diff options
Diffstat (limited to 'arch/m68k/fpsp040/x_operr.S')
| -rw-r--r-- | arch/m68k/fpsp040/x_operr.S | 356 |
1 files changed, 356 insertions, 0 deletions
diff --git a/arch/m68k/fpsp040/x_operr.S b/arch/m68k/fpsp040/x_operr.S new file mode 100644 index 000000000000..b0f54bcb49a7 --- /dev/null +++ b/arch/m68k/fpsp040/x_operr.S @@ -0,0 +1,356 @@ +| +| x_operr.sa 3.5 7/1/91 +| +| fpsp_operr --- FPSP handler for operand error exception +| +| See 68040 User's Manual pp. 9-44f +| +| Note 1: For trap disabled 040 does the following: +| If the dest is a fp reg, then an extended precision non_signaling +| NAN is stored in the dest reg. If the dest format is b, w, or l and +| the source op is a NAN, then garbage is stored as the result (actually +| the upper 32 bits of the mantissa are sent to the integer unit). If +| the dest format is integer (b, w, l) and the operr is caused by +| integer overflow, or the source op is inf, then the result stored is +| garbage. +| There are three cases in which operr is incorrectly signaled on the +| 040. This occurs for move_out of format b, w, or l for the largest +| negative integer (-2^7 for b, -2^15 for w, -2^31 for l). +| +| On opclass = 011 fmove.(b,w,l) that causes a conversion +| overflow -> OPERR, the exponent in wbte (and fpte) is: +| byte 56 - (62 - exp) +| word 48 - (62 - exp) +| long 32 - (62 - exp) +| +| where exp = (true exp) - 1 +| +| So, wbtemp and fptemp will contain the following on erroneously +| signalled operr: +| fpts = 1 +| fpte = $4000 (15 bit externally) +| byte fptm = $ffffffff ffffff80 +| word fptm = $ffffffff ffff8000 +| long fptm = $ffffffff 80000000 +| +| Note 2: For trap enabled 040 does the following: +| If the inst is move_out, then same as Note 1. +| If the inst is not move_out, the dest is not modified. +| The exceptional operand is not defined for integer overflow +| during a move_out. +| + +| Copyright (C) Motorola, Inc. 1990 +| All Rights Reserved +| +| THIS IS UNPUBLISHED PROPRIETARY SOURCE CODE OF MOTOROLA +| The copyright notice above does not evidence any +| actual or intended publication of such source code. + +X_OPERR: |idnt 2,1 | Motorola 040 Floating Point Software Package + + |section 8 + +#include "fpsp.h" + + |xref mem_write + |xref real_operr + |xref real_inex + |xref get_fline + |xref fpsp_done + |xref reg_dest + + .global fpsp_operr +fpsp_operr: +| + link %a6,#-LOCAL_SIZE + fsave -(%a7) + moveml %d0-%d1/%a0-%a1,USER_DA(%a6) + fmovemx %fp0-%fp3,USER_FP0(%a6) + fmoveml %fpcr/%fpsr/%fpiar,USER_FPCR(%a6) + +| +| Check if this is an opclass 3 instruction. +| If so, fall through, else branch to operr_end +| + btstb #TFLAG,T_BYTE(%a6) + beqs operr_end + +| +| If the destination size is B,W,or L, the operr must be +| handled here. +| + movel CMDREG1B(%a6),%d0 + bfextu %d0{#3:#3},%d0 |0=long, 4=word, 6=byte + cmpib #0,%d0 |determine size; check long + beq operr_long + cmpib #4,%d0 |check word + beq operr_word + cmpib #6,%d0 |check byte + beq operr_byte + +| +| The size is not B,W,or L, so the operr is handled by the +| kernel handler. Set the operr bits and clean up, leaving +| only the integer exception frame on the stack, and the +| fpu in the original exceptional state. +| +operr_end: + bsetb #operr_bit,FPSR_EXCEPT(%a6) + bsetb #aiop_bit,FPSR_AEXCEPT(%a6) + + moveml USER_DA(%a6),%d0-%d1/%a0-%a1 + fmovemx USER_FP0(%a6),%fp0-%fp3 + fmoveml USER_FPCR(%a6),%fpcr/%fpsr/%fpiar + frestore (%a7)+ + unlk %a6 + bral real_operr + +operr_long: + moveql #4,%d1 |write size to d1 + moveb STAG(%a6),%d0 |test stag for nan + andib #0xe0,%d0 |clr all but tag + cmpib #0x60,%d0 |check for nan + beq operr_nan + cmpil #0x80000000,FPTEMP_LO(%a6) |test if ls lword is special + bnes chklerr |if not equal, check for incorrect operr + bsr check_upper |check if exp and ms mant are special + tstl %d0 + bnes chklerr |if d0 is true, check for incorrect operr + movel #0x80000000,%d0 |store special case result + bsr operr_store + bra not_enabled |clean and exit +| +| CHECK FOR INCORRECTLY GENERATED OPERR EXCEPTION HERE +| +chklerr: + movew FPTEMP_EX(%a6),%d0 + andw #0x7FFF,%d0 |ignore sign bit + cmpw #0x3FFE,%d0 |this is the only possible exponent value + bnes chklerr2 +fixlong: + movel FPTEMP_LO(%a6),%d0 + bsr operr_store + bra not_enabled +chklerr2: + movew FPTEMP_EX(%a6),%d0 + andw #0x7FFF,%d0 |ignore sign bit + cmpw #0x4000,%d0 + bcc store_max |exponent out of range + + movel FPTEMP_LO(%a6),%d0 + andl #0x7FFF0000,%d0 |look for all 1's on bits 30-16 + cmpl #0x7FFF0000,%d0 + beqs fixlong + + tstl FPTEMP_LO(%a6) + bpls chklepos + cmpl #0xFFFFFFFF,FPTEMP_HI(%a6) + beqs fixlong + bra store_max +chklepos: + tstl FPTEMP_HI(%a6) + beqs fixlong + bra store_max + +operr_word: + moveql #2,%d1 |write size to d1 + moveb STAG(%a6),%d0 |test stag for nan + andib #0xe0,%d0 |clr all but tag + cmpib #0x60,%d0 |check for nan + beq operr_nan + cmpil #0xffff8000,FPTEMP_LO(%a6) |test if ls lword is special + bnes chkwerr |if not equal, check for incorrect operr + bsr check_upper |check if exp and ms mant are special + tstl %d0 + bnes chkwerr |if d0 is true, check for incorrect operr + movel #0x80000000,%d0 |store special case result + bsr operr_store + bra not_enabled |clean and exit +| +| CHECK FOR INCORRECTLY GENERATED OPERR EXCEPTION HERE +| +chkwerr: + movew FPTEMP_EX(%a6),%d0 + andw #0x7FFF,%d0 |ignore sign bit + cmpw #0x3FFE,%d0 |this is the only possible exponent value + bnes store_max + movel FPTEMP_LO(%a6),%d0 + swap %d0 + bsr operr_store + bra not_enabled + +operr_byte: + moveql #1,%d1 |write size to d1 + moveb STAG(%a6),%d0 |test stag for nan + andib #0xe0,%d0 |clr all but tag + cmpib #0x60,%d0 |check for nan + beqs operr_nan + cmpil #0xffffff80,FPTEMP_LO(%a6) |test if ls lword is special + bnes chkberr |if not equal, check for incorrect operr + bsr check_upper |check if exp and ms mant are special + tstl %d0 + bnes chkberr |if d0 is true, check for incorrect operr + movel #0x80000000,%d0 |store special case result + bsr operr_store + bra not_enabled |clean and exit +| +| CHECK FOR INCORRECTLY GENERATED OPERR EXCEPTION HERE +| +chkberr: + movew FPTEMP_EX(%a6),%d0 + andw #0x7FFF,%d0 |ignore sign bit + cmpw #0x3FFE,%d0 |this is the only possible exponent value + bnes store_max + movel FPTEMP_LO(%a6),%d0 + asll #8,%d0 + swap %d0 + bsr operr_store + bra not_enabled + +| +| This operr condition is not of the special case. Set operr +| and aiop and write the portion of the nan to memory for the +| given size. +| +operr_nan: + orl #opaop_mask,USER_FPSR(%a6) |set operr & aiop + + movel ETEMP_HI(%a6),%d0 |output will be from upper 32 bits + bsr operr_store + bra end_operr +| +| Store_max loads the max pos or negative for the size, sets +| the operr and aiop bits, and clears inex and ainex, incorrectly +| set by the 040. +| +store_max: + orl #opaop_mask,USER_FPSR(%a6) |set operr & aiop + bclrb #inex2_bit,FPSR_EXCEPT(%a6) + bclrb #ainex_bit,FPSR_AEXCEPT(%a6) + fmovel #0,%FPSR + + tstw FPTEMP_EX(%a6) |check sign + blts