Edinburgh IMP77 Compiler - Version 8.4 1 %begin .section ".text" .Ltext0: .section ".rodata" .LC0: .byte 40 .asciz "Imp77 precedence and associativity test." .skip 214 .LC11: .byte 85 .asciz "a * b // c * d is left associative and with equal precedence, i.e. ((a * b) // c) * d" .skip 169 .LC7: .byte 37 .asciz "This grammar would support the above:" .skip 217 .LC12: .byte 33 .asciz "P = ;" .skip 221 .LC13: .byte 46 .asciz "P = | ;" .skip 208 .LC14: .byte 26 .asciz "P = ;" .skip 228 .LC20: .byte 51 .asciz "p ^^ q ^^ r is left associative, i.e. (p ^^ q) ^^ r" .skip 203 .LC21: .byte 34 .asciz "P = ;" .skip 220 .LC22: .byte 49 .asciz "P = | ;" .skip 205 .LC23: .byte 27 .asciz "P = \"^^\" ;" .skip 227 .section ".text" .align 4 .global main .proc 04 main: .LFB185: .register %g7, #ignore .LVL0: save %sp, -4096, %sp .LVL1: add %sp, -1984, %sp ldx [%g7+40], %g1 stx %g1, [%fp+2039] mov 0, %g1 2 mov %i1, %o1 call _imp_initialise, 0 mov %i0, %o0 .LVL2: .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) mov 256, %o2 sethi %hi(.LC0), %o1 or %o1, %lo(.LC0), %o1 call memcpy, 0 add %fp, 1783, %o0 .LVL3: sethi %hi(5120), %i4 xor %i4, -520, %i5 add %fp, 2047, %g1 add %g1, %i5, %i5 mov 256, %o2 add %fp, 1783, %o1 call memcpy, 0 mov %i5, %o0 .LVL4: mov 256, %o2 mov %i5, %o1 call memcpy, 0 add %fp, -777, %o0 .LVL5: .LBE171: .LBB172: .LBB173: xor %i4, -784, %i5 add %fp, 2047, %g1 add %g1, %i5, %i5 mov 256, %o2 add %fp, -777, %o1 call memcpy, 0 mov %i5, %o0 .LVL6: call _imp_printstring, 0 mov %i5, %o0 .LVL7: .LBE173: .LBE172: .LBB174: .LBB175: call _imp_newlines, 0 mov 2, %o0 .LVL8: .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 256, %o2 sethi %hi(.LC11), %o1 or %o1, %lo(.LC11), %o1 call memcpy, 0 add %fp, 1783, %o0 .LVL9: xor %i4, -264, %i3 add %fp, 2047, %g1 add %g1, %i3, %i3 mov 256, %o2 add %fp, 1783, %o1 call memcpy, 0 mov %i3, %o0 .LVL10: mov 256, %o2 mov %i3, %o1 call memcpy, 0 add %fp, 503, %o0 .LVL11: .LBE176: .LBB177: .LBB178: mov 256, %o2 add %fp, 503, %o1 call memcpy, 0 mov %i5, %o0 .LVL12: call _imp_printstring, 0 mov %i5, %o0 .LVL13: .LBE178: .LBE177: .LBB179: .LBB180: call _imp_newline, 0 sethi %hi(.LC7), %i3 .LVL14: .LBE180: .LBE179: .LBB181: .LBB182: call _imp_newline, 0 or %i3, %lo(.LC7), %i3 .LVL15: .LBE182: .LBE181: .LBB183: 94 newline 95 print string("This grammar would support the above:"); newline mov 256, %o2 mov %i3, %o1 call memcpy, 0 add %fp, 1783, %o0 .LVL16: xor %i4, -8, %i4 add %fp, 2047, %g1 add %g1, %i4, %i4 mov 256, %o2 add %fp, 1783, %o1 call memcpy, 0 mov %i4, %o0 .LVL17: mov 256, %o2 mov %i4, %o1 call