func ginscmp(op gc.Op, t *gc.Type, n1, n2 *gc.Node, likely int) *obj.Prog {
if t.IsInteger() && n1.Op == gc.OLITERAL && n1.Int64() == 0 && n2.Op != gc.OLITERAL {
op = gc.Brrev(op)
n1, n2 = n2, n1
}
var r1, r2, g1, g2 gc.Node
gc.Regalloc(&r1, t, n1)
gc.Regalloc(&g1, n1.Type, &r1)
gc.Cgen(n1, &g1)
gmove(&g1, &r1)
if t.IsInteger() && n2.Op == gc.OLITERAL && n2.Int64() == 0 {
gins(arm.ACMP, &r1, n2)
} else {
gc.Regalloc(&r2, t, n2)
gc.Regalloc(&g2, n1.Type, &r2)
gc.Cgen(n2, &g2)
gmove(&g2, &r2)
gins(optoas(gc.OCMP, t), &r1, &r2)
gc.Regfree(&g2)
gc.Regfree(&r2)
}
gc.Regfree(&g1)
gc.Regfree(&r1)
return gc.Gbranch(optoas(op, t), nil, likely)
}
func ginscmp(op gc.Op, t *gc.Type, n1, n2 *gc.Node, likely int) *obj.Prog {
if t.IsInteger() && n1.Op == gc.OLITERAL && n2.Op != gc.OLITERAL {
// Reverse comparison to place constant last.
op = gc.Brrev(op)
n1, n2 = n2, n1
}
var r1, r2, g1, g2 gc.Node
gc.Regalloc(&r1, t, n1)
gc.Regalloc(&g1, n1.Type, &r1)
gc.Cgen(n1, &g1)
gmove(&g1, &r1)
if t.IsInteger() && gc.Isconst(n2, gc.CTINT) {
ginscon2(optoas(gc.OCMP, t), &r1, n2.Int64())
} else {
gc.Regalloc(&r2, t, n2)
gc.Regalloc(&g2, n1.Type, &r2)
gc.Cgen(n2, &g2)
gmove(&g2, &r2)
gcmp(optoas(gc.OCMP, t), &r1, &r2)
gc.Regfree(&g2)
gc.Regfree(&r2)
}
gc.Regfree(&g1)
gc.Regfree(&r1)
return gc.Gbranch(optoas(op, t), nil, likely)
}
func ginscmp(op gc.Op, t *gc.Type, n1, n2 *gc.Node, likely int) *obj.Prog {
if t.IsInteger() || t.Etype == gc.Tptr {
if (n1.Op == gc.OLITERAL || n1.Op == gc.OADDR && n1.Left.Op == gc.ONAME) && n2.Op != gc.OLITERAL {
// Reverse comparison to place constant (including address constant) last.
op = gc.Brrev(op)
n1, n2 = n2, n1
}
}
// General case.
var r1, r2, g1, g2 gc.Node
// A special case to make write barriers more efficient.
// Comparing the first field of a named struct can be done directly.
base := n1
if n1.Op == gc.ODOT && n1.Left.Type.IsStruct() && n1.Left.Type.Field(0).Sym == n1.Sym {
base = n1.Left
}
if base.Op == gc.ONAME && base.Class != gc.PAUTOHEAP || n1.Op == gc.OINDREG {
r1 = *n1
} else {
gc.Regalloc(&r1, t, n1)
gc.Regalloc(&g1, n1.Type, &r1)
gc.Cgen(n1, &g1)
gmove(&g1, &r1)
}
if n2.Op == gc.OLITERAL && t.IsInteger() || n2.Op == gc.OADDR && n2.Left.Op == gc.ONAME && n2.Left.Class == gc.PEXTERN {
r2 = *n2
} else {
gc.Regalloc(&r2, t, n2)
gc.Regalloc(&g2, n1.Type, &r2)
gc.Cgen(n2, &g2)
gmove(&g2, &r2)
}
gins(optoas(gc.OCMP, t), &r1, &r2)
if r1.Op == gc.OREGISTER {
gc.Regfree(&g1)
gc.Regfree(&r1)
}
if r2.Op == gc.OREGISTER {
gc.Regfree(&g2)
gc.Regfree(&r2)
}
return gc.Gbranch(optoas(op, t), nil, likely)
}
func bgen_float(n *gc.Node, wantTrue bool, likely int, to *obj.Prog) {
nl := n.Left
nr := n.Right
op := n.Op
if !wantTrue {
// brcom is not valid on floats when NaN is involved.
