123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488 |
- .BP
- .AP "EM INTERPRETER"
- .nf
- .ta 8 16 24 32 40 48 56 64 72 80
- .so em.i
- .fi
- .BP
- .AP "EM CODE TABLES"
- The following table is used by the assembler for EM machine
- language.
- It specifies the opcodes used for each instruction and
- how arguments are mapped to machine language arguments.
- The table is presented in three columns,
- each line in each column contains three or four fields.
- Each line describes a range of interpreter opcodes by
- specifying for which instruction the range is used, the type of the
- opcodes (mini, shortie, etc..) and range for the instruction
- argument.
- .A
- The first field on each line gives the EM instruction mnemonic,
- the second field gives some flags.
- If the opcodes are minis or shorties the third field specifies
- how many minis/shorties are used.
- The last field gives the number of the (first) interpreter
- opcode.
- .N 1
- Flags :
- .IS 3
- .N 1
- Opcode type, only one of the following may be specified.
- .PS - 5 " "
- .PT -
- opcode without argument
- .PT m
- mini
- .PT s
- shortie
- .PT 2
- opcode with 2-byte signed argument
- .PT 4
- opcode with 4-byte signed argument
- .PT 8
- opcode with 8-byte signed argument
- .PE
- Secondary (escaped) opcodes.
- .PS - 5 " "
- .PT e
- The opcode thus marked is in the secondary opcode group instead
- of the primary
- .PE
- restrictions on arguments
- .PS - 5 " "
- .PT N
- Negative arguments only
- .PT P
- Positive and zero arguments only
- .PE
- mapping of arguments
- .PS - 5 " "
- .PT w
- argument must be divisible by the wordsize and is divided by the
- wordsize before use as opcode argument.
- .PT o
- argument ( possibly after division ) must be >= 1 and is
- decremented before use as opcode argument
- .PE
- .IE
- If the opcode type is 2,4 or 8 the resulting argument is used as
- opcode argument (least significant byte first).
- .N
- If the opcode type is mini, the argument is added
- to the first opcode - if in range - .
- If the argument is negative, the absolute value minus one is
- used in the algorithm above.
- .N
- For shorties with positive arguments the first opcode is used
- for arguments in the range 0..255, the second for the range
- 256..511, etc..
- For shorties with negative arguments the first opcode is used
- for arguments in the range -1..-256, the second for the range
- -257..-512, etc..
- The byte following the opcode contains the least significant
- byte of the argument.
- First some examples of these specifications.
- .PS - 5
- .PT "aar mwPo 1 34"
- Indicates that opcode 34 is used as a mini for Positive
- instruction arguments only.
- The w and o indicate division and decrementing of the
- instruction argument.
- Because the resulting argument must be zero ( only opcode 34 may be used
- ), this mini can only be used for instruction argument 2.
- Conclusion: opcode 34 is for "AAR 2".
- .PT "adp sP 1 41"
- Opcode 41 is used as shortie for ADP with arguments in the range
- 0..255.
- .PT "bra sN 2 60"
- Opcode 60 is used as shortie for BRA with arguments -1..-256,
- 61 is used for arguments -257..-512.
- .PT "zer e- 145"
- Escaped opcode 145 is used for ZER.
- .PE
- The interpreter opcode table:
- .N 1
- .IS 3
- .DS B
- .so itables
- .DE 0
- .IE
- .P
- The table above results in the following dispatch tables.
- Dispatch tables are used by interpreters to jump to the
- routines implementing the EM instructions, indexed by the next opcode.
- Each line of the dispatch tables gives the routine names
- of eight consecutive opcodes, preceded by the first opcode number
- on that line.
- Routine names consist of an EM mnemonic followed by a suffix.
- The suffices show the encoding used for each opcode.
