1 // 2 // sys_dosa.s 3 // x86 assembly-language DOS-dependent routines. 4 5 #include "asm_i386.h" 6 #include "quakeasm.h" 7 8 9 .data 10 11 .align 4 12 fpenv: 13 .long 0, 0, 0, 0, 0, 0, 0, 0 14 15 .text 16 17 .globl C(MaskExceptions) 18 C(MaskExceptions): 19 fnstenv fpenv 20 orl $0x3F,fpenv 21 fldenv fpenv 22 23 ret 24 25 #if 0 26 .globl C(unmaskexceptions) 27 C(unmaskexceptions): 28 fnstenv fpenv 29 andl $0xFFFFFFE0,fpenv 30 fldenv fpenv 31 32 ret 33 #endif 34 35 .data 36 37 .align 4 38 .globl ceil_cw, single_cw, full_cw, cw, pushed_cw 39 ceil_cw: .long 0 40 single_cw: .long 0 41 full_cw: .long 0 42 cw: .long 0 43 pushed_cw: .long 0 44 45 .text 46 47 .globl C(Sys_LowFPPrecision) 48 C(Sys_LowFPPrecision): 49 fldcw single_cw 50 51 ret 52 53 .globl C(Sys_HighFPPrecision) 54 C(Sys_HighFPPrecision): 55 fldcw full_cw 56 57 ret 58 59 .globl C(Sys_PushFPCW_SetHigh) 60 C(Sys_PushFPCW_SetHigh): 61 fnstcw pushed_cw 62 fldcw full_cw 63 64 ret 65 66 .globl C(Sys_PopFPCW) 67 C(Sys_PopFPCW): 68 fldcw pushed_cw 69 70 ret 71 72 .globl C(Sys_SetFPCW) 73 C(Sys_SetFPCW): 74 fnstcw cw 75 movl cw,%eax 76 #if id386 77 andb $0xF0,%ah 78 orb $0x03,%ah // round mode, 64-bit precision 79 #endif 80 movl %eax,full_cw 81 82 #if id386 83 andb $0xF0,%ah 84 orb $0x0C,%ah // chop mode, single precision 85 #endif 86 movl %eax,single_cw 87 88 #if id386 89 andb $0xF0,%ah 90 orb $0x08,%ah // ceil mode, single precision 91 #endif 92 movl %eax,ceil_cw 93 94 ret 95 96
