Hi All,
I compile the following code with mips-elf-gcc 4.3.2:
---------------------------------------------------------
unsigned long long shift(unsigned long long x, unsigned int n)
{
return x << n;
}
---------------------------------------------------------
$mips-elf-gcc -EL -Os -G0 -mips32r2 -fno-pic -fno-builtin
-mno-abicalls -c -o a.o skull.c
$mips-elf-objdump -r -S a.o
a.o: file format elf32-littlemips
Disassembly of section .text:
00000000 <shift>:
0: 27bdffe8 addiu sp,sp,-24
4: afbf0014 sw ra,20(sp)
8: 0c000000 jal 0 <shift>
8: R_MIPS_26 __ashldi3
c: 00000000 nop
10: 8fbf0014 lw ra,20(sp)
14: 03e00008 jr ra
18: 27bd0018 addiu sp,sp,24
But, with an older version 3.4.0, I get totally different results:
$mips-elf-gcc -EL -Os -G0 -mips32r2 -fno-pic -fno-builtin
-mno-abicalls -c -o a.o skull.c
$mips-elf-objdump -r -S a.o
a.o: file format elf32-littlemips
Disassembly of section .text:
00000000 <shift>:
0: 00063e80 sll a3,a2,0x1a
4: 04e10004 bgez a3,18 <shift+0x18>
8: 00000000 nop
c: 00c41804 sllv v1,a0,a2
10: 10000007 b 30 <shift+0x30>
14: 00001021 move v0,zero
18: 10e00004 beqz a3,2c <shift+0x2c>
1c: 00c51804 sllv v1,a1,a2
20: 00063823 negu a3,a2
24: 00e43806 srlv a3,a0,a3
28: 00671825 or v1,v1,a3
2c: 00c41004 sllv v0,a0,a2
30: 03e00008 jr ra
34: 00000000 nop
__ashldi3 seems to be an built-in function, but the option
-fno-builtin does not suppress it.
How can I inform gcc not to refer to the function __ashldi3 since
there are no libgcc, libc and libe available in this distribution of
gcc.
Best Regards,
PRC
June 8, 2009
