Reviewed-by: Chao Li <lichao@loongson.cn>


Thanks,
Chao
在 2023/4/27 22:51, Dongyan Qian 写道:
REF: https://bugzilla.tianocore.org/show_bug.cgi?id=4432

The sc.w/sc.d instruction will destroy the reg_t0
Use reg_t1 to avoid context reg_t0 being corrupted.
Optimize function SyncIncrement and SyncDecrement.

Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Liming Gao <gaoliming@byosoft.com.cn>
Cc: Zhiguang Liu <zhiguang.liu@intel.com>
Cc: Chao Li <lichao@loongson.cn>
Signed-off-by: Dongyan Qian <qiandongyan@loongson.cn>
---
 .../LoongArch64/AsmSynchronization.S          | 30 ++++++++-----------
 1 file changed, 12 insertions(+), 18 deletions(-)

diff --git a/MdePkg/Library/BaseSynchronizationLib/LoongArch64/AsmSynchronization.S b/MdePkg/Library/BaseSynchronizationLib/LoongArch64/AsmSynchronization.S
index fdd50c54b5..03865bf2c9 100644
--- a/MdePkg/Library/BaseSynchronizationLib/LoongArch64/AsmSynchronization.S
+++ b/MdePkg/Library/BaseSynchronizationLib/LoongArch64/AsmSynchronization.S
@@ -53,9 +53,9 @@ ASM_PFX(AsmInternalSyncCompareExchange32):
 1:
   ll.w  $t0, $a0, 0x0
   bne   $t0, $a1, 2f
-  move  $t0, $a2
-  sc.w  $t0, $a0, 0x0
-  beqz  $t0, 1b
+  move  $t1, $a2
+  sc.w  $t1, $a0, 0x0
+  beqz  $t1, 1b
   b     3f
 2:
   dbar  0
@@ -76,9 +76,9 @@ ASM_PFX(AsmInternalSyncCompareExchange64):
 1:
   ll.d  $t0, $a0, 0x0
   bne   $t0, $a1, 2f
-  move  $t0, $a2
-  sc.d  $t0, $a0, 0x0
-  beqz  $t0, 1b
+  move  $t1, $a2
+  sc.d  $t1, $a0, 0x0
+  beqz  $t1, 1b
   b     3f
 2:
   dbar  0
@@ -94,13 +94,10 @@ AsmInternalSyncIncrement (
   )
 **/
 ASM_PFX(AsmInternalSyncIncrement):
-  move     $t0, $a0
-  dbar     0
-  ld.w     $t1, $t0, 0x0
-  li.w     $t2, 1
-  amadd.w  $t1, $t2, $t0
+  li.w     $t0, 1
+  amadd.w  $zero, $t0, $a0
 
-  ld.w     $a0, $t0, 0x0
+  ld.w     $a0, $a0, 0
   jirl     $zero, $ra, 0
 
 /**
@@ -111,12 +108,9 @@ AsmInternalSyncDecrement (
   )
 **/
 ASM_PFX(AsmInternalSyncDecrement):
-  move     $t0, $a0
-  dbar     0
-  ld.w     $t1, $t0, 0x0
-  li.w     $t2, -1
-  amadd.w  $t1, $t2, $t0
+  li.w     $t0, -1
+  amadd.w  $zero, $t0, $a0
 
-  ld.w     $a0, $t0, 0x0
+  ld.w     $a0, $a0, 0
   jirl     $zero, $ra, 0
 .end