Document the .risu format in the README

Document the .risu file format in the README, rather than in
three duplicate comments in risugen, arm.risu and thumb.risu.

1 files changed, 0 insertions, 21 deletions

diff --git a/thumb.risu b/thumb.risu
index bf77906..6f31879 100644
--- a/thumb.risu
+++ b/thumb.risu
@@ -13,27 +13,6 @@
 
 .mode thumb
 
-# The format here is:
-# insnname encodingname bitfield ...
-# (and we'll have a trailing bit for specifying constraints later)
-# where each bitfield is either:
-#  var:sz  specifying a variable field of size sz (sz == 0 if :sz omitted)
-#  [01]*   specifying fixed bits
-# Field names beginning 'r' are special as they are assumed to be general
-# purpose registers. They get an automatic "cannot be 13 or 15" (sp/pc)
-# constraint.
-# The optional eval-block at the end of the line (which must be
-# enclosed in braces) is a perl statement to be evaluated and which
-# must return true if the generated statement is OK, false if the
-# generator should retry with a fresh random number. It is evaluated
-# in a context where variables with the same names as the defined
-# variable fields are initialised. The intention is that odd cases
-# where you need to apply some sort of constraint to the generated
-# instruction can be handled via this mechanism.
-# NB that there is no sanity checking that you don't do bad things
-# in the eval block, although there is a basic check for syntax
-# errors and and we bail out if the constraint returns failure too often.
-
 #ADD T1 000 1100 rm:3 rn:3 rd:3
 #ADD T3 11101 01 1000 s rn:4 0 imma:3 rd:4 immb:2 type:2 rm:4