Haodong Wang wrote:
Hi Steve,
Thanks for the information. I know the symbol should be unique.
Actually, I changed the symbol many time (very unique), but the
compiler still complains the same thing. If I move the same code
(such as a function) to another code file, then everything is fine. I
am just confused...
If you make your code like mine, with numeric symbol names which are
dynamically substituted with unique names, your problems will go away.
L1 is *not* a unique name, if you look at the assembly output.
Steve
Steve Underwood wrote:
Haodong Wang wrote:
Hi,
Sometime I have a strange problem when I do jump in my assembly code
(embedded in C), the compiler always complains "Error: symbol 'L1'
is already defined". I changed the symbol, but it still complains
the same problem. Is that the bug in mspgcc? Any solution to get
around? Thanks!
" mov #1000, r8 \n"
"L1: \n"
" mov #1000, r9 \n"
......
" jnz L1 \n"
haodong
Defining L1 creates a symbol in the assembly language code with a
fixed name. If you do that more than once you will get an error tht
the symbol is already defined. If you try something like the
following that doesn't happen, as the actual names of the labels are
generated dynamically (I just grabbed a suitable example from my own
source code. This does an efficient Q1.15 multiply for machines with
no hardware multiplier).
Steve
__asm__ (
" tst %[x] \n"
" jge 2f \n"
" mov #-1,%[x1] \n"
" jmp 2f \n"
"6: \n"
" add %[x],%A[z] \n"
" addc %[x1],%B[z] \n"
"1: \n"
" rla %[x] \n"
" rlc %[x1] \n"
"2: \n"
" rra %[y] \n"
" jc 5f \n"
" jne 1b \n"
" jmp 4f \n"
"5: \n"
" sub %[x],%A[z] \n"
" subc %[x1],%B[z] \n"
"3: \n"
" rla %[x] \n"
" rlc %[x1] \n"
" rra %[y] \n"
" jnc 6b \n"
" cmp #0xFFFF,%[y] \n"
" jne 3b \n"
"4: \n"
//Shift to Q1.15 format (i.e. the top 16 bits are returned)
" rla %A[z] \n"
" rlc %B[z] \n"
" mov %B[z],%[x1] \n"
: [z] "+r"(z), [x1] "+r"(x1)
: [x] "r"(x), [y] "r"(y));
