Changeset 345 for soft/giet_vm/giet_libs/mwmr_channel.c

Timestamp:

Jun 25, 2014, 2:19:37 PM (10 years ago)

Author:

cfuguet

Message:

giet_vm optimizations:

• Several modifications in GIET_VM in order to support compilation with GCC optimizations (-O2) activated.

• Adding missing volatile in some global variables.

• Using ioread and iowrite utility functions in peripheral drivers which prevent GCC to remove writes or reads in hardware memory mapped registers.

• Code refactoring of stdio printf functions. Now, shr_printf and tty_printf function reuse the same function body. The only difference is that shr_printf wraps printf function call with TTY get lock and release lock.

File:

• soft/giet_vm/giet_libs/mwmr_channel.c (modified) (1 diff)

soft/giet_vm/giet_libs/mwmr_channel.c

@@ -43 +43 @@
     register unsigned int delay = 100;
     asm volatile (
-            "mwmr_lock_try:                    \n"
+            "1:                               \n"
             "ll   $2,    0(%0)                \n" /* $2 <= lock current value */
-            "bnez $2,    mwmr_lock_delay    \n" /* retry after delay if lock busy */
+            "bnez $2,    2f                   \n" /* retry after delay if lock busy */
             "li   $3,    1                    \n" /* $3 <= argument for sc */
             "sc   $3,    0(%0)                \n" /* try to get lock */
-            "bnez $3,    mwmr_lock_ok        \n" /* exit if atomic */
-            "mwmr_lock_delay:                \n"
-            "move $4,    %1                 \n" /* $4 <= delay */
-            "mwmr_lock_loop:                \n"
-            "beqz $4,    mwmr_lock_loop        \n" /* test end delay */
-            "addi $4,    $4,  -1            \n" /* $4 <= $4 - 1 */
-            "j           mwmr_lock_try        \n" /* retry ll */
-            "nop                            \n"
-            "mwmr_lock_ok:                    \n"
+            "bnez $3,    3f                   \n" /* exit if atomic */
+            "2:                               \n"
+            "move $4,    %1                   \n" /* $4 <= delay */
+            "4:                               \n"
+            "beqz $4,    4b                   \n" /* test end delay */
+            "addi $4,    $4,  -1              \n" /* $4 <= $4 - 1 */
+            "j           1b                   \n" /* retry ll */
+            "nop                              \n"
+            "3:                               \n"
             :
             :"r"(plock), "r"(delay)