Extend #decode: to support decoding of multiple instructions

This commit extends `AcProcessorDescription class >> #decode:` to
support decoding of multiple instructions from an byte array (for now
only for fixed-width instructions). This is useful to decode a chunk
of binary code at once.

src/ArchC-Core/AcProcessorDescription.class.st

@@ -153,10 +153,16 @@ AcProcessorDescription >> decodeBits: aBitVector [
 AcProcessorDescription >> decodeableFormFor: code [
 	self hasConstantInstructionWidth ifTrue: [
 		(code isKindOf: ByteArray)"Sigh, Pharo has no #isByteArray"
-			ifTrue: [ 
-				code size == (self constantInstructionWidth // 8) 
-					ifFalse: [ self error: 'Invalid bytes (too few or too much)' ].
-				^code toBitVectorEndian: self endian ].
+			ifTrue: [
+				| bitsPerInsn bytesPerInsn bvs |
+
+				bitsPerInsn := self constantInstructionWidth.
+				bytesPerInsn := bitsPerInsn // 8.
+				code size == bytesPerInsn
+					ifTrue: [ ^ code toBitVectorEndian: self endian ].
+				(code size \\ bytesPerInsn) ~~ 0
+					ifTrue: [ self error: 'Invalid bytes (too few or too much)' ].
+				^ (1 to: code size // bytesPerInsn) collect: [ :i | code toBitVector: bitsPerInsn endian: self endian startingAt: (i - 1) * bytesPerInsn + 1 ]].
 		(code isCollection and:[code isSequenceable])
 			ifTrue:[ ^code ].
 		^code toBitVector: self constantInstructionWidth

src/ArchC-Core/ByteArray.extension.st

@@ -1,14 +1,28 @@
 Extension { #name : #ByteArray }
 
 { #category : #'*ArchC-Core' }
-ByteArray >> toBitVectorEndian: endian [
-	self assert: self size isPowerOfTwo.
+ByteArray >> toBitVector: xlen endian: endian startingAt: startIndex [
+	self assert: (xlen \\ 8) == 0.
+	self assert: (xlen // 8) isPowerOfTwo.
+
 	endian ifBig: [
-		^ (BitVector concatAll: (self collect: [ :aByte | aByte toBitVector: 8] as: Array)) simplify
+		^ (BitVector concatAll: ((startIndex to: startIndex + (xlen // 8) - 1 by:  1) collect: [ :i | (self at:i) toBitVector: 8] as: Array)) simplify
 	] ifLittle: [
-		^ (BitVector concatAll: (self reverse collect: [ :aByte | aByte toBitVector: 8] as: Array)) simplify
+		^ (BitVector concatAll: ((startIndex + (xlen // 8) - 1 to: startIndex by: -1) collect: [ :i | (self at:i) toBitVector: 8] as: Array)) simplify
 	].
 
+	"
+	#[ 16r0A 16r0B 16r0C 16r0D ] toBitVector: 32 endian: Endian little startingAt: 1
+	#[ 16r0A 16r0B 16r0C 16r0D ] toBitVector: 32 endian: Endian big startingAt: 1
+	"
+
+	"Created: / 18-06-2024 / 22:32:07 / Jan Vrany <jan.vrany@labware.com>"
+]
+
+{ #category : #'*ArchC-Core' }
+ByteArray >> toBitVectorEndian: endian [
+	^ self toBitVector: self size * 8 endian: endian startingAt: 1
+
 	"
 	#[ 16r0A 16r0B 16r0C 16r0D ] toBitVectorEndian: Endian little.
 	#[ 16r0A 16r0B 16r0C 16r0D ] toBitVectorEndian: Endian big.