From: visitor x <visitor20212@outlook.com>
To: "gcc-help@gcc.gnu.org" <gcc-help@gcc.gnu.org>
Subject: When will gcc assign local variables to registers?
Date: Tue, 10 Nov 2020 11:27:51 +0000 [thread overview]
Message-ID: <SL2PR02MB35968C6DE34B614513F5E57C83E90@SL2PR02MB3596.apcprd02.prod.outlook.com> (raw)
Hello,
I'm trying to distinguish local variable assigned to register from a binary.
I got that compilers will assign some local variable to registers rather than stack for performance reason, while which variable depends on the compiler. I also found there is a calling convention on x64 that the first six arguments are passed to register (when the class is INTEGER).
However, I got almost nothing about the rest of the case. I am aware that compilers are free to arrange variables in both stack and registers, but what pricinple or specification will they follow?
Is there any materials about gcc's behavior on deciding which variables should be kept in registers? Or any other hint to find variables stored in register from a bianry?
visitor20
next reply other threads:[~2020-11-10 11:27 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-10 11:27 visitor x [this message]
2020-11-10 15:24 ` Andrew Haley
[not found] <SL2PR02MB3596DBDC06124B066570F3D383E80@SL2PR02MB3596.apcprd02.prod.outlook.com>
2020-11-12 5:04 ` visitor x
2020-11-12 6:54 ` Henri Cloetens
2020-11-12 11:43 ` x visitor
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