subs requires a lo register (#1402)

kilograham · web-flow · commit c026314e1702 · 2023-05-29T11:10:11.000-05:00
diff --git a/src/rp2_common/pico_platform/include/pico/platform.h b/src/rp2_common/pico_platform/include/pico/platform.h
@@ -504,7 +504,7 @@ static inline void busy_wait_at_least_cycles(uint32_t minimum_cycles) {
     pico_default_asm (
         "1: subs %0, #3\n"
         "bcs 1b\n"
-        : "+r" (minimum_cycles) : : "memory"
+        : "+l" (minimum_cycles) : : "memory"
     );
 }
 

Original file line number	Diff line number	Diff line change
`@@ -504,7 +504,7 @@ static inline void busy_wait_at_least_cycles(uint32_t minimum_cycles) {`
`504`	`504`	`pico_default_asm (`
`505`	`505`	`"1: subs %0, #3\n"`
`506`	`506`	`"bcs 1b\n"`
`507`		`- : "+r" (minimum_cycles) : : "memory"`
	`507`	`+ : "+l" (minimum_cycles) : : "memory"`
`508`	`508`	`);`
`509`	`509`	`}`
`510`	`510`