I am searching for a compiler or better IDE for C which could generate completely linked program, including functions from CRT, in assembler form. Is there any? I tried Visual C Express 2008. It has a disassembler, but its somewhat strange. I mean for some reason it shows many "strange" lines of code, such as mov a,#3 in about 100 lines.... It for study purposes. Thanks for tips.
gcc will generate ASM files. If you use gcc -Wa,-adhln -g [source.c] gcc and as will interleave the C source lines with the generated assembly code.
clang with LLVM will generate high quality ASM files.
Example:
This C function:
long Fibonacci(long x) {
if (x == 0) return 0;
if (x == 1) return 1;
return Fibonacci(x - 1) + Fibonacci(x - 2);
}
Becomes this ASM file:
_Fibonacci:
Leh_func_begin1:
pushq %rbp
Ltmp0:
movq %rsp, %rbp
Ltmp1:
subq $32, %rsp
Ltmp2:
movq %rdi, -16(%rbp)
movq -16(%rbp), %rax
cmpq $0, %rax
jne LBB1_2
movq $0, -8(%rbp)
jmp LBB1_5
LBB1_2:
movq -16(%rbp), %rax
cmpq $1, %rax
jne LBB1_4
movq $1, -8(%rbp)
jmp LBB1_5
LBB1_4:
movq -16(%rbp), %rax
movabsq $1, %rcx
subq %rcx, %rax
movq %rax, %rdi
callq _Fibonacci
movq -16(%rbp), %rcx
movabsq $2, %rdx
subq %rdx, %rcx
movq %rcx, %rdi
movq %rax, -24(%rbp)
callq _Fibonacci
movq -24(%rbp), %rcx
addq %rax, %rcx
movq %rcx, -8(%rbp)
LBB1_5:
movq -8(%rbp), %rax
addq $32, %rsp
popq %rbp
ret
Leh_func_end1:
When you do this, you will want optimizations OFF.
It is also possible to interleave the generated ASM code with the higher level source, such as the writer has done HERE.