avoid fallback JSR peek for common case pointer+offset

codeGenCpu6502/src/prog8/codegen/cpu6502/BuiltinFunctionsAsmGen.kt

@@ -1067,6 +1067,8 @@ internal class BuiltinFunctionsAsmGen(private val program: PtProgram,
                     val varname = asmgen.asmVariableName(pointer)
                     asmgen.assignExpressionToRegister(result.second, RegisterOrPair.Y)
                     asmgen.out("  lda  ($varname),y")
+                } else if(addrExpr.operator in arrayOf("+", "-") && addrExpr.left is PtIdentifier) {
+                    readValueFromPointerPlusOrMinOffset(addrExpr.left as PtIdentifier, addrExpr.operator, addrExpr.right, BaseDataType.BOOL)
                 } else fallback()
             }
             else -> fallback()
@@ -1112,6 +1114,8 @@ internal class BuiltinFunctionsAsmGen(private val program: PtProgram,
                         lda  ($varname),y
                         tay
                         txa""")
+                } else if(addrExpr.operator in arrayOf("+", "-") && addrExpr.left is PtIdentifier) {
+                    readValueFromPointerPlusOrMinOffset(addrExpr.left as PtIdentifier, addrExpr.operator, addrExpr.right, BaseDataType.UWORD)
                 } else fallback()
             }
             else -> fallback()
@@ -1129,6 +1133,37 @@ internal class BuiltinFunctionsAsmGen(private val program: PtProgram,
         }
     }
 
+    private fun readValueFromPointerPlusOrMinOffset(ptr: PtIdentifier, operator: String, offset: PtExpression, dt: BaseDataType) {
+        val varname = asmgen.asmVariableName(ptr)
+        asmgen.assignExpressionToRegister(offset, RegisterOrPair.AY)
+        if(operator=="+")
+            asmgen.out("""
+                clc
+                adc  $varname
+                sta  P8ZP_SCRATCH_W1
+                tya
+                adc  $varname+1
+                sta  P8ZP_SCRATCH_W1+1""")
+        else
+            asmgen.out("""
+                sec
+                sbc  $varname
+                sta  P8ZP_SCRATCH_W1
+                tya
+                sbc  $varname+1
+                sta  P8ZP_SCRATCH_W1+1""")
+
+        if (dt.isByteOrBool) {
+            if(asmgen.isTargetCpu(CpuType.CPU65C02)) {
+                asmgen.out("  lda  (P8ZP_SCRATCH_W1)")
+            } else {
+                asmgen.out("  ldy  #0 |  lda  (P8ZP_SCRATCH_W1),y")
+            }
+        } else if(dt.isWord) {
+            asmgen.out("  jsr  prog8_lib.func_peekw.from_scratchW1")
+        } else throw AssemblyError("unsupported type for peek $dt")
+    }
+
     private fun funcPeekL(fcall: PtBuiltinFunctionCall, resultRegister: RegisterOrPair?) {
         // TODO optimize for the simple cases
         asmgen.assignExpressionToRegister(fcall.args[0], RegisterOrPair.AY)

compiler/res/prog8lib/prog8_funcs.asm

@@ -435,6 +435,7 @@ func_peek   .proc
 	; -- read the byte value on the address in AY, into A
 	sta  P8ZP_SCRATCH_W1
 	sty  P8ZP_SCRATCH_W1+1
+from_scratchW1
 	ldy  #0
 	lda  (P8ZP_SCRATCH_W1),y
 	rts
@@ -444,6 +445,7 @@ func_peekw   .proc
 	; -- read the word value on the address in AY, into AY
 	sta  P8ZP_SCRATCH_W1
 	sty  P8ZP_SCRATCH_W1+1
+from_scratchW1
 	ldy  #0
 	lda  (P8ZP_SCRATCH_W1),y
 	pha
@@ -458,6 +460,7 @@ func_peekl   .proc
 	; -- read the ;pmg value on the address in AY, into R0:R1
 	sta  P8ZP_SCRATCH_W1
 	sty  P8ZP_SCRATCH_W1+1
+from_scratchW1
 	ldy  #0
 	lda  (P8ZP_SCRATCH_W1),y
 	sta  cx16.r0

compiler/src/prog8/compiler/astprocessing/CodeDesugarer.kt

@@ -297,6 +297,17 @@ _after:
                     val peek = FunctionCallExpression(IdentifierReference(listOf("peekbool"), arrayIndexedExpression.position), mutableListOf(address), arrayIndexedExpression.position)
                     return listOf(IAstModification.ReplaceNode(arrayIndexedExpression, peek, parent))
                 }
+            } else if(arrayVar.datatype.sub==BaseDataType.LONG) {
+                // use peekl/pokel
+                if(parent is AssignTarget) {
+                    val assignment = parent.parent as Assignment
+                    val args = mutableListOf(address, assignment.value)
+                    val poke = FunctionCallStatement(IdentifierReference(listOf("pokel"), arrayIndexedExpression.position), args, false, arrayIndexedExpression.position)
+                    return listOf(IAstModification.ReplaceNode(assignment, poke, assignment.parent))
+                } else {
+                    val peek = FunctionCallExpression(IdentifierReference(listOf("peekl"), arrayIndexedExpression.position), mutableListOf(address), arrayIndexedExpression.position)
+                    return listOf(IAstModification.ReplaceNode(arrayIndexedExpression, peek, parent))
+                }
             } else if(arrayVar.datatype.sub==BaseDataType.FLOAT) {
                 // use peekf/pokef
                 if(parent is AssignTarget) {

docs/source/todo.rst

@@ -1,12 +1,15 @@
 TODO
 ====
 
+- optimized translation for pokeX and peekX if address =  pointer + uwordoffset.
+
+
 STRUCTS and TYPED POINTERS
 --------------------------
 