load_neg + movel #0x7fffffff,%d0 + bsr operr_store + bra end_operr +load_neg: + movel #0x80000000,%d0 + bsr operr_store + bra end_operr + +| +| This routine stores the data in d0, for the given size in d1, +| to memory or data register as required. A read of the fline +| is required to determine the destination. +| +operr_store: + movel %d0,L_SCR1(%a6) |move write data to L_SCR1 + movel %d1,-(%a7) |save register size + bsrl get_fline |fline returned in d0 + movel (%a7)+,%d1 + bftst %d0{#26:#3} |if mode is zero, dest is Dn + bnes dest_mem +| +| Destination is Dn. Get register number from d0. Data is on +| the stack at (a7). D1 has size: 1=byte,2=word,4=long/single +| + andil #7,%d0 |isolate register number + cmpil #4,%d1 + beqs op_long |the most frequent case + cmpil #2,%d1 + bnes op_con + orl #8,%d0 + bras op_con +op_long: + orl #0x10,%d0 +op_con: + movel %d0,%d1 |format size:reg for reg_dest + bral reg_dest |call to reg_dest returns to caller +| ;of operr_store +| +| Destination is memory. Get <ea> from integer exception frame +| and call mem_write. +| +dest_mem: + leal L_SCR1(%a6),%a0 |put ptr to write data in a0 + movel EXC_EA(%a6),%a1 |put user destination address in a1 + movel %d1,%d0 |put size in d0 + bsrl mem_write + rts +| +| Check the exponent for $c000 and the upper 32 bits of the +| mantissa for $ffffffff. If both are true, return d0 clr +| and store the lower n bits of the least lword of FPTEMP +| to d0 for write out. If not, it is a real operr, and set d0. +| +check_upper: + cmpil #0xffffffff,FPTEMP_HI(%a6) |check if first byte is all 1's + bnes true_operr |if not all 1's then was true operr + cmpiw #0xc000,FPTEMP_EX(%a6) |check if incorrectly signalled + beqs not_true_operr |branch if not true operr + cmpiw #0xbfff,FPTEMP_EX(%a6) |check if incorrectly signalled + beqs not_true_operr |branch if not true operr +true_operr: + movel #1,%d0 |signal real operr + rts +not_true_operr: + clrl %d0 |signal no real operr + rts + +| +| End_operr tests for operr enabled. If not, it cleans up the stack +| and does an rte. If enabled, it cleans up the stack and branches +| to the kernel operr handler with only the integer exception +| frame on the stack and the fpu in the original exceptional state +| with correct data written to the destination. +| +end_operr: + btstb #operr_bit,FPCR_ENABLE(%a6) + beqs not_enabled +enabled: + moveml USER_DA(%a6),%d0-%d1/%a0-%a1 + fmovemx USER_FP0(%a6),%fp0-%fp3 + fmoveml USER_FPCR(%a6),%fpcr/%fpsr/%fpiar + frestore (%a7)+ + unlk %a6 + bral real_operr + +not_enabled: +| +| It is possible to have either inex2 or inex1 exceptions with the +| operr. If the inex enable bit is set in the FPCR, and either +| inex2 or inex1 occurred, we must clean up and branch to the +| real inex handler. +| +ck_inex: + moveb FPCR_ENABLE(%a6),%d0 + andb FPSR_EXCEPT(%a6),%d0 + andib #0x3,%d0 + beq operr_exit +| +| Inexact enabled and reported, and we must take an inexact exception. +| +take_inex: + moveb #INEX_VEC,EXC_VEC+1(%a6) + movel USER_FPSR(%a6),FPSR_SHADOW(%a6) + orl #sx_mask,E_BYTE(%a6) + moveml USER_DA(%a6),%d0-%d1/%a0-%a1 + fmovemx USER_FP0(%a6),%fp0-%fp3 + fmoveml USER_FPCR(%a6),%fpcr/%fpsr/%fpiar + frestore (%a7)+ + unlk %a6 + bral real_inex +| +| Since operr is only an E1 exception, there is no need to frestore +| any state back to the fpu. +| +operr_exit: + moveml USER_DA(%a6),%d0-%d1/%a0-%a1 + fmovemx USER_FP0(%a6),%fp0-%fp3 + fmoveml USER_FPCR(%a6),%fpcr/%fpsr/%fpiar + unlk %a6 + bral fpsp_done + + |end |