min/max float

compiler/examples/test.p8

@@ -13,7 +13,7 @@
         ubyte[4] uba = [4,200,10,15]
         word[4] wa = [400,-200,-1000,1500]
         uword[4] uwa = [4000,200,1000,150]
-        float[4] fa = [-2.22, 3.33, -5.55, 1.11]
+        float[6] fa = [-2.22, 3.33, -5.55, 1.11, 9999.99, -999.99]
         c64scr.print("    X=")
         c64scr.print_ub(X)
         c64.CHROUT('\n')
@@ -26,8 +26,8 @@
 ;        word wmax = max(wa)
 ;        uword uwmin = min(uwa)
 ;        uword uwmax = max(uwa)
-;        float fmin = min(fa)
-;        float fmax = max(fa)
+        float fmin = min(fa)
+        float fmax = max(fa)
 
         c64scr.print_b(bmin)
         c64.CHROUT(',')
@@ -46,10 +46,10 @@
 ;        c64scr.print_uw(uwmax)
 ;        c64.CHROUT('\n')
 ;
-;        c64flt.print_f(fmin)
-;        c64.CHROUT(',')
-;        c64flt.print_f(fmax)
-;        c64.CHROUT('\n')
+        c64flt.print_f(fmin)
+        c64.CHROUT(',')
+        c64flt.print_f(fmax)
+        c64.CHROUT('\n')
 
         c64scr.print("    X=")
         c64scr.print_ub(X)

compiler/src/prog8/compiler/target/c64/Commodore64.kt

@@ -12,8 +12,8 @@ import kotlin.math.pow
 
 
 // 5-byte cbm MFLPT format limitations:
-const val FLOAT_MAX_POSITIVE = 1.7014118345e+38
-const val FLOAT_MAX_NEGATIVE = -1.7014118345e+38
+const val FLOAT_MAX_POSITIVE = 1.7014118345e+38         // bytes: 255,127,255,255,255
+const val FLOAT_MAX_NEGATIVE = -1.7014118345e+38        // bytes: 255,255,255,255,255
 
 const val BASIC_LOAD_ADDRESS = 0x0801
 const val RAW_LOAD_ADDRESS = 0xc000

prog8lib/prog8lib.p8

@@ -1206,9 +1206,37 @@ func_max_w	.proc
 		.pend
 		
 func_max_f	.proc
-		dex
-		rts
 		.warn "todo func_max_f"
+		lda  #<_min_float
+		ldy  #>_min_float
+		jsr  c64.MOVFM			; fac1=min(float)
+		lda  #255
+		sta  _cmp_mod+1			; compare using 255 so we keep larger values
+_minmax_entry	jsr  pop_array_and_lengthY
+		stx  SCRATCH_ZPREGX
+		dey
+		sty  SCRATCH_ZPREG
+-		lda  SCRATCH_ZPWORD1
+		ldy  SCRATCH_ZPWORD1+1
+		jsr  c64.FCOMP
+_cmp_mod	cmp  #255			; will be modified
+		bne  +
+		; fac1 is smaller/larger, so store the new value instead
+		lda  SCRATCH_ZPWORD1
+		ldy  SCRATCH_ZPWORD1+1
+		jsr  c64.MOVFM
++		lda  #5
+		clc
+		adc  SCRATCH_ZPWORD1
+		sta  SCRATCH_ZPWORD1
+		bcc  +
+		inc  SCRATCH_ZPWORD1+1
++		ldy  SCRATCH_ZPREG
+		dey
+		sty  SCRATCH_ZPREG
+		bpl  -
+		jmp  push_fac1_as_result
+_min_float	.byte  255,255,255,255,255	; -1.7014118345e+38
 		.pend
 
 pop_array_and_lengthY	.proc
@@ -1276,11 +1304,15 @@ func_min_w	.proc
 		.pend
 		
 func_min_f	.proc
-		dex
-		rts
-		.warn "todo func_min_f"
+		lda  #<_max_float
+		ldy  #>_max_float
+		jsr  c64.MOVFM			; fac1=max(float)
+		lda  #1
+		sta  func_max_f._cmp_mod+1	; compare using 1 so we keep smaller values
+		jmp  func_max_f._minmax_entry
+_max_float	.byte  255,127,255,255,255	; 1.7014118345e+38
 		.pend
-		
+
 
 func_len_str	.proc
 		; -- push length of 0-terminated string on stack