From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received-SPF: Pass (sender SPF authorized) identity=mailfrom; client-ip=192.55.52.43; helo=mga05.intel.com; envelope-from=ruiyu.ni@intel.com; receiver=edk2-devel@lists.01.org Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 9F4582112E025 for ; Thu, 13 Sep 2018 02:49:57 -0700 (PDT) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 13 Sep 2018 02:49:56 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.53,368,1531810800"; d="scan'208";a="83155387" Received: from ray-dev.ccr.corp.intel.com ([10.239.9.8]) by orsmga003.jf.intel.com with ESMTP; 13 Sep 2018 02:49:55 -0700 From: Ruiyu Ni To: edk2-devel@lists.01.org Cc: Jiewen Yao , Liming Gao , Michael D Kinney Date: Thu, 13 Sep 2018 17:50:46 +0800 Message-Id: <20180913095046.9480-1-ruiyu.ni@intel.com> X-Mailer: git-send-email 2.16.1.windows.1 Subject: [PATCH v3] MdePkg/SynchronizationLib: fix Interlocked[De|In]crement return value X-BeenThere: edk2-devel@lists.01.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: EDK II Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 13 Sep 2018 09:49:57 -0000 Today's InterlockedIncrement()/InterlockedDecrement() guarantees to perform atomic increment/decrement but doesn't guarantee the return value equals to the new value. The patch fixes the behavior to use "XADD" instruction to guarantee the return value equals to the new value. The patch calls intrinsic functions for MSVC tool chain, calls the NASM implementation for INTEL tool chain and calls GCC inline assembly implementation (GccInline.c) for GCC tool chain. Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Ruiyu Ni Cc: Jiewen Yao Cc: Liming Gao Cc: Michael D Kinney --- MdePkg/Include/Library/SynchronizationLib.h | 6 +-- .../BaseSynchronizationLib.inf | 18 ++++----- .../BaseSynchronizationLibInternals.h | 6 +-- .../BaseSynchronizationLib/Ia32/GccInline.c | 18 ++++----- .../Ia32/InterlockedDecrement.c | 42 --------------------- .../Ia32/InterlockedDecrement.nasm | 10 ++--- .../Ia32/InterlockedIncrement.c | 43 ---------------------- .../Ia32/InterlockedIncrement.nasm | 7 ++-- ...lockedDecrement.c => InterlockedDecrementMsc.c} | 4 +- ...lockedIncrement.c => InterlockedIncrementMsc.c} | 4 +- .../BaseSynchronizationLib/Synchronization.c | 6 +-- .../BaseSynchronizationLib/SynchronizationGcc.c | 6 +-- .../BaseSynchronizationLib/SynchronizationMsc.c | 6 +-- .../Library/BaseSynchronizationLib/X64/GccInline.c | 19 +++++----- .../X64/InterlockedDecrement.nasm | 8 ++-- .../X64/InterlockedIncrement.nasm | 5 ++- 16 files changed, 56 insertions(+), 152 deletions(-) delete mode 100644 MdePkg/Library/BaseSynchronizationLib/Ia32/InterlockedDecrement.c delete mode 100644 MdePkg/Library/BaseSynchronizationLib/Ia32/InterlockedIncrement.c rename MdePkg/Library/BaseSynchronizationLib/{X64/InterlockedDecrement.c => InterlockedDecrementMsc.c} (87%) rename MdePkg/Library/BaseSynchronizationLib/{X64/InterlockedIncrement.c => InterlockedIncrementMsc.c} (87%) diff --git a/MdePkg/Include/Library/SynchronizationLib.h b/MdePkg/Include/Library/SynchronizationLib.h index da69f6ff5e..ce3bce04f5 100644 --- a/MdePkg/Include/Library/SynchronizationLib.h +++ b/MdePkg/Include/Library/SynchronizationLib.h @@ -144,8 +144,7 @@ ReleaseSpinLock ( Performs an atomic increment of the 32-bit unsigned integer specified by Value and