Use -flto and -flto-partition only as needed

Author: dhalbert

ports/atmel-samd/Makefile

@@ -124,7 +124,7 @@ $(echo PERIPHERALS_CHIP_FAMILY=$(PERIPHERALS_CHIP_FAMILY))
 ifeq ($(DEBUG), 1)
   CFLAGS += -ggdb3 -Og -Os
   # You may want to disable -flto if it interferes with debugging.
-  CFLAGS += -flto -flto-partition=none
+  CFLAGS += -flto -flto-partition=one
   # You may want to enable these flags to make setting breakpoints easier.
   # CFLAGS += -fno-inline -fno-ipa-sra
   ifeq ($(CHIP_FAMILY), samd21)
@@ -147,10 +147,11 @@ else
     CFLAGS += -finline-limit=$(CFLAGS_INLINE_LIMIT)
   endif
 
-  CFLAGS += -flto -flto-partition=none
+  CFLAGS += -flto
 
   ifeq ($(CIRCUITPY_FULL_BUILD),0)
     CFLAGS += --param inline-unit-growth=15 --param max-inline-insns-auto=20
+    CFLAGS += -flto-partition=one
   endif
 
   ifdef CFLAGS_BOARD
@@ -168,6 +169,7 @@ CFLAGS += \
 	-msoft-float \
 	-mfloat-abi=soft \
 	-DSAMD21
+        -flto-partition=one
 endif
 ifeq ($(CHIP_FAMILY), samd51)
 CFLAGS += \

ports/nrf/Makefile

@@ -91,7 +91,7 @@ ifeq ($(DEBUG), 1)
 else
   OPTIMIZATION_FLAGS ?= -O2 -fno-inline-functions
   CFLAGS += -DNDEBUG -ggdb3
-  CFLAGS += -flto -flto-partition=none
+  # If -flto is needed, give it in OPTIMIZATION_FLAGS per board
 endif
 
 ifeq ($(NRF_DEBUG_PRINT), 1)

ports/nrf/boards/bluemicro833/mpconfigboard.mk

@@ -50,4 +50,4 @@ SUPEROPT_GC = 0
 SUPEROPT_VM = 0
 
 # Override optimization to keep binary small
-OPTIMIZATION_FLAGS = -Os
+OPTIMIZATION_FLAGS = -Os -flto -flto-partition=one

ports/nrf/boards/microbit_v2/mpconfigboard.mk

@@ -30,6 +30,6 @@ CIRCUITPY_USB = 0
 MICROPY_PY_ASYNC_AWAIT = 0
 
 # Override optimization to keep binary small
-OPTIMIZATION_FLAGS = -Os
+OPTIMIZATION_FLAGS = -Os -flto -flto-partition=one
 SUPEROPT_VM = 0
 SUPEROPT_GC = 0

ports/nrf/boards/pca10100/mpconfigboard.mk

@@ -40,4 +40,4 @@ SUPEROPT_GC = 0
 SUPEROPT_VM = 0
 
 # Override optimization to keep binary small
-OPTIMIZATION_FLAGS = -Os
+OPTIMIZATION_FLAGS = -Os -flto -flto-partition=one

ports/nrf/boards/simmel/mpconfigboard.mk

@@ -48,6 +48,6 @@ CIRCUITPY_ZLIB = 0
 #CIRCUITPY_ENABLE_MPY_NATIVE = 1
 
 # Override optimization to keep binary small
-OPTIMIZATION_FLAGS = -Os
+OPTIMIZATION_FLAGS = -Os -flto -flto-partition=one
 SUPEROPT_VM = 0
 SUPEROPT_GC = 0