diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/m68k/fpsp040/x_snan.S |
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'arch/m68k/fpsp040/x_snan.S')
-rw-r--r-- | arch/m68k/fpsp040/x_snan.S | 277 |
1 files changed, 277 insertions, 0 deletions
diff --git a/arch/m68k/fpsp040/x_snan.S b/arch/m68k/fpsp040/x_snan.S new file mode 100644 index 00000000000..039af573312 --- /dev/null +++ b/arch/m68k/fpsp040/x_snan.S @@ -0,0 +1,277 @@ +| +| x_snan.sa 3.3 7/1/91 +| +| fpsp_snan --- FPSP handler for signalling NAN exception +| +| SNAN for float -> integer conversions (integer conversion of +| an SNAN) is a non-maskable run-time exception. +| +| For trap disabled the 040 does the following: +| If the dest data format is s, d, or x, then the SNAN bit in the NAN +| is set to one and the resulting non-signaling NAN (truncated if +| necessary) is transferred to the dest. If the dest format is b, w, +| or l, then garbage is written to the dest (actually the upper 32 bits +| of the mantissa are sent to the integer unit). +| +| For trap enabled the 040 does the following: +| If the inst is move_out, then the results are the same as for trap +| disabled with the exception posted. If the instruction is not move_ +| out, the dest. is not modified, and the exception is posted. +| + +| Copyright (C) Motorola, Inc. 1990 +| All Rights Reserved +| +| THIS IS UNPUBLISHED PROPRIETARY SOURCE CODE OF MOTOROLA +| The copyright notice above does not evidence any +| actual or intended publication of such source code.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_SNAN: |idnt 2,1 | Motorola 040 Floating Point Software Package + + |section 8 + +#include "fpsp.h" + + |xref get_fline + |xref mem_write + |xref real_snan + |xref real_inex + |xref fpsp_done + |xref reg_dest + + .global fpsp_snan +fpsp_snan: + 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 trap enabled +| + btstb #snan_bit,FPCR_ENABLE(%a6) + bnes ena |If enabled, then branch + + bsrl move_out |else SNAN disabled +| +| It is possible to have an inex1 exception with the +| snan. 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 end_snan +| +| Inexact enabled and reported, and we must take an inexact exception. +| +take_inex: + moveb #INEX_VEC,EXC_VEC+1(%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 +| +| SNAN is enabled. Check if inst is move_out. +| Make any corrections to the 040 output as necessary. +| +ena: + btstb #5,CMDREG1B(%a6) |if set, inst is move out + beq not_out + + bsrl move_out + +report_snan: + moveb (%a7),VER_TMP(%a6) + cmpib #VER_40,(%a7) |test for orig unimp frame + bnes ck_rev + moveql #13,%d0 |need to zero 14 lwords + bras rep_con +ck_rev: + moveql #11,%d0 |need to zero 12 lwords +rep_con: + clrl (%a7) +loop1: + clrl -(%a7) |clear and dec a7 + dbra %d0,loop1 + moveb VER_TMP(%a6),(%a7) |format a busy frame + moveb #BUSY_SIZE-4,1(%a7) + 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_snan +| +| Exit snan handler by expanding the unimp frame into a busy frame +| +end_snan: + bclrb #E1,E_BYTE(%a6) + + moveb (%a7),VER_TMP(%a6) + cmpib #VER_40,(%a7) |test for orig unimp frame + bnes ck_rev2 + moveql #13,%d0 |need to zero 14 lwords + bras rep_con2 +ck_rev2: + moveql #11,%d0 |need to zero 12 lwords +rep_con2: + clrl (%a7) +loop2: + clrl -(%a7) |clear and dec a7 + dbra %d0,loop2 + moveb VER_TMP(%a6),(%a7) |format a busy frame + moveb #BUSY_SIZE-4,1(%a7) |write busy size + 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 fpsp_done + +| +| Move_out +| +move_out: + movel EXC_EA(%a6),%a0 |get <ea> from exc frame + + bfextu CMDREG1B(%a6){#3:#3},%d0 |move rx field to d0{2:0} + cmpil #0,%d0 |check for long + beqs sto_long |branch if move_out long + + cmpil #4,%d0 |check for word + beqs sto_word |branch if move_out word + + cmpil #6,%d0 |check for byte + beqs sto_byte |branch if move_out byte + +| +| Not byte, word or long +| + rts +| +| Get the 32 most significant bits of etemp mantissa +| +sto_long: + movel ETEMP_HI(%a6),%d1 + movel #4,%d0 |load byte count +| +| Set signalling nan bit +| + bsetl #30,%d1 +| +| Store to the users destination address +| + tstl %a0 |check if <ea> is 0 + beqs wrt_dn |destination is a data register + + movel %d1,-(%a7) |move the snan onto the stack + movel %a0,%a1 |load dest addr into a1 + movel %a7,%a0 |load src addr of snan into a0 + bsrl mem_write |write snan to user memory + movel (%a7)+,%d1 |clear off stack + rts +| +| Get the 16 most significant bits of etemp mantissa +| +sto_word: + movel ETEMP_HI(%a6),%d1 + movel #2,%d0 |load byte count +| +| Set signalling nan bit +| + bsetl #30,%d1 +| +| Store to the users destination address +| + tstl %a0 |check if <ea> is 0 + beqs wrt_dn |destination is a data register + + movel %d1,-(%a7) |move the snan onto the stack + movel %a0,%a1 |load dest addr into a1 + movel %a7,%a0 |point to low word + bsrl mem_write |write snan to user memory + movel (%a7)+,%d1 |clear off stack + rts +| +| Get the 8 most significant bits of etemp mantissa +| +sto_byte: + movel ETEMP_HI(%a6),%d1 + movel #1,%d0 |load byte count +| +| Set signalling nan bit +| + bsetl #30,%d1 +| +| Store to the users destination address +| + tstl %a0 |check if <ea> is 0 + beqs wrt_dn |destination is a data register + movel %d1,-(%a7) |move the snan onto the stack + movel %a0,%a1 |load dest addr into a1 + movel %a7,%a0 |point to source byte + bsrl mem_write |write snan to user memory + movel (%a7)+,%d1 |clear off stack + rts + +| +| wrt_dn --- write to a data register +| +| We get here with D1 containing the data to write and D0 the +| number of bytes to write: 1=byte,2=word,4=long. +| +wrt_dn: + movel %d1,L_SCR1(%a6) |data + movel %d0,-(%a7) |size + bsrl get_fline |returns fline word in d0 + movel %d0,%d1 + andil #0x7,%d1 |d1 now holds register number + movel (%sp)+,%d0 |get original size + cmpil #4,%d0 + beqs wrt_long + cmpil #2,%d0 + bnes wrt_byte +wrt_word: + orl #0x8,%d1 + bral reg_dest +wrt_long: + orl #0x10,%d1 + bral reg_dest +wrt_byte: + bral reg_dest +| +| Check if it is a src nan or dst nan +| +not_out: + movel DTAG(%a6),%d0 + bfextu %d0{#0:#3},%d0 |isolate dtag in lsbs + + cmpib #3,%d0 |check for nan in destination + bnes issrc |destination nan has priority +dst_nan: + btstb #6,FPTEMP_HI(%a6) |check if dest nan is an snan + bnes issrc |no, so check source for snan + movew FPTEMP_EX(%a6),%d0 + bras cont +issrc: + movew ETEMP_EX(%a6),%d0 +cont: + btstl #15,%d0 |test for sign of snan + beqs clr_neg + bsetb #neg_bit,FPSR_CC(%a6) + bra report_snan +clr_neg: + bclrb #neg_bit,FPSR_CC(%a6) + bra report_snan + + |end |