add X_ldiw macro

Author: nerdralph

src/macros.inc

@@ -1,5 +1,30 @@
+; Ralph Doncaster public domain AVR assembler macros
 
 .macro GLABEL name
      .global \name
      \name:
 .endm
+
+; in/out require an io register at address < 0x40
+.macro LOAD rd, ioreg
+    .if \ioreg > 0x3F
+    lds \rd, \ioreg
+    .else
+    in \rd, \ioreg
+    .endif
+.endm
+
+.macro STORE ioreg, rr
+    .if \ioreg > 0x3F
+    sts \ioreg, \rr
+    .else
+    out \ioreg, \rr
+    .endif
+.endm
+
+; example: X_ldiw 24, 12345
+.macro X_ldiw rd, K
+    ldi \rd, lo8(\K)
+    ldi (\rd)+1, hi8(\K)
+.endm
+

src/millis.S

@@ -10,6 +10,7 @@
 GLABEL millis_impl
     ldi ZL, lo8(t0_millis)
     ldi ZH, hi8(t0_millis)
+;    X_ldiw 30, t0_millis                ; Z = t0_millis
   _reload:
     ld r22, Z
     ldd r23, Z+1