| MOTOROLA MICROPROCESSOR & MEMORY TECHNOLOGY GROUP | M68000 Hi-Performance Microprocessor Division | M68040 Software Package | | M68040 Software Package Copyright (c) 1993, 1994 Motorola Inc. | All rights reserved. | | THE SOFTWARE is provided on an "AS IS" basis and without warranty. | To the maximum extent permitted by applicable law, | MOTOROLA DISCLAIMS ALL WARRANTIES WHETHER EXPRESS OR IMPLIED, | INCLUDING IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A | PARTICULAR PURPOSE and any warranty against infringement with | regard to the SOFTWARE (INCLUDING ANY MODIFIED VERSIONS THEREOF) | and any accompanying written materials. | | To the maximum extent permitted by applicable law, | IN NO EVENT SHALL MOTOROLA BE LIABLE FOR ANY DAMAGES WHATSOEVER | (INCLUDING WITHOUT LIMITATION, DAMAGES FOR LOSS OF BUSINESS | PROFITS, BUSINESS INTERRUPTION, LOSS OF BUSINESS INFORMATION, OR | OTHER PECUNIARY LOSS) ARISING OF THE USE OR INABILITY TO USE THE | SOFTWARE. Motorola assumes no responsibility for the maintenance | and support of the SOFTWARE. | | You are hereby granted a copyright license to use, modify, and | distribute the SOFTWARE so long as this entire notice is retained | without alteration in any modified and/or redistributed versions, | and that such modified versions are clearly identified as such. | No licenses are granted by implication, estoppel or otherwise | under any patents or trademarks of Motorola, Inc. | | gen_except.sa 3.7 1/16/92 | | gen_except --- FPSP routine to detect reportable exceptions | | This routine compares the exception enable byte of the | user_fpcr on the stack with the exception status byte | of the user_fpsr. | | Any routine which may report an exceptions must load | the stack frame in memory with the exceptional operand(s). | | Priority for exceptions is: | | Highest: bsun | snan | operr | ovfl | unfl | dz | inex2 | Lowest: inex1 | | Note: The IEEE standard specifies that inex2 is to be | reported if ovfl occurs and the ovfl enable bit is not | set but the inex2 enable bit is. | |GEN_EXCEPT IDNT 2,1 Motorola 040 Floating Point Software Package .text .include "fpsp.defs" | xref real_trace | xref fpsp_done | xref fpsp_fmt_error exc_tbl: .long bsun_exc .long commonE1 .long commonE1 .long ovfl_unfl .long ovfl_unfl .long commonE1 .long commonE3 .long commonE3 .long no_match .global gen_except gen_except: cmpib #IDLE_SIZE-4,a7@(1) |test for idle frame beq do_check |go handle idle frame cmpib #UNIMP_40_SIZE-4,a7@(1) |test for orig unimp frame beqs unimp_x |go handle unimp frame cmpib #UNIMP_41_SIZE-4,a7@(1) |test for rev unimp frame beqs unimp_x |go handle unimp frame cmpib #BUSY_SIZE-4,a7@(1) |if size <> 0x60, fmt error bnel fpsp_fmt_error lea a7@(BUSY_SIZE+LOCAL_SIZE),a1 |init a1 so fpsp.h | ;equates will work | Fix up the new busy frame with entries from the unimp frame | movel a6@(ETEMP_EX),a1@(ETEMP_EX) |copy etemp from unimp movel a6@(ETEMP_HI),a1@(ETEMP_HI) |frame to busy frame movel a6@(ETEMP_LO),a1@(ETEMP_LO) | movel a6@(CMDREG1B),a1@(CMDREG1B) |set inst in frame to unimp movel a6@(CMDREG1B),d0 |fix cmd1b to make it andl #0x03c30000,d0 |work for cmd3b bfextu a6@(CMDREG1B){#13:#1},d1 |extract bit 2 lsll #5,d1 | swap d1 orl d1,d0 |put it in the right place bfextu a6@(CMDREG1B){#10:#3},d1 |extract bit 3,4,5 lsll #2,d1 swap d1 orl d1,d0 |put them in the right place movel d0,a1@(CMDREG3B) |in the busy frame | | Or in the FPSR from the emulation with the