From: GAMMELJL AT SLU DOT EDU
Date: Tue, 01 Sep 1998 15:15:37 -0500 (CDT)
Subject: Getting registers for arguments and inlining functions
To: djgpp AT delorie DOT com
Message-id: <01J1AOXNWNZ694JQYE@SLU.EDU>
Organization: SAINT LOUIS UNIVERSITY  St. Louis, MO
MIME-version: 1.0
Precedence: bulk

By looking at the .s file below ones sees that the function zadd is
not inline.  The call _zadd__Fii has not been eliminated.  In fact
the .s file looks exactly like the one with no effort to inline.
How does one make the compiler do inlining? I have read "An inline
function is as fast as a macro" where I got the scheme for declaring
zadd to be inline, but I don't get what I expected in the .s file.
I explain what I expected below.

_____________Source code for codename.cc_________________________________

extern inline int zadd(int m,int n) __attribute__ ((regparm(2)));
int i,j,k;
                          I am indebted to Nate Eldredge for
main()                    telling me how to use the above
 {i=2;                    attribute to cause the compiler
  j=3;                    to pass the arguments of zadd in
  zadd(i,j);              registers.
  return 0;
 }

inline int 
zadd(int m,int n)
  {k=m+n;
  }
________The .s file produce by gxx codename.cc -S -O2_____________________

	.file	"example9.cc"
gcc2_compiled.:
___gnu_compiled_cplusplus:
.text
	.align 2
.globl _main
_main:
	pushl %ebp
	movl %esp,%ebp
	call ___main
	movl $2,_i
	movl $3,_j
	movl $3,%edx
	movl $2,%eax
        call _zadd__Fii -------> I expected to see addl %edx,%eax here;
	xorl %eax,%eax
        leave                         (see below)
	ret
	.align 2
_zadd__Fii:
	pushl %ebp
	movl %esp,%ebp
        addl %edx,%eax   ------> namely, this line, and nothing else.
	movl %eax,_k
	leave
	ret
.globl _i
.data
	.align 2
_i:
	.space 4
.globl _j
	.align 2
_j:
	.space 4
.globl _k
	.align 2
_k:
	.space 4