From 8d4b47298b6c9eeb9a3f79a5b80d894f80ed4a45 Mon Sep 17 00:00:00 2001 From: Michael Smith Date: Sat, 27 Dec 2025 03:05:05 +0000 Subject: Do away with memcpy/memset/memcmp Now everything is either explicitly a rep thing, or explicitly some other small run of reasonably efficient instructions. No library calls or function call overhead of any kind. Code size remains nice and small. Ban a few other bad libc functions while we're at it. More can be added later if we decide that's a useful idea. This will require some discipline and workarounds to cope with Clang's tendency to shove mem* calls in places you don't want them even when you tell it not to. Well, c'est la vie. I'm a little nervous that the __builtin_memmove() usage in shuntvars() could still one day emit actual library calls. It appears we're not importing memmove() from anywhere at the moment, though. So I guess it's good enough for now. Also I had to get rid of alloca() in con_.c but that was kind of bad anyway, so that's fine. --- src/build/gluegen.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'src/build') diff --git a/src/build/gluegen.c b/src/build/gluegen.c index 33ba600..b0649ca 100644 --- a/src/build/gluegen.c +++ b/src/build/gluegen.c @@ -877,8 +877,9 @@ _( "") _( "static inline void shuntvars() {") _( "#ifdef _WIN32") for (int i = 1; i < ncvars; ++i) { -F( " memmove(&%.*s->v1, &%.*s->v2, sizeof(struct con_var_common));", +F( " __builtin_memmove(&%.*s->v1, &%.*s->v2, ", cvar_names[i].len, cvar_names[i].s, cvar_names[i].len, cvar_names[i].s) +_( " sizeof(struct con_var_common));") } _( "#endif") _( "}") -- cgit v1.2.3-54-g00ecf