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Diffstat (limited to 'arch/m68k/math-emu/fp_decode.h')
| -rw-r--r-- | arch/m68k/math-emu/fp_decode.h | 417 |
1 files changed, 417 insertions, 0 deletions
diff --git a/arch/m68k/math-emu/fp_decode.h b/arch/m68k/math-emu/fp_decode.h new file mode 100644 index 0000000..759679d --- /dev/null +++ b/arch/m68k/math-emu/fp_decode.h @@ -0,0 +1,417 @@ +/* + * fp_decode.h + * + * Copyright Roman Zippel, 1997. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, and the entire permission notice in its entirety, + * including the disclaimer of warranties. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. The name of the author may not be used to endorse or promote + * products derived from this software without specific prior + * written permission. + * + * ALTERNATIVELY, this product may be distributed under the terms of + * the GNU General Public License, in which case the provisions of the GPL are + * required INSTEAD OF the above restrictions. (This clause is + * necessary due to a potential bad interaction between the GPL and + * the restrictions contained in a BSD-style copyright.) + * + * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED + * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE + * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, + * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR + * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, + * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED + * OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#ifndef _FP_DECODE_H +#define _FP_DECODE_H + +/* These macros do the dirty work of the instr decoding, several variables + * can be defined in the source file to modify the work of these macros, + * currently the following variables are used: + * ... + * The register usage: + * d0 - will contain source operand for data direct mode, + * otherwise scratch register + * d1 - upper 16bit are reserved for caller + * lower 16bit may contain further arguments, + * is destroyed during decoding + * d2 - contains first two instruction words, + * first word will be used for extension word + * a0 - will point to source/dest operand for any indirect mode + * otherwise scratch register + * a1 - scratch register + * a2 - base addr to the task structure + * + * the current implementation doesn't check for every disallowed + * addressing mode (e.g. pc relative modes as destination), as long + * as it only means a new addressing mode, which should not appear + * in a program and that doesn't crash the emulation, I think it's + * not a problem to allow these modes. + */ + +do_fmovem=0 +do_fmovem_cr=0 +do_no_pc_mode=0 +do_fscc=0 + +| first decoding of the instr type +| this separates the conditional instr +.macro fp_decode_cond_instr_type + bfextu %d2{#8,#2},%d0 + jmp ([0f:w,%pc,%d0*4]) + + .align 4 +0: +| .long "f<op>","fscc/fdbcc" +| .long "fbccw","fbccl" +.endm + +| second decoding of the instr type +| this separates most move instr +.macro fp_decode_move_instr_type + bfextu %d2{#16,#3},%d0 + jmp ([0f:w,%pc,%d0*4]) + + .align 4 +0: +| .long "f<op> fpx,fpx","invalid instr" +| .long "f<op> <ea>,fpx","fmove fpx,<ea>" +| .long "fmovem <ea>,fpcr","fmovem <ea>,fpx" +| .long "fmovem fpcr,<ea>","fmovem fpx,<ea>" +.endm + +| extract the source specifier, specifies +| either source fp register or data format +.macro fp_decode_sourcespec + bfextu %d2{#19,#3},%d0 +.endm + +| decode