diff options
Diffstat (limited to 'arch/m68k/fpsp040/gen_except.S')
| -rw-r--r-- | arch/m68k/fpsp040/gen_except.S | 467 |
1 files changed, 467 insertions, 0 deletions
diff --git a/arch/m68k/fpsp040/gen_except.S b/arch/m68k/fpsp040/gen_except.S new file mode 100644 index 000000000..3642cb7e3 --- /dev/null +++ b/arch/m68k/fpsp040/gen_except.S @@ -0,0 +1,467 @@ +| +| 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. +| +| +| Copyright (C) Motorola, Inc. 1990 +| All Rights Reserved +| +| For details on the license for this file, please see the +| file, README, in this same directory. + +GEN_EXCEPT: |idnt 2,1 | Motorola 040 Floating Point Software Package + + |section 8 + +#include "fpsp.h" + + |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-4,1(%a7) |test for idle frame + beq do_check |go handle idle frame + cmpib #UNIMP_40_SIZE-4,1(%a7) |test for orig unimp frame + beqs unimp_x |go handle unimp frame + cmpib #UNIMP_41_SIZE-4,1(%a7) |test for rev unimp frame + beqs unimp_x |go handle unimp frame + cmpib #BUSY_SIZE-4,1(%a7) |if size <> $60, fmt error + bnel fpsp_fmt_error + leal BUSY_SIZE+LOCAL_SIZE(%a7),%a1 |init a1 so fpsp.h +| ;equates will work +| Fix up the new busy frame with entries from the unimp frame +| + movel ETEMP_EX(%a6),ETEMP_EX(%a1) |copy etemp from unimp + movel ETEMP_HI(%a6),ETEMP_HI(%a1) |frame to busy frame + movel ETEMP_LO(%a6),ETEMP_LO(%a1) + movel CMDREG1B(%a6),CMDREG1B(%a1) |set inst in frame to unimp + movel CMDREG1B(%a6),%d0 |fix cmd1b to make it + andl #0x03c30000,%d0 |work for cmd3b + bfextu CMDREG1B(%a6){#13:#1},%d1 |extract bit 2 + lsll #5,%d1 + swap %d1 + orl %d1,%d0 |put it in the right place + bfextu CMDREG1B(%a6){#10:#3},%d1 |extract bit 3,4,5 + lsll #2,%d1 + swap %d1 + orl %d1,%d0 |put them in the right place + movel %d0,CMDREG3B(%a1) |in the busy frame +| +| Or in the FPSR from the emulation with the USER_FPSR on the stack. +| + fmovel %FPSR,%d0 + orl %d0,USER_FPSR(%a6) + movel USER_FPSR(%a6),FPSR_SHADOW(%a1) |set exc bits + orl #sx_mask,E_BYTE(%a1) + bra do_clean + +| +| Frame is an unimp frame possible resulting from an fmove <ea>,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-4,1(%a7) |test for orig unimp frame + bnes test_rev + leal UNIMP_40_SIZE+LOCAL_SIZE(%a7),%a1 + bras unimp_con +test_rev: + cmpib #UNIMP_41_SIZE-4,1(%a7) |test for rev unimp frame + bnel fpsp_fmt_error |if not $28 or $30 + leal UNIMP_41_SIZE+LOCAL_SIZE(%a7),%a1 + +unimp_con: +| +| Fix up the new unimp frame with entries from the old unimp frame +| + movel CMDREG1B(%a6),CMDREG1B(%a1) |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,USER_FPSR(%a6) + 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,USER_FPSR(%a6) +| +| On a busy frame, we must clear the nmnexc bits. +| + cmpib #BUSY_SIZE-4,1(%a7) |check frame type + bnes check_fr |if busy, clr nmnexc + clrw NMNEXC(%a6) |clr