1918767 - Use of __forceinline / __attribute__((always_inline)) causes excessive stack usage in some build configurations

Status: RESOLVED FIXED

(NSS :: Libraries, defect, P2)

Description

[John Schanck [:jschanck]]

Many HACL* functions are annotated with inline __forceinline (msvc) or inline __attribute__((always_inline)) (gcc/clang) via the KRML_MUSTINLINE macro.

This causes, among other things, generate_keypair_a2 in the new ML-KEM code to use over 400 KB of stack space (due to several copies of a fully-unrolled SHA3 implementation get inlined into the function).

We should define KRML_MUSTINLINE as inline to give the compiler more flexibility avoid excessive stack usage.

Comment 1

[John Schanck [:jschanck]]

Attachment: Bug 1918767 - override default definition of KRML_MUSTINLINE. r=#nss-reviewers

Comment 2

[John Schanck [:jschanck]]

https://hg.mozilla.org/projects/nss/rev/18b287c5128e489b483cc156cdc7a51e41185c65

Comment 3

[Robert Relyea]

Don't we need the same for gmake builds?
bob