destination format for fmove reg,ea +.macro fp_decode_dest_format + bfextu %d2{#19,#3},%d0 +.endm + +| decode source register for fmove reg,ea +.macro fp_decode_src_reg + bfextu %d2{#22,#3},%d0 +.endm + +| extract the addressing mode +| it depends on the instr which of the modes is valid +.macro fp_decode_addr_mode + bfextu %d2{#10,#3},%d0 + jmp ([0f:w,%pc,%d0*4]) + + .align 4 +0: +| .long "data register direct","addr register direct" +| .long "addr register indirect" +| .long "addr register indirect postincrement" +| .long "addr register indirect predecrement" +| .long "addr register + index16" +| .long "extension mode1","extension mode2" +.endm + +| extract the register for the addressing mode +.macro fp_decode_addr_reg + bfextu %d2{#13,#3},%d0 +.endm + +| decode the 8bit diplacement from the brief extension word +.macro fp_decode_disp8 + move.b %d2,%d0 + ext.w %d0 +.endm + +| decode the index of the brief/full extension word +.macro fp_decode_index + bfextu %d2{#17,#3},%d0 | get the register nr + btst #15,%d2 | test for data/addr register + jne 1\@f + printf PDECODE,"d%d",1,%d0 + jsr fp_get_data_reg + jra 2\@f +1\@: printf PDECODE,"a%d",1,%d0 + jsr fp_get_addr_reg + move.l %a0,%d0 +2\@: +debug lea "'l'.w,%a0" + btst #11,%d2 | 16/32 bit size? + jne 3\@f +debug lea "'w'.w,%a0" + ext.l %d0 +3\@: printf PDECODE,":%c",1,%a0 + move.w %d2,%d1 | scale factor + rol.w #7,%d1 + and.w #3,%d1 +debug move.l "%d1,-(%sp)" +debug ext.l "%d1" + printf PDECODE,":%d",1,%d1 +debug move.l "(%sp)+,%d1" + lsl.l %d1,%d0 +.endm + +| decode the base displacement size +.macro fp_decode_basedisp + bfextu %d2{#26,#2},%d0 + jmp ([0f:w,%pc,%d0*4]) + + .align 4 +0: +| .long "reserved","null displacement" +| .long "word displacement","long displacement" +.endm + +.macro fp_decode_outerdisp + bfextu %d2{#30,#2},%d0 + jmp ([0f:w,%pc,%d0*4]) + + .align 4 +0: +| .long "no memory indirect action/reserved","null outer displacement" +| .long "word outer displacement","long outer displacement" +.endm + +| get the extension word and test for brief or full extension type +.macro fp_get_test_extword label + fp_get_instr_word %d2,fp_err_ua1 + btst #8,%d2 + jne \label +.endm + + +| test if %pc is the base register for the indirect addr mode +.macro fp_test_basereg_d16 label + btst #20,%d2 + jeq \label +.endm + +| test if %pc is the base register for one of the extended modes +.macro fp_test_basereg_ext label + btst #19,%d2 + jeq \label +.endm + +.macro fp_test_suppr_index label + btst #6,%d2 + jne \label +.endm + + +| addressing mode: data register direct +.macro fp_mode_data_direct + fp_decode_addr_reg + printf PDECODE,"d%d",1,%d0 +.endm + +| addressing mode: address register indirect +.macro fp_mode_addr_indirect + fp_decode_addr_reg + printf PDECODE,"(a%d)",1,%d0 + jsr fp_get_addr_reg +.endm + +| adjust stack for byte moves from/to stack +.macro fp_test_sp_byte_move + .if !do_fmovem + .if do_fscc + move.w #6,%d1 + .endif + cmp.w #7,%d0 + jne 1\@f + .if !do_fscc + cmp.w #6,%d1 + jne 1\@f + .endif + move.w #4,%d1 +1\@: + .endif +.endm + +| addressing mode: address register indirect with postincrement +.macro fp_mode_addr_indirect_postinc + fp_decode_addr_reg + printf PDECODE,"(a%d)+",1,%d0 + fp_test_sp_byte_move + jsr fp_get_addr_reg + move.l %a0,%a1 | save addr + .if do_fmovem + lea (%a0,%d1.w*4),%a0 + .if !do_fmovem_cr + lea (%a0,%d1.w*8),%a0 + .endif + .else + add.w (fp_datasize,%d1.w*2),%a0 + .endif + jsr fp_put_addr_reg + move.l %a1,%a0 +.endm + +| addressing mode: address register indirect with predecrement +.macro fp_mode_addr_indirect_predec + fp_decode_addr_reg + printf PDECODE,"-(a%d)",1,%d0 + fp_test_sp_byte_move + jsr fp_get_addr_reg + .if do_fmovem + .if !do_fmovem_cr + lea (-12,%a0),%a1 | setup to addr of 1st reg to move + neg.w %d1 + lea (%a0,%d1.w*4),%a0 + add.w %d1,%d1 + lea (%a0,%d1.w*4),%a0 + jsr fp_put_addr_reg + move.l %a1,%a0 + .else + neg.w %d1 + lea (%a0,%d1.w*4),%a0 + jsr fp_put_addr_reg + .endif + .else + sub.w (fp_datasize,%d1.w*2),%a0 + jsr fp_put_addr_reg + .endif +.endm + +| addressing mode: address register/programm counter indirect +| with 16bit displacement +.macro fp_mode_addr_indirect_disp16 + .if !do_no_pc_mode + fp_test_basereg_d16 1f + printf PDECODE,"pc" + fp_get_pc %a0 + jra 2f + .endif +1: fp_decode_addr_reg + printf PDECODE,"a%d",1,%d0 + jsr fp_get_addr_reg +2: fp_get_instr_word %a1,fp_err_ua1 + printf PDECODE,"@(%x)",1,%a1 + add.l %a1,%a0 +.endm + +| perform preindex (if I/IS == 0xx and xx != 00) +.macro fp_do_preindex + moveq #3,%d0 + and.w %d2,%d0 + jeq 1f + btst #2,%d2 + jne 1f + printf PDECODE,")@(" + getuser.l (%a1),%a1,fp_err_ua1,%a1 +debug jra "2f" +1: printf PDECODE,"," +2: +.endm + +| perform postindex (if I/IS == 1xx) +.macro fp_do_postindex + btst #2,%d2 + jeq 1f + printf PDECODE,")@(" + getuser.l (%a1),%a1,fp_err_ua1,%a1 +debug jra "2f" +1: printf PDECODE,"," +2: +.endm + +| all other indirect addressing modes will finally end up here +.macro fp_mode_addr_indirect_extmode0 + .if !do_no_pc_mode + fp_test_basereg_ext 1f + printf PDECODE,"pc" + fp_get_pc %a0 + jra 2f + .endif +1: fp_decode_addr_reg + printf PDECODE,"a%d",1,%d0 + jsr fp_get_addr_reg +2: move.l %a0,%a1 + swap %d2 + fp_get_test_extword 3f + | addressing mode: address register/programm counter indirect + | with index and 8bit displacement + fp_decode_disp8 +debug ext.l "%d0" + printf PDECODE,"@(%x,",1,%d0 + add.w %d0,%a1 + fp_decode_index + add.l %d0,%a1 + printf PDECODE,")" + jra 9f +3: | addressing mode: address register/programm counter memory indirect + | with base and/or outer displacement + btst #7,%d2 | base register suppressed? + jeq 1f + printf PDECODE,"!" + sub.l %a1,%a1 +1: printf PDECODE,"@(" + fp_decode_basedisp + + .long fp_ill,1f + .long 2f,3f + +#ifdef FPU_EMU_DEBUG +1: printf PDECODE,"0" | null base displacement + jra 1f +#endif +2: fp_get_instr_word %a0,fp_err_ua1 | 16bit base displacement + printf PDECODE,"%x:w",1,%a0 + jra 4f +3: fp_get_instr_long %a0,fp_err_ua1 | 32bit base displacement + printf PDECODE,"%x:l",1,%a0 +4: add.l %a0,%a1 +1: + fp_do_postindex + fp_test_suppr_index 1f + fp_decode_index + add.l %d0,%a1 +1: fp_do_preindex + + fp_decode_outerdisp + + .long 5f,1f + .long 2f,3f + +#ifdef FPU_EMU_DEBUG +1: printf PDECODE,"0" | null outer displacement + jra 1f +#endif +2: fp_get_instr_word %a0,fp_err_ua1 | 16bit outer displacement + printf PDECODE,"%x:w",1,%a0 + jra 4f +3: fp_get_instr_long %a0,fp_err_ua1 | 32bit outer displacement + printf PDECODE,"%x:l",1,%a0 +4: add.l %a0,%a1 +1: +5: printf PDECODE,")" +9: move.l %a1,%a0 + swap %d2 +.endm + +| get the absolute short address from user space +.macro fp_mode_abs_short + fp_get_instr_word %a0,fp_err_ua1 + printf PDECODE,"%x.w",1,%a0 +.endm + +| get the absolute long address from user space +.macro fp_mode_abs_long + fp_get_instr_long %a0,fp_err_ua1 + printf PDECODE,"%x.l",1,%a0 +.endm + +#endif /* _FP_DECODE_H */ |