returns the incremented value. The increment operation must be - performed using MP safe mechanisms. The state of the return value is not - guaranteed to be MP safe. + performed using MP safe mechanisms. If Value is NULL, then ASSERT(). @@ -166,8 +165,7 @@ InterlockedIncrement ( Performs an atomic decrement of the 32-bit unsigned integer specified by Value and returns the decremented value. The decrement operation must be - performed using MP safe mechanisms. The state of the return value is not - guaranteed to be MP safe. + performed using MP safe mechanisms. If Value is NULL, then ASSERT(). diff --git a/MdePkg/Library/BaseSynchronizationLib/BaseSynchronizationLib.inf b/MdePkg/Library/BaseSynchronizationLib/BaseSynchronizationLib.inf index 0be1d4331f..427e959f2e 100755 --- a/MdePkg/Library/BaseSynchronizationLib/BaseSynchronizationLib.inf +++ b/MdePkg/Library/BaseSynchronizationLib/BaseSynchronizationLib.inf @@ -34,9 +34,9 @@ [Sources.IA32] Ia32/InterlockedCompareExchange64.c | MSFT Ia32/InterlockedCompareExchange32.c | MSFT Ia32/InterlockedCompareExchange16.c | MSFT - Ia32/InterlockedDecrement.c | MSFT - Ia32/InterlockedIncrement.c | MSFT - SynchronizationMsc.c | MSFT + InterlockedIncrementMsc.c | MSFT + InterlockedDecrementMsc.c | MSFT + SynchronizationMsc.c | MSFT Ia32/InterlockedCompareExchange64.nasm| INTEL Ia32/InterlockedCompareExchange32.nasm| INTEL @@ -54,17 +54,15 @@ [Sources.X64] X64/InterlockedCompareExchange64.c | MSFT X64/InterlockedCompareExchange32.c | MSFT X64/InterlockedCompareExchange16.c | MSFT + InterlockedIncrementMsc.c | MSFT + InterlockedDecrementMsc.c | MSFT + SynchronizationMsc.c | MSFT X64/InterlockedCompareExchange64.nasm| INTEL X64/InterlockedCompareExchange32.nasm| INTEL X64/InterlockedCompareExchange16.nasm| INTEL - - X64/InterlockedDecrement.c | MSFT - X64/InterlockedIncrement.c | MSFT - SynchronizationMsc.c | MSFT - - X64/InterlockedDecrement.nasm| INTEL - X64/InterlockedIncrement.nasm| INTEL + X64/InterlockedDecrement.nasm | INTEL + X64/InterlockedIncrement.nasm | INTEL Synchronization.c | INTEL Ia32/InternalGetSpinLockProperties.c | GCC diff --git a/MdePkg/Library/BaseSynchronizationLib/BaseSynchronizationLibInternals.h b/MdePkg/Library/BaseSynchronizationLib/BaseSynchronizationLibInternals.h index 37edd7c188..8c363a8585 100644 --- a/MdePkg/Library/BaseSynchronizationLib/BaseSynchronizationLibInternals.h +++ b/MdePkg/Library/BaseSynchronizationLib/BaseSynchronizationLibInternals.h @@ -27,8 +27,7 @@ Performs an atomic increment of the 32-bit unsigned integer specified by Value and returns the incremented value. The increment operation must be - performed using MP safe mechanisms. The state of the return value is not - guaranteed to be MP safe. + performed using MP safe mechanisms. @param Value A pointer to the 32-bit value to increment. @@ -47,8 +46,7 @@ InternalSyncIncrement ( Performs an atomic decrement of the 32-bit unsigned integer specified by Value and returns the decrement value. The decrement operation must be - performed using MP safe mechanisms. The state of the return value is not - guaranteed to be MP safe. + performed using MP safe mechanisms. @param Value A pointer to the 32-bit value to decrement. diff --git a/MdePkg/Library/BaseSynchronizationLib/Ia32/GccInline.c b/MdePkg/Library/BaseSynchronizationLib/Ia32/GccInline.c index 4ab293f243..d82e0205f5 