Hello.
I am trying to use GCC 11.2 on Ubuntu 21.04 (x86_64 Linux hosted cross toolchains, gcc-arm-11.2-2022.02-x86_64-arm-none-eabi.tar.xz) to compile a program for STM32 (Cortex-M).
If I use float in the program, the build fails with an error "internal compiler error: Illegal instruction". If I do not use float, the build succeeds. If I change the toolchain path in Makefile to 10.3, the build succeeds with and without float.
Here is an example of the code I am trying to build:
#include "main.h" int main(void){ float f; while(1){ f = f + 0.1; }; }
And here is my Makefile:
TARGET = firmware DEBUG = 1 OPT = -O2 BUILD_DIR = build C_SOURCES = \ main.c ASM_SOURCES = \ startup.s #Path to GCC10.3 GCC_PATH = ~/soft/gcc-arm-none-eabi/bin #Path to GCC11.2 #GCC_PATH = ~/soft/gcc-arm-11.2-2022.02-x86_64-arm-none-eabi/bin PREFIX = arm-none-eabi- CC = $(GCC_PATH)/$(PREFIX)gcc AS = $(GCC_PATH)/$(PREFIX)gcc -x assembler-with-cpp CP = $(GCC_PATH)/$(PREFIX)objcopy SZ = $(GCC_PATH)/$(PREFIX)size HEX = $(CP) -O ihex BIN = $(CP) -O binary -S CPU = -mcpu=cortex-m7 FPU = -mfpu=fpv5-sp-d16 FLOAT-ABI = -mfloat-abi=hard MCU = $(CPU) -mthumb $(FPU) $(FLOAT-ABI) AS_DEFS = C_DEFS = \ -DSTM32F730xx AS_INCLUDES = C_INCLUDES = \ -ISrc # compile gcc flags ASFLAGS = $(MCU) $(AS_DEFS) $(AS_INCLUDES) $(OPT) -Wall -fdata-sections -ffunction-sections CFLAGS = $(MCU) $(C_DEFS) $(C_INCLUDES) $(OPT) -Wall -fdata-sections -ffunction-sections ifeq ($(DEBUG), 1) CFLAGS += -g -gdwarf-2 endif CFLAGS += -MMD -MP -MF"$(@:%.o=%.d)" LDSCRIPT = linker.ld # libraries LIBS = -lc -lm -lnosys LIBDIR = LDFLAGS = $(MCU) -specs=nano.specs -T$(LDSCRIPT) $(LIBDIR) $(LIBS) -Wl,-Map=$(BUILD_DIR)/$(TARGET).map,--cref -Wl,--gc-sections -Wl,--print-memory-usage # default action: build all all: $(BUILD_DIR)/$(TARGET).elf $(BUILD_DIR)/$(TARGET).hex $(BUILD_DIR)/$(TARGET).bin ####################################### # build the application ####################################### # list of objects OBJECTS = $(addprefix $(BUILD_DIR)/,$(notdir $(C_SOURCES:.c=.o))) vpath %.c $(sort $(dir $(C_SOURCES))) # list of ASM program objects OBJECTS += $(addprefix $(BUILD_DIR)/,$(notdir $(ASM_SOURCES:.s=.o))) vpath %.s $(sort $(dir $(ASM_SOURCES))) $(BUILD_DIR)/%.o: %.c Makefile | $(BUILD_DIR) $(CC) -c $(CFLAGS) -Wa,-a,-ad,-alms=$(BUILD_DIR)/$(notdir $(<:.c=.lst)) $< -o $@ $(BUILD_DIR)/%.o: %.s Makefile | $(BUILD_DIR) $(AS) -c $(CFLAGS) $< -o $@ $(BUILD_DIR)/$(TARGET).elf: $(OBJECTS) Makefile $(CC) $(OBJECTS) $(LDFLAGS) -o $@ $(SZ) $@ $(BUILD_DIR)/%.hex: $(BUILD_DIR)/%.elf | $(BUILD_DIR) $(HEX) $< $@ $(BUILD_DIR)/%.bin: $(BUILD_DIR)/%.elf | $(BUILD_DIR) $(BIN) $< $@ $(BUILD_DIR): mkdir $@ clean: -rm -fR $(BUILD_DIR) -include $(wildcard $(BUILD_DIR)/*.d)
If I try to build with GCC 11.2, I get an error:
main.c:8:17: internal compiler error: Illegal instruction 8 | f = f + 0.1; | ^
If I just change GCC_PATH in Makefile to 10.3, the build succeeds.
Same issue on Cortex-r52 target with
-march=armv8-r -mtune=cortex-r52 -mfpu=vfpv3-d16 -mfloat-abi=hard
it compiles fine with arm-none-eabi-gcc10 and arm-none-eabi-gcc9 but not with new toochain based on gcc 11.2-2022.02 float.c:61:9: internal compiler error: Illegal instruction 61 | float x = 3.4;By the way I tried to compile also with
AArch32 GNU/Linux target with hard float (arm-none-linux-gnueabihf)
And I have the same error with float types
Hi,
Thank you for reporting this issue. This is a known issue that is planned to be fixed in the next release: https://bugs.linaro.org/show_bug.cgi?id=5825
In the meantime, our suggestion would be to switch back to an older version of GCC.
Best Regards,Salman