Implement ROMable modules. Add math module.

mp_module_obj_t can now be put in ROM.

Configuration of float type is now similar to longint: can now choose
none, float or double as the implementation.

math module has basic math functions.  For STM port, these are not yet
implemented (they are just stub functions).

1 files changed, 48 insertions, 0 deletions

diff --git a/stm/math.c b/stm/math.c
new file mode 100644
index 000000000..ac680f6b7
--- /dev/null
+++ b/stm/math.c
@@ -0,0 +1,48 @@
+#include <math.h>
+
+// these 2 functions seem to actually work... no idea why
+// replacing with libgcc does not work (probably due to wrong calling conventions)
+double __aeabi_f2d(float x) {
+    // TODO
+    return 0.0;
+}
+
+float __aeabi_d2f(double x) {
+    // TODO
+    return 0.0;
+}
+
+/*
+double sqrt(double x) {
+    // TODO
+    return 0.0;
+}
+*/
+
+float sqrtf(float x) {
+    asm volatile (
+            "vsqrt.f32  %[r], %[x]\n"
+            : [r] "=t" (x)
+            : [x] "t"  (x));
+    return x;
+}
+
+// TODO we need import these functions from some library (eg musl or newlib)
+float powf(float x, float y) { return 0.0; }
+float expf(float x) { return 0.0; }
+float logf(float x) { return 0.0; }
+float log2f(float x) { return 0.0; }
+float log10f(float x) { return 0.0; }
+float coshf(float x) { return 0.0; }
+float sinhf(float x) { return 0.0; }
+float tanhf(float x) { return 0.0; }
+float acoshf(float x) { return 0.0; }
+float asinhf(float x) { return 0.0; }
+float atanhf(float x) { return 0.0; }
+float cosf(float x) { return 0.0; }
+float sinf(float x) { return 0.0; }
+float tanf(float x) { return 0.0; }
+float acosf(float x) { return 0.0; }
+float asinf(float x) { return 0.0; }
+float atanf(float x) { return 0.0; }
+float atan2f(float x, float y) { return 0.0; }