Now running up to the first required kernel call.

If memory address validation is turned off it runs a lot further.

test/codegen/extrwi.dis

@@ -0,0 +1,9 @@
+
+extrwi.o:     file format elf64-powerpc
+
+
+Disassembly of section .text:
+
+0000000082010000 <.text>:
+    82010000:	54 a7 ef 3e 	rlwinm  r7,r5,29,28,31
+    82010004:	4e 80 00 20 	blr

test/codegen/extrwi.s

@@ -0,0 +1,11 @@
+# This is a variant of rlwinmx:
+# extrwi ra,rs,n,b (n > 0) == rlwinm ra,rs,b+n,32-n,31
+
+# REGISTER_IN r5 0x30
+
+# rlwinm r7, r5, 29, 28, 31
+extrwi r7, r5, 4, 25
+
+blr
+# REGISTER_OUT r5 0x30
+# REGISTER_OUT r7 0x06