chore: vendor go dependencies

1 files changed, 274 insertions, 0 deletions

diff --git a/vendor/github.com/ebitengine/purego/struct_arm64.go b/vendor/github.com/ebitengine/purego/struct_arm64.go
new file mode 100644
index 0000000..11c36bd
--- /dev/null
+++ b/vendor/github.com/ebitengine/purego/struct_arm64.go
@@ -0,0 +1,274 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: 2024 The Ebitengine Authors
+
+package purego
+
+import (
+	"math"
+	"reflect"
+	"unsafe"
+)
+
+func getStruct(outType reflect.Type, syscall syscall15Args) (v reflect.Value) {
+	outSize := outType.Size()
+	switch {
+	case outSize == 0:
+		return reflect.New(outType).Elem()
+	case outSize <= 8:
+		r1 := syscall.a1
+		if isAllFloats, numFields := isAllSameFloat(outType); isAllFloats {
+			r1 = syscall.f1
+			if numFields == 2 {
+				r1 = syscall.f2<<32 | syscall.f1
+			}
+		}
+		return reflect.NewAt(outType, unsafe.Pointer(&struct{ a uintptr }{r1})).Elem()
+	case outSize <= 16:
+		r1, r2 := syscall.a1, syscall.a2
+		if isAllFloats, numFields := isAllSameFloat(outType); isAllFloats {
+			switch numFields {
+			case 4:
+				r1 = syscall.f2<<32 | syscall.f1
+				r2 = syscall.f4<<32 | syscall.f3
+			case 3:
+				r1 = syscall.f2<<32 | syscall.f1
+				r2 = syscall.f3
+			case 2:
+				r1 = syscall.f1
+				r2 = syscall.f2
+			default:
+				panic("unreachable")
+			}
+		}
+		return reflect.NewAt(outType, unsafe.Pointer(&struct{ a, b uintptr }{r1, r2})).Elem()
+	default:
+		if isAllFloats, numFields := isAllSameFloat(outType); isAllFloats && numFields <= 4 {
+			switch numFields {
+			case 4:
+				return reflect.NewAt(outType, unsafe.Pointer(&struct{ a, b, c, d uintptr }{syscall.f1, syscall.f2, syscall.f3, syscall.f4})).Elem()
+			case 3:
+				return reflect.NewAt(outType, unsafe.Pointer(&struct{ a, b, c uintptr }{syscall.f1, syscall.f2, syscall.f3})).Elem()
+			default:
+				panic("unreachable")
+			}
+		}
+		// create struct from the Go pointer created in arm64_r8
+		// weird pointer dereference to circumvent go vet
+		return reflect.NewAt(outType, *(*unsafe.Pointer)(unsafe.Pointer(&syscall.arm64_r8))).Elem()
+	}
+}
+
+// https://github.com/ARM-software/abi-aa/blob/main/sysvabi64/sysvabi64.rst
+const (
+	_NO_CLASS = 0b00
+	_FLOAT    = 0b01
+	_INT      = 0b11
+)
+
+func addStruct(v reflect.Value, numInts, numFloats, numStack *int, addInt, addFloat, addStack func(uintptr), keepAlive []interface{}) []interface{} {
+	if v.Type().Size() == 0 {
+		return keepAlive
+	}
+
+	if hva, hfa, size := isHVA(v.Type()), isHFA(v.Type()), v.Type().Size(); hva || hfa || size <= 16 {
+		// if this doesn't fit entirely in registers then
+		// each element goes onto the stack
+		if hfa && *numFloats+v.NumField() > numOfFloats {
+			*numFloats = numOfFloats
+		} else if hva && *numInts+v.NumField() > numOfIntegerRegisters() {
+			*numInts = numOfIntegerRegisters()
+		}
+
+		placeRegisters(v, addFloat, addInt)
+	} else {
+		keepAlive = placeStack(v, keepAlive, addInt)
+	}
+	return keepAlive // the struct was allocated so don't panic
+}
+
+func placeRegisters(v reflect.Value, addFloat func(uintptr), addInt func(uintptr)) {
+	var val uint64
+	var shift byte
+	var flushed bool
+	class := _NO_CLASS
+	var place func(v reflect.Value)
+	place = func(v reflect.Value) {
+		var numFields int
+		if v.Kind() == reflect.Struct {
+			numFields = v.Type().NumField()
+		} else {
+			numFields = v.Type().Len()
+		}
+		for k := 0; k < numFields; k++ {
+			flushed = false
+			var f reflect.Value
+			if v.Kind() == reflect.Struct {
+				f = v.Field(k)
+			} else {
+				f = v.Index(k)
+			}
+			if shift >= 64 {
+				shift = 0
+				flushed = true
+				if class == _FLOAT {
+					addFloat(uintptr(val))
+				} else {
+					addInt(uintptr(val))
+				}
+			}
+			switch f.Type().Kind() {
+			case reflect.Struct:
+				place(f)
+			case reflect.Bool:
+				if f.Bool() {
+					val |= 1
+				}
+				shift += 8
+				class |= _INT
+			case reflect.Uint8:
+				val |= f.Uint() << shift
+				shift += 8
+				class |= _INT
+			case reflect.Uint16:
+				val |= f.Uint() << shift
+				shift += 16
+				class |= _INT
