diff --git a/lib/arm-mes/arm.M1 b/lib/arm-mes/arm.M1
index 3cbe43e9..cc60dbe0 100644
--- a/lib/arm-mes/arm.M1
+++ b/lib/arm-mes/arm.M1
@@ -24,12 +24,29 @@
 # reduced instruction set: r0, r1 (some r2 for shift, r3 for mul, div)
 # FIXME: count instructions
 
+DEFINE R0 0
+DEFINE R1 1
+DEFINE R2 2
+DEFINE R3 3
+DEFINE R7 7
+DEFINE R14 E
+DEFINE PC F
+
+DEFINE IMMEDIATE32BOX 000000ea
+
+# The E means "always".
 #DEFINE add____$i32,(%r0) xx
 #DEFINE add____$i32,(%r1) xx
 #DEFINE add____$i32,0x32(%r0) xx
-DEFINE add____$i8,%r0 0090e2 # adds    r0, r0, #xx
-DEFINE add____$i8,%r1 1091e2 # adds    r1, r1, #xx
-DEFINE add____$i8,%r13 d09de2 # adds    r13, r13, #xx
+#                     020090e0 # adds r0, r0, r2; ADDS = '0' op3 op1 '09' op2 'e0'
+#                     030091e0 # adds r0, r1, r3
+#                     031091e0 # adds r1, r1, r3
+#                     030090e0 # adds r0, r0, r3
+DEFINE add____$i8,%r0   0090e2 # adds r0, r0, #xx; ADDSI = immediate op1 '09' op2 'e2'
+#                       0091e2 # adds r0, r1, #xx; ADDSI = immediate op1 '09' op2 'e2'
+#                       1090e2 # adds r1, r0, #xx; ADDSI = immediate op1 '09' op2 'e2'
+DEFINE add____$i8,%r1   1091e2 # adds    r1, r1, #xx
+DEFINE add____$i8,%r13  d09de2 # adds    r13, r13, #xx
 #DEFINE add____$i8,(%r0) xx
 #DEFINE add____$i8,(%r1) xx
 #DEFINE add____$i8,0x32 xx
@@ -224,7 +241,7 @@ DEFINE ldr____%r0,(%sp,#$i8) 009de5  # ldr r0, [r13+xx]
 DEFINE ldr____%r1,(%sp,#$i8) 109de5  # ldr r1, [r13+xx]
 DEFINE add____%r2,%r0,%r1,lsl#4 012280e0
 DEFINE add____%r2,$i8 2082e2
-DEFINE bl ba
+DEFINE bl eb
 DEFINE b ea
 DEFINE sxtb__%r0,%r0 7000afe6
 DEFINE sxtb__%r1,%r1 7110afe6