mirror of
https://github.com/golang/go
synced 2024-11-12 00:40:23 -07:00
cmd/compile/internal/gc: remove redundant Nod(OXXX, ...) pattern
The pattern
n := Nod(OXXX, nil, nil)
Nodconst(n, ...)
was a leftover from the C days where n must be heap allocated.
No change in benchmarks, none expected as n escapes anyway.
name old time/op new time/op delta
Template 391ms ± 6% 388ms ± 5% ~ (p=0.659 n=20+20)
GoTypes 1.27s ± 1% 1.27s ± 2% ~ (p=0.828 n=18+20)
Compiler 6.16s ± 2% 6.15s ± 1% ~ (p=0.947 n=20+20)
name old alloc/op new alloc/op delta
Template 63.7MB ± 0% 63.7MB ± 0% ~ (p=0.414 n=20+20)
GoTypes 219MB ± 0% 219MB ± 0% ~ (p=0.904 n=20+20)
Compiler 980MB ± 0% 980MB ± 0% +0.00% (p=0.007 n=20+19)
name old allocs/op new allocs/op delta
Template 586k ± 0% 586k ± 0% ~ (p=0.564 n=19+20)
GoTypes 1.80M ± 0% 1.80M ± 0% ~ (p=0.718 n=20+20)
Compiler 7.74M ± 0% 7.74M ± 0% ~ (p=0.358 n=20+20)
The reuse of nc in multiple overlapping scopes in walk.go is the worst.
Change-Id: I4ed6a63f7ffbfff68124ad609f6e3a68d95cbbba
Reviewed-on: https://go-review.googlesource.com/21015
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This commit is contained in:
Dave Cheney
parent
1374515a1c
commit
a4be24cbe6
@ -1405,10 +1405,10 @@ OpSwitch:
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switch t.Etype {
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case TSTRING:
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if Isconst(l, CTSTR) {
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r := Nod(OXXX, nil, nil)
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Nodconst(r, Types[TINT], int64(len(l.Val().U.(string))))
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var r Node
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Nodconst(&r, Types[TINT], int64(len(l.Val().U.(string))))
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r.Orig = n
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n = r
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n = &r
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}
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case TARRAY:
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@ -1418,10 +1418,10 @@ OpSwitch:
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if callrecv(l) { // has call or receive
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break
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}
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r := Nod(OXXX, nil, nil)
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Nodconst(r, Types[TINT], t.Bound)
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var r Node
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Nodconst(&r, Types[TINT], t.Bound)
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r.Orig = n
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n = r
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n = &r
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}
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n.Type = Types[TINT]
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@ -3509,10 +3509,10 @@ func walkdiv(n *Node, init *Nodes) *Node {
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// n1 = nl * magic >> w (HMUL)
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case TUINT8, TUINT16, TUINT32:
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nc := Nod(OXXX, nil, nil)
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var nc Node
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Nodconst(nc, nl.Type, int64(m.Um))
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n1 := Nod(OHMUL, nl, nc)
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Nodconst(&nc, nl.Type, int64(m.Um))
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n1 := Nod(OHMUL, nl, &nc)
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n1 = typecheck(n1, Erv)
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if m.Ua != 0 {
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// Select a Go type with (at least) twice the width.
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@ -3539,24 +3539,24 @@ func walkdiv(n *Node, init *Nodes) *Node {
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n2 := Nod(OADD, conv(n1, twide), conv(nl, twide))
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// shift by m.s
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nc := Nod(OXXX, nil, nil)
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var nc Node
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Nodconst(nc, Types[TUINT], int64(m.S))
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n = conv(Nod(ORSH, n2, nc), nl.Type)
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Nodconst(&nc, Types[TUINT], int64(m.S))
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n = conv(Nod(ORSH, n2, &nc), nl.Type)
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} else {
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// n = n1 >> m.s
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nc := Nod(OXXX, nil, nil)
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var nc Node
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Nodconst(nc, Types[TUINT], int64(m.S))
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n = Nod(ORSH, n1, nc)
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Nodconst(&nc, Types[TUINT], int64(m.S))
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n = Nod(ORSH, n1, &nc)
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}
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// n1 = nl * magic >> w
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case TINT8, TINT16, TINT32:
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nc := Nod(OXXX, nil, nil)
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var nc Node
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Nodconst(nc, nl.Type, m.Sm)
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n1 := Nod(OHMUL, nl, nc)
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Nodconst(&nc, nl.Type, m.Sm)
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n1 := Nod(OHMUL, nl, &nc)
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n1 = typecheck(n1, Erv)
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if m.Sm < 0 {
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// add the numerator.
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@ -3564,16 +3564,16 @@ func walkdiv(n *Node, init *Nodes) *Node {
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}
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// shift by m.s
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nc = Nod(OXXX, nil, nil)
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var ns Node
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Nodconst(nc, Types[TUINT], int64(m.S))
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n2 := conv(Nod(ORSH, n1, nc), nl.Type)
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Nodconst(&ns, Types[TUINT], int64(m.S))
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n2 := conv(Nod(ORSH, n1, &ns), nl.Type)
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// add 1 iff n1 is negative.