- .N
- The following suffices exist:
- .N 1
- .VS 1 0
- .IS 4
- .PS - 11
- .PT .z
- no arguments
- .PT .l
- 16-bit argument
- .PT .lw
- 16-bit argument divided by the wordsize
- .PT .p
- positive 16-bit argument
- .PT .pw
- positive 16-bit argument divided by the wordsize
- .PT .n
- negative 16-bit argument
- .PT .nw
- negative 16-bit argument divided by the wordsize
- .PT .s<num>
- shortie with <num> as high order argument byte
- .PT .sw<num>
- shortie with argument divided by the wordsize
- .PT .<num>
- mini with <num> as argument
- .PT .<num>W
- mini with <num>*wordsize as argument
- .PE 3
- <num> is a possibly negative integer.
- .VS 1 1
- .IE
- The dispatch table for the 256 primary opcodes:
- .DS B
- 0 loc.0 loc.1 loc.2 loc.3 loc.4 loc.5 loc.6 loc.7
- 8 loc.8 loc.9 loc.10 loc.11 loc.12 loc.13 loc.14 loc.15
- 16 loc.16 loc.17 loc.18 loc.19 loc.20 loc.21 loc.22 loc.23
- 24 loc.24 loc.25 loc.26 loc.27 loc.28 loc.29 loc.30 loc.31
- 32 loc.32 loc.33 aar.1W adf.s0 adi.1W adi.2W adp.l adp.1
- 40 adp.2 adp.s0 adp.s-1 ads.1W and.1W asp.1W asp.2W asp.3W
- 48 asp.4W asp.5W asp.w0 beq.l beq.s0 bge.s0 bgt.s0 ble.s0
- 56 blm.s0 blt.s0 bne.s0 bra.l bra.s-1 bra.s-2 bra.s0 bra.s1
- 64 cal.1 cal.2 cal.3 cal.4 cal.5 cal.6 cal.7 cal.8
- 72 cal.9 cal.10 cal.11 cal.12 cal.13 cal.14 cal.15 cal.16
- 80 cal.17 cal.18 cal.19 cal.20 cal.21 cal.22 cal.23 cal.24
- 88 cal.25 cal.26 cal.27 cal.28 cal.s0 cff.z cif.z cii.z
- 96 cmf.s0 cmi.1W cmi.2W cmp.z cms.s0 csa.1W csb.1W dec.z
- 104 dee.w0 del.w-1 dup.1W dvf.s0 dvi.1W fil.l inc.z ine.lw
- 112 ine.w0 inl.-1W inl.-2W inl.-3W inl.w-1 inn.s0 ior.1W ior.s0
- 120 lae.l lae.w0 lae.w1 lae.w2 lae.w3 lae.w4 lae.w5 lae.w6
- 128 lal.p lal.n lal.0 lal.-1 lal.w0 lal.w-1 lal.w-2 lar.W
- 136 ldc.0 lde.lw lde.w0 ldl.0 ldl.w-1 lfr.1W lfr.2W lfr.s0
- 144 lil.w-1 lil.w0 lil.0 lil.1W lin.l lin.s0 lni.z loc.l
- 152 loc.-1 loc.s0 loc.s-1 loe.lw loe.w0 loe.w1 loe.w2 loe.w3
- 160 loe.w4 lof.l lof.1W lof.2W lof.3W lof.4W lof.s0 loi.l
- 168 loi.1 loi.1W loi.2W loi.3W loi.4W loi.s0 lol.pw lol.nw
- 176 lol.0 lol.1W lol.2W lol.3W lol.-1W lol.-2W lol.-3W lol.-4W
- 184 lol.-5W lol.-6W lol.-7W lol.-8W lol.w0 lol.w-1 lxa.1 lxl.1
- 192 lxl.2 mlf.s0 mli.1W mli.2W rck.1W ret.0 ret.1W ret.s0
- 200 rmi.1W sar.1W sbf.s0 sbi.1W sbi.2W sdl.w-1 set.s0 sil.w-1
- 208 sil.w0 sli.1W ste.lw ste.w0 ste.w1 ste.w2 stf.l stf.W
- 216 stf.2W stf.s0 sti.1 sti.1W sti.2W sti.3W sti.4W sti.s0
- 224 stl.pw stl.nw stl.0 stl.1W stl.-1W stl.-2W stl.-3W stl.-4W
- 232 stl.-5W stl.w-1 teq.z tgt.z tlt.z tne.z zeq.l zeq.s0