p1 := gc.Gbranch(obj.AJMP, nil, 0)
p2 := gc.Gbranch(obj.AJMP, nil, 0)
gc.Patch(p1, gc.Pc)
// No need to avoid re-genning ninit.
bgen_float(n, true, -likely, p2)
gc.Patch(gc.Gbranch(obj.AJMP, nil, 0), to)
gc.Patch(p2, gc.Pc)
return
}
if gc.Thearch.Use387 {
op = gc.Brrev(op) // because the args are stacked
if op == gc.OGE || op == gc.OGT {
// only < and <= work right with NaN; reverse if needed
nl, nr = nr, nl
op = gc.Brrev(op)
}
var ax, n2, tmp gc.Node
gc.Nodreg(&tmp, nr.Type, x86.REG_F0)
gc.Nodreg(&n2, nr.Type, x86.REG_F0+1)
gc.Nodreg(&ax, gc.Types[gc.TUINT16], x86.REG_AX)
if gc.Simsimtype(nr.Type) == gc.TFLOAT64 {
if nl.Ullman > nr.Ullman {
gc.Cgen(nl, &tmp)
gc.Cgen(nr, &tmp)
gins(x86.AFXCHD, &tmp, &n2)
} else {
gc.Cgen(nr, &tmp)
gc.Cgen(nl, &tmp)
}
gins(x86.AFUCOMPP, &tmp, &n2)
} else {
// TODO(rsc): The moves back and forth to memory
// here are for truncating the value to 32 bits.
// This handles 32-bit comparison but presumably
// all the other ops have the same problem.
// We need to figure out what the right general
// solution is, besides telling people to use float64.
var t1 gc.Node
gc.Tempname(&t1, gc.Types[gc.TFLOAT32])
var t2 gc.Node
gc.Tempname(&t2, gc.Types[gc.TFLOAT32])
gc.Cgen(nr, &t1)
gc.Cgen(nl, &t2)
gmove(&t2, &tmp)
gins(x86.AFCOMFP, &t1, &tmp)
}
gins(x86.AFSTSW, nil, &ax)
gins(x86.ASAHF, nil, nil)
} else {
// Not 387
if !nl.Addable {
nl = gc.CgenTemp(nl)
}
if !nr.Addable {
nr = gc.CgenTemp(nr)
}
var n2 gc.Node
gc.Regalloc(&n2, nr.Type, nil)
gmove(nr, &n2)
nr = &n2
if nl.Op != gc.OREGISTER {
var n3 gc.Node
gc.Regalloc(&n3, nl.Type, nil)
gmove(nl, &n3)
nl = &n3
}
if op == gc.OGE || op == gc.OGT {
// only < and <= work right with NopN; reverse if needed
nl, nr = nr, nl
op = gc.Brrev(op)
}
gins(foptoas(gc.OCMP, nr.Type, 0), nl, nr)
if nl.Op == gc.OREGISTER {
gc.Regfree(nl)
}
gc.Regfree(nr)
}
switch op {
case gc.OEQ:
// neither NE nor P
p1 := gc.Gbranch(x86.AJNE, nil, -likely)
p2 := gc.Gbranch(x86.AJPS, nil, -likely)
gc.Patch(gc.Gbranch(obj.AJMP, nil, 0), to)
gc.Patch(p1, gc.Pc)
gc.Patch(p2, gc.Pc)
case gc.ONE:
// either NE or P
gc.Patch(gc.Gbranch(x86.AJNE, nil, likely), to)
gc.Patch(gc.Gbranch(x86.AJPS, nil, likely), to)
default:
gc.Patch(gc.Gbranch(optoas(op, nr.Type), nil, likely), to)
}
}