Questions tagged [compilers]
Questions about programs that read code in one language (source language) and translate it into an equivalent program in another language (target language).
674 questions
0 votes
3 answers
490 views
If a literal like 0.45 has exact decimal precision, why can’t compilers preserve that and avoid floating-point rounding issues?
In most languages, writing a floating-point literal like 0.45 produces a binary IEEE-754 double that is actually stored as something slightly less than 0.45 (e.g., 0.44999999999999996). Because of ...
- 9
3 votes
0 answers
56 views
(Prolog) Warren's Abstract Machine, Argument Registers
I am currently reading "Warren's Abstract Machine: A Tutorial Reconstruction" and I'm trying to follow along with the exercise as well as code my own implementation. I am trying to ...
- 31
0 votes
0 answers
56 views
How to minimize parentheses when stringifying arithmetic AST for right-to-left evaluation languages with different precedence rule?
I'm looking at translations to and from APL, which has right-to-left evaluation and no operator precedence. Is there a known algorithm to minimize parentheses usage when keeping the same operators for ...
- 123
3 votes
2 answers
187 views
Is there any research on "fixed points of bugs"?
Is there any research on or at least formulation of the concept of "fixed points of bugs"? That is, suppose we have an implementation $I$ (e.g., a compiler or interpreter) of a programming ...
- 117
1 vote
0 answers
52 views
Why does the G-machine push arguments before the function for application (MKAP)?
I'm reading The implementation of functional programming languages (1987) by Peyton Jones and he mentions (p.307) that the MKAP (make application) instruction is more convenient if the argument is ...
- 111
1 vote
0 answers
35 views
$IN[BB]=\emptyset$ for all $BB$ instead of $IN[BB]=U,\text{for all other BB != BB_EXIT}$ in Init of Anticipated Expression Dataflow analysis in SSA
I am implementing an LLVM pass for anticipated expressions using dataflow analysis and code hoisting. The reference I am following is the Purple Dragon Book (Compilers: Principles, Techniques, and ...
- 1,184
1 vote
0 answers
57 views
Drawing the syntax tree for directly converting Regex to DFA
I am learning compiler design and I came across a problem for converting a Regex to DFA by direct method. But I couldn't draw the syntax tree or I would say I couldn't find a systematic approach for ...
12 votes
3 answers
2k views
Why is a program operating system dependent?
I understand that processors belonging to different architectures have different instruction set and therefore a program compiled for one processor (hardware platform) can't run on a processor with ...
- 129
0 votes
1 answer
100 views
Number of LR(0) item sets of the grammar (Dragon Book, exercise 4.6.7)
I'm stuck on exercise 4.6.7 part b from the dragon book. The task is to show that the given grammar Gn: S → Aibi for 1 ≤ i ≤ nAi → ajAi | aj for 1 ≤ i,j ≤ n i≠j has ...
2 votes
0 answers
62 views
Reference counting operation insertion in syntax tree
This question might be too open-ended, but I can't seem to find any resources online. When implementing reference counting as a form of GC in a language, how do you know when to increase/decrease ...
- 53
1 vote
2 answers
567 views
How do logic gates handle if-else statements?
There are questions here and on electrical engeneering stackexchange with similar titles, but they do not quite address the part that is bugging me. I hope I can explain it here in a clear way and ...
- 761
1 vote
1 answer
69 views
How can the symbol table be used in code generation after the semantic analysis phase?
I am writing a basic compiler that compiles a language down into custom bytecode instructions. The language allows for variable shadowing (this is a cause of one of the main problems I am running into)...
- 123
1 vote
1 answer
62 views
Livout analysis of control flow graph of a program
I just started reading about data flow analysis in compilers and I am trying to understand the concept of live-out variables. For this I read the algorithm to compute live-out variables in each bloc ...
- 111
1 vote
1 answer
98 views
Possible mistake in a book regarding parsing and lexical analysis
I was just reading a book (Algorithms and Theory of Computation Handbook, Volume 1) and I came across the following passage : "From a practical point of view, for each grammar G = (Σ,V, S, P) ...
- 91
1 vote
1 answer
60 views
How would setjmp differ in runtime environments with stack-allocated vs. heap-allocated stack frames?
I am stumped on Engineering a Compiler, 3rd ed. Section 6.3, Review Question 1. The book uses the term 'activation record' to refer to a generalized procedure frame. The question asks: In C, '...
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