+			case reflect.Uint32:
+				val |= f.Uint() << shift
+				shift += 32
+				class |= _INT
+			case reflect.Uint64:
+				addInt(uintptr(f.Uint()))
+				shift = 0
+				flushed = true
+			case reflect.Int8:
+				val |= uint64(f.Int()&0xFF) << shift
+				shift += 8
+				class |= _INT
+			case reflect.Int16:
+				val |= uint64(f.Int()&0xFFFF) << shift
+				shift += 16
+				class |= _INT
+			case reflect.Int32:
+				val |= uint64(f.Int()&0xFFFF_FFFF) << shift
+				shift += 32
+				class |= _INT
+			case reflect.Int64:
+				addInt(uintptr(f.Int()))
+				shift = 0
+				flushed = true
+			case reflect.Float32:
+				if class == _FLOAT {
+					addFloat(uintptr(val))
+					val = 0
+					shift = 0
+				}
+				val |= uint64(math.Float32bits(float32(f.Float()))) << shift
+				shift += 32
+				class |= _FLOAT
+			case reflect.Float64:
+				addFloat(uintptr(math.Float64bits(float64(f.Float()))))
+				shift = 0
+				flushed = true
+			case reflect.Array:
+				place(f)
+			default:
+				panic("purego: unsupported kind " + f.Kind().String())
+			}
+		}
+	}
+	place(v)
+	if !flushed {
+		if class == _FLOAT {
+			addFloat(uintptr(val))
+		} else {
+			addInt(uintptr(val))
+		}
+	}
+}
+
+func placeStack(v reflect.Value, keepAlive []interface{}, addInt func(uintptr)) []interface{} {
+	// Struct is too big to be placed in registers.
+	// Copy to heap and place the pointer in register
+	ptrStruct := reflect.New(v.Type())
+	ptrStruct.Elem().Set(v)
+	ptr := ptrStruct.Elem().Addr().UnsafePointer()
+	keepAlive = append(keepAlive, ptr)
+	addInt(uintptr(ptr))
+	return keepAlive
+}
+
+// isHFA reports a Homogeneous Floating-point Aggregate (HFA) which is a Fundamental Data Type that is a
+// Floating-Point type and at most four uniquely addressable members (5.9.5.1 in [Arm64 Calling Convention]).
+// This type of struct will be placed more compactly than the individual fields.
+//
+// [Arm64 Calling Convention]: https://github.com/ARM-software/abi-aa/blob/main/sysvabi64/sysvabi64.rst
+func isHFA(t reflect.Type) bool {
+	// round up struct size to nearest 8 see section B.4
+	structSize := roundUpTo8(t.Size())
+	if structSize == 0 || t.NumField() > 4 {
+		return false
+	}
+	first := t.Field(0)
+	switch first.Type.Kind() {
+	case reflect.Float32, reflect.Float64:
+		firstKind := first.Type.Kind()
+		for i := 0; i < t.NumField(); i++ {
+			if t.Field(i).Type.Kind() != firstKind {
+				return false
+			}
+		}
+		return true
+	case reflect.Array:
+		switch first.Type.Elem().Kind() {
+		case reflect.Float32, reflect.Float64:
+			return true
+		default:
+			return false
+		}
+	case reflect.Struct:
+		for i := 0; i < first.Type.NumField(); i++ {
+			if !isHFA(first.Type) {
+				return false
+			}
+		}
+		return true
+	default:
+		return false
+	}
+}
+
+// isHVA reports a Homogeneous Aggregate with a Fundamental Data Type that is a Short-Vector type
+// and at most four uniquely addressable members (5.9.5.2 in [Arm64 Calling Convention]).
+// A short vector is a machine type that is composed of repeated instances of one fundamental integral or
+// floating-point type. It may be 8 or 16 bytes in total size (5.4 in [Arm64 Calling Convention]).
+// This type of struct will be placed more compactly than the individual fields.
+//
+// [Arm64 Calling Convention]: https://github.com/ARM-software/abi-aa/blob/main/sysvabi64/sysvabi64.rst
+func isHVA(t reflect.Type) bool {
+	// round up struct size to nearest 8 see section B.4
+	structSize := roundUpTo8(t.Size())
+	if structSize == 0 || (structSize != 8 && structSize != 16) {
+		return false
+	}
+	first := t.Field(0)
+	switch first.Type.Kind() {
+	case reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Int8, reflect.Int16, reflect.Int32:
+		firstKind := first.Type.Kind()
+		for i := 0; i < t.NumField(); i++ {
+			if t.Field(i).Type.Kind() != firstKind {
+				return false
+			}
+		}
+		return true
+	case reflect.Array:
+		switch first.Type.Elem().Kind() {
+		case reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Int8, reflect.Int16, reflect.Int32:
+			return true
+		default:
+			return false
+		}
+	default:
+		return false
+	}
+}