Merge branch 'develop-0.18' of https://github.com/catseye/SixtyPical into inconsistent-initialization

HISTORY.md

@@ -13,7 +13,8 @@ History of SixtyPical
 *   When the range of a location is known, `inc` and `dec`
     on it will usually shift the known instead of invalidating it.
 *   `cmp` instruction can now perform a 16-bit unsigned comparison
-    of `word` memory locations (at the cost of trashing `a`.)
+    of `word` memory locations and `word` literals (at the cost of
+    trashing the `a` register.)
 *   Fixed pathological memory use in the lexical scanner - should
     be much less inefficient now when parsing large source files.
 *   Reorganized the examples in `eg/rudiments/` to make them

eg/rudiments/cmp-litword.60p

@@ -0,0 +1,64 @@
+// Include `support/${PLATFORM}.60p` before this source
+// Should print ENGGL
+
+word w1
+
+define main routine
+  outputs w1
+  trashes a, x, y, z, n, c, v
+{
+    copy 4000, w1
+
+    cmp w1, 4000
+    if z {
+        ld a, 69  // E
+        call chrout
+    } else {
+        ld a, 78  // N
+        call chrout
+    }
+
+    copy 4000, w1
+
+    cmp w1, 4001
+    if z {
+        ld a, 69  // E
+        call chrout
+    } else {
+        ld a, 78  // N
+        call chrout
+    }
+
+    copy 20002, w1
+
+    cmp w1, 20001 // 20002 >= 20001
+    if c {
+        ld a, 71  // G
+        call chrout
+    } else {
+        ld a, 76  // L
+        call chrout
+    }
+
+    copy 20001, w1
+
+    cmp w1, 20001 // 20001 >= 20001
+    if c {
+        ld a, 71  // G
+        call chrout
+    } else {
+        ld a, 76  // L
+        call chrout
+    }
+
+    copy 20000, w1
+
+    cmp w1, 20001 // 20000 < 20001
+    if c {
+        ld a, 71  // G
+        call chrout
+    } else {
+        ld a, 76  // L
+        call chrout
+    }
+}

eg/rudiments/example.60p

@@ -1,14 +1,43 @@
 byte lives
 
+byte table[16] hexchars : "0123456789ABCDEF"
+
+define prbyte routine
+  inputs a, hexchars
+  trashes a, z, n, c, v
+{
+    save x {
+        save a {
+            st off, c
+            shr a
+            shr a
+            shr a
+            shr a
+            and a, 15
+            ld x, a
+            ld a, hexchars + x
+            call chrout
+        }
+        save a {
+            and a, 15
+            ld x, a
+            ld a, hexchars + x
+            call chrout
+        }
+    }
+}
+
 define main routine
-  inputs lives
+  inputs lives, hexchars
   outputs lives
   trashes a, x, z, n, c, v
-  {
-      ld a, 0
-      st a, lives
-      ld x, lives
-      st off, c
-      add x, 1
-      st x, lives
-  }
+{
+    ld a, 0
+    st a, lives
+    ld x, lives
+    st off, c
+    inc x
+    st x, lives
+    ld a, lives
+    call prbyte
+}

eg/rudiments/if.60p

@@ -1,12 +0,0 @@
-define main routine
-  inputs a
-  outputs a
-  trashes z, n, c
-{
-    cmp a, 42
-    if z {
-        ld a, 7
-    } else {
-        ld a, 23
-    }
-}

eg/rudiments/word-table.60p

@@ -1,16 +1,41 @@
+// Include `support/${PLATFORM}.60p` before this source
+// Should print YY
+
 word one
 word table[256] many
 
 define main routine
   inputs one, many
   outputs one, many
-  trashes a, x, y, n, z
+  trashes a, x, y, c, n, z
 {
     ld x, 0
-    ld y, 0
+    ld y, 1
     copy 777, one
     copy one, many + x
+    copy 888, one
     copy one, many + y
+
+    ld x, 1
+    ld y, 0
+
     copy many + x, one
+    cmp one, 888
+    if z {
+        ld a, 89
+        call chrout
+    } else {
+        ld a, 78
+        call chrout
+    }
+
     copy many + y, one
+    cmp one, 777
+    if z {
+        ld a, 89
+        call chrout
+    } else {
+        ld a, 78
+        call chrout
+    }
 }

src/sixtypical/compiler.py

@@ -402,6 +402,16 @@ class Compiler(object):
             self.emitter.emit(CMP(Absolute(Offset(src_label, 1))))
             self.emitter.resolve_label(end_label)
             return
+        if isinstance(src, ConstantRef) and src.type == TYPE_WORD:
+            dest_label = self.get_label(dest.name)
+            self.emitter.emit(LDA(Absolute(dest_label)))
+            self.emitter.emit(CMP(Immediate(Byte(src.low_byte()))))
+            end_label = Label('end_label')
+            self.emitter.emit(BNE(Relative(end_label)))
+            self.emitter.emit(LDA(Absolute(Offset(dest_label, 1))))
+            self.emitter.emit(CMP(Immediate(Byte(src.high_byte()))))
+            self.emitter.resolve_label(end_label)
+            return
         cls = {
             'a': CMP,
             'x': CPX,

tests/SixtyPical Analysis.md

@@ -1207,6 +1207,28 @@ Some rudimentary tests for `cmp`.
     | }
     ? UnmeaningfulReadError: zb
 
+`cmp` can compare against a literal word.
+
+    | word za
+    | 
+    | define main routine
+    |   inputs za
+    |   trashes a, z, c, n
+    | {
+    |     cmp za, 4000
+    | }
+    = ok
+
+    | word za
+    | 
+    | define main routine
+    |   inputs za
+    |   trashes z, c, n
+    | {
+    |     cmp za, 4000
+    | }
+    ? ForbiddenWriteError: a
+
 ### and ###
 
 Some rudimentary tests for `and`.

tests/SixtyPical Compilation.md

@@ -395,15 +395,21 @@ Compiling 16-bit `cmp`.
     |   trashes a, z, c, n
     | {
     |     cmp za, zb
+    |     cmp za, 4000
     | }
     = $080D   LDA $EA61
-    = $0810   CMP $081C
+    = $0810   CMP $0828
     = $0813   BNE $081B
     = $0815   LDA $EA62
-    = $0818   CMP $081D
-    = $081B   RTS
-    = $081C   .byte $BB
-    = $081D   .byte $0B
+    = $0818   CMP $0829
+    = $081B   LDA $EA61
+    = $081E   CMP #$A0
+    = $0820   BNE $0827
+    = $0822   LDA $EA62
+    = $0825   CMP #$0F
+    = $0827   RTS
+    = $0828   .byte $BB
+    = $0829   .byte $0B
 
 Compiling `if`.