100644 --- a/MdePkg/Library/BaseSynchronizationLib/Ia32/GccInline.c +++ b/MdePkg/Library/BaseSynchronizationLib/Ia32/GccInline.c @@ -20,8 +20,7 @@ Performs an atomic increment of the 32-bit unsigned integer specified by Value and returns the incremented value. The increment operation must be - performed using MP safe mechanisms. The state of the return value is not - guaranteed to be MP safe. + performed using MP safe mechanisms. @param Value A pointer to the 32-bit value to increment. @@ -37,9 +36,10 @@ InternalSyncIncrement ( UINT32 Result; __asm__ __volatile__ ( + "movl $1, %%eax \n\t" "lock \n\t" - "incl %2 \n\t" - "movl %2, %%eax " + "xadd %%eax, %2 \n\t" + "inc %%eax " : "=a" (Result), // %0 "=m" (*Value) // %1 : "m" (*Value) // %2 @@ -57,8 +57,7 @@ InternalSyncIncrement ( Performs an atomic decrement of the 32-bit unsigned integer specified by Value and returns the decremented value. The decrement operation must be - performed using MP safe mechanisms. The state of the return value is not - guaranteed to be MP safe. + performed using MP safe mechanisms. @param Value A pointer to the 32-bit value to decrement. @@ -74,9 +73,10 @@ InternalSyncDecrement ( UINT32 Result; __asm__ __volatile__ ( - "lock \n\t" - "decl %2 \n\t" - "movl %2, %%eax " + "movl $-1, %%eax \n\t" + "lock \n\t" + "xadd %%eax, %2 \n\t" + "dec %%eax " : "=a" (Result), // %0 "=m" (*Value) // %1 : "m" (*Value) // %2 diff --git a/MdePkg/Library/BaseSynchronizationLib/Ia32/InterlockedDecrement.c b/MdePkg/Library/BaseSynchronizationLib/Ia32/InterlockedDecrement.c deleted file mode 100644 index 354a0e7ab1..0000000000 --- a/MdePkg/Library/BaseSynchronizationLib/Ia32/InterlockedDecrement.c +++ /dev/null @@ -1,42 +0,0 @@ -/** @file - InterlockedDecrement function - - Copyright (c) 2006 - 2016, Intel Corporation. All rights reserved.
- This program and the accompanying materials - are licensed and made available under the terms and conditions of the BSD License - which accompanies this distribution. The full text of the license may be found at - http://opensource.org/licenses/bsd-license.php. - - THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, - WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. - -**/ - - - - -/** - Performs an atomic decrement of an 32-bit unsigned integer. - - Performs an atomic decrement of the 32-bit unsigned integer specified by - Value and returns the decrement value. The decrement operation must be - performed using MP safe mechanisms. The state of the return value is not - guaranteed to be MP safe. - - @param Value A pointer to the 32-bit value to decrement. - - @return The decrement value. - -**/ -UINT32 -EFIAPI -InternalSyncDecrement ( - IN volatile UINT32 *Value - ) -{ - _asm { - mov eax, Value - lock dec dword ptr [eax] - mov eax, [eax] - } -} diff --git a/MdePkg/Library/BaseSynchronizationLib/Ia32/InterlockedDecrement.nasm b/MdePkg/Library/BaseSynchronizationLib/Ia32/InterlockedDecrement.nasm index 4c46041186..dd5a8de3ed 100644 --- a/MdePkg/Library/BaseSynchronizationLib/Ia32/InterlockedDecrement.nasm +++ b/MdePkg/Library/BaseSynchronizationLib/Ia32/InterlockedDecrement.nasm @@ -1,6 +1,6 @@ ;------------------------------------------------------------------------------ ; -; Copyright (c) 2006 - 2016, Intel Corporation. All rights reserved.
+; Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.
