examples/returns: demonstrate return types

examples/returns/asm.go

@@ -0,0 +1,66 @@
+// +build ignore
+
+package main
+
+import (
+	. "github.com/mmcloughlin/avo/build"
+	. "github.com/mmcloughlin/avo/operand"
+)
+
+func main() {
+	Package("github.com/mmcloughlin/avo/examples/returns")
+
+	// Multiple unnamed return values.
+	TEXT("Interval", "func(start, size uint64) (uint64, uint64)")
+	start := Load(Param("start"), GP64v())
+	size := Load(Param("size"), GP64v())
+	end := size
+	ADDQ(start, end)
+	Store(start, ReturnIndex(0))
+	Store(end, ReturnIndex(1))
+	RET()
+
+	// Butterfly demonstrates multiple named return values.
+	TEXT("Butterfly", "func(x0, x1 float64) (y0, y1 float64)")
+	x0 := Load(Param("x0"), Xv())
+	x1 := Load(Param("x1"), Xv())
+	y0, y1 := Xv(), Xv()
+	MOVSD(x0, y0)
+	ADDSD(x1, y0)
+	MOVSD(x0, y1)
+	SUBSD(x1, y1)
+	Store(y0, Return("y0"))
+	Store(y1, Return("y1"))
+	RET()
+
+	// Septuple returns an array of seven of the given byte.
+	TEXT("Septuple", "func(byte) [7]byte")
+	b := Load(ParamIndex(0), GP8v())
+	for i := 0; i < 7; i++ {
+		Store(b, ReturnIndex(0).Index(i))
+	}
+	RET()
+
+	// CriticalLine returns the complex value 0.5 + it on Riemann's critical line.
+	TEXT("CriticalLine", "func(t float64) complex128")
+	t := Load(Param("t"), Xv())
+	half := Xv()
+	MOVSD(ConstData("half", F64(0.5)), half)
+	Store(half, ReturnIndex(0).Real())
+	Store(t, ReturnIndex(0).Imag())
+	RET()
+
+	// NewStruct initializes a Struct value.
+	TEXT("NewStruct", "func(w uint16, p [2]float64, q uint64) Struct")
+	w := Load(Param("w"), GP16v())
+	x := Load(Param("p").Index(0), Xv())
+	y := Load(Param("p").Index(1), Xv())
+	q := Load(Param("q"), GP64v())
+	Store(w, ReturnIndex(0).Field("Word"))
+	Store(x, ReturnIndex(0).Field("Point").Index(0))
+	Store(y, ReturnIndex(0).Field("Point").Index(1))
+	Store(q, ReturnIndex(0).Field("Quad"))
+	RET()
+
+	Generate()
+}