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+/*
+ * 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 */