132 lines
4.5 KiB
LLVM
132 lines
4.5 KiB
LLVM
; External declaration of the puts function
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declare i32 @puts(i8* nocapture) nounwind
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declare i64 @llvm.abs.i64(i64, i1 immarg)
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define [21 x i8] @i64ToString(i64 %val_org) {
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%val = alloca i64
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store i64 %val_org, i64* %val
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%val_copy = add i64 0, %val_org
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; https://stackoverflow.com/a/7123710
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; an algorithm for translating ints to strings
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; s = ''
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; sign = ''
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; if i < 0:
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; sign = '-'
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; i = -i
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; while True:
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; remainder = i % 10
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; i = i / 10
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; s = chr(ord('0') + remainder) + s
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; if i == 0:
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; break
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; return sign + s
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; allocate memory for the string, and store the temp variable into it
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%string_ptr = alloca [21 x i8]
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store [21 x i8] c"\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00", [21 x i8]* %string_ptr
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; create a pointer to the array
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%array_index_ptr = alloca i32
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store i32 0, i32* %array_index_ptr
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br label %while_point
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while_point:
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%val.tmp = load i64, i64* %val; load i64, i64* %val
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%val.1 = call i64 @llvm.abs.i64(i64 %val.tmp, i1 true)
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%tmp = load i32, i32* %array_index_ptr
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%array_pointer.1 = getelementptr [21 x i8], [21 x i8]* %string_ptr, i32 0, i32 %tmp
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%array_index_ptr.1 = add i32 %tmp, 1
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store i32 %array_index_ptr.1, i32* %array_index_ptr
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; this should not work, but it does
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%remainder = srem i64 %val.1, 10
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%remainder_tmp = alloca i64
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store i64 %remainder, i64* %remainder_tmp
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%remainder_tmp8 = bitcast i64* %remainder_tmp to i8*
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%remainder8 = load i8, i8* %remainder_tmp8
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%i = sdiv i64 %val.1, 10
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%char = add i8 48, %remainder8
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store i8 %char, i8* %array_pointer.1 ; update string!
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store i64 %i, i64* %val
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%while_condition = icmp eq i64 %i, 0
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br i1 %while_condition, label %while_break, label %while_point
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while_break:
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; get last_pointer
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%array_index_ptr.0 = load i32, i32* %array_index_ptr
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%array_pointer.0 = getelementptr [21 x i8], [21 x i8]* %string_ptr, i32 0, i32 %array_index_ptr.0
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; check if p is below 0
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%condition = icmp slt i64 %val_copy, 0
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br i1 %condition, label %negative_check_true, label %negative_check_false
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negative_check_true:
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store i8 45, i8* %array_pointer.0
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br label %negative_check_done
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negative_check_false:
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; store i8 43, i8* %array_pointer.0
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br label %negative_check_done
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negative_check_done:
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%noop = add i32 0, 0
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; load the result and return it
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call void @reverseI64String([21 x i8]* %string_ptr)
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%res = load [21 x i8],[21 x i8]* %string_ptr
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ret [21 x i8] %res
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}
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define void @reverseI64String([21 x i8]* %string) {
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%new_string = alloca [21 x i8]
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store [21 x i8] c"\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00", [21 x i8]* %new_string
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%reverse_index = alloca i32
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store i32 20, i32* %reverse_index
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%new_index = alloca i32
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store i32 0, i32* %new_index
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br label %while_start
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while_start:
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%reverse_index.0 = load i32, i32* %reverse_index
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%reverse_ptr = getelementptr [21 x i8], [21 x i8]* %string, i32 0, i32 %reverse_index.0
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%reverse_index.1 = sub i32 %reverse_index.0, 1
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store i32 %reverse_index.1, i32* %reverse_index
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%new_index.0 = load i32, i32* %new_index
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%new_ptr = getelementptr [21 x i8], [21 x i8]* %new_string, i32 0, i32 %new_index.0
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%break_condition = icmp slt i32 %reverse_index.0, 0
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br i1 %break_condition, label %break, label %ok
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ok:
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%value = load i8, i8* %reverse_ptr
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%condition = icmp eq i8 %value, 0
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br i1 %condition, label %while_start, label %not_zero
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not_zero:
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store i8 %value, i8* %new_ptr
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%new_index.1 = add i32 %new_index.0, 1
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store i32 %new_index.1, i32* %new_index
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br label %while_start
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break:
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%copy = load [21 x i8], [21 x i8]* %new_string
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store [21 x i8] %copy, [21 x i8]* %string
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; start iterating over the original string in reverse
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; if i == '\00' ignore
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; else put value into new_string at new i, then new i + 1
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ret void
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}
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; Definition of main function
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define i32 @main() { ; i32()*
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; %val = add i64 -123456789, 0
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%val = add i64 -133780085, 0
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%print_res = call [21 x i8] @i64ToString(i64 %val)
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%ptr = alloca [21 x i8]
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store [21 x i8] %print_res, [21 x i8]* %ptr
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%printable = bitcast [21 x i8]* %ptr to i8*
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call i32 @puts(i8* %printable)
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ret i32 0
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}
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