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nc = Nod(OXXX, nil, nil)
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var nneg Node
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Nodconst(nc, Types[TUINT], int64(w)-1)
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n3 := Nod(ORSH, nl, nc) // n4 = -1 iff n1 is negative.
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Nodconst(&nneg, Types[TUINT], int64(w)-1)
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n3 := Nod(ORSH, nl, &nneg) // n4 = -1 iff n1 is negative.
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n = Nod(OSUB, n2, n3)
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// apply sign.
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@ -3606,10 +3606,10 @@ func walkdiv(n *Node, init *Nodes) *Node {
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// signed modulo 2^pow is like ANDing
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// with the last pow bits, but if nl < 0,
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// nl & (2^pow-1) is (nl+1)%2^pow - 1.
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nc := Nod(OXXX, nil, nil)
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var nc Node
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Nodconst(nc, Types[Simtype[TUINT]], int64(w)-1)
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n1 := Nod(ORSH, nl, nc) // n1 = -1 iff nl < 0.
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Nodconst(&nc, Types[Simtype[TUINT]], int64(w)-1)
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n1 := Nod(ORSH, nl, &nc) // n1 = -1 iff nl < 0.
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if pow == 1 {
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n1 = typecheck(n1, Erv)
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n1 = cheapexpr(n1, init)
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@ -3617,21 +3617,21 @@ func walkdiv(n *Node, init *Nodes) *Node {
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// n = (nl+ε)&1 -ε where ε=1 iff nl<0.
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n2 := Nod(OSUB, nl, n1)
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nc := Nod(OXXX, nil, nil)
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Nodconst(nc, nl.Type, 1)
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n3 := Nod(OAND, n2, nc)
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var nc Node
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Nodconst(&nc, nl.Type, 1)
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n3 := Nod(OAND, n2, &nc)
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n = Nod(OADD, n3, n1)
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} else {
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// n = (nl+ε)&(nr-1) - ε where ε=2^pow-1 iff nl<0.
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nc := Nod(OXXX, nil, nil)
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var nc Node
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Nodconst(nc, nl.Type, (1<<uint(pow))-1)
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n2 := Nod(OAND, n1, nc) // n2 = 2^pow-1 iff nl<0.
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Nodconst(&nc, nl.Type, (1<<uint(pow))-1)
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n2 := Nod(OAND, n1, &nc) // n2 = 2^pow-1 iff nl<0.
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n2 = typecheck(n2, Erv)
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n2 = cheapexpr(n2, init)
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n3 := Nod(OADD, nl, n2)
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n4 := Nod(OAND, n3, nc)
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n4 := Nod(OAND, n3, &nc)
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n = Nod(OSUB, n4, n2)
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}
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@ -3640,28 +3640,28 @@ func walkdiv(n *Node, init *Nodes) *Node {
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// arithmetic right shift does not give the correct rounding.
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// if nl >= 0, nl >> n == nl / nr
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// if nl < 0, we want to add 2^n-1 first.
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nc := Nod(OXXX, nil, nil)
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var nc Node
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Nodconst(nc, Types[Simtype[TUINT]], int64(w)-1)
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n1 := Nod(ORSH, nl, nc) // n1 = -1 iff nl < 0.
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Nodconst(&nc, Types[Simtype[TUINT]], int64(w)-1)
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n1 := Nod(ORSH, nl, &nc) // n1 = -1 iff nl < 0.
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if pow == 1 {
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// nl+1 is nl-(-1)
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n.Left = Nod(OSUB, nl, n1)
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} else {
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// Do a logical right right on -1 to keep pow bits.
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nc := Nod(OXXX, nil, nil)
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var nc Node
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Nodconst(nc, Types[Simtype[TUINT]], int64(w)-int64(pow))
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n2 := Nod(ORSH, conv(n1, tounsigned(nl.Type)), nc)
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Nodconst(&nc, Types[Simtype[TUINT]], int64(w)-int64(pow))
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n2 := Nod(ORSH, conv(n1, tounsigned(nl.Type)), &nc)
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n.Left = Nod(OADD, nl, conv(n2, nl.Type))
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}
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// n = (nl + 2^pow-1) >> pow
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n.Op = ORSH
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nc = Nod(OXXX, nil, nil)
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Nodconst(nc, Types[Simtype[TUINT]], int64(pow))
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n.Right = nc
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var n2 Node
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Nodconst(&n2, Types[Simtype[TUINT]], int64(pow))
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n.Right = &n2
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n.Typecheck = 0
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}
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@ -3671,21 +3671,21 @@ func walkdiv(n *Node, init *Nodes) *Node {
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break
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}
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nc := Nod(OXXX, nil, nil)
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var nc Node
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if n.Op == OMOD {
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// n = nl & (nr-1)
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n.Op = OAND
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Nodconst(nc, nl.Type, nr.Val().U.(*Mpint).Int64()-1)
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Nodconst(&nc, nl.Type, nr.Val().U.(*Mpint).Int64()-1)
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} else {
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// n = nl >> pow
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n.Op = ORSH
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Nodconst(nc, Types[Simtype[TUINT]], int64(pow))
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Nodconst(&nc, Types[Simtype[TUINT]], int64(pow))
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}
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n.Typecheck = 0
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n.Right = nc
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n.Right = &nc
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}
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goto ret
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