qbe-backend/test/sum.ssa

# Simple test for addressing modes.

export
function w $sum(l %arr, w %num) {
@start
@loop
	%n1 =w phi @start %num, @loop1 %n2
	%s0 =w phi @start 0, @loop1 %s1
	%n2 =w sub %n1, 1
	%c =w cslew %n1, 0
	jnz %c, @end, @loop1
@loop1
	%idx0 =l extsw %n2
	%idx1 =l mul 4, %idx0
	%idx2 =l add %idx1, %arr
	%w =w loadw %idx2
	%s1 =w add %w, %s0
	jmp @loop
@end
	ret %s0
}

# >>> driver
# extern int sum(int *, int);
# int arr[] = { 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21 };
# #define N sizeof arr / sizeof arr[0]
# int main() {
# 	int i, s;
# 	for (s=i=0; i<N; i++) s+=arr[i];
# 	return !(sum(arr, N) == s);
# }
# <<<