llvm dev - Jun 2007 - [LLVMdev] LLVM assembly without basic block

Hello, guys.

I just wonder if there is any way to spit out LLVM assembly without any basic
block division.
E.g., 
If I emit LLVM assembly for the following simple code:
------------------------------------------------------------
void f_loop(long* c, long sz) {

   long i;
   for (i = 0; i < sz; i++) {
      long offset = i * sz;
      long* out = c + offset;
      out[i] = 0;
   }
}
------------------------------------------------------------
You know the LLVM assembly is printed out as follows for this code.
------------------------------------------------------------
void %f_loop(int* %c, int %sz) {
entry:
        %sz = cast int %sz to uint              ; <uint> [#uses=1]
        %tmp18 = setgt int %sz, 0               ; <bool> [#uses=1]
        br bool %tmp18, label %bb, label %return

bb:             ; preds = %bb, %entry
        %indvar = phi uint [ 0, %entry ], [ %indvar.next, %bb ]         ;
<uint> [#uses=2]
        %i.0.0 = cast uint %indvar to int               ; <int> [#uses=2]
        %tmp2 = mul int %i.0.0, %sz             ; <int> [#uses=1]
        %tmp4.sum = add int %tmp2, %i.0.0               ; <int> [#uses=1]
        %tmp7 = getelementptr int* %c, int %tmp4.sum            ; <int*>
[#uses=1]
        store int 0, int* %tmp7
        %indvar.next = add uint %indvar, 1              ; <uint> [#uses=2]
        %exitcond = seteq uint %indvar.next, %sz                ; <bool>
[#uses=1]
        br bool %exitcond, label %return, label %bb

return:         ; preds = %bb, %entry
        ret void
}
------------------------------------------------------------
As you can see, there are three basic blocks composing this code.
Is there any way to get the assembly for this function without any basic block
division?
I know this may be absurd but curious.

Thanks,
Seung Jae Lee

Seung Jae Lee wrote:
> Hello, guys.
> 
> I just wonder if there is any way to spit out LLVM assembly without any
basic block division.
I believe you cannot do that, since the basic blocks are defined by the control
flow graph, i.e. by the points in the
program to which (conditional or unconditional) jumps go. In other words, basic
blocks are defined by the destination of
goto (in particular those in loops and tests) and calls.

If you restrict yourself to a single basic block, you need to avoid tests and
loops.

-- 
Basile STARYNKEVITCH         http://starynkevitch.net/Basile/
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