1 files changed, 40 insertions, 0 deletions
diff --git a/src/VBox/Devices/EFI/Firmware/MdePkg/Library/BaseLib/Ia32/MultU64x64.nasm b/src/VBox/Devices/EFI/Firmware/MdePkg/Library/BaseLib/Ia32/MultU64x64.nasm
new file mode 100644
index 00000000..b477d607
--- /dev/null
+++ b/src/VBox/Devices/EFI/Firmware/MdePkg/Library/BaseLib/Ia32/MultU64x64.nasm
@@ -0,0 +1,40 @@
+;------------------------------------------------------------------------------
+;
+; Copyright (c) 2006, Intel Corporation. All rights reserved.<BR>
+; SPDX-License-Identifier: BSD-2-Clause-Patent
+;
+; Module Name:
+;
+;   MultU64x64.nasm
+;
+; Abstract:
+;
+;   Calculate the product of a 64-bit integer and another 64-bit integer
+;
+;------------------------------------------------------------------------------
+
+    SECTION .text
+
+;------------------------------------------------------------------------------
+; UINT64
+; EFIAPI
+; InternalMathMultU64x64 (
+;   IN      UINT64                    Multiplicand,
+;   IN      UINT64                    Multiplier
+;   );
+;------------------------------------------------------------------------------
+global ASM_PFX(InternalMathMultU64x64)
+ASM_PFX(InternalMathMultU64x64):
+    push    ebx
+    mov     ebx, [esp + 8]              ; ebx <- M1[0..31]
+    mov     edx, [esp + 16]             ; edx <- M2[0..31]
+    mov     ecx, ebx
+    mov     eax, edx
+    imul    ebx, [esp + 20]             ; ebx <- M1[0..31] * M2[32..63]
+    imul    edx, [esp + 12]             ; edx <- M1[32..63] * M2[0..31]
+    add     ebx, edx                    ; carries are abandoned
+    mul     ecx                         ; edx:eax <- M1[0..31] * M2[0..31]
+    add     edx, ebx                    ; carries are abandoned
+    pop     ebx
+    ret
+