https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81907
dongkyun.s at samsung dot com changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|RESOLVED |UNCONFIRMED
Resolution|DUPLICATE |---
--- Comment #7 from dongkyun.s at samsung dot com ---
> Different tuning. Though maybe at -Os should be almost the same except for
> the allowance for using the instructions that are in cortex-a12 rather than
> a9 (for the -mcpu case).
I attached .o files made by '-mtune=cortex-a9' and 'mtune=cortex-a12' (same as
-mcpu case).
Could you describe more in detail about this why memset is added on cortex-a9
or below ?
memset_test_cortex-a9.o: file format elf32-littlearm
Disassembly of section .text:
...
00000022 <test_func>:
22: b51f push {r0, r1, r2, r3, r4, lr}
24: 2210 movs r2, #16
26: 2100 movs r1, #0
28: 4668 mov r0, sp
2a: f7ff fffe bl 0 <memset>
> But really memset is part of the C standard here and you don't use
> -fno-hoisting option;
Which option do you mean? (I'm sorry, but, fno-hoisting is not found)
> Not a bug, see PR 63393 comment #5 for explanation of why.
This is not related to freestanding implementations. Again, option is different
by '-mcpu or -mtune' only.
(1) CFLAGS: -Os -mtune=cortex-a9
(CC) memset_test.o
(CC) main.o
gcc-linaro-6.3.1-2017.02-x86_64_arm-linux-gnueabi/bin/arm-linux-gnueabi-ld
-Bstatic -o memset_test \
memset_test.o main.o \
--start-group
-L/home/dongkyun.s/tmp/memset_test/gcc-linaro-6.3.1-2017.02-x86_64_arm-linux-gnueabi/bin/../lib/gcc/arm-linux-gnueabi/6.3.1
-lgcc --end-group -Map memset_test.map #--gc-sections
memset_test.c:(.text+0x2a): undefined reference to `memset'
(2) CFLAGS: -Os -mtune=cortex-a12
(CC) memset_test.o
(CC) main.o
gcc-linaro-6.3.1-2017.02-x86_64_arm-linux-gnueabi/bin/arm-linux-gnueabi-ld
-Bstatic -o memset_test \
memset_test.o main.o \
--start-group
-L/home/dongkyun.s/tmp/memset_test/gcc-linaro-6.3.1-2017.02-x86_64_arm-linux-gnueabi/bin/../lib/gcc/arm-linux-gnueabi/6.3.1
-lgcc --end-group -Map memset_test.map #--gc-sections
BUILD_TARGETS=memset_test.bin memset_test.txt memset_test.dis memset_test.ver
Build Done!
