I am working on a ARM Cortex A15 and using GCC compile (actually integrating it with TI's SYS/BIOS using XDC tools...)
After I enable -ftlo flag, I am having a performance loss about %30, which is a significant value. I am doing simple benchmark tests like pi and prime number calculating and also system dependent procedural tests.
Below are my compile and link flags. Is this amount of downgrade possible without any errors? Is there a possible cause for this? From what I searched through the internet, I come across benchmarks that flto may not improve the performance but I didn't see such a performance loss...
# Compile options.
C_OPTS = -w\
-mcpu=cortex-a15 \
-mtune=cortex-a15 \
-mabi=aapcs \
-mapcs \
-mfpu=neon \
-mfloat-abi=hard \
-O3 \
-flto \
-fno-strict-aliasing \
-fno-delete-null-pointer-checks \
-fno-strict-overflow \
# Linker options.
L_OPTS = -nostartfiles \
-static \
-Wl,--gc-sections \
-Wl,-Map,$(BUILD_DIR)/$(NAME).map \
-mfloat-abi=hard \
-e wbcd_ep \
-flto \
-fuse-linker-plugin \