reflect, internal/reflectlite: embed reflectlite types into reflect types

src/internal/reflectlite/endian_big.go

@@ -0,0 +1,36 @@
+//go:build mips
+
+package reflectlite
+
+import "unsafe"
+
+// loadValue loads a value that may or may not be word-aligned. The number of
+// bytes given in size are loaded. The biggest possible size it can load is that
+// of an uintptr.
+func loadValue(ptr unsafe.Pointer, size uintptr) uintptr {
+	loadedValue := uintptr(0)
+	for i := uintptr(0); i < size; i++ {
+		loadedValue <<= 8
+		loadedValue |= uintptr(*(*byte)(ptr))
+		ptr = unsafe.Add(ptr, 1)
+	}
+	return loadedValue
+}
+
+// storeValue is the inverse of loadValue. It stores a value to a pointer that
+// doesn't need to be aligned.
+func storeValue(ptr unsafe.Pointer, size, value uintptr) {
+	// This could perhaps be optimized using bits.ReverseBytes32 if needed.
+	value <<= (unsafe.Sizeof(uintptr(0)) - size) * 8
+	for i := uintptr(0); i < size; i++ {
+		*(*byte)(ptr) = byte(value >> ((unsafe.Sizeof(uintptr(0)) - 1) * 8))
+		ptr = unsafe.Add(ptr, 1)
+		value <<= 8
+	}
+}
+
+// maskAndShift cuts out a part of a uintptr. Note that the offset may not be 0.
+func maskAndShift(value, offset, size uintptr) uintptr {
+	mask := ^uintptr(0) >> ((unsafe.Sizeof(uintptr(0)) - size) * 8)
+	return (uintptr(value) >> ((unsafe.Sizeof(uintptr(0)) - offset - size) * 8)) & mask
+}