Edinburgh IMP77 Compiler - Version 8.4 1 %begin .Ltext0: .align 2 .global main main: .LFB185: .LVL0: mov x16, 5984 sub sp, sp, x16 stp x29, x30, [sp] add x29, sp, 0 stp x19, x20, [sp, 16] stp x21, x22, [sp, 32] stp x23, x24, [sp, 48] stp x25, x26, [sp, 64] adrp x2, :got:__stack_chk_guard ldr x2, [x2, #:got_lo12:__stack_chk_guard] ldr x3, [x2] str x3, [x29, 5976] mov x3,0 2 bl _imp_initialise .LVL1: .LBB171: 3 ! 4 ! Precedence of operators 5 ! 6 ! Highest: 1. \ (complement, unary not) 7 ! 2. \, \\, <<, >> 8 ! 3. *, /, //, & 9 ! Lowest: 4. +, - (unary and binary), !, !! 10 ! 11 ! In general, sub-expressions with operators of equal precedence are evaluated from left to right. 12 ! 13 ! The one exception to the left-hand precedence rule is that consecutive 14 ! exponentiations are evaluated from right to left; thus A**B**C is 15 ! evaluated as A**(B**C), not as (A**B)**C. (Imp80 documentation) 16 17 ! Arithmetic operators: 18 19 ! |...| modulus also: !...! (deprecated some time ago) 20 21 ! ! inclusive or 22 ! !! exclusive or 23 ! & and 24 25 ! \ real exponentiation also: ^ (Imp77) or ** (ERCC compilers) 26 ! \\ integer exponentiation also: ^^ (Imp77) or **** 27 28 ! * multiply 29 ! / real division 30 ! // integer division 31 32 ! << left shift 33 ! >> right shift 34 35 ! + plus 36 ! - minus 37 38 ! + unary + 39 ! - unary - 40 ! \ unary not also ~ (can be *displayed* as: ¬ (¬)) 41 42 ! . string concatenation 43 44 ! Comparison operators: 45 ! = eq 46 ! # not equals also \= and <> (Imp80 documentation) 47 ! == address equals 48 ! ## address not equals also \== 49 ! -> string resolution (a difficult to classify hybrid of a comparison and an assignment operator) 50 ! <= less than or equals 51 ! < less than 52 ! >= greater than or equals 53 ! > 54 55 ! Assignment operators: 56 ! = assignment 57 ! == pointer assignment 58 ! <- jam transfer 59 ! -> string resolution 60 61 ! Data structure operators: 62 ! _ record field 63 ! () array indexing 64 ! [] pointer increment (a Hamish extension in 68000 Imp only) 65 66 ! Other: 67 ! @ may be considered an operator in %real literals, usually handled by a BIP. 68 69 70 %const %integer a = 19, b = 17, c = 5, d = 3 71 %integer x = a * b // c * d 72 print string("Imp77 precedence and associativity test."); newlines(2) adrp x22, .LANCHOR0 add x22, x22, :lo12:.LANCHOR0 add x21, x29, 4096 add x21, x21, 1624 mov x19, 256 mov x2, x19 mov x1, x22 mov x0, x21 bl memcpy .LVL2: add x20, x29, 344 mov x2, x19 mov x1, x21 mov x0, x20 bl memcpy .LVL3: add x23, x29, 3160 mov x2, x19 mov x1, x20 mov x0, x23 bl memcpy .LVL4: .LBE171: .LBB172: .LBB173: add x20, x29, 80 mov x2, x19 mov x1, x23 mov x0, x20 bl memcpy .LVL5: mov x0, x20 bl _imp_printstring .LVL6: .LBE173: .LBE172: .LBB174: .LBB175: mov w0, 2 bl _imp_newlines .LVL7: .LDL1: .LDL2: .LBE175: .LBE174: .LBB176: 73 %if x = 21 %start 74 print string("In a * b // c * d, '*' has higher priority than '/'."); newline 75 print string("A second test with '/' will be needed to determine associativity:"); newline 76 x = a // c // d 77 %if x = 1 %start 78 print string("a // c // d is right associative, i.e. a // (b // c)"); newline 79 %else %if x = 19 80 print string("a // c // d is left associative, i.e. (a // b) // c"); newline 81 %else 82 print string("a // c // d is something weird! I give up."); newline 83 %finish 84 %else %if x = 19 85 print string("a * b // c * d is right associative and with equal precedence, i.e. a * (b // (c * d))"); newline 86 newline 87 print string("This grammar would support the above:"); newline 88 newline 