Date: Sun, 26 Oct 1997 18:50:44 +0000 From: Richard Hirst To: linux-m68k@lists.linux-m68k.org Subject: Re: L68K: FPU Emulation patches References: <19971026172812.59385@sleepie.demon.co.uk> In-Reply-To: <19971026172812.59385@sleepie.demon.co.uk>; from Richard Hirst on Sun, Oct 26, 1997 at 05:28:12PM +0000 Sender: owner-linux-m68k@phil.uni-sb.de On Sun, Oct 26, 1997 at 05:28:12PM +0000, Richard Hirst wrote: ...and then at 18:45 he wrote again including the patches (see below)!!! > Hi, > Below are some patches for the fpu emulation code > "ftp://ftp.nocrew.pp.se/pub/linux/mathemu-2.0.21.diff.gz". > NOTE the diffs are not made from the head of the source tree. I guess > you want to 'cd arch/m68k/math-emu' and 'patch -p1' - sorry about that. > > With these patches in a 2.0.29 tree, I can boot to multi-user, and the > system is pretty stable. It is not perfect; I have a perl script which > doesn't run. YMMV. > > Without these patches I couldn't boot multi-user, and certainly couldn't > run two simple programs which both use floating point at the same time. > > I run this on a 68LC040 on a Motorola MVME162 board, so don't ask me to > build you Atari/Amiga kernels with FPU emulation ;) > > I fully support the idea of developing a new emulator, but given > constraints on my time, I figured it was worth fixing a few bugs in the > existing code. > > Richard. > diff -cr orig/fpu_calc.c tidy/fpu_calc.c *** orig/fpu_calc.c Sat Sep 20 00:02:22 1997 --- tidy/fpu_calc.c Sat Sep 20 00:20:02 1997 *************** *** 437,447 **** /* LC040 does a predecrement on its own; we don't need to do it*/ if(m68k_is040or060 != 4) *reg -= step; ea->ea_tdisp = 0; } ! /* fix LC040 so that postincr= predecr+postincr */ if ((ea->ea_flags & EA_POSTINCR) && (m68k_is040or060 == 4)) { #ifdef DEBUG --- 437,451 ---- /* LC040 does a predecrement on its own; we don't need to do it*/ + #ifdef LC040_DOES_PREDECREMENT + /* Maybe some LC040s do predecrement, but mine certainly + * doesn't. Richard Hirst, 970920. */ if(m68k_is040or060 != 4) + #endif *reg -= step; ea->ea_tdisp = 0; } ! #ifdef LC040_DOES_PREDECREMENT /* fix LC040 so that postincr= predecr+postincr */ if ((ea->ea_flags & EA_POSTINCR) && (m68k_is040or060 == 4)) { #ifdef DEBUG *************** *** 454,460 **** *reg -= step; } ! /* Grab the register contents. */ src = (char *)*reg; #ifdef DEBUG --- 458,464 ---- *reg -= step; } ! #endif /* Grab the register contents. */ src = (char *)*reg; #ifdef DEBUG *************** *** 607,619 **** } #endif /* LC040 does a predecrement on its own; we don't need to do it*/ if(m68k_is040or060 != 4) *reg -= step; ea->ea_tdisp = 0; } ! /* fix LC040 so that postincr= predecr+postincr */ if ((ea->ea_flags & EA_POSTINCR) && (m68k_is040or060 == 4)) { #ifdef DEBUG --- 611,625 ---- } #endif + #ifdef LC040_DOES_PREDECREMENT /* LC040 does a predecrement on its own; we don't need to do it*/ if(m68k_is040or060 != 4) + #endif *reg -= step; ea->ea_tdisp = 0; } ! #ifdef LC040_DOES_PREDECREMENT /* fix LC040 so that postincr= predecr+postincr */ if ((ea->ea_flags & EA_POSTINCR) && (m68k_is040or060 == 4)) { #ifdef DEBUG *************** *** 626,633 **** *reg -= step; } ! ! /* calculate the effective