 - implement the remaining TODO's in PointerAssignmentsGen.
 - optimize deref in PointerAssignmentsGen: optimize 'forceTemporary' to only use a temporary when the offset is >0
-- optimize the float copying in assignIndexedPointer() (also word?)
+- optimize the float copying in assignIndexedPointer() (also word and long?)
 - optimize augmented assignments to indexed pointer targets like sprptr[2]^^.y++  (these are now not performend in-place but as a regular assignment)
 - implement even more struct instance assignments (via memcopy) in CodeDesugarer (see the TODO) (add to documentation as well, paragraph 'Structs')
 - support @nosplit pointer arrays?
@@ -24,6 +27,8 @@ Future Things and Ideas
   This will break some existing programs that depend on value wrap arounds, but gives more intuitive constant number handling.
   Can give descriptive error message for old syntax that still includes the type name?
 - improve ANTLR grammar with better error handling (as suggested by Qwen AI)
+- add documentation for more library modules instead of just linking to the source code
+- add an Index to the documentation
 - allow memory() to occur in array initializer
 - when a complete block is removed because unused, suppress all info messages about everything in the block being removed
 - fix the line, cols in Position, sometimes they count from 0 sometimes from 1

examples/c64/simplemultiplexer.p8

@@ -36,7 +36,7 @@ irq {
     ; Here is the actual multiplexing routine.
     ; it's a raster irq just after the start of the sprite,
     ; that updates the Y position of all the sprits,
-    ; and registers a new rater irq for that next row of sprites.
+    ; and registers a new raster irq for that next row of sprites.
     ; If the bottom of the screen is reached, it resets the X position of the sprites as well,
     ; and moves the sprites back to the top of the screen.
     sub multiplexer() -> bool {
@@ -51,12 +51,15 @@ irq {
                 first_sprite_X = 0
             sprites.set_sprites_Y(sprites_Y)
             while c64.RASTER != cx16.r2 {
-                ; wait until raster line after sprite has been fully drawn (at least 24 lines down)
+                ; wait until raster line after sprites have been fully drawn (at least 24 lines down)
             }
             sprites.set_sprites_X(first_sprite_X)        ; we can now update the X positions without risk of sprite tearing
             system_irq = true
         } else {
+            ; only set the new Y positions. But it's possible to change other attributes as well ofcourse (colors, x-position, data)
+            ; but raster timing is critical for that if you want to avoid tearing and glitches. Can probably not be done here at this raster position...
             sprites.set_sprites_Y(sprites_Y)
+            c64.SPXY[0]++
         }
 
         sys.set_rasterline(sprites_Y+1)

examples/test.p8

@@ -3,45 +3,17 @@
 
 main {
     sub start() {
-        long @shared lv1 = -9999
+        ^^bool flags
-;        txt.print_uw(lsw(lv1))
+        ^^word words
-;        txt.spc()
+        ^^long longs
-;        txt.print_w(lv1 as word)
-;        txt.spc()
-;        txt.print_uw(lv1 as uword)
-;        txt.spc()
-;        txt.print_b(lv1 as byte)
-;        txt.spc()
-;        txt.print_ub(lv1 as ubyte)
-;        txt.spc()
-;        txt.print_w(msw(lv1 << 8) as word)
-;        txt.spc()
-;        txt.print_w(lsw(lv1 >> 8) as word)
 
 
-        txt.nl()
+        ; TODO optimized translation of the peekX and pokeX calls:
-        txt.nl()
+        if flags[cx16.r0]
-        lv1 = -9876543
+            flags[cx16.r0] = true
-        conv.str_ub0(123)
+        if words[cx16.r0]!=0
-        txt.print(conv.str_l(lv1))
+            words[cx16.r0] = 9990
-        txt.spc()
+        if longs[cx16.r0]!=0
-        txt.print(conv.string_out)
+            longs[cx16.r0] = 999999
-        txt.nl()
-        lv1 = 123456
-        txt.print(conv.str_l(lv1))
-        txt.spc()
-        txt.print(conv.string_out)
-        txt.nl()
-        lv1 = -2147483647
-        txt.print(conv.str_l(lv1))
-        txt.spc()
-        txt.print(conv.string_out)
-        txt.nl()
-        lv1 = 2147483647
-        txt.print(conv.str_l(lv1))
-        txt.spc()
-        txt.print(conv.string_out)
-        txt.nl()
-
     }
 }