USER_FPSR on the stack. | fmovel FPSR,d0 | orl d0,a6@(USER_FPSR) movel a6@(USER_FPSR),a1@(FPSR_SHADOW) |set exc bits orl #sx_mask,a1@(E_BYTE) bra do_clean | | Frame is an unimp frame possible resulting from an fmove ,fp0 | that caused an exception | | a1 is modified to point into the new frame allowing fpsp equates | to be valid. | unimp_x: cmpib #UNIMP_40_SIZE-4,a7@(1) |test for orig unimp frame bnes test_rev lea a7@(UNIMP_40_SIZE+LOCAL_SIZE),a1 bras unimp_con test_rev: cmpib #UNIMP_41_SIZE-4,a7@(1) |test for rev unimp frame bnel fpsp_fmt_error |if not 0x28 or 0x30 lea a7@(UNIMP_41_SIZE+LOCAL_SIZE),a1 unimp_con: | | Fix up the new unimp frame with entries from the old unimp frame | movel a6@(CMDREG1B),a1@(CMDREG1B) |set inst in frame to unimp | | Or in the FPSR from the emulation with the USER_FPSR on the stack. | fmovel FPSR,d0 | orl d0,a6@(USER_FPSR) bra do_clean | | Frame is idle, so check for exceptions reported through | USER_FPSR and set the unimp frame accordingly. | A7 must be incremented to the point before the | idle fsave vector to the unimp vector. | do_check: addl #4,A7 |point A7 back to unimp frame | | Or in the FPSR from the emulation with the USER_FPSR on the stack. | fmovel FPSR,d0 | orl d0,a6@(USER_FPSR) | | On a busy frame, we must clear the nmnexc bits. | cmpib #BUSY_SIZE-4,a7@(1) |check frame type bnes check_fr |if busy, clr nmnexc clrw a6@(NMNEXC) |clr nmnexc & nmcexc btst #5,a6@(CMDREG1B) |test for fmove out bnes frame_com movel a6@(USER_FPSR),a6@(FPSR_SHADOW) |set exc bits orl #sx_mask,a6@(E_BYTE) bras frame_com check_fr: cmpb #UNIMP_40_SIZE-4,a7@(1) beqs frame_com clrw a6@(NMNEXC) frame_com: moveb a6@(FPCR_ENABLE),d0 |get fpcr enable byte andb a6@(FPSR_EXCEPT),d0 |and in the fpsr exc byte bfffo d0{#24:#8},d1 |test for first set bit lea exc_tbl,a0 |load jmp table address subib #24,d1 |normalize bit offset to 0-8 movel a0@(d1:w:4),a0 |load routine address based | ;based on first enabled exc jmp a0@ |jump to routine | | Bsun is not possible in unimp or unsupp | bsun_exc: bra do_clean | | The typical work to be done to the unimp frame to report an | exception is to set the E1/E3 byte and clr the U flag. | commonE1 does this for E1 exceptions, which are snan, | operr, and dz. commonE3 does this for E3 exceptions, which | are inex2 and inex1, and also clears the E1 exception bit | left over from the unimp exception. | commonE1: bset #E1,a6@(E_BYTE) |set E1 flag bra commonE |go clean and exit commonE3: tstb a6@(UFLG_TMP) |test flag for unsup/unimp state bnes unsE3 uniE3: bset #E3,a6@(E_BYTE) |set E3 flag bclr #E1,a6@(E_BYTE) |clr E1 from unimp bra commonE unsE3: tstb a6@(RES_FLG) bnes unsE3_0 | unsE3_1: bset #E3,a6@(E_BYTE) |set E3 flag unsE3_0: bclr #E1,a6@(E_BYTE) |clr E1 flag movel a6@(CMDREG1B),d0 andl #0x03c30000,d0 |work for cmd3b bfextu a6@(CMDREG1B){#13:#1},d1 |extract bit 2 lsll #5,d1 | swap d1 orl d1,d0 |put it in the right place bfextu a6@(CMDREG1B){#10:#3},d1 |extract bit 3,4,5 lsll #2,d1 swap d1 orl d1,d0 |put them in the right place movel d0,a6@(CMDREG3B) |in the busy frame commonE: bclr #UFLAG,a6@(T_BYTE) |clr U flag from unimp bra do_clean |go clean and exit | | No bits in the enable byte match existing exceptions. Check for | the case of the ovfl exc without the ovfl enabled, but with | inex2 enabled. | no_match: btst #inex2_bit,a6@(FPCR_ENABLE) |check for ovfl/inex2 case beqs no_exc |if clear, exit btst #ovfl_bit,a6@(FPSR_EXCEPT) |now check ovfl beqs no_exc |if clear, exit bras ovfl_unfl |go to unfl_ovfl to determine if | ;it is an unsupp or unimp exc | No exceptions are to be reported. If the instruction was | unimplemented, no FPU restore is necessary. If it was | unsupported, we must perform the restore. no_exc: tstb a6@(UFLG_TMP) |test flag for unsupp/unimp state beqs uni_no_exc uns_no_exc: tstb a6@(RES_FLG) |check if frestore is needed bne do_clean |if clear, no frestore needed uni_no_exc: moveml a6@(USER_DA),d0-d1/a0-a1 fmovemx a6@(USER_FP0),fp0-fp3 fmoveml a6@(USER_FPCR),fpcr/fpsr/fpi unlk a6 bra finish_up | | Unsupported Data Type Handler: | Ovfl: | An fmoveout that results in an overflow is reported this way. | Unfl: | An fmoveout that results in an underflow is reported this way. | | Unimplemented Instruction Handler: | Ovfl: | Only scosh, setox, ssinh, stwotox, and scale can set overflow in | this manner. | Unfl: | Stwotox, setox, and scale can set underflow in this manner. | Any of the other Library Routines such that f(x)=x in which | x is an extended denorm can report an underflow exception. | It is the responsibility of the exception-causing exception | to make sure that WBTEMP is correct. | | The exceptional operand is in FP_SCR1. | ovfl_unfl: tstb a6@(UFLG_TMP) |test flag for unsupp/unimp state beqs ofuf_con | | The caller was from an unsupported data type trap. Test if the | caller set CU_ONLY. If so, the exceptional operand is expected in | FPTEMP, rather than WBTEMP. | tstb a6@(CU_ONLY) |test if inst is cu-only beq unsE3 | move.w #0xfe,a6@(CU_SAVEPC) clrb a6@(CU_SAVEPC) bset #E1,a6@(E_BYTE) |set E1 exception flag movew a6@(ETEMP_EX),a6@(FPTEMP_EX) movel a6@(ETEMP_HI),a6@(FPTEMP_HI) movel a6@(ETEMP_LO),a6@(FPTEMP_LO) bset #fptemp15_bit,a6@(DTAG) |set fpte15 bclr #UFLAG,a6@(T_BYTE) |clr U flag from unimp bra do_clean |go clean and exit ofuf_con: moveb a7@,a6@(VER_TMP) |save version number cmpib #BUSY_SIZE-4,a7@(1) |check for busy frame beqs busy_fr |if unimp, grow to busy cmpib #VER_40,a7@ |test for orig unimp frame bnes try_41 |if not, test for rev frame moveql #13,d0 |need to zero 14 lwords bras ofuf_fin try_41: cmpib #VER_41,a7@ |test for rev unimp frame bnel fpsp_fmt_error |if neither, exit with error moveql #11,d0 |need to zero 12 lwords ofuf_fin: clrl a7@ loop1: clrl a7@- |clear and dec a7 dbra d0,loop1 moveb a6@(VER_TMP),a7@ moveb #BUSY_SIZE-4,a7@(1) |write busy fmt word. busy_fr: movel a6@(FP_SCR1),a6@(WBTEMP_EX) |write movel a6@(FP_SCR1+4),a6@(WBTEMP_HI) |execptional op to movel a6@(FP_SCR1+8),a6@(WBTEMP_LO) |wbtemp bset #E3,a6@(E_BYTE) |set E3 flag bclr #E1,a6@(E_BYTE) |make sure E1 is clear bclr #UFLAG,a6@(T_BYTE) |clr U flag movel a6@(USER_FPSR),a6@(FPSR_SHADOW) orl #sx_mask,a6@(E_BYTE) movel a6@(CMDREG1B),d0 |fix cmd1b to make it andl #0x03c30000,d0 |work for cmd3b bfextu a6@(CMDREG1B){#13:#1},d1 |extract bit 2 lsll #5,d1 | swap d1 orl d1,d0 |put it in the right place bfextu a6@(CMDREG1B){#10:#3},d1 |extract bit 3,4,5 lsll #2,d1 swap d1 orl d1,d0 |put them in the right place movel d0,a6@(CMDREG3B) |in the busy frame | | Check if the frame to be restored is busy or unimp. |** NOTE *** Bug fix for errata (0d43b #3) | If the frame is unimp, we must create a busy frame to | fix the bug with the nmnexc bits in cases in which they | are set by a previous instruction and not cleared by | the save. The frame will be unimp only if the final | instruction in an emulation routine caused the exception | by doing an fmove ,fp0. The exception operand, in | internal format, is in fptemp. | do_clean: cmpib #UNIMP_40_SIZE-4,a7@(1) bnes do_con moveql #13,d0 |in orig, need to zero 14 lwords bras do_build do_con: cmpib #UNIMP_41_SIZE-4,a7@(1) bnes do_restore |frame must be busy moveql #11,d0 |in rev, need to zero 12 lwords do_build: moveb a7@,a6@(VER_TMP) clrl a7@ loop2: clrl a7@- |clear and dec a7 dbra d0,loop2 | | Use a1 as pointer into new frame. a6 is not correct if an unimp or | busy frame was created as the result of an exception on the final | instruction of an emulation routine. | | We need to set the nmcexc bits if the exception is E1. Otherwise, | the exc taken will be inex2. | lea a7@(BUSY_SIZE+LOCAL_SIZE),a1 |init a1 for new frame moveb a6@(VER_TMP),a7@ |write busy fmt word moveb #BUSY_SIZE-4,a7@(1) movel a6@(FP_SCR1),a1@(WBTEMP_EX) |write movel a6@(FP_SCR1+4),a1@(WBTEMP_HI) |exceptional op to movel a6@(FP_SCR1+8),a1@(WBTEMP_LO) |wbtemp | btst.b #E1,a1@(E_BYTE) | beq.b do_restore bfextu a6@(USER_FPSR){#17:#4},d0 |get snan/operr/ovfl/unfl bits bfins d0,a1@(NMCEXC){#4:#4} |and insert them in nmcexc movel a6@(USER_FPSR),a1@(FPSR_SHADOW) |set exc bits orl #sx_mask,a1@(E_BYTE) do_restore: moveml a6@(USER_DA),d0-d1/a0-a1 fmovemx a6@(USER_FP0),fp0-fp3 fmoveml a6@(USER_FPCR),fpcr/fpsr/fpi frestore a7@+ tstb a6@(RES_FLG) |RES_FLG indicates a "continuation" frame beq cont bsr bug1384 cont: unlk a6 | | If trace mode enabled, then go to trace handler. This handler | cannot have any fp instructions. If there are fp inst's and an | exception has been restored into the machine then the exception | will occur upon execution of the fp inst. This is not desirable | in the kernel (supervisor mode). See MC68040 manual Section 9.3.8. | finish_up: btst #7,a7@ |test T1 in SR bnes g_trace btst #6,a7@ |test T0 in SR bnes g_trace bral fpsp_done | | Change integer stack to look like trace stack | The address of the instruction that caused the | exception is already in the integer stack (is | the same as the saved friar) | | If the current frame is already a 6-word stack then all | that needs to be done is to change the vector# to TRACE. | If the frame is only a 4-word stack (meaning we got here | on an Unsupported data type exception), then we need to grow | the stack an extra 2 words and get the FPI from the FPU. | g_trace: bftst sp@(EXC_VEC-4){#0:#4} bne g_easy subql #4,sp |make room movel sp@(4),sp@ movel sp@(8),sp@(4) subl #BUSY_SIZE,sp fsave sp@ fmovel fpi,sp@(BUSY_SIZE+EXC_EA-4) frestore sp@ addl #BUSY_SIZE,sp g_easy: movew #TRACE_VEC,a7@(EXC_VEC-4) bral real_trace | | This is a work-around for hardware bug 1384. | bug1384: link a5,#0 fsave sp@- cmpib #0x41,sp@ | check for correct frame beq frame_41 bgt nofix | if more advanced mask, do nada frame_40: tstb sp@(1) | check to see if idle bne notidle idle40: clrl sp@ | get rid of old fsave frame movel d1,a6@(USER_D1) | save d1 movew #8,d1 | place unimp frame instead loop40: clrl sp@- dbra d1,loop40 movel a6@(USER_D1),d1 | restore d1 movel #0x40280000,sp@- frestore sp@+ unlk a5 | rts frame_41: tstb sp@(1) | check to see if idle bne notidle | idle41: clrl sp@ | get rid of old fsave frame movel d1,a6@(USER_D1) | save d1 movew #10,d1 | place unimp frame instead loop41: clrl sp@- dbra d1,loop41 movel a6@(USER_D1),d1 | restore d1 movel #0x41300000,sp@- frestore sp@+ unlk a5 | rts notidle: bclr #etemp15_bit,a5@(-40) | frestore sp@+ unlk a5 | rts nofix: frestore sp@+ unlk a5 | rts | end