89 print string("P = ;"); newline 90 print string("P = | ;"); newline 91 print string("P = ;"); newline 92 %else %if x = 192 93 print string("a * b // c * d is left associative and with equal precedence, i.e. ((a * b) // c) * d"); newline mov x2, x19 add x1, x22, x19 mov x0, x21 bl memcpy .LVL8: add x24, x29, 600 mov x2, x19 mov x1, x21 mov x0, x24 bl memcpy .LVL9: add x23, x29, 4096 add x23, x23, 344 mov x2, x19 mov x1, x24 mov x0, x23 bl memcpy .LVL10: .LBE176: .LBB177: .LBB178: mov x2, x19 mov x1, x23 mov x0, x20 bl memcpy .LVL11: mov x0, x20 bl _imp_printstring .LVL12: .LBE178: .LBE177: .LBB179: .LBB180: bl _imp_newline .LVL13: .LBE180: .LBE179: .LBB181: .LBB182: bl _imp_newline .LVL14: .LBE182: .LBE181: .LBB183: 94 newline 95 print string("This grammar would support the above:"); newline add x26, x22, 1024 add x25, x22, 512 mov x2, x19 mov x1, x25 mov x0, x21 bl memcpy .LVL15: add x24, x29, 856 mov x2, x19 mov x1, x21 mov x0, x24 bl memcpy .LVL16: add x23, x29, 4096 add x23, x23, 88 mov x2, x19 mov x1, x24 mov x0, x23 bl memcpy .LVL17: .LBE183: .LBB184: .LBB185: mov x2, x19 mov x1, x23 mov x0, x20 bl memcpy .LVL18: mov x0, x20 bl _imp_printstring .LVL19: .LBE185: .LBE184: .LBB186: .LBB187: bl _imp_newline .LVL20: .LBE187: .LBE186: .LBB188: .LBB189: bl _imp_newline .LVL21: .LBE189: .LBE188: .LBB190: 96 newline 97 print string("P = ;"); newline mov x2, x19 add x1, x22, 768 mov x0, x21 bl memcpy .LVL22: add x24, x29, 1112 mov x2, x19 mov x1, x21 mov x0, x24 bl memcpy .LVL23: add x23, x29, 3928 mov x2, x19 mov x1, x24 mov x0, x23 bl memcpy .LVL24: .LBE190: .LBB191: .LBB192: mov x2, x19 mov x1, x23 mov x0, x20 bl memcpy .LVL25: mov x0, x20 bl _imp_printstring .LVL26: .LBE192: .LBE191: .LBB193: .LBB194: bl _imp_newline .LVL27: .LBE194: .LBE193: .LBB195: 98 print string("P = | ;"); newline mov x2, x19 mov x1, x26 mov x0, x21 bl memcpy .LVL28: add x24, x29, 1368 mov x2, x19 mov x1, x21 mov x0, x24 bl memcpy .LVL29: add x23, x29, 3672 mov x2, x19 mov x1, x24 mov x0, x23 bl memcpy .LVL30: .LBE195: .LBB196: .LBB197: mov x2, x19 mov x1, x23 mov x0, x20 bl memcpy .LVL31: mov x0, x20 bl _imp_printstring .LVL32: .LBE197: .LBE196: .LBB198: .LBB199: bl _imp_newline .LVL33: .LBE199: .LBE198: .LBB200: 99 print string("P = ;"); newline mov x2, x19 add x1, x22, 1280 mov x0, x21 bl memcpy .LVL34: add x24, x29, 1624 mov x2, x19 mov x1, x21 mov x0, x24 bl memcpy .LVL35: add x23, x29, 3416 mov x2, x19 mov x1, x24 mov x0, x23 bl memcpy .LVL36: .LBE200: .LBB201: .LBB202: mov x2, x19 mov x1, x23 mov x0, x20 bl memcpy .LVL37: mov x0, x20 bl _imp_printstring .LVL38: .LBE202: .LBE201: .LBB203: .LBB204: bl _imp_newline .LVL39: .LDL3: .LDL4: .LBE204: .LBE203: .LBB205: .LBB206: bl _imp_newline .LVL40: .LDL5: .LBE206: .LBE205: .LBB207: 100 %else 101 print string("a * b // c * d uses some weird non-standard combination of precedence and associativity!"); newline 102 %finish 103 newline 104 105 106 %const %integer p = 4, q = 3, r = 2 107 %integer y 108 109 y = p ^^ q ^^ r 110 111 %if y = 262144 %start 112 print string("p ^^ q ^^ r is right associative, i.e. p ^^ (q ^^ r)"); newline 113 newline 114 print string("This grammar would support the above:"); newline 115 newline 116 print string("P = ;"); newline 117 print string("P = | ;"); newline 118 print string("P = ""^^"" ;"); newline 119 %else %if y = 4096 120 print string("p ^^ q ^^ r is left associative, i.e. (p ^^ q) ^^ r"); newline add x23, x22, 2048 mov x2, x19 add x1, x22, 1536 mov x0, x21 bl memcpy .LVL41: add x24, x29, 1880 mov x2, x19 mov x1, x21 mov x0, x24 bl memcpy .LVL42: mov x2, x19 mov x1, x24 mov x0, x21 bl memcpy .LVL43: .LBE207: .LBB208: .LBB209: mov x2, x19 mov x1, x21 mov x0, x20 bl memcpy .LVL44: mov x0, x20 bl _imp_printstring .LVL45: .LBE209: .LBE208: .LBB210: .LBB211: bl _imp_newline .LVL46: .LBE211: .LBE210: .LBB212: .LBB213: bl _imp_newline .LVL47: .LBE213: .LBE212: .LBB214: 121 newline 122 print string("This grammar would support the above:"); newline add x21, x29, 4096 add x21, x21, 1368 mov x2, x19 mov x1, x25 mov x0, x21 bl memcpy .LVL48: add x24, x29, 2136 mov x2, x19 mov x1, x21 mov x0, x24 bl memcpy .LVL49: mov x2, x19 mov x1, x24 mov x0, x21 bl memcpy .LVL50: .LBE214: .LBB215: .LBB216: mov x2, x19 mov x1, x21 mov x0, x20 bl memcpy .LVL51: mov x0, x20 bl _imp_printstring .LVL52: .LBE216: .LBE215: .LBB217: .LBB218: bl _imp_newline .LVL53: .LBE218: .LBE217: .LBB219: .LBB220: bl _imp_newline .LVL54: .LBE220: .LBE219: .LBB221: 123 newline 124 print string("P = ;"); newline add x21, x29, 4096 add x21, x21, 1112 mov x2, x19 add x1, x22, 1792 mov x0, x21 bl memcpy .LVL55: add x24, x29, 2392 mov x2, x19 mov x1, x21 mov x0, x24 bl memcpy .LVL56: mov x2, x19 mov x1, x24 mov x0, x21 bl memcpy .LVL57: .LBE221: .LBB222: .LBB223: mov x2, x19 mov x1, x21 mov x0, x20 bl memcpy .LVL58: mov x0, x20 bl _imp_printstring .LVL59: .LBE223: .LBE222: .LBB224: .LBB225: bl _imp_newline .LVL60: .LBE225: .LBE224: .LBB226: 125 print string("P = | ;"); newline add x21, x29, 4096 add x21, x21, 856 mov x2, x19 mov x1, x23 mov x0, x21 bl memcpy .LVL61: add x23, x29, 2648 mov x2, x19 mov x1, x21 mov x0, x23 bl memcpy .LVL62: mov x2, x19 mov x1, x23 mov x0, x21 bl memcpy .LVL63: .LBE226: .LBB227: .LBB228: mov x2, x19 mov x1, x21 mov x0, x20 bl memcpy .LVL64: mov x0, x20 bl _imp_printstring .LVL65: .LBE228: .LBE227: .LBB229: .LBB230: bl _imp_newline .LVL66: .LBE230: .LBE229: .LBB231: 126 print string("P = ""^^"" ;"); newline add x21, x29, 4096 add x21, x21, 600 mov x2, x19 add x1, x22, 2304 mov x0, x21 bl memcpy .LVL67: add x22, x29, 2904 mov x2, x19 mov x1, x21 mov x0, x22 bl memcpy .LVL68: mov x2, x19 mov x1, x22 mov x0, x21 bl memcpy .LVL69: .LBE231: .LBB232: .LBB233: mov x2, x19 mov x1, x21 mov x0, x20 bl memcpy .LVL70: mov x0, x20 bl _imp_printstring .LVL71: .LBE233: .LBE232: .LBB234: .LBB235: bl _imp_newline .LVL72: .LDL6: .LBE235: .LBE234: .LBB236: .LBB237: bl _imp_newline .LVL73: .LBE237: .LBE236: .LBB238: .LBB239: mov w0, 0 bl exit .LVL74: .LBE239: .LBE238: .LFE185: .section .rodata .align 3 .set .LANCHOR0,. + 0 .LC0: .byte 40 .string "Imp77 precedence and associativity test." .zero 214 .LC11: .byte 85 .string "a * b // c * d is left associative and with equal precedence, i.e. ((a * b) // c) * d" .zero 169 .LC7: .byte 37 .string "This grammar would support the above:" .zero 217 .LC12: .byte 33 .string "P = ;" .zero 221 .LC13: .byte 46 .string "P = | ;" .zero 208 .LC14: .byte 26 .string "P = ;" .zero 228 .LC20: .byte 51 .string "p ^^ q ^^ r is left associative, i.e. (p ^^ q) ^^ r" .zero 203 .LC21: .byte 34 .string "P = ;" .zero 220 .LC22: .byte 49 .string "P = | ;" .zero 205 .LC23: .byte 27 .string "P = \"^^\" ;" .zero 227 .Letext0: 127 %else 128 print string("p ^^ q ^^ r is something weird! ("); write(y, 0); print string(") - I give up."); newline 129 %finish 130 newline 131 132 ! The remaining issue to be checked is how left/right associativity interact when the precedence is the same, 133 ! which is only the case for exponentiation and shifts together, eg 134 ! 135 ! a << b << c ^^ d ^^ e or a ^^ b ^^ c >> d >> e 136 ! 137 138 %endofprogram 89 Statements compiled