beginning of a reference libm in C

include/math.h

@@ -37,6 +37,9 @@ float __fastcall__ roundf(float x);              /* C99 */
 /* double trunc(double x); */              /* C99 */
 float __fastcall__ truncf(float x);              /* C99 */
 
+/* double ceil(double x) */
+float ceilf(float x);              /* C99 */
+
 /* beware, this is not standard */
 #ifndef M_PI
 #define M_PI    3.14159265358979323846f

libsrc/Makefile

@@ -176,7 +176,8 @@ endif
 
 SRCDIRS = $(SRCDIR)
 
-SRCDIRS += float/softfloat
+SRCDIRS += float/softfloat \
+	float/softmath
 
 ifeq ($(TARGET),$(filter $(TARGET),$(CBMS)))
   SRCDIRS += cbm

libsrc/float/readme.md

@@ -91,7 +91,7 @@ Related to fp stuff are:
 ### Roadmap
 
 - Test/Fix using the Softfloat lib some more
-- Find some generic math functions that we can use
+- Find some more generic math functions that we can use in softmath
 - When all obvious tests have been created and work OK, we can merge
 
 After the merge, the following things can be done more or less independent from
@@ -140,6 +140,14 @@ NOT WORKING YET:
 
 - float values written as "12.34f" work, but "12.34" does not - should it?
 
+TODO:
+
+- more tests are needed
+    - warnings
+    - errors
+    - register variables
+    - more/all tests should check local/global/register variables
+
 ### Files & Functions
 
 #### assignment.c
@@ -256,27 +264,28 @@ DoConversion        Emit code to convert the given expression to a new type
 ### variants
 
 The floating point support calls library functions for any operations on non
-constant values
+constant values.
 
 #### softfloat
 
 This is a Port of "Berkeley SoftFloat Release 2c". It is currently used by
 default for all targets.
 
-- missing are all math functions (we might port another existing lib for that)
+#### softmath
+
+Contains a collection of math functions, hopefully some day enough to completely
+implement math.h in C. This is currently used by default for all targets.
 
 #### cbmkernal
 
-This is a wrapper to the CBM kernal functions.
-
-- this one is fairly complete, including math functions
-- the only missing function is ftosrsubeax
-  - WANTED: which can be easily added once testcode is found that actually triggers it :)
+This is a wrapper to the CBM kernal functions. This is fairly complete,
+including math functions. To use this, link against c64-fp754kernal.o. The c64
+samples will do this by default.
 
 #### ieee754
 
 This should become a freestanding IEEE754 library, which can completely replace
-the softfloat library.
+the softfloat (and softmath) library.
 
 - basically everything missing except addition/substraction
   - compare functions are missing
@@ -298,7 +307,7 @@ historical float routines by woz :) unfortunately not ieee754
 
 ### runtime functions
 
-these must be available in the runtime library
+These must be available in the runtime library.
 ```
 func        description                       softfloat cbmfp   wozfp   754     codegen.c
 
@@ -330,27 +339,27 @@ ftoseqeax   Test for equal                      *       *       -       -
 ```
 ### math.h functions
 
-these are optional, required for standard libm
+These are optional, required for standard libm.
 ```
-func        description                       softfloat cbmfp   wozfp   754
+func        description                       softmath  cbmfp   wozfp   754
 
-/* C99 */
 float powf(float f, float a)                    -       *       -       -
-float sinf(float s)                             -       *       -       -
-float cosf(float s)                             -       *       -       -
+float sinf(float s)                             *       *       -       -
+float cosf(float s)                             *       *       -       -
 float logf(float x)                             -       *       *       -
 float expf(float x)                             -       *       -       -
 float sqrtf(float x)                            -       *       -       -
 float tanf(float x)                             -       *       -       -
 float atanf(float x)                            -       *       -       -
-float fabsf(float x)                            -       *       -       -
-float roundf(float x)                           -       *       -       -
-float truncf(float x)                           -       *       -       -
+float fabsf(float x)                            *       *       -       -
+float roundf(float x)                           *       *       -       -
+float truncf(float x)                           *       *       -       -
+float ceilf(float x)                            *       -       -       -
 ```
 
