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6g: avoid too-large immediate constants

R=ken2
CC=golang-dev
https://golang.org/cl/2566042
This commit is contained in:
Russ Cox 2010-10-20 00:40:06 -04:00
parent 97f3a80d93
commit c00f9f49bb
4 changed files with 37 additions and 26 deletions

View File

@ -537,9 +537,7 @@ agen(Node *n, Node *res)
gmove(&n1, &n3);
}
nodconst(&n2, types[tptr], v*w);
gins(optoas(OADD, types[tptr]), &n2, &n3);
ginscon(optoas(OADD, types[tptr]), v*w, &n3);
gmove(&n3, res);
regfree(&n3);
break;
@ -596,8 +594,7 @@ agen(Node *n, Node *res)
p1->from.index = p1->from.type;
p1->from.type = p1->to.type + D_INDIR;
} else {
nodconst(&n1, t, w);
gins(optoas(OMUL, t), &n1, &n2);
ginscon(optoas(OMUL, t), w, &n2);
gins(optoas(OADD, types[tptr]), &n2, &n3);
gmove(&n3, res);
}
@ -621,10 +618,8 @@ agen(Node *n, Node *res)
fatal("agen: bad ONAME class %#x", n->class);
}
cgen(n->heapaddr, res);
if(n->xoffset != 0) {
nodconst(&n1, types[TINT64], n->xoffset);
gins(optoas(OADD, types[tptr]), &n1, res);
}
if(n->xoffset != 0)
ginscon(optoas(OADD, types[tptr]), n->xoffset, res);
break;
case OIND:
@ -633,10 +628,8 @@ agen(Node *n, Node *res)
case ODOT:
agen(nl, res);
if(n->xoffset != 0) {
nodconst(&n1, types[TINT64], n->xoffset);
gins(optoas(OADD, types[tptr]), &n1, res);
}
if(n->xoffset != 0)
ginscon(optoas(OADD, types[tptr]), n->xoffset, res);
break;
case ODOTPTR:
@ -653,8 +646,7 @@ agen(Node *n, Node *res)
gins(ATESTB, nodintconst(0), &n1);
regfree(&n1);
}
nodconst(&n1, types[TINT64], n->xoffset);
gins(optoas(OADD, types[tptr]), &n1, res);
ginscon(optoas(OADD, types[tptr]), n->xoffset, res);
}
break;
}

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@ -123,6 +123,7 @@ Node* nodarg(Type*, int);
void nodreg(Node*, Type*, int);
void nodindreg(Node*, Type*, int);
void gconreg(int, vlong, int);
void ginscon(int, vlong, Node*);
void buildtxt(void);
Plist* newplist(void);
int isfat(Type*);

View File

@ -1292,10 +1292,8 @@ slicearray:
if(smallintconst(&nodes[2]) && smallintconst(&nodes[4])) {
v = mpgetfix(nodes[2].val.u.xval) *
mpgetfix(nodes[4].val.u.xval);
if(v != 0) {
nodconst(&n1, types[tptr], v);
gins(optoas(OADD, types[tptr]), &n1, &nodes[0]);
}
if(v != 0)
ginscon(optoas(OADD, types[tptr]), v, &nodes[0]);
} else {
regalloc(&n1, types[tptr], &nodes[2]);
gmove(&nodes[2], &n1);
@ -1409,10 +1407,8 @@ sliceslice:
gins(optoas(OAS, types[tptr]), &n2, &n1);
v = mpgetfix(nodes[1].val.u.xval) *
mpgetfix(nodes[3].val.u.xval);
if(v != 0) {
nodconst(&n2, types[tptr], v);
gins(optoas(OADD, types[tptr]), &n2, &n1);
}
if(v != 0)
ginscon(optoas(OADD, types[tptr]), v, &n1);
} else {
gmove(&nodes[1], &n1);
if(!smallintconst(&nodes[3]) || mpgetfix(nodes[3].val.u.xval) != 1)

View File

@ -430,11 +430,33 @@ fatal("shouldnt be used");
void
gconreg(int as, vlong c, int reg)
{
Node n1, n2;
Node nr;
nodreg(&nr, types[TINT64], reg);
ginscon(as, c, &nr);
}
/*
* generate
* as $c, n
*/
void
ginscon(int as, vlong c, Node *n2)
{
Node n1, ntmp;
nodconst(&n1, types[TINT64], c);
nodreg(&n2, types[TINT64], reg);
gins(as, &n1, &n2);
if(as != AMOVQ && (c < -1LL<<31 || c >= 1LL<<31)) {
// cannot have 64-bit immediokate in ADD, etc.
// instead, MOV into register first.
regalloc(&ntmp, types[TINT64], N);
gins(AMOVQ, &n1, &ntmp);
gins(as, &ntmp, n2);
regfree(&ntmp);
return;
}
gins(as, &n1, n2);
}
#define CASE(a,b) (((a)<<16)|((b)<<0))