Use backtick code blocks for syntax highlighting

19-02.md

@@ -102,13 +102,15 @@ pipelines mean that an AGI can now slow down execution of an instruction
 that's *three* instructions away from the AGI (because four instructions
 can execute in two cycles). So, for example, the code sequence
 
-    add edx,4     ;U-pipe cycle 1
-    mov ecx,[ebx] ;V-pipe cycle 1
-    add ebx,4     ;U-pipe cycle 2
-    mov [edx],ecx ;V-pipe cycle 3
-                  ; due to AGI
-                  ; (would have been
-                  ; V-pipe cycle 2)
+```nasm
+add edx,4     ;U-pipe cycle 1
+mov ecx,[ebx] ;V-pipe cycle 1
+add ebx,4     ;U-pipe cycle 2
+mov [edx],ecx ;V-pipe cycle 3
+              ; due to AGI
+              ; (would have been
+              ; V-pipe cycle 2)
+```
 
 takes three cycles rather than the two cycles it should take, because
 EDX was modified on cycle 1 and an attempt was made to use it on cycle
@@ -116,10 +118,12 @@ two, before the AGI had time to clear—even though there are two
 instructions between the instructions that are actually involved in the
 AGI. Rearranging the code like
 
-    mov ecx,[ebx]   ;U-pipe cycle 1
-    add ebx,4       ;V-pipe cycle 1
-    mov [edx+4],ecx ;U-pipe cycle 2
-    add edx,4       ;V-pipe cycle 2
+```nasm
+mov ecx,[ebx]   ;U-pipe cycle 1
+add ebx,4       ;V-pipe cycle 1
+mov [edx+4],ecx ;U-pipe cycle 2
+add edx,4       ;V-pipe cycle 2
+```
 
 makes it functionally identical, but cuts the cycles to 2—a 50 percent
 improvement. Clearly, avoiding AGIs becomes a much more challenging and