 ### extra functions
 
-optional utility functions.
+Optional utility functions.
 ```
 func        description                       softfloat cbmfp   wozfp   754
 

libsrc/float/softmath/readme.txt

@@ -0,0 +1,12 @@
+
+This is a collection of various math related functions found in math.h. All
+functions are single precision (only), and are rather selected for their
+compactness than speed.
+
+STILL MISSING:
+
+float logf(float x)
+float expf(float x)
+float sqrtf(float x)
+float tanf(float x)
+float atanf(float x)

libsrc/float/softmath/softmath-ceilf.c

@@ -0,0 +1,13 @@
+
+#include <math.h>
+
+float ceilf(float x)
+{
+    int n = (int) x;
+
+    if (n >= x) {
+        return n;
+    }
+
+    return n + 1;
+}

libsrc/float/softmath/softmath-cosf.c

@@ -0,0 +1,67 @@
+
+/* nicked from https://github.com/AZHenley/cosine/blob/master/cosine.c */
+
+/*
+MIT License
+
+Copyright (c) 2020 Austin Henley
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+*/
+
+#include <math.h>
+
+#define RUNTERMS    8
+float cosf(float x)
+{
+    int i;
+    int div;
+    float num;
+    float result = 1.0f;
+    float inter = 1.0f;
+    float comp;
+    float den;
+
+    div = (int)(x / M_PI);
+
+    x = x - (div * M_PI);
+
+    num = x * x;
+    for (i = 1; i <= RUNTERMS; i++) {
+        comp = 2.0f * i;
+        den = comp * (comp - 1.0f);
+        inter *= num / den;
+        if (i % 2 == 0) {
+            result += inter;
+        } else {
+            result -= inter;
+        }
+    }
+
+    if (div % 2 != 0) {
+        return result * -1.0f;
+    }
+    return result;
+}
+
+#if 0
+float c(float x) {
+    return sinf(x + (M_PI / 2.0));
+}
+#endif

libsrc/float/softmath/softmath-fabsf.c

@@ -0,0 +1,6 @@
+
+#include <math.h>
+
+float fabsf(float x) {
+    return x < 0.0 ? -x : x;
+}

libsrc/float/softmath/softmath-powf.c

@@ -0,0 +1,7 @@
+
+#include <math.h>
+
+float powf(float x, float y)
+{
+    return expf(x * logf(y));
+}

libsrc/float/softmath/softmath-roundf.c

@@ -0,0 +1,10 @@
+
+#include <math.h>
+
+float roundf(float x)
+{
+    if (x > 0.0f) {
+        return (float)((signed)(x + 0.5f));
+    }
+    return (float)((signed)(x - 0.5f));
+}

libsrc/float/softmath/softmath-sinf.c

@@ -0,0 +1,6 @@
+
+#include <math.h>
+
+float sinf(float x) {
+    return cosf(x - (M_PI / 2.0));
+}

libsrc/float/softmath/softmath-truncf.c

@@ -0,0 +1,7 @@
+
+#include <math.h>
+
+float truncf(float x)
+{
+    return (float)((signed)x);
+}

samples/mathtest.c

@@ -3,6 +3,10 @@
 #include <math.h>
 #include <conio.h>  // for cgetc
 
+#ifdef __SIM6502__
+#define cgetc()
+#endif
+
 char buf[100];
 
 /*
@@ -98,7 +102,7 @@ float roundtruncvals[22] = {
 void roundtruncabs(void)
 {
     int n;
-    printf("round/truncate:\n");
+    printf("round/trunc:\n");
     for (n = 0; n < 21; n++) {
         printf("%12s", _ftostr(buf, roundtruncvals[n]));
         printf("%12s", _ftostr(buf, roundf(roundtruncvals[n])));
@@ -106,10 +110,11 @@ void roundtruncabs(void)
         printf("\n");
     }
     printf("<key>\n"); cgetc();
-    printf("abs:\n");
+    printf("abs/ceil:\n");
     for (n = 0; n < 21; n++) {
         printf("%12s", _ftostr(buf, roundtruncvals[n]));
         printf("%12s", _ftostr(buf, fabsf(roundtruncvals[n])));
+        printf("%12s", _ftostr(buf, ceilf(roundtruncvals[n])));
         printf("\n");
     }
     printf("<key>\n"); cgetc();
@@ -202,6 +207,6 @@ int main(void)
 {
     roundtruncabs();
     sincostanatan();
-    powersqrt();
     logexp();
+    powersqrt();
 }