From 053c4fe52fd6a1faf0746e86a666a286afa10e19 Mon Sep 17 00:00:00 2001
From: Daggolin <Daggolin@Gmx.de>
Date: Thu, 2 Nov 2023 23:50:06 +0100
Subject: [PATCH] Add win32/q3asm.asm from jk2mv for MSVC builds.

---
 codemp/CMakeLists.txt  |   6 +++
 codemp/win32/q3asm.asm | 110 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 116 insertions(+)
 create mode 100644 codemp/win32/q3asm.asm

diff --git a/codemp/CMakeLists.txt b/codemp/CMakeLists.txt
index c043dd22a6..bcb0b5f5d4 100644
--- a/codemp/CMakeLists.txt
+++ b/codemp/CMakeLists.txt
@@ -271,6 +271,12 @@ if(BuildMPEngine OR BuildMPDed)
 		)
 	endif()
 
+	if(MSVC)
+		set(MPEngineAndDedCommonFiles ${MPEngineAndDedCommonFiles}
+			"${MPDir}/win32/q3asm.asm"
+		)
+	endif()
+
 	if(WIN32)
 		set(MPEngineAndDedCommonFiles ${MPEngineAndDedCommonFiles})
 	endif(WIN32)
diff --git a/codemp/win32/q3asm.asm b/codemp/win32/q3asm.asm
new file mode 100644
index 0000000000..4e51802789
--- /dev/null
+++ b/codemp/win32/q3asm.asm
@@ -0,0 +1,110 @@
+; ===========================================================================
+; Copyright (C) 2011 Thilo Schulz <thilo@tjps.eu>
+; 
+; This file is part of Quake III Arena source code.
+; 
+; Quake III Arena source code is free software; you can redistribute it
+; and/or modify it under the terms of the GNU General Public License as
+; published by the Free Software Foundation; either version 2 of the License,
+; or (at your option) any later version.
+; 
+; Quake III Arena source code is distributed in the hope that it will be
+; useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
+; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+; GNU General Public License for more details.
+; 
+; You should have received a copy of the GNU General Public License
+; along with Quake III Arena source code; if not, write to the Free Software
+; Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+; ===========================================================================
+
+; MASM ftol conversion functions using SSE or FPU
+; assume __cdecl calling convention is being used for x86, __fastcall for x64
+
+IFNDEF ARCH_X86_64
+.686p
+.xmm
+.model flat, c
+ENDIF
+
+.data
+ALIGN 16
+ssemask DWORD 0FFFFFFFFh, 0FFFFFFFFh, 0FFFFFFFFh, 00000000h
+
+.code
+
+; dummy
+IFNDEF ARCH_X86_64
+	.safeseh SEH_handler
+	SEH_handler   proc
+		ret
+	SEH_handler   endp
+ENDIF
+
+IFDEF ARCH_X86_64
+	Sys_SnapVector PROC
+		movaps xmm1, ssemask		; initialize the mask register
+		movups xmm0, [rcx]			; here is stored our vector. Read 4 values in one go
+		movaps xmm2, xmm0			; keep a copy of the original data
+		andps xmm0, xmm1			; set the fourth value to zero in xmm0
+		andnps xmm1, xmm2			; copy fourth value to xmm1 and set rest to zero
+		cvtps2dq xmm0, xmm0			; convert 4 single fp to int
+		cvtdq2ps xmm0, xmm0			; convert 4 int to single fp
+		orps xmm0, xmm1				; combine all 4 values again
+		movups [rcx], xmm0			; write 3 rounded and 1 unchanged values back to memory
+		ret
+	Sys_SnapVector ENDP
+
+	Q_VMftol PROC
+		movss xmm0, dword ptr [rdi + rbx * 4]
+		cvttss2si eax, xmm0
+		ret
+	Q_VMftol ENDP
+
+	qvmcall64 PROC
+		push rsi					; push non-volatile registers to stack
+		push rdi
+		push rbx
+		push rcx					; need to save pointer in rcx so we can write back the programData value to caller
+
+		; registers r8 and r9 have correct value already thanx to __fastcall
+		xor rbx, rbx				; opStackOfs starts out being 0
+		mov rdi, rdx				; opStack
+		mov esi, dword ptr [rcx]	; programStack
+
+		call qword ptr [r8]			; instructionPointers[0] is also the entry point
+
+		pop rcx
+
+		mov dword ptr [rcx], esi	; write back the programStack value
+		mov al, bl					; return opStack offset
+
+		pop rbx
+		pop rdi
+		pop rsi
+
+		ret
+	qvmcall64 ENDP
+ELSE
+	Sys_SnapVector PROC
+		mov eax, dword ptr 4[esp]	; store address of vector in eax
+		movaps xmm1, ssemask		; initialize the mask register for maskmovdqu
+		movups xmm0, [eax]			; here is stored our vector. Read 4 values in one go
+		movaps xmm2, xmm0			; keep a copy of the original data
+		andps xmm0, xmm1			; set the fourth value to zero in xmm0
+		andnps xmm1, xmm2			; copy fourth value to xmm1 and set rest to zero
+		cvtps2dq xmm0, xmm0			; convert 4 single fp to int
+		cvtdq2ps xmm0, xmm0			; convert 4 int to single fp
+		orps xmm0, xmm1				; combine all 4 values again
+		movups [eax], xmm0			; write 3 rounded and 1 unchanged values back to memory
+		ret
+	Sys_SnapVector ENDP
+
+	Q_VMftol PROC
+		movss xmm0, dword ptr [edi + ebx * 4]
+		cvttss2si eax, xmm0
+		ret
+	Q_VMftol ENDP
+ENDIF
+
+end