address */ sig = calc_ea(ea, (char *)*reg, &dst); --- 632,638 ---- *reg -= step; } ! #endif /* calculate the effective address */ sig = calc_ea(ea, (char *)*reg, &dst); diff -cr orig/fpu_emul.c tidy/fpu_emul.c *** orig/fpu_emul.c Sat Sep 20 00:02:22 1997 --- tidy/fpu_emul.c Sat Sep 20 00:33:17 1997 *************** *** 89,97 **** int fpu_emulate(struct frame *frame, struct fpframe *fpf) { ! static struct instruction insn; ! static struct fpemu fe; int word, optype, sig; globlframe= frame; --- 89,98 ---- int fpu_emulate(struct frame *frame, struct fpframe *fpf) { ! struct instruction insn; ! struct fpemu fe; int word, optype, sig; + static int fpu_state_frame = 0; globlframe= frame; *************** *** 147,152 **** --- 148,162 ---- insn.is_opcode = word; optype = (word & 0x01C0); + /* + * If this isn't an fsave/frestore, then the FPU is now in the + * IDLE state, not the NULL state. The value 0x01000100 is chosen + * such that it should work for all CPU types. + */ + + if (optype != 0x0100 && optype != 0x0140) + fpu_state_frame = 0x01000100; + word = fusword(frame->f_pc + 2); #ifdef DEBUG if (word < 0) { *************** *** 234,246 **** } else if (optype == 0x0100) { ! /* type 4: fsave (privileged): store NULL frame */ if((frame->f_sr &0x2000) !=0) { insn.is_advance = 2; /* 2 bytes long */ sig=fpu_decode_ea(frame, &insn, &insn.is_ea0,insn.is_opcode); insn.is_datasize=0x4; ! word= 0; /* This is the actual NULL frame */ ! sig=fpu_store_ea(frame,&insn,&insn.is_ea0,(char*) &word); #ifdef DEBUG if (fpu_debug_level & DL_INSN) printk(" fpu_emulate: fsave\n"); --- 244,255 ---- } else if (optype == 0x0100) { ! /* type 4: fsave (privileged): store state frame */ if((frame->f_sr &0x2000) !=0) { insn.is_advance = 2; /* 2 bytes long */ sig=fpu_decode_ea(frame, &insn, &insn.is_ea0,insn.is_opcode); insn.is_datasize=0x4; ! sig=fpu_store_ea(frame,&insn,&insn.is_ea0,(char*) &fpu_state_frame); #ifdef DEBUG if (fpu_debug_level & DL_INSN) printk(" fpu_emulate: fsave\n"); *************** *** 258,266 **** insn.is_advance = 2; /* 2 bytes long */ sig=fpu_decode_ea(frame,&insn,&insn.is_ea0,insn.is_opcode); insn.is_datasize=0x4; ! /* Restore a NULL frame. Note that this can be the ! * only type that needs to be restored */ ! sig=fpu_load_ea(frame,&insn,&insn.is_ea0,(char*) &word); #ifdef DEBUG if (fpu_debug_level & DL_INSN) printk(" fpu_emulate: frestore\n"); --- 267,274 ---- insn.is_advance = 2; /* 2 bytes long */ sig=fpu_decode_ea(frame,&insn,&insn.is_ea0,insn.is_opcode); insn.is_datasize=0x4; ! /* Restore a state frame */ ! sig=fpu_load_ea(frame,&insn,&insn.is_ea0,(char*) &fpu_state_frame); #ifdef DEBUG if (fpu_debug_level & DL_INSN) printk(" fpu_emulate: frestore\n"); *************** *** 414,419 **** --- 422,428 ---- int sig; int reglist; int fpu_to_mem; + int mask; /* move to/from control registers */ reglist = (insn->is_word1 & 0x1c00) >> 10; *************** *** 434,490 **** return SIGILL; } ! if (reglist & 4) { ! /* fpcr */ ! if ((insn->is_ea0.ea_flags & EA_DIRECT) && ! insn->is_ea0.ea_regnum >= 8 /* address reg */) { ! /* attempted to copy FPCR to An */ ! #ifdef DEBUG ! printk(" fpu_emul_fmovmcr: tried to copy FPCR from/to A%d\n", ! insn->is_ea0.ea_regnum & 7); ! #endif ! return SIGILL; ! } ! if (fpu_to_mem) { ! sig = fpu_store_ea(frame, insn, &insn->is_ea0, ! (char *)&fpf->fpf_fpcr); ! } else { ! sig = fpu_load_ea(frame, insn, &insn->is_ea0, ! (char *)&fpf->fpf_fpcr); ! } ! } ! if (sig) { return sig; } ! ! if (reglist & 2) { ! /* fpsr */ ! if ((insn->is_ea0.ea_flags & EA_DIRECT) && ! insn->is_ea0.ea_regnum >= 8 /* address reg */) { ! /* attempted to copy FPSR to An */ ! #ifdef DEBUG ! printk(" fpu_emul_fmovmcr: tried to copy FPSR from/to A%d\n", ! insn->is_ea0.ea_regnum & 7); ! #endif ! return SIGILL; ! } ! if (fpu_to_mem) { ! sig = fpu_store_ea(frame, insn, &insn->is_ea0, ! (char *)&fpf->fpf_fpsr); ! } else { ! sig = fpu_load_ea(frame, insn, &insn->is_ea0, ! (char *)&fpf->fpf_fpsr); ! } ! } ! if (sig) { return sig; } ! ! if (reglist & 1) { ! /* fpiar - can be moved to/from An */ ! if (fpu_to_mem) { ! sig = fpu_store_ea(frame, insn, &insn->is_ea0, ! (char *)&fpf->fpf_fpiar); ! } else { ! sig = fpu_load_ea(frame, insn, &insn->is_ea0, ! (char *)&fpf->fpf_fpiar); ! } } return sig; } --- 443,507 ---- return SIGILL; } ! if (insn->is_ea0.ea_flags & EA_PREDECR) ! mask = 1; ! else ! mask = 4; ! ! while (!sig && mask >= 1 && mask <= 4) ! { ! if (mask == 4 && (reglist & 4)) { ! /* fpcr */ ! if ((insn->is_ea0.ea_flags & EA_DIRECT) && ! insn->is_ea0.ea_regnum >= 8 /* address reg */) { ! /* attempted to copy FPCR to An */ ! #ifdef DEBUG ! printk(" fpu_emul_fmovmcr: tried to copy FPCR from/to A%d\n", ! insn->is_ea0.ea_regnum & 7); ! #endif ! return SIGILL; ! } ! if (fpu_to_mem) { ! sig = fpu_store_ea(frame, insn, &insn->is_ea0, ! (char *)&fe->fe_fpcr); ! } else { ! sig = fpu_load_ea(frame, insn, &insn->is_ea0, ! (char *)&fe->fe_fpcr); ! } ! } ! else if (mask == 2 && (reglist & 2)) { ! /* fpsr */ ! if ((insn->is_ea0.ea_flags & EA_DIRECT) && ! insn->is_ea0.ea_regnum >= 8 /* address reg */) { ! /* attempted to copy FPSR to An */ ! #ifdef DEBUG ! printk(" fpu_emul_fmovmcr: tried to copy FPSR from/to A%d\n", ! insn->is_ea0.ea_regnum & 7); ! #endif ! return SIGILL; ! } ! if (fpu_to_mem) { ! sig = fpu_store_ea(frame, insn, &insn->is_ea0, ! (char *)&fe->fe_fpsr); ! } else { ! sig = fpu_load_ea(frame, insn, &insn->is_ea0, ! (char *)&fe->fe_fpsr); ! } ! } ! else if (mask == 1 && (reglist & 1)) { ! /* fpiar - can be moved to/from An */ ! if (fpu_to_mem) { ! sig = fpu_store_ea(frame, insn, &insn->is_ea0, ! (char *)&fpf->fpf_fpiar); ! } else { ! sig = fpu_load_ea(frame, insn, &insn->is_ea0, ! (char *)&fpf->fpf_fpiar); ! } ! } ! if (insn->is_ea0.ea_flags & EA_PREDECR) ! mask <<= 1; ! else ! mask >>= 1; } return sig; } *************** *** 549,555 **** } while ((0 <= regnum) && (regnum < 8)) { ! regmask = 1 << regnum; if (regmask & reglist) { if (fpu_to_mem) { sig = fpu_store_ea(frame, insn, &insn->is_ea0, --- 566,575 ---- } while ((0 <= regnum) && (regnum < 8)) { ! if (order < 0) ! regmask = 1 << regnum; ! else ! regmask = 1 << (7 - regnum); if (regmask & reglist) { if (fpu_to_mem) { sig = fpu_store_ea(frame, insn, &insn->is_ea0, Only in tidy: fpu_emul.c.swp -- Home: richard@sleepie.demon.co.uk Work: Richard.Hirst@net-tel.co.uk www: http://www.sleepie.demon.co.uk Home of the MVME166 Linux Port!