Update ARM inline assembly constraints.
Inline assembly in uECC_vli_add is underspecified; the output
registers are written to before the input registers are fully
consumed. Updating the constraints to include earlyclobber `&`.
diff --git a/asm_arm.inc b/asm_arm.inc
index e3c8cb1..12e747f 100644
--- a/asm_arm.inc
+++ b/asm_arm.inc
@@ -20,19 +20,19 @@
#endif
#if (uECC_PLATFORM == uECC_arm_thumb)
- #define REG_RW "+l"
- #define REG_WRITE "=l"
+ #define REG_RW "+&l"
+ #define REG_WRITE "=&l"
#else
- #define REG_RW "+r"
- #define REG_WRITE "=r"
+ #define REG_RW "+&r"
+ #define REG_WRITE "=&r"
#endif
#if (uECC_PLATFORM == uECC_arm_thumb || uECC_PLATFORM == uECC_arm_thumb2)
- #define REG_RW_LO "+l"
- #define REG_WRITE_LO "=l"
+ #define REG_RW_LO "+&l"
+ #define REG_WRITE_LO "=&l"
#else
- #define REG_RW_LO "+r"
- #define REG_WRITE_LO "=r"
+ #define REG_RW_LO "+&r"
+ #define REG_WRITE_LO "=&r"
#endif
#if (uECC_PLATFORM == uECC_arm_thumb2)