nmnexc & nmcexc + btstb #5,CMDREG1B(%a6) |test for fmove out + bnes frame_com + movel USER_FPSR(%a6),FPSR_SHADOW(%a6) |set exc bits + orl #sx_mask,E_BYTE(%a6) + bras frame_com +check_fr: + cmpb #UNIMP_40_SIZE-4,1(%a7) + beqs frame_com + clrw NMNEXC(%a6) +frame_com: + moveb FPCR_ENABLE(%a6),%d0 |get fpcr enable byte + andb FPSR_EXCEPT(%a6),%d0 |and in the fpsr exc byte + bfffo %d0{#24:#8},%d1 |test for first set bit + leal 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: + bsetb #E1,E_BYTE(%a6) |set E1 flag + bra commonE |go clean and exit + +commonE3: + tstb UFLG_TMP(%a6) |test flag for unsup/unimp state + bnes unsE3 +uniE3: + bsetb #E3,E_BYTE(%a6) |set E3 flag + bclrb #E1,E_BYTE(%a6) |clr E1 from unimp + bra commonE + +unsE3: + tstb RES_FLG(%a6) + bnes unsE3_0 +unsE3_1: + bsetb #E3,E_BYTE(%a6) |set E3 flag +unsE3_0: + bclrb #E1,E_BYTE(%a6) |clr E1 flag + movel CMDREG1B(%a6),%d0 + andl #0x03c30000,%d0 |work for cmd3b + bfextu CMDREG1B(%a6){#13:#1},%d1 |extract bit 2 + lsll #5,%d1 + swap %d1 + orl %d1,%d0 |put it in the right place + bfextu CMDREG1B(%a6){#10:#3},%d1 |extract bit 3,4,5 + lsll #2,%d1 + swap %d1 + orl %d1,%d0 |put them in the right place + movel %d0,CMDREG3B(%a6) |in the busy frame + +commonE: + bclrb #UFLAG,T_BYTE(%a6) |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: + btstb #inex2_bit,FPCR_ENABLE(%a6) |check for ovfl/inex2 case + beqs no_exc |if clear, exit + btstb #ovfl_bit,FPSR_EXCEPT(%a6) |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 UFLG_TMP(%a6) |test flag for unsupp/unimp state + beqs uni_no_exc +uns_no_exc: + tstb RES_FLG(%a6) |check if frestore is needed + bne do_clean |if clear, no frestore needed +uni_no_exc: + moveml USER_DA(%a6),%d0-%d1/%a0-%a1 + fmovemx USER_FP0(%a6),%fp0-%fp3 + fmoveml USER_FPCR(%a6),%fpcr/%fpsr/%fpiar + 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 UFLG_TMP(%a6) |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 CU_ONLY(%a6) |test if inst is cu-only + beq unsE3 +| move.w #$fe,CU_SAVEPC(%a6) + clrb CU_SAVEPC(%a6) + bsetb #E1,E_BYTE(%a6) |set E1 exception flag + movew ETEMP_EX(%a6),FPTEMP_EX(%a6) + movel ETEMP_HI(%a6),FPTEMP_HI(%a6) + movel ETEMP_LO(%a6),FPTEMP_LO(%a6) + bsetb #fptemp15_bit,DTAG(%a6) |set fpte15 + bclrb #UFLAG,T_BYTE(%a6) |clr U flag from unimp + bra do_clean |go clean and exit + +ofuf_con: + moveb (%a7),VER_TMP(%a6) |save version number + cmpib #BUSY_SIZE-4,1(%a7) |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 VER_TMP(%a6),(%a7) + moveb #BUSY_SIZE-4,1(%a7) |write busy fmt word. +busy_fr: + movel FP_SCR1(%a6),WBTEMP_EX(%a6) |write + movel FP_SCR1+4(%a6),WBTEMP_HI(%a6) |exceptional op to + movel FP_SCR1+8(%a6),WBTEMP_LO(%a6) |wbtemp + bsetb #E3,E_BYTE(%a6) |set E3 flag + bclrb #E1,E_BYTE(%a6) |make sure E1 is clear + bclrb #UFLAG,T_BYTE(%a6) |clr U flag + movel USER_FPSR(%a6),FPSR_SHADOW(%a6) + orl #sx_mask,E_BYTE(%a6) + movel CMDREG1B(%a6),%d0 |fix cmd1b to make it + andl #0x03c30000,%d0 |work for cmd3b + bfextu CMDREG1B(%a6){#13:#1},%d1 |extract bit 2 + lsll #5,%d1 + swap %d1 + orl %d1,%d0 |put it in the right place + bfextu CMDREG1B(%a6){#10:#3},%d1 |extract bit 3,4,5 + lsll #2,%d1 + swap %d1 + orl %d1,%d0 |put them in the right place + movel %d0,CMDREG3B(%a6) |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 <ea>,fp0. The exception operand, in +| internal format, is in fptemp. +| +do_clean: + cmpib #UNIMP_40_SIZE-4,1(%a7) + bnes do_con + moveql #13,%d0 |in orig, need to zero 14 lwords + bras do_build +do_con: + cmpib #UNIMP_41_SIZE-4,1(%a7) + bnes do_restore |frame must be busy + moveql #11,%d0 |in rev, need to zero 12 lwords + +do_build: + moveb (%a7),VER_TMP(%a6) + 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. +| + leal BUSY_SIZE+LOCAL_SIZE(%a7),%a1 |init a1 for new frame + moveb VER_TMP(%a6),(%a7) |write busy fmt word + moveb #BUSY_SIZE-4,1(%a7) + movel FP_SCR1(%a6),WBTEMP_EX(%a1) |write + movel FP_SCR1+4(%a6),WBTEMP_HI(%a1) |exceptional op to + movel FP_SCR1+8(%a6),WBTEMP_LO(%a1) |wbtemp +| btst.b #E1,E_BYTE(%a1) +| beq.b do_restore + bfextu USER_FPSR(%a6){#17:#4},%d0 |get snan/operr/ovfl/unfl bits + bfins %d0,NMCEXC(%a1){#4:#4} |and insert them in nmcexc + movel USER_FPSR(%a6),FPSR_SHADOW(%a1) |set exc bits + orl #sx_mask,E_BYTE(%a1) + +do_restore: + moveml USER_DA(%a6),%d0-%d1/%a0-%a1 + fmovemx USER_FP0(%a6),%fp0-%fp3 + fmoveml USER_FPCR(%a6),%fpcr/%fpsr/%fpiar + frestore (%a7)+ + tstb RES_FLG(%a6) |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: + btstb #7,(%a7) |test T1 in SR + bnes g_trace + btstb #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 FPIAR from the FPU. +| +g_trace: + bftst EXC_VEC-4(%sp){#0:#4} + bne g_easy + + subw #4,%sp | make room + movel 4(%sp),(%sp) + movel 8(%sp),4(%sp) + subw #BUSY_SIZE,%sp + fsave (%sp) + fmovel %fpiar,BUSY_SIZE+EXC_EA-4(%sp) + frestore (%sp) + addw #BUSY_SIZE,%sp + +g_easy: + movew #TRACE_VEC,EXC_VEC-4(%a7) + 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 1(%sp) | check to see if idle + bne notidle +idle40: + clrl (%sp) | get rid of old fsave frame + movel %d1,USER_D1(%a6) | save d1 + movew #8,%d1 | place unimp frame instead +loop40: clrl -(%sp) + dbra %d1,loop40 + movel USER_D1(%a6),%d1 | restore d1 + movel #0x40280000,-(%sp) + frestore (%sp)+ + unlk %a5 + rts + +frame_41: + tstb 1(%sp) | check to see if idle + bne notidle +idle41: + clrl (%sp) | get rid of old fsave frame + movel %d1,USER_D1(%a6) | save d1 + movew #10,%d1 | place unimp frame instead +loop41: clrl -(%sp) + dbra %d1,loop41 + movel USER_D1(%a6),%d1 | restore d1 + movel #0x41300000,-(%sp) + frestore (%sp)+ + unlk %a5 + rts + +notidle: + bclrb #etemp15_bit,-40(%a5) + frestore (%sp)+ + unlk %a5 + rts + +nofix: + frestore (%sp)+ + unlk %a5 + rts + + |end |