- 240 zeq.s1 zer.s0 zge.s0 zgt.s0 zle.s0 zlt.s0 zne.s0 zne.s-1
- 248 zre.lw zre.w0 zrl.-1W zrl.-2W zrl.w-1 zrl.nw escape1 escape2
- .DE 2
- The list of secondary opcodes (escape1):
- .N 1
- .DS B
- 0 aar.l aar.z adf.l adf.z adi.l adi.z ads.l ads.z
- 8 adu.l adu.z and.l and.z asp.lw ass.l ass.z bge.l
- 16 bgt.l ble.l blm.l bls.l bls.z blt.l bne.l cai.z
- 24 cal.l cfi.z cfu.z ciu.z cmf.l cmf.z cmi.l cmi.z
- 32 cms.l cms.z cmu.l cmu.z com.l com.z csa.l csa.z
- 40 csb.l csb.z cuf.z cui.z cuu.z dee.lw del.pw del.nw
- 48 dup.l dus.l dus.z dvf.l dvf.z dvi.l dvi.z dvu.l
- 56 dvu.z fef.l fef.z fif.l fif.z inl.pw inl.nw inn.l
- 64 inn.z ior.l ior.z lar.l lar.z ldc.l ldf.l ldl.pw
- 72 ldl.nw lfr.l lil.pw lil.nw lim.z los.l los.z lor.s0
- 80 lpi.l lxa.l lxl.l mlf.l mlf.z mli.l mli.z mlu.l
- 88 mlu.z mon.z ngf.l ngf.z ngi.l ngi.z nop.z rck.l
- 96 rck.z ret.l rmi.l rmi.z rmu.l rmu.z rol.l rol.z
- 104 ror.l ror.z rtt.z sar.l sar.z sbf.l sbf.z sbi.l
- 112 sbi.z sbs.l sbs.z sbu.l sbu.z sde.l sdf.l sdl.pw
- 120 sdl.nw set.l set.z sig.z sil.pw sil.nw sim.z sli.l
- 128 sli.z slu.l slu.z sri.l sri.z sru.l sru.z sti.l
- 136 sts.l sts.z str.s0 tge.z tle.z trp.z xor.l xor.z
- 144 zer.l zer.z zge.l zgt.l zle.l zlt.l zne.l zrf.l
- 152 zrf.z zrl.pw dch.z exg.s0 exg.l exg.z lpb.z gto.l
- .DE 2
- Finally, the list of opcodes with four byte arguments (escape2).
- .DS
- 0 loc
- .DE 0
- .BP
- .AP "AN EXAMPLE PROGRAM"
- .DS B
- 1 program example(output);
- 2 {This program just demonstrates typical EM code.}
- 3 type rec = record r1: integer; r2:real; r3: boolean end;
- 4 var mi: integer; mx:real; r:rec;
- 5
- 6 function sum(a,b:integer):integer;
- 7 begin
- 8 sum := a + b
- 9 end;
- 10
- 11 procedure test(var r: rec);
- 12 label 1;
- 13 var i,j: integer;
- 14 x,y: real;
- 15 b: boolean;
- 16 c: char;
- 17 a: array[1..100] of integer;
- 18
- 19 begin
- 20 j := 1;
- 21 i := 3 * j + 6;
- 22 x := 4.8;
- 23 y := x/0.5;
- 24 b := true;
- 25 c := 'z';
- 26 for i:= 1 to 100 do a[i] := i * i;
- 27 r.r1 := j+27;
- 28 r.r3 := b;
- 29 r.r2 := x+y;
- 30 i := sum(r.r1, a[j]);
- 31 while i > 0 do begin j := j + r.r1; i := i - 1 end;
- 32 with r do begin r3 := b; r2 := x+y; r1 := 0 end;
- 33 goto 1;
- 34 1: writeln(j, i:6, x:9:3, b)
- 35 end; {test}
- 36 begin {main program}
- 37 mx := 15.96;
- 38 mi := 99;
- 39 test(r)
- 40 end.
- .DE 0
- .BP
- The EM code as produced by the Pascal-VU compiler is given below. Comments
- have been added manually. Note that this code has already been optimized.
