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| author | Russ Cox <rsc@golang.org> | 2014-02-19 17:08:55 -0500 |
|---|---|---|
| committer | Russ Cox <rsc@golang.org> | 2014-02-19 17:08:55 -0500 |
| commit | bad327a9d33e61c1c5f9056a2beedec9abe545cc (patch) | |
| tree | 47da2af3d74ac686ce698918c2beb5089698ef83 /src/cmd/5g | |
| parent | 7d216d05e6113b834b231e932696307805abec14 (diff) | |
| download | go-bad327a9d33e61c1c5f9056a2beedec9abe545cc.tar.gz | |
cmd/5g, cmd/8g: zero ambiguously live values on entry
The code here is being restored after its deletion in CL 14430048.
I restored the copy in cmd/6g in CL 56430043 but neglected the
other two.
This is the reason that enabling precisestack only worked on amd64.
LGTM=r
R=r
CC=golang-codereviews
https://codereview.appspot.com/66170043
Diffstat (limited to 'src/cmd/5g')
| -rw-r--r-- | src/cmd/5g/ggen.c | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/src/cmd/5g/ggen.c b/src/cmd/5g/ggen.c index 18431c2bf..b9930f49e 100644 --- a/src/cmd/5g/ggen.c +++ b/src/cmd/5g/ggen.c @@ -9,10 +9,13 @@ #include "gg.h" #include "opt.h" +static Prog* appendpp(Prog*, int, int, int, int32, int, int, int32); + void defframe(Prog *ptxt) { uint32 frame; + Prog *p, *p1; // fill in argument size ptxt->to.type = D_CONST2; @@ -24,6 +27,41 @@ defframe(Prog *ptxt) frame = rnd(maxstksize+maxarg, widthptr); ptxt->to.offset = frame; maxstksize = 0; + + p = ptxt; + if(stkzerosize > 0) { + p = appendpp(p, AMOVW, D_CONST, NREG, 0, D_REG, 0, 0); + p = appendpp(p, AADD, D_CONST, NREG, 4+frame-stkzerosize, D_REG, 1, 0); + p->reg = REGSP; + p = appendpp(p, AADD, D_CONST, NREG, stkzerosize, D_REG, 2, 0); + p->reg = 1; + p1 = p = appendpp(p, AMOVW, D_REG, 0, 0, D_OREG, 1, 4); + p->scond |= C_PBIT; + p = appendpp(p, ACMP, D_REG, 1, 0, D_NONE, 0, 0); + p->reg = 2; + p = appendpp(p, ABNE, D_NONE, NREG, 0, D_BRANCH, NREG, 0); + patch(p, p1); + } +} + +static Prog* +appendpp(Prog *p, int as, int ftype, int freg, int32 foffset, int ttype, int treg, int32 toffset) +{ + Prog *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. |