From 863a5c1734f9c6d4da43c1b3f3f9b528d7c8dcf1 Mon Sep 17 00:00:00 2001
From: Glenn Ruben Bakke <glennbakke@gmail.com>
Date: Tue, 18 Jul 2017 00:18:05 +0200
Subject: [PATCH] nrf: Add support for floating point on nrf52 targets.

Duplicating pattern for detecting location of libm, libc and libgcc
from teensy port. Activating MICROPY_FLOAT_IMPL (FLOAT) for nrf52 targets
and adding libs into the compile. For nrf51 targets it is still set to
NONE as code grows to much (about 30k).

Some numbers on flash use if MICROPY_FLOAT_IMPL is set to
MICROPY_FLOAT_IMPL_FLOAT and math libraries are enabled (lgcc, lc, lm).

nrf51:
======

without float support:
   text	   data	    bss	    dec	    hex	filename
 144088	    260	  30020	 174368	  2a920	build-pca10028/firmware.elf

with float support:
   text	   data	    bss	    dec	    hex	filename
 176228	   1336	  30020	 207584	  32ae0	build-pca10028/firmware.elf

nrf52:
======

without float support:
   text	   data	    bss	    dec	    hex	filename
 142040	    356	  36236	 178632	  2b9c8	build-pca10040/firmware.elf

with float support:
   text	   data	    bss	    dec	    hex	filename
 165068	   1436	  36236	 202740	  317f4	build-pca10040/firmware.elf
---
 nrf/Makefile       | 12 +++++++++++-
 nrf/mpconfigport.h |  5 +++++
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/nrf/Makefile b/nrf/Makefile
index 83ed917c52..1b0a7c655b 100644
--- a/nrf/Makefile
+++ b/nrf/Makefile
@@ -90,7 +90,17 @@ CFLAGS += -Os -DNDEBUG
 LDFLAGS += -Os
 endif
 
-LIBS += \
+LIBS = \
+
+ifeq ($(MCU_VARIANT), nrf52)
+LIBM_FILE_NAME   = $(shell $(CC) $(CFLAGS) -print-file-name=libm.a)
+LIBC_FILE_NAME   = $(shell $(CC) $(CFLAGS) -print-file-name=libc.a)
+LIBGCC_FILE_NAME = $(shell $(CC) $(CFLAGS) -print-libgcc-file-name)
+
+LIBS += -L $(dir $(LIBM_FILE_NAME)) -lm
+LIBS += -L $(dir $(LIBC_FILE_NAME)) -lc
+LIBS += -L $(dir $(LIBGCC_FILE_NAME)) -lgcc
+endif
 
 SRC_LIB = $(addprefix lib/,\
 	libc/string0.c \
diff --git a/nrf/mpconfigport.h b/nrf/mpconfigport.h
index 4c437f0232..e90c5a4ccd 100644
--- a/nrf/mpconfigport.h
+++ b/nrf/mpconfigport.h
@@ -45,7 +45,12 @@
 #define MICROPY_REPL_AUTO_INDENT    (1)
 #define MICROPY_ENABLE_SOURCE_LINE  (0)
 #define MICROPY_LONGINT_IMPL        (MICROPY_LONGINT_IMPL_MPZ)
+#if NRF51
 #define MICROPY_FLOAT_IMPL          (MICROPY_FLOAT_IMPL_NONE)
+#else
+#define MICROPY_FLOAT_IMPL          (MICROPY_FLOAT_IMPL_FLOAT)
+#endif
+
 #define MICROPY_OPT_COMPUTED_GOTO   (0)
 #define MICROPY_OPT_CACHE_MAP_LOOKUP_IN_BYTECODE (0)
 #define MICROPY_OPT_MPZ_BITWISE     (0)