diff --git a/code/qcommon/vm_x86.c b/code/qcommon/vm_x86.c index 8701fd83..bfdf79b5 100644 --- a/code/qcommon/vm_x86.c +++ b/code/qcommon/vm_x86.c @@ -329,7 +329,7 @@ qboolean EmitMovEBXEDI(vm_t *vm, int andit) { /* ================= DoSyscall -Uses asm to get arguments from stack to work around different calling conventions +Uses asm to retrieve arguments from registers to work around different calling conventions ================= */ @@ -342,7 +342,6 @@ static void DoSyscall(void) int programStack; int *opStack; - // Get arguments directly from registers to work around different calling conventions #ifdef _MSC_VER __asm { @@ -417,8 +416,8 @@ int EmitCallProcedure(vm_t *vm) retval = compiledOfs; EmitString("F7 D0"); // not eax - // use ecx register to store DoSyscall address - EmitString("B9"); // mov ecx, DoSyscall + // use edx register to store DoSyscall address + EmitString("BA"); // mov edx, DoSyscall Emit4((intptr_t) DoSyscall); // align the stack pointer to a 16-byte-boundary @@ -427,7 +426,7 @@ int EmitCallProcedure(vm_t *vm) EmitString("83 E4 F0"); // and esp, 0xFFFFFFF0 // call the syscall wrapper function - EmitString("FF D1"); // call ecx + EmitString("FF D2"); // call edx // reset the stack pointer to its previous value EmitString("89 EC"); // mov esp, ebp @@ -442,26 +441,24 @@ int EmitCallProcedure(vm_t *vm) void EmitCall(vm_t *vm, int sysCallOfs) { - EmitString("51"); // push ecx - EmitString("8B 0D"); // mov ecx, dword ptr [&vm->codeBase] + EmitString("8B 15"); // mov edx, [dword ptr vm->codeBase] Emit4((intptr_t) &vm->codeBase); if(sysCallOfs) { if(sysCallOfs < 0x80 || sysCallOfs > 0x7f) { - EmitString("83 C1"); // add ecx, sysCallOfs + EmitString("83 C2"); // add edx, sysCallOfs Emit1(sysCallOfs); } else { - EmitString("81 C1"); // add ecx, sysCallOfs + EmitString("81 C2"); // add edx, sysCallOfs Emit4(sysCallOfs); } } - EmitString("FF D1"); // call ecx - EmitString("59"); // pop ecx + EmitString("FF D2"); // call edx } /* @@ -1258,7 +1255,7 @@ void VM_Compile( vm_t *vm, vmHeader_t *header ) { break; case OP_DIVI: EmitString( "8B 47 FC" ); // mov eax,dword ptr [edi-4] - EmitString( "99" ); // cdq + EmitString( "99" ); // cdq EmitString( "F7 3F" ); // idiv dword ptr [edi] EmitString( "89 47 FC" ); // mov dword ptr [edi-4],eax EmitCommand(LAST_COMMAND_SUB_DI_4); // sub edi, 4 @@ -1272,7 +1269,7 @@ void VM_Compile( vm_t *vm, vmHeader_t *header ) { break; case OP_MODI: EmitString( "8B 47 FC" ); // mov eax,dword ptr [edi-4] - EmitString( "99" ); // cdq + EmitString( "99" ); // cdq EmitString( "F7 3F" ); // idiv dword ptr [edi] EmitString( "89 57 FC" ); // mov dword ptr [edi-4],edx EmitCommand(LAST_COMMAND_SUB_DI_4); // sub edi, 4 @@ -1546,18 +1543,16 @@ int VM_CallCompiled( vm_t *vm, int *args ) { popad } #else - /* These registers are used as scratch registers and are destroyed after the - * call. Do not use clobber, so they can be used as input for the asm. */ - unsigned eax; - unsigned ebx; - unsigned ecx; - unsigned edx; - __asm__ volatile( - "call *%6" - : "+S" (programStack), "+D" (opStack), - "=a" (eax), "=b" (ebx), "=c" (ecx), "=d" (edx) - : "mr" (vm->codeBase + vm->entryOfs) + "pushal\r\n" + "movl %0, %%esi\r\n" + "movl %1, %%edi\r\n" + "call *%2\r\n" + "movl %%edi, %1\r\n" + "movl %%esi, %0\r\n" + "popal\r\n" + : "+g" (programStack), "+g" (opStack) + : "g" (vm->codeBase + vm->entryOfs) : "cc", "memory" ); #endif