; This program and the accompanying materials ; are licensed and made available under the terms and conditions of the BSD License ; which accompanies this distribution. The full text of the license may be found at @@ -32,8 +32,8 @@ ;------------------------------------------------------------------------------ global ASM_PFX(InternalSyncDecrement) ASM_PFX(InternalSyncDecrement): - mov eax, [esp + 4] - lock dec dword [eax] - mov eax, [eax] + mov ecx, [esp + 4] + mov eax, 0FFFFFFFFh + lock xadd dword [ecx], eax + dec eax ret - diff --git a/MdePkg/Library/BaseSynchronizationLib/Ia32/InterlockedIncrement.c b/MdePkg/Library/BaseSynchronizationLib/Ia32/InterlockedIncrement.c deleted file mode 100644 index c61a550119..0000000000 --- a/MdePkg/Library/BaseSynchronizationLib/Ia32/InterlockedIncrement.c +++ /dev/null @@ -1,43 +0,0 @@ -/** @file - InterLockedIncrement function - - Copyright (c) 2006 - 2016, Intel Corporation. All rights reserved.
- This program and the accompanying materials - are licensed and made available under the terms and conditions of the BSD License - which accompanies this distribution. The full text of the license may be found at - http://opensource.org/licenses/bsd-license.php. - - THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, - WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. - -**/ - - - - -/** - Performs an atomic increment of an 32-bit unsigned integer. - - Performs an atomic increment of the 32-bit unsigned integer specified by - Value and returns the incremented value. The increment operation must be - performed using MP safe mechanisms. The state of the return value is not - guaranteed to be MP safe. - - @param Value A pointer to the 32-bit value to increment. - - @return The incremented value. - -**/ -UINT32 -EFIAPI -InternalSyncIncrement ( - IN volatile UINT32 *Value - ) -{ - _asm { - mov eax, Value - lock inc dword ptr [eax] - mov eax, [eax] - } -} - diff --git a/MdePkg/Library/BaseSynchronizationLib/Ia32/InterlockedIncrement.nasm b/MdePkg/Library/BaseSynchronizationLib/Ia32/InterlockedIncrement.nasm index 3902c73275..0677e4bf78 100644 --- a/MdePkg/Library/BaseSynchronizationLib/Ia32/InterlockedIncrement.nasm +++ b/MdePkg/Library/BaseSynchronizationLib/Ia32/InterlockedIncrement.nasm @@ -32,8 +32,9 @@ ;------------------------------------------------------------------------------ global ASM_PFX(InternalSyncIncrement) ASM_PFX(InternalSyncIncrement): - mov eax, [esp + 4] - lock inc dword [eax] - mov eax, [eax] + mov ecx, [esp + 4] + mov eax, 1 + lock xadd dword [ecx], eax + inc eax ret diff --git a/MdePkg/Library/BaseSynchronizationLib/X64/InterlockedDecrement.c b/MdePkg/Library/BaseSynchronizationLib/InterlockedDecrementMsc.c similarity index 87% rename from MdePkg/Library/BaseSynchronizationLib/X64/InterlockedDecrement.c rename to MdePkg/Library/BaseSynchronizationLib/InterlockedDecrementMsc.c index da402cd4c6..6dc9502ea6 100644 --- a/MdePkg/Library/BaseSynchronizationLib/X64/InterlockedDecrement.c +++ b/MdePkg/Library/BaseSynchronizationLib/InterlockedDecrementMsc.c @@ -1,7 +1,7 @@ /** @file InterlockedDecrement function - Copyright (c) 2006 - 2016, Intel Corporation. All rights reserved.
+ Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.
This program and the accompanying materials are licensed and made available under the terms and conditions of the BSD License which accompanies this distribution. The full text of the license may be found at @@ -41,6 +41,6 @@ InternalSyncDecrement ( IN volatile UINT32 *Value ) { - return _InterlockedDecrement ((long *)(UINTN)(Value)); + return _InterlockedDecrement ((long *)(Value)); } diff --git a/MdePkg/Library/BaseSynchronizationLib/X64/InterlockedIncrement.c b/MdePkg/Library/BaseSynchronizationLib/InterlockedIncrementMsc.c similarity index 87% rename from MdePkg/Library/BaseSynchronizationLib/X64/InterlockedIncrement.c rename to MdePkg/Library/BaseSynchronizationLib/InterlockedIncrementMsc.c index bbd1384602..8327d81a87 100644 --- a/MdePkg/Library/BaseSynchronizationLib/X64/InterlockedIncrement.c +++ b/MdePkg/Library/BaseSynchronizationLib/InterlockedIncrementMsc.c @@ -1,7 +1,7 @@ /** @file InterLockedIncrement function - Copyright (c) 2006 - 2016, Intel Corporation. All rights reserved.
+ Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.
This program and the accompanying materials are licensed and made available under the terms and conditions of the BSD License which accompanies this distribution. The full text of the license may be found at @@ -41,6 +41,6 @@ InternalSyncIncrement ( IN volatile UINT32 *Value ) { - return _InterlockedIncrement ((long *)(UINTN)(Value)); + return _InterlockedIncrement ((long *)(Value)); } diff --git a/MdePkg/Library/BaseSynchronizationLib/Synchronization.c b/MdePkg/Library/BaseSynchronizationLib/Synchronization.c index 76c5a1275c..0ab59ca702 100644 --- a/MdePkg/Library/BaseSynchronizationLib/Synchronization.c +++ b/MdePkg/Library/BaseSynchronizationLib/Synchronization.c @@ -231,8 +231,7 @@ ReleaseSpinLock ( Performs an atomic increment of the 32-bit unsigned integer specified by Value and returns the incremented value. The increment operation must be - performed using MP safe mechanisms. The state of the return value is not - guaranteed to be MP safe. + performed using MP safe mechanisms. If Value is NULL, then ASSERT(). @@ -256,8 +255,7 @@ InterlockedIncrement ( Performs an atomic decrement of the 32-bit unsigned integer specified by Value and returns the decremented value. The decrement operation must be - performed using MP safe mechanisms. The state of the return value is not - guaranteed to be MP safe. + performed using MP safe mechanisms. If Value is NULL, then ASSERT(). diff --git a/MdePkg/Library/BaseSynchronizationLib/SynchronizationGcc.c b/MdePkg/Library/BaseSynchronizationLib/SynchronizationGcc.c index 5ac548b19f..177739d3da 100644 --- a/MdePkg/Library/BaseSynchronizationLib/SynchronizationGcc.c +++ b/MdePkg/Library/BaseSynchronizationLib/SynchronizationGcc.c @@ -247,8 +247,7 @@ ReleaseSpinLock ( Performs an atomic increment of the 32-bit unsigned integer specified by Value and returns the incremented value. The increment operation must be - performed using MP safe mechanisms. The state of the return value is not - guaranteed to be MP safe. + performed using MP safe mechanisms. If Value is NULL, then ASSERT(). @@ -272,8 +271,7 @@ InterlockedIncrement ( Performs an atomic decrement of the 32-bit unsigned integer specified by Value and returns the decremented value. The decrement operation must be - performed using MP safe mechanisms. The state of the return value is not - guaranteed to be MP safe. + performed using MP safe mechanisms. If Value is NULL, then ASSERT(). diff --git a/MdePkg/Library/BaseSynchronizationLib/SynchronizationMsc.c b/MdePkg/Library/BaseSynchronizationLib/SynchronizationMsc.c index e3298c8ab4..6ab2d71870 100644 --- a/MdePkg/Library/BaseSynchronizationLib/SynchronizationMsc.c +++ b/MdePkg/Library/BaseSynchronizationLib/SynchronizationMsc.c @@ -249,8 +249,7 @@ ReleaseSpinLock ( Performs an atomic increment of the 32-bit unsigned integer specified by Value and returns the incremented value. The increment operation must be - performed using MP safe mechanisms. The state of the return value is not - guaranteed to be MP safe. + performed using MP safe mechanisms. If Value is NULL, then ASSERT(). @@ -274,8 +273,7 @@ InterlockedIncrement ( Performs an atomic decrement of the 32-bit unsigned integer specified by Value and returns the decremented value. The decrement operation must be - performed using MP safe mechanisms. The state of the return value is