From abc642973db46fbce7494d34ea0ef2539b339be0 Mon Sep 17 00:00:00 2001
From: Damien George <damien.p.george@gmail.com>
Date: Sat, 30 Nov 2019 23:03:09 +1100
Subject: [PATCH] py/dynruntime: Add support for float API to make/get floats.

We don't want to add a feature flag to .mpy files that indicate float
support because it will get complex and difficult to use.  Instead the .mpy
is built using whatever precision it chooses (float or double) and the
native glue API will convert between this choice and what the host runtime
actually uses.
---
 py/dynruntime.h  | 16 ++++++++++++++++
 py/dynruntime.mk | 10 ++++++++++
 tools/mpy_ld.py  |  2 +-
 3 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/py/dynruntime.h b/py/dynruntime.h
index 34cf6010c4..a83aa905c1 100644
--- a/py/dynruntime.h
+++ b/py/dynruntime.h
@@ -190,4 +190,20 @@ static inline void mp_raise_OSError_dyn(int er) {
     nlr_raise(mp_call_function_n_kw(mp_load_global(MP_QSTR_OSError), 1, 0, &args[0]));
 }
 
+/******************************************************************************/
+// Floating point
+
+#define mp_obj_new_float_from_f(f)  (mp_fun_table.obj_new_float_from_f((f)))
+#define mp_obj_new_float_from_d(d)  (mp_fun_table.obj_new_float_from_d((d)))
+#define mp_obj_get_float_to_f(o)    (mp_fun_table.obj_get_float_to_f((o)))
+#define mp_obj_get_float_to_d(o)    (mp_fun_table.obj_get_float_to_d((o)))
+
+#if MICROPY_FLOAT_IMPL == MICROPY_FLOAT_IMPL_FLOAT
+#define mp_obj_new_float(f)         (mp_obj_new_float_from_f((f)))
+#define mp_obj_get_float(o)         (mp_obj_get_float_to_f((o)))
+#elif MICROPY_FLOAT_IMPL == MICROPY_FLOAT_IMPL_DOUBLE
+#define mp_obj_new_float(f)         (mp_obj_new_float_from_d((f)))
+#define mp_obj_get_float(o)         (mp_obj_get_float_to_d((o)))
+#endif
+
 #endif // MICROPY_INCLUDED_PY_DYNRUNTIME_H
diff --git a/py/dynruntime.mk b/py/dynruntime.mk
index b01b80e0dd..8b65745afd 100644
--- a/py/dynruntime.mk
+++ b/py/dynruntime.mk
@@ -46,6 +46,7 @@ ifeq ($(ARCH),x86)
 CROSS =
 CFLAGS += -m32 -fno-stack-protector
 MPY_CROSS_FLAGS += -mcache-lookup-bc
+MICROPY_FLOAT_IMPL ?= double
 
 else ifeq ($(ARCH),x64)
 
@@ -53,12 +54,14 @@ else ifeq ($(ARCH),x64)
 CROSS =
 CFLAGS += -fno-stack-protector
 MPY_CROSS_FLAGS += -mcache-lookup-bc
+MICROPY_FLOAT_IMPL ?= double
 
 else ifeq ($(ARCH),armv7m)
 
 # thumb
 CROSS = arm-none-eabi-
 CFLAGS += -mthumb -mcpu=cortex-m3
+MICROPY_FLOAT_IMPL ?= none
 
 else ifeq ($(ARCH),armv7emsp)
 
@@ -66,6 +69,7 @@ else ifeq ($(ARCH),armv7emsp)
 CROSS = arm-none-eabi-
 CFLAGS += -mthumb -mcpu=cortex-m4
 CFLAGS += -mfpu=fpv4-sp-d16 -mfloat-abi=hard
+MICROPY_FLOAT_IMPL ?= float
 
 else ifeq ($(ARCH),armv7emdp)
 
@@ -73,23 +77,29 @@ else ifeq ($(ARCH),armv7emdp)
 CROSS = arm-none-eabi-
 CFLAGS += -mthumb -mcpu=cortex-m7
 CFLAGS += -mfpu=fpv5-d16 -mfloat-abi=hard
+MICROPY_FLOAT_IMPL ?= double
 
 else ifeq ($(ARCH),xtensa)
 
 # xtensa
 CROSS = xtensa-lx106-elf-
 CFLAGS += -mforce-l32
+MICROPY_FLOAT_IMPL ?= none
 
 else ifeq ($(ARCH),xtensawin)
 
 # xtensawin
 CROSS = xtensa-esp32-elf-
 CFLAGS +=
+MICROPY_FLOAT_IMPL ?= float
 
 else
 $(error architecture '$(ARCH)' not supported)
 endif
 
+MICROPY_FLOAT_IMPL_UPPER = $(shell echo $(MICROPY_FLOAT_IMPL) | tr '[:lower:]' '[:upper:]')
+CFLAGS += -DMICROPY_FLOAT_IMPL=MICROPY_FLOAT_IMPL_$(MICROPY_FLOAT_IMPL_UPPER)
+
 CFLAGS += $(CFLAGS_EXTRA)
 
 ################################################################################
diff --git a/tools/mpy_ld.py b/tools/mpy_ld.py
index 07105caac9..ec600f9671 100755
--- a/tools/mpy_ld.py
+++ b/tools/mpy_ld.py
@@ -663,7 +663,7 @@ def link_objects(env, native_qstr_vals_len, native_qstr_objs_len):
 
     # Resolve unknown symbols
     mp_fun_table_sec = Section('.external.mp_fun_table', b'', 0)
-    fun_table = {key: 63 + idx
+    fun_table = {key: 67 + idx
         for idx, key in enumerate([
             'mp_type_type',
             'mp_type_str',