- .DS B
- mes 2,2,2 ; wordsize 2, pointersize 2
- .1
- rom 't.p\e000' ; the name of the source file
- hol 552,-32768,0 ; externals and buf occupy 552 bytes
- exp $sum ; sum can be called from other modules
- pro $sum,2 ; procedure sum; 2 bytes local storage
- lin 8 ; code from source line 8
- ldl 0 ; load two locals ( a and b )
- adi 2 ; add them
- ret 2 ; return the result
- end 2 ; end of procedure ( still two bytes local storage )
- .2
- rom 1,99,2 ; descriptor of array a[]
- exp $test ; the compiler exports all level 0 procedures
- pro $test,226 ; procedure test, 226 bytes local storage
- .3
- rom 4.8F8 ; assemble Floating point 4.8 (8 bytes) in
- .4 ; global storage
- rom 0.5F8 ; same for 0.5
- mes 3,-226,2,2 ; compiler temporary not referenced by address
- mes 3,-24,2,0 ; the same is true for i, j, b and c in test
- mes 3,-22,2,0
- mes 3,-4,2,0
- mes 3,-2,2,0
- mes 3,-20,8,0 ; and for x and y
- mes 3,-12,8,0
- lin 20 ; maintain source line number
- loc 1
- stl -4 ; j := 1
- lni ; lin 21 prior to optimization
- lol -4
- loc 3
- mli 2
- loc 6
- adi 2
- stl -2 ; i := 3 * j + 6
- lni ; lin 22 prior to optimization
- lae .3
- loi 8
- lal -12
- sti 8 ; x := 4.8
- lni ; lin 23 prior to optimization
- lal -12
- loi 8
- lae .4
- loi 8
- dvf 8
- lal -20
- sti 8 ; y := x / 0.5
- lni ; lin 24 prior to optimization
- loc 1
- stl -22 ; b := true
- lni ; lin 25 prior to optimization
- loc 122
- stl -24 ; c := 'z'
- lni ; lin 26 prior to optimization
- loc 1
- stl -2 ; for i:= 1
- 2
- lol -2
- dup 2
- mli 2 ; i*i
- lal -224
- lol -2
- lae .2
- sar 2 ; a[i] :=
- lol -2
- loc 100
- beq *3 ; to 100 do
- inl -2 ; increment i and loop
- bra *2
- 3
- lin 27
- lol -4
- loc 27
- adi 2 ; j + 27
- sil 0 ; r.r1 :=
- lni ; lin 28 prior to optimization
- lol -22 ; b
- lol 0
- stf 10 ; r.r3 :=
- lni ; lin 29 prior to optimization
- lal -20
- loi 16
- adf 8 ; x + y
- lol 0
- adp 2
- sti 8 ; r.r2 :=
- lni ; lin 23 prior to optimization
- lal -224
- lol -4
- lae .2
- lar 2 ; a[j]
- lil 0 ; r.r1
- cal $sum ; call now
- asp 4 ; remove parameters from stack
- lfr 2 ; get function result
- stl -2 ; i :=
- 4
- lin 31
- lol -2
- zle *5 ; while i > 0 do
- lol -4
- lil 0
- adi 2
- stl -4 ; j := j + r.r1
- del -2 ; i := i - 1
- bra *4 ; loop
- 5
- lin 32
- lol 0
- stl -226 ; make copy of address of r
- lol -22
- lol -226
- stf 10 ; r3 := b
- lal -20
- loi 16
- adf 8
- lol -226
- adp 2
- sti 8 ; r2 := x + y
- loc 0
- sil -226 ; r1 := 0
- lin 34 ; note the abscence of the unnecesary jump
- lae 22 ; address of output structure
- lol -4
- cal $_wri ; write integer with default width
- asp 4 ; pop parameters
- lae 22
- lol -2
- loc 6
- cal $_wsi ; write integer width 6
- asp 6
- lae 22
- lal -12
- loi 8
- loc 9
- loc 3
- cal $_wrf ; write fixed format real, width 9, precision 3
- asp 14
- lae 22
- lol -22
- cal $_wrb ; write boolean, default width
- asp 4
- lae 22
- cal $_wln ; writeln
- asp 2
- ret 0 ; return, no result
- end 226
- exp $_main
- pro $_main,0 ; main program
- .6
- con 2,-1,22 ; description of external files
- .5
- rom 15.96F8
- fil .1 ; maintain source file name
- lae .6 ; description of external files
- lae 0 ; base of hol area to relocate buffer addresses
- cal $_ini ; initialize files, etc...
