Thought I was the only one [LWN.net]

Thought I was the only one

Posted May 25, 2026 16:12 UTC (Mon) by mjg59 (subscriber, #23239)
In reply to: Thought I was the only one by gmprice
Parent article: Dirk and Linus discuss AI and kernel development

Arguably godbolt.org is exactly the replacement for that, making it massively easier to verify across all the compilers you care about

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Thought I was the only one

Posted May 25, 2026 16:32 UTC (Mon) by gmprice (subscriber, #167884) [Link] (4 responses)

Objdump is perfectly serviceable and installed by default with any major devtool package :)

Generate assembly language directly with -S

Posted May 25, 2026 16:53 UTC (Mon) by jreiser (subscriber, #11027) [Link] (2 responses)

The -S command-line flag to some compilers (generate assembly language text instead of binary instructions) is enough if you have a text editor. (You might also learn some exotica that the compiler performs behind your back!)

Generate assembly language directly with -S

Posted May 26, 2026 14:01 UTC (Tue) by willy (subscriber, #9762) [Link]

The kernel build system supports "make fs/buffer.s" to generate the assembly rather than the fs/buffer.o file that would normally be built. It's a little more symbolic than running objdump -S but doesn't tell you how many bytes each insn is compiled to. It's sometimes better for a before/after comparison of a code change.

Generate assembly language directly with -S

Posted Jun 4, 2026 8:22 UTC (Thu) by renox (guest, #23785) [Link]

Generating the assembly language isn't the hard part: finding where your code is when it has been inlined/mixed in the optimised build *is* the hard part.

Thought I was the only one

Posted May 25, 2026 16:55 UTC (Mon) by mjg59 (subscriber, #23239) [Link]

Yes, but the full range of compilers supported by the kernel is rather more tedious to install from packages