gc: inline append when len<cap
issue 1604
R=rsc, bradfitz
CC=golang-dev
https://golang.org/cl/4313062
diff --git a/src/cmd/8g/ggen.c b/src/cmd/8g/ggen.c
index 920725c..2231525 100644
--- a/src/cmd/8g/ggen.c
+++ b/src/cmd/8g/ggen.c
@@ -915,7 +915,7 @@
Node nodes[5];
Node n1, n2, nres, ntemp;
vlong v;
- int i, narg;
+ int i, narg, nochk;
if(n->op != OCALLFUNC)
goto no;
@@ -953,6 +953,7 @@
// len = hb[3] - lb[2] (destroys hb)
n2 = *res;
n2.xoffset += Array_nel;
+ n2.type = types[TUINT32];
if(smallintconst(&nodes[3]) && smallintconst(&nodes[2])) {
v = mpgetfix(nodes[3].val.u.xval) -
@@ -971,6 +972,7 @@
// cap = nel[1] - lb[2] (destroys nel)
n2 = *res;
n2.xoffset += Array_cap;
+ n2.type = types[TUINT32];
if(smallintconst(&nodes[1]) && smallintconst(&nodes[2])) {
v = mpgetfix(nodes[1].val.u.xval) -
@@ -999,6 +1001,7 @@
// ary = old[0] + (lb[2] * width[4]) (destroys old)
n2 = *res;
n2.xoffset += Array_array;
+ n2.type = types[tptr];
if(smallintconst(&nodes[2]) && smallintconst(&nodes[4])) {
v = mpgetfix(nodes[2].val.u.xval) *
@@ -1026,6 +1029,7 @@
sliceslice:
if(!fix64(n->list, narg))
goto no;
+ nochk = n->etype; // skip bounds checking
ntemp.op = OXXX;
if(!sleasy(n->list->n->right)) {
Node *n0;
@@ -1055,11 +1059,13 @@
n2 = nodes[0];
n2.xoffset += Array_nel;
n2.type = types[TUINT32];
- cmpandthrow(&nodes[1], &n2);
+ if(!nochk)
+ cmpandthrow(&nodes[1], &n2);
// ret.nel = old.nel[0]-lb[1];
n2 = nodes[0];
n2.xoffset += Array_nel;
+ n2.type = types[TUINT32];
regalloc(&n1, types[TUINT32], N);
gins(optoas(OAS, types[TUINT32]), &n2, &n1);
@@ -1068,22 +1074,25 @@
n2 = nres;
n2.xoffset += Array_nel;
+ n2.type = types[TUINT32];
gins(optoas(OAS, types[TUINT32]), &n1, &n2);
regfree(&n1);
} else { // old[lb:hb]
- // if(hb[2] > old.cap[0]) goto throw;
n2 = nodes[0];
n2.xoffset += Array_cap;
n2.type = types[TUINT32];
- cmpandthrow(&nodes[2], &n2);
-
- // if(lb[1] > hb[2]) goto throw;
- cmpandthrow(&nodes[1], &nodes[2]);
+ if (!nochk) {
+ // if(hb[2] > old.cap[0]) goto throw;
+ cmpandthrow(&nodes[2], &n2);
+ // if(lb[1] > hb[2]) goto throw;
+ cmpandthrow(&nodes[1], &nodes[2]);
+ }
// ret.len = hb[2]-lb[1]; (destroys hb[2])
n2 = nres;
n2.xoffset += Array_nel;
-
+ n2.type = types[TUINT32];
+
if(smallintconst(&nodes[2]) && smallintconst(&nodes[1])) {
v = mpgetfix(nodes[2].val.u.xval) -
mpgetfix(nodes[1].val.u.xval);
@@ -1102,6 +1111,7 @@
// ret.cap = old.cap[0]-lb[1]; (uses hb[2])
n2 = nodes[0];
n2.xoffset += Array_cap;
+ n2.type = types[TUINT32];
regalloc(&n1, types[TUINT32], &nodes[2]);
gins(optoas(OAS, types[TUINT32]), &n2, &n1);
@@ -1110,12 +1120,14 @@
n2 = nres;
n2.xoffset += Array_cap;
+ n2.type = types[TUINT32];
gins(optoas(OAS, types[TUINT32]), &n1, &n2);
regfree(&n1);
// ret.array = old.array[0]+lb[1]*width[3]; (uses lb[1])
n2 = nodes[0];
n2.xoffset += Array_array;
+ n2.type = types[tptr];
regalloc(&n1, types[tptr], &nodes[1]);
if(smallintconst(&nodes[1]) && smallintconst(&nodes[3])) {
@@ -1135,6 +1147,7 @@
n2 = nres;
n2.xoffset += Array_array;
+ n2.type = types[tptr];
gins(optoas(OAS, types[tptr]), &n1, &n2);
regfree(&n1);