memcpy, 0 add %fp, 247, %o0 .LVL18: .LBE183: .LBB184: .LBB185: mov 256, %o2 add %fp, 247, %o1 call memcpy, 0 mov %i5, %o0 .LVL19: call _imp_printstring, 0 mov %i5, %o0 .LVL20: .LBE185: .LBE184: .LBB186: .LBB187: call _imp_newline, 0 sethi %hi(4096), %i4 .LVL21: .LBE187: .LBE186: .LBB188: .LBB189: call _imp_newline, 0 xor %i4, -776, %i2 .LVL22: .LBE189: .LBE188: .LBB190: 96 newline 97 print string("P = ;"); newline mov 256, %o2 sethi %hi(.LC12), %o1 or %o1, %lo(.LC12), %o1 call memcpy, 0 add %fp, 1783, %o0 .LVL23: add %fp, 2047, %g1 add %g1, %i2, %i2 mov 256, %o2 add %fp, 1783, %o1 call memcpy, 0 mov %i2, %o0 .LVL24: mov 256, %o2 mov %i2, %o1 call memcpy, 0 add %fp, -9, %o0 .LVL25: .LBE190: .LBB191: .LBB192: mov 256, %o2 add %fp, -9, %o1 call memcpy, 0 mov %i5, %o0 .LVL26: call _imp_printstring, 0 mov %i5, %o0 .LVL27: .LBE192: .LBE191: .LBB193: .LBB194: call _imp_newline, 0 xor %i4, -520, %i2 .LVL28: .LBE194: .LBE193: .LBB195: 98 print string("P = | ;"); newline mov 256, %o2 sethi %hi(.LC13), %o1 or %o1, %lo(.LC13), %o1 call memcpy, 0 add %fp, 1783, %o0 .LVL29: add %fp, 2047, %g1 add %g1, %i2, %i2 mov 256, %o2 add %fp, 1783, %o1 call memcpy, 0 mov %i2, %o0 .LVL30: mov 256, %o2 mov %i2, %o1 call memcpy, 0 add %fp, -265, %o0 .LVL31: .LBE195: .LBB196: .LBB197: mov 256, %o2 add %fp, -265, %o1 call memcpy, 0 mov %i5, %o0 .LVL32: call _imp_printstring, 0 mov %i5, %o0 .LVL33: .LBE197: .LBE196: .LBB198: .LBB199: call _imp_newline, 0 xor %i4, -264, %i2 .LVL34: .LBE199: .LBE198: .LBB200: 99 print string("P = ;"); newline mov 256, %o2 sethi %hi(.LC14), %o1 or %o1, %lo(.LC14), %o1 call memcpy, 0 add %fp, 1783, %o0 .LVL35: add %fp, 2047, %g1 add %g1, %i2, %i2 mov 256, %o2 add %fp, 1783, %o1 call memcpy, 0 mov %i2, %o0 .LVL36: mov 256, %o2 mov %i2, %o1 call memcpy, 0 add %fp, -521, %o0 .LVL37: .LBE200: .LBB201: .LBB202: mov 256, %o2 add %fp, -521, %o1 call memcpy, 0 mov %i5, %o0 .LVL38: call _imp_printstring, 0 mov %i5, %o0 .LVL39: .LBE202: .LBE201: .LBB203: .LBB204: call _imp_newline, 0 xor %i4, -8, %i4 .LVL40: .LDL3: .LDL4: .LBE204: .LBE203: .LBB205: .LBB206: call _imp_newline, 0 nop .LVL41: .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 mov 256, %o2 sethi %hi(.LC20), %o1 or %o1, %lo(.LC20), %o1 call memcpy, 0 add %fp, 1783, %o0 .LVL42: add %fp, 2047, %g1 add %g1, %i4, %i4 mov 256, %o2 add %fp, 1783, %o1 call memcpy, 0 mov %i4, %o0 .LVL43: mov 256, %o2 mov %i4, %o1 call memcpy, 0 add %fp, 1783, %o0 .LVL44: .LBE207: .LBB208: .LBB209: mov 256, %o2 add %fp, 1783, %o1 call memcpy, 0 mov %i5, %o0 .LVL45: call _imp_printstring, 0 mov %i5, %o0 .LVL46: .LBE209: .LBE208: .LBB210: .LBB211: call _imp_newline, 0 nop .LVL47: .LBE211: .LBE210: .LBB212: .LBB213: call _imp_newline, 0 nop .LVL48: .LBE213: .LBE212: .LBB214: 121 newline 122 print string("This grammar would support the above:"); newline mov 256, %o2 mov %i3, %o1 call memcpy, 0 add %fp, 1527, %o0 .LVL49: mov 256, %o2 add %fp, 1527, %o1 call memcpy, 0 add %fp, -1801, %o0 .LVL50: mov 256, %o2 add %fp, -1801, %o1 call memcpy, 0 add %fp, 1527, %o0 .LVL51: .LBE214: .LBB215: .LBB216: mov 256, %o2 add %fp, 1527, %o1 call memcpy, 0 mov %i5, %o0 .LVL52: call _imp_printstring, 0 mov %i5, %o0 .LVL53: .LBE216: .LBE215: .LBB217: .LBB218: call _imp_newline, 0 nop .LVL54: .LBE218: .LBE217: .LBB219: .LBB220: call _imp_newline, 0 nop .LVL55: .LBE220: .LBE219: .LBB221: 123 newline 124 print string("P = ;"); newline mov 256, %o2 sethi %hi(.LC21), %o1 or %o1, %lo(.LC21), %o1 call memcpy, 0 add %fp, 1271, %o0 .LVL56: mov 256, %o2 add %fp, 1271, %o1 call memcpy, 0 add %fp, -1545, %o0 .LVL57: mov 256, %o2 add %fp, -1545, %o1 call memcpy, 0 add %fp, 1271, %o0 .LVL58: .LBE221: .LBB222: .LBB223: mov 256, %o2 add %fp, 1271, %o1 call memcpy, 0 mov %i5, %o0 .LVL59: call _imp_printstring, 0 mov %i5, %o0 .LVL60: .LBE223: .LBE222: .LBB224: .LBB225: call _imp_newline, 0 nop .LVL61: .LBE225: .LBE224: .LBB226: 125 print string("P = | ;"); newline mov 256, %o2 sethi %hi(.LC22), %o1 or %o1, %lo(.LC22), %o1 call memcpy, 0 add %fp, 1015, %o0 .LVL62: mov 256, %o2 add %fp, 1015, %o1 call memcpy, 0 add %fp, -1289, %o0 .LVL63: mov 256, %o2 add %fp, -1289, %o1 call memcpy, 0 add %fp, 1015, %o0 .LVL64: .LBE226: .LBB227: .LBB228: mov 256, %o2 add %fp, 1015, %o1 call memcpy, 0 mov %i5, %o0 .LVL65: call _imp_printstring, 0 mov %i5, %o0 .LVL66: .LBE228: .LBE227: .LBB229: .LBB230: call _imp_newline, 0 nop .LVL67: .LBE230: .LBE229: .LBB231: 126 print string("P = ""^^"" ;"); newline mov 256, %o2 sethi %hi(.LC23), %o1 or %o1, %lo(.LC23), %o1 call memcpy, 0 add %fp, 759, %o0 .LVL68: mov 256, %o2 add %fp, 759, %o1 call memcpy, 0 add %fp, -1033, %o0 .LVL69: mov 256, %o2 add %fp, -1033, %o1 call memcpy, 0 add %fp, 759, %o0 .LVL70: .LBE231: .LBB232: .LBB233: mov 256, %o2 add %fp, 759, %o1 call memcpy, 0 mov %i5, %o0 .LVL71: call _imp_printstring, 0 mov %i5, %o0 .LVL72: .LBE233: .LBE232: .LBB234: .LBB235: call _imp_newline, 0 nop .LVL73: .LDL6: .LBE235: .LBE234: .LBB236: .LBB237: call _imp_newline, 0 nop .LVL74: .LBE237: .LBE236: .LBB238: .LBB239: call exit, 0 mov 0, %o0 .LVL75: .LBE239: .LBE238: nop .LFE185: .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