Add partial assembly sollution for day 10

2 files changed, 36 insertions, 2 deletions

diff --git a/10/part2.c b/10/part2.c
index ffe0f55..5e766d4 100644
--- a/10/part2.c
+++ b/10/part2.c
@@ -33,7 +33,10 @@ void insert_value_sorted(int *list, size_t *size, int value)
     list[low] = value;
 }
 
-uint64_t pos_seq(const int *input, size_t input_size)
+#ifdef USE_ASM
+uint64_t possible_seq(const int *input, size_t input_size);
+#else
+uint64_t possible_seq(const int *input, size_t input_size)
 {
     // Use char to optimize for size
     const static char TRIB[] = { 1, 1, 2, 4, 7 };
@@ -53,6 +56,7 @@ uint64_t pos_seq(const int *input, size_t input_size)
 
     return res;
 }
+#endif
 
 uint64_t solve(const char *filename)
 {
@@ -74,7 +78,7 @@ uint64_t solve(const char *filename)
 
     fclose(file);
 
-    return pos_seq(input, input_size);
+    return possible_seq(input, input_size);
 }
 
 int main(int argc, char *argv[])
diff --git a/10/possible_seq.asm b/10/possible_seq.asm
new file mode 100644
index 0000000..15c6586
--- /dev/null
+++ b/10/possible_seq.asm
@@ -0,0 +1,30 @@
+global possible_seq
+
+section .data
+    TRIB:   dq 1, 1, 2, 4, 7                ; tribonacci sequence (without first 2 zeroes)
+
+section .text
+
+possible_seq:
+    mov         eax, 1                      ; set up return value
+    xor         ecx, ecx                    ; # of connected elements counter
+    lea         rdx, [rdi + 4 * rsi - 4]    ; pointer to the last element
+    lea         r8, [rel TRIB]
+    jmp         .loop
+.ncon:
+    imul        rax, qword [r8 + 8 * rcx]
+    xor         ecx, ecx
+    add         rdi, 4
+    cmp         rdi, rdx
+    jae         .return
+.loop:
+    mov         esi, dword [rdi + 4]
+    sub         esi, dword [rdi]
+    cmp         esi, 1
+    jne         .ncon
+    inc         ecx
+    add         rdi, 4
+    cmp         rdi, rdx
+    jb          .loop
+.return:
+    ret