- asp 4
- lin 37
- lae .5
- loi 8
- lae 2
- sti 8 ; mx := 15.96
- lni ; lin 38 prior to optimization
- loc 99
- ste 0 ; mi := 99
- lni ; lin 39 prior to optimization
- lae 10 ; address of r
- cal $test
- asp 2
- loc 0 ; normal exit
- cal $_hlt ; cleanup and finish
- asp 2
- end 0
- mes 5 ; reals were used
- .DE 0
- The compact code corresponding to the above program is listed below.
- Read it horizontally, line by line, not column by column.
- Each number represents a byte of compact code, printed in decimal.
- The first two bytes form the magic word.
- .N 1
- .IS 3
- .DS B
- 173 0 159 122 122 122 255 242 1 161 250 124 116 46 112 0
- 255 156 245 40 2 245 0 128 120 155 249 123 115 117 109 160
- 249 123 115 117 109 122 67 128 63 120 3 122 88 122 152 122
- 242 2 161 121 219 122 255 155 249 124 116 101 115 116 160 249
- 124 116 101 115 116 245 226 0 242 3 161 253 128 123 52 46
- 56 255 242 4 161 253 128 123 48 46 53 255 159 123 245 30
- 255 122 122 255 159 123 96 122 120 255 159 123 98 122 120 255
- 159 123 116 122 120 255 159 123 118 122 120 255 159 123 100 128
- 120 255 159 123 108 128 120 255 67 140 69 121 113 116 68 73
- 116 69 123 81 122 69 126 3 122 113 118 68 57 242 3 72
- 128 58 108 112 128 68 58 108 72 128 57 242 4 72 128 44
- 128 58 100 112 128 68 69 121 113 98 68 69 245 122 0 113
- 96 68 69 121 113 118 182 73 118 42 122 81 122 58 245 32
- 255 73 118 57 242 2 94 122 73 118 69 220 10 123 54 118
- 18 122 183 67 147 73 116 69 147 3 122 104 120 68 73 98
- 73 120 111 130 68 58 100 72 136 2 128 73 120 4 122 112
- 128 68 58 245 32 255 73 116 57 242 2 59 122 65 120 20
- 249 123 115 117 109 8 124 64 122 113 118 184 67 151 73 118
- 128 125 73 116 65 120 3 122 113 116 41 118 18 124 185 67
- 152 73 120 113 245 30 255 73 98 73 245 30 255 111 130 58
- 100 72 136 2 128 73 245 30 255 4 122 112 128 69 120 104
- 245 30 255 67 154 57 142 73 116 20 249 124 95 119 114 105
- 8 124 57 142 73 118 69 126 20 249 124 95 119 115 105 8
- 126 57 142 58 108 72 128 69 129 69 123 20 249 124 95 119
- 114 102 8 134 57 142 73 98 20 249 124 95 119 114 98 8
- 124 57 142 20 249 124 95 119 108 110 8 122 88 120 152 245
- 226 0 155 249 125 95 109 97 105 110 160 249 125 95 109 97
- 105 110 120 242 6 151 122 119 142 255 242 5 161 253 128 125
- 49 53 46 57 54 255 50 242 1 57 242 6 57 120 20 249
- 124 95 105 110 105 8 124 67 157 57 242 5 72 128 57 122
- 112 128 68 69 219 110 120 68 57 130 20 249 124 116 101 115
- 116 8 122 69 120 20 249 124 95 104 108 116 8 122 152 120
- 159 124 160 255 159 125 255
- .DE 0
- .IE
- .MS T A 0
- .ME
- .BP
- .MS B A 0
- .ME
- .CT
|