not - guaranteed to be MP safe. + performed using MP safe mechanisms. If Value is NULL, then ASSERT(). diff --git a/MdePkg/Library/BaseSynchronizationLib/X64/GccInline.c b/MdePkg/Library/BaseSynchronizationLib/X64/GccInline.c index 5224dd063f..4c4d6e3fc7 100644 --- a/MdePkg/Library/BaseSynchronizationLib/X64/GccInline.c +++ b/MdePkg/Library/BaseSynchronizationLib/X64/GccInline.c @@ -15,14 +15,12 @@ - /** Performs an atomic increment of an 32-bit unsigned integer. Performs an atomic increment of the 32-bit unsigned integer specified by Value and returns the incremented value. The increment operation must be - performed using MP safe mechanisms. The state of the return value is not - guaranteed to be MP safe. + performed using MP safe mechanisms. @param Value A pointer to the 32-bit value to increment. @@ -38,9 +36,10 @@ InternalSyncIncrement ( UINT32 Result; __asm__ __volatile__ ( + "movl $1, %%eax \n\t" "lock \n\t" - "incl %2 \n\t" - "mov %2, %%eax " + "xadd %%eax, %2 \n\t" + "inc %%eax " : "=a" (Result), // %0 "=m" (*Value) // %1 : "m" (*Value) // %2 @@ -57,8 +56,7 @@ InternalSyncIncrement ( Performs an atomic decrement of the 32-bit unsigned integer specified by Value and returns the decremented value. The decrement operation must be - performed using MP safe mechanisms. The state of the return value is not - guaranteed to be MP safe. + performed using MP safe mechanisms. @param Value A pointer to the 32-bit value to decrement. @@ -74,9 +72,10 @@ InternalSyncDecrement ( UINT32 Result; __asm__ __volatile__ ( - "lock \n\t" - "decl %2 \n\t" - "mov %2, %%eax " + "movl $-1, %%eax \n\t" + "lock \n\t" + "xadd %%eax, %2 \n\t" + "dec %%eax " : "=a" (Result), // %0 "=m" (*Value) // %1 : "m" (*Value) // %2 diff --git a/MdePkg/Library/BaseSynchronizationLib/X64/InterlockedDecrement.nasm b/MdePkg/Library/BaseSynchronizationLib/X64/InterlockedDecrement.nasm index 60f43111fe..dabdca945e 100644 --- a/MdePkg/Library/BaseSynchronizationLib/X64/InterlockedDecrement.nasm +++ b/MdePkg/Library/BaseSynchronizationLib/X64/InterlockedDecrement.nasm @@ -1,6 +1,6 @@ ;------------------------------------------------------------------------------ ; -; Copyright (c) 2006 - 2016, Intel Corporation. All rights reserved.
+; Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.
; This program and the accompanying materials ; are licensed and made available under the terms and conditions of the BSD License ; which accompanies this distribution. The full text of the license may be found at @@ -33,7 +33,7 @@ ;------------------------------------------------------------------------------ global ASM_PFX(InternalSyncDecrement) ASM_PFX(InternalSyncDecrement): - lock dec dword [rcx] - mov eax, [rcx] + mov eax, 0FFFFFFFFh + lock xadd dword [rcx], eax + dec eax ret - diff --git a/MdePkg/Library/BaseSynchronizationLib/X64/InterlockedIncrement.nasm b/MdePkg/Library/BaseSynchronizationLib/X64/InterlockedIncrement.nasm index 7f877b5774..77379d998e 100644 --- a/MdePkg/Library/BaseSynchronizationLib/X64/InterlockedIncrement.nasm +++ b/MdePkg/Library/BaseSynchronizationLib/X64/InterlockedIncrement.nasm @@ -33,7 +33,8 @@ ;------------------------------------------------------------------------------ global ASM_PFX(InternalSyncIncrement) ASM_PFX(InternalSyncIncrement): - lock inc dword [rcx] - mov eax, [rcx] + mov eax, 1 + lock xadd dword [rcx], eax + inc eax ret -- 2.16.1.windows.1