
Prog* prog; // actual instruction
Flow* p1; // predecessors of this instruction: p1,
Flow* p2; // and then p2 linked though p2link.
Flow* p2link;
Flow* s1; // successors of this instruction (at most two: s1 and s2).
Flow* s2;
Flow* link; // next instruction in function code
int32 active; // usable by client
int32 rpo; // reverse post ordering
uint16 loop; // x5 for every loop
uchar refset; // diagnostic generated
};
struct Graph
{
Flow* start;
int num;
// After calling flowrpo, rpo lists the flow nodes in reverse postorder,
// and each non-dead Flow node f has g->rpo[f->rpo] == f.
Flow** rpo;
};
void fixjmp(Prog*);
Graph* flowstart(Prog*, int);
void flowrpo(Graph*);
void flowend(Graph*);
int noreturn(Prog*);
Flow* uniqp(Flow*);
Flow* uniqs(Flow*);