Thanks Mihai DonÈu. Is there any compiler option where i can disable inlining for all the static functions of a program instead of doing that with __attribute__((noinline)) for each function inside the code. ?
Regards,
--John
--- On Sat, 27/9/08, Mihai Donțu <mihai.dontu@xxxxxxxxx> wrote:
> From: Mihai Donțu <mihai.dontu@xxxxxxxxx>
> Subject: Re: how to avoid default inlining of static functions at O3 ?
> To: gcc-help@xxxxxxxxxxx, fromu2john@xxxxxxxxx
> Date: Saturday, 27 September, 2008, 12:46 AM
> On Friday 26 September 2008, john wrote:
> > Hi,
> > I am using gcc 3.4.6 (gcc version 3.4.6 20060404
> (Red Hat 3.4.6-3))
> > and trying a simple C program which was given at the
> end of this mail along
> > with its assembly code.
> >
> > I am compiling the program using -O3
>
> From gcc info page (function attributes):
> `noinline': This function attribute prevents a
> function from being
> considered for inlining.
>
> __attribute__((noinline)) static void test2();
>
> > /usr/bin/gcc -c -pipe -m32 -D_REENTRANT -fPIC -W
> -Wall -Wextra -O -O3
> > -DSERVER -DMONITORS
> -DHA_KEY='"NONE"' test.c -S -o test.s
> >
> > I see that at optimization level O3, the compiler is
> defaultly inlining my
> > static functions. Is there a way to avoid inlining
> static functions for C
> > programs ?
> >
> >
> > -fno-inline may avoid inlining all functions. There is
> -fno-default-inline,
> > but that is for C++.
> >
> > Thanks for any help in advance,
> > Regards
> > --John
> >
> >
> >
> > #include<stdio.h>
> > void test(int a, int b, int c)
> > {
> > int d;
> > d=a*b*c;
> > printf("%d * %d * %d is
> %d\n",a,b,c,d);
> > }
> >
> >
> >
> > static void test2(int a, int b, int c)
> > {
> > int d;
> > d=a+b+c;
> > printf("%d + %d + %d is
> %d\n",a,b,c,d);
> > }
> >
> > int main(int argc, char *argv[])
> > {
> > test(1,2,3);
> > test2(4,5,6);
> > }
> >
> >
> >
> > .file "test.c"
> > .section
> .rodata.str1.1,"aMS",@
> > progbits,1
> > ..LC0:
> > .string "%d * %d * %d is %d\n"
> > .text
> > .p2align 2,,3
> > ..globl test
> > .type test, @function
> > test:
> > pushl %ebp
> > movl %esp, %ebp
> > pushl %esi
> > movl 8(%ebp), %esi
> > movl 12(%ebp), %ecx
> > movl %esi, %eax
> > pushl %ebx
> > movl 16(%ebp), %edx
> > imull %ecx, %eax
> > subl $12, %esp
> > imull %edx, %eax
> > pushl %eax
> > pushl %edx
> > pushl %ecx
> > call .L2
> > ..L2:
> > popl %ebx
> > addl $_GLOBAL_OFFSET_TABLE_+[.-.L2] , %ebx
> > pushl %esi
> > leal .LC0@GOTOFF(%ebx), %eax
> > pushl %eax
> > call printf@PLT
> > leal -8(%ebp), %esp
> > popl %ebx
> > popl %esi
> > leave
> > ret
> > .size test, .-test
> > .section .rodata.str1.1
> > ..LC1:
> > .string "%d + %d + %d is %d\n"
> > .text
> > .p2align 2,,3
> > ..globl main
> > .type main, @function
> > main:
> > pushl %ebp
> > movl %esp, %ebp
> > pushl %ebx
> > pushl %eax
> > andl $-16, %esp
> > subl $20, %esp
> > pushl $3
> > pushl $2
> > pushl $1
> > call .L5
> > ..L5:
> > popl %ebx
> > addl $_GLOBAL_OFFSET_TABLE_+[.-.L5] , %ebx
> > call test@PLT
> > movl $15, (%esp)
> > pushl $6
> > pushl $5
> > pushl $4
> > leal .LC1@GOTOFF(%ebx), %eax
> > pushl %eax
> > call printf@PLT
> > addl $32, %esp
> > movl -4(%ebp), %ebx
> > leave
> > ret
> > .size main, .-main
> > .section
> .note.GNU-stack,"",@progbits
> > .ident "GCC: (GNU) 3.4.6 20060404 (Red
> Hat 3.4.6-3)"
>
> --
> Mihai Donțu
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