[dev.power64] cmd/9g: implement zerorange

LGTM=rsc
R=rsc, iant
CC=golang-codereviews
https://golang.org/cl/121540043

diff --git a/src/cmd/9g/ggen.c b/src/cmd/9g/ggen.c
index 999b630faa22d3d06c067a67b6cf15e0c9ee1e45..09f51536a52c9b6f2fe4809aef1580112473b7e9 100644 (file)
--- a/src/cmd/9g/ggen.c
+++ b/src/cmd/9g/ggen.c
@@ -9,13 +9,13 @@
 #include "gg.h"
 #include "opt.h"
 
-//static Prog *appendpp(Prog*, int, int, vlong, int, vlong);
-static Prog *zerorange(Prog *p, vlong frame, vlong lo, vlong hi, uint32 *ax);
+static Prog *appendpp(Prog *p, int as, int ftype, int freg, vlong foffset, int ttype, int treg, vlong toffset);
+static Prog *zerorange(Prog *p, vlong frame, vlong lo, vlong hi);
 
 void
 defframe(Prog *ptxt)
 {
-       uint32 frame, r0;
+       uint32 frame;
        Prog *p;
        vlong hi, lo;
        NodeList *l;
@@ -34,7 +34,6 @@ defframe(Prog *ptxt)
        // when it looks for pointers.
        p = ptxt;
        lo = hi = 0;
-       r0 = 0;
        // iterate through declarations - they are sorted in decreasing xoffset order.
        for(l=curfn->dcl; l != nil; l = l->next) {
                n = l->n;
@@ -51,43 +50,69 @@ defframe(Prog *ptxt)
                        continue;
                }
                // zero old range
-               p = zerorange(p, frame, lo, hi, &r0);
+               p = zerorange(p, frame, lo, hi);
 
                // set new range
                hi = n->xoffset + n->type->width;
                lo = n->xoffset;
        }
        // zero final range
-       zerorange(p, frame, lo, hi, &r0);
+       zerorange(p, frame, lo, hi);
 }
 
 static Prog*
-zerorange(Prog *p, vlong frame, vlong lo, vlong hi, uint32 *r0)
+zerorange(Prog *p, vlong frame, vlong lo, vlong hi)
 {
-       vlong cnt/*, i*/;
+       vlong cnt, i;
+       Prog *p1;
+       Node *f;
 
        cnt = hi - lo;
        if(cnt == 0)
                return p;
-       fprint(2, "zerorange TODO: %P, frame:%lld, lo:%lld, hi:%lld, r0: %p (%d)\n", p, frame, lo, hi, r0, *r0);
+       if(cnt < 4*widthptr) {
+               for(i = 0; i < cnt; i += widthptr)
+                       p = appendpp(p, AMOVD, D_REG, REGZERO, 0, D_OREG, REGSP, 8+frame+lo+i);
+       } else if(cnt <= 128*widthptr) {
+               p = appendpp(p, AADD, D_CONST, NREG, 8+frame+lo-8, D_REG, REGRT1, 0);
+               p->reg = REGSP;
+               p = appendpp(p, ADUFFZERO, D_NONE, NREG, 0, D_OREG, NREG, 0);
+               f = sysfunc("duffzero");
+               naddr(f, &p->to, 1);
+               afunclit(&p->to, f);
+               p->to.offset = 4*(128-cnt/widthptr);
+       } else {
+               p = appendpp(p, AMOVD, D_CONST, NREG, 8+frame+lo-8, D_REG, REGTMP, 0);
+               p = appendpp(p, AADD, D_REG, REGTMP, 0, D_REG, REGRT1, 0);
+               p->reg = REGSP;
+               p = appendpp(p, AMOVD, D_CONST, NREG, cnt, D_REG, REGTMP, 0);
+               p = appendpp(p, AADD, D_REG, REGTMP, 0, D_REG, REGRT2, 0);
+               p->reg = REGRT1;
+               p1 = p = appendpp(p, AMOVDU, D_REG, REGZERO, 0, D_OREG, REGRT1, widthptr);
+               p = appendpp(p, ACMP, D_REG, REGRT1, 0, D_REG, REGRT2, 0);
+               p = appendpp(p, ABNE, D_NONE, NREG, 0, D_BRANCH, NREG, 0);
+               patch(p, p1);
+       }
        return p;
 }
 
-/*static*/ Prog*
-appendpp(Prog *p, int as, int ftype, vlong foffset, int ttype, vlong toffset)
+static Prog*
+appendpp(Prog *p, int as, int ftype, int freg, vlong foffset, int ttype, int treg, vlong toffset)
 {
        Prog *q;
-       q = mal(sizeof(*q));    
-       clearp(q);      
-       q->as = as;     
-       q->lineno = p->lineno;  
-       q->from.type = ftype;   
-       q->from.offset = foffset;       
-       q->to.type = ttype;     
-       q->to.offset = toffset; 
-       q->link = p->link;      
-       p->link = q;    
-       return q;       
+       q = mal(sizeof(*q));
+       clearp(q);
+       q->as = as;
+       q->lineno = p->lineno;
+       q->from.type = ftype;
+       q->from.reg = freg;
+       q->from.offset = foffset;
+       q->to.type = ttype;
+       q->to.reg = treg;
+       q->to.offset = toffset;
+       q->link = p->link;
+       p->link = q;
+       return q;
 }
 
 // Sweep the prog list to mark any used nodes.