better asm loop

2018-01-02 22:51:10 +01:00
parent 5cbc9fa6dd
commit a3df4d79e1
2 changed files with 4 additions and 17 deletions
@@ -26,15 +26,14 @@ static inline bool isDynAlloc(const void *obj)
 /** Tight asm loop */
 #define __asm_loop(cycles) \
 do { \
-    register uint32_t _count = cycles; \
+    register uint32_t _count asm ("r4") = cycles; \
    asm volatile( \
        ".syntax unified\n" \
        ".thumb\n" \
-            "ldr r4, =%0\n" \
        "0:" \
-            "subs r4, #1\n" \
+            "subs %0, #1\n" \
            "bne 0b\n" \
-        : /* no outputs */ : "g" (cycles) : "r4"); \
+        : "+r" (_count)); \
 } while(0)

 #endif //GEX_CORTEX_UTILS_H