The libcore.rlib size more than doubled since 1.47

[tmiasko]

The libcore.rlib size for x86_64-unknown-linux-gnu target:

Toolchain	MB
nightly	76
nightly*	20
beta	48
1.48	47
1.47	36
1.46	29
1.45	29
1.44	28
1.43	27
1.42	27
1.41	27
1.40	28
1.39	26
1.38	26
1.37	27
1.36	27
1.35	27
1.34	27
1.33	26
1.32	26
1.31	26

nightly* = libcore without stdarch

diff --git a/library/core/src/lib.rs b/library/core/src/lib.rs
index 5b19bf6b80f..cc4344a30aa 100644
--- a/library/core/src/lib.rs
+++ b/library/core/src/lib.rs
@@ -284,7 +284,6 @@
 // `core_arch` depends on libcore, but the contents of this module are
 // set up in such a way that directly pulling it here works such that the
 // crate uses the this crate as its libcore.
-#[path = "../../stdarch/crates/core_arch/src/mod.rs"]
 #[allow(
     missing_docs,
     missing_debug_implementations,
@@ -297,7 +296,93 @@
 // merged. It currently cannot because bootstrap fails as the lint hasn't been defined yet.
 #[allow(clashing_extern_declarations)]
 #[unstable(feature = "stdsimd", issue = "48556")]
-mod core_arch;
+mod core_arch {
+    pub mod arch {
+        #[stable(feature = "a", since = "1.0.0")]
+        pub mod x86 {
+            #[allow(non_camel_case_types)]
+            #[stable(feature = "a", since = "1.0.0")]
+            #[derive(Copy, Clone)]
+            pub struct __m128i;
+            #[stable(feature = "a", since = "1.0.0")]
+            pub unsafe fn _mm_pause() {
+                todo!();
+            }
+            #[stable(feature = "a", since = "1.0.0")]
+            pub unsafe fn _mm_set1_epi8(_: i8) -> __m128i {
+                todo!();
+            }
+            #[stable(feature = "a", since = "1.0.0")]
+            pub unsafe fn _mm_or_si128(_: __m128i, _: __m128i) -> __m128i {
+                todo!();
+            }
+            #[stable(feature = "a", since = "1.0.0")]
+            pub unsafe fn _mm_movemask_epi8(_: __m128i) -> i32 {
+                todo!();
+            }
+            #[stable(feature = "a", since = "1.0.0")]
+            pub unsafe fn _mm_load_si128(_: *const __m128i) -> __m128i {
+                todo!();
+            }
+            #[stable(feature = "a", since = "1.0.0")]
+            pub unsafe fn _mm_loadu_si128(_: *const __m128i) -> __m128i {
+                todo!();
+            }
+            #[stable(feature = "a", since = "1.0.0")]
+            pub unsafe fn _mm_store_si128(_: *mut __m128i, _: __m128i) {
+                todo!();
+            }
+            #[stable(feature = "a", since = "1.0.0")]
+            pub unsafe fn _mm_cmpeq_epi8(_: __m128i, _: __m128i) -> __m128i {
+                todo!();
+            }
+            #[stable(feature = "a", since = "1.0.0")]
+            pub unsafe fn _mm_cmpgt_epi8(_: __m128i, _: __m128i) -> __m128i {
+                todo!();
+            }
+            #[stable(feature = "a", since = "1.0.0")]
+            pub unsafe fn _mm_setzero_si128() -> __m128i {
+                todo!();
+            }
+            #[stable(feature = "a", since = "1.0.0")]
+            pub fn has_cpuid() -> bool {
+                todo!();
+            }
+            #[stable(feature = "a", since = "1.0.0")]
+            pub struct CpuidResult {
+                /// EAX register.
+                #[stable(feature = "simd_x86", since = "1.27.0")]
+                pub eax: u32,
+                /// EBX register.
+                #[stable(feature = "simd_x86", since = "1.27.0")]
+                pub ebx: u32,
+                /// ECX register.
+                #[stable(feature = "simd_x86", since = "1.27.0")]
+                pub ecx: u32,
+                /// EDX register.
+                #[stable(feature = "simd_x86", since = "1.27.0")]
+                pub edx: u32,
+            }
+            #[stable(feature = "a", since = "1.0.0")]
+            pub unsafe fn __cpuid(_: u32) -> CpuidResult {
+                todo!();
+            }
+            #[stable(feature = "a", since = "1.0.0")]
+            pub unsafe fn __cpuid_count(_: u32, _: u32) -> CpuidResult {
+                todo!();
+            }
+            #[stable(feature = "a", since = "1.0.0")]
+            pub unsafe fn _xgetbv(_: u32) -> u64 {
+                todo!();
+            }
+        }
+        #[stable(feature = "a", since = "1.0.0")]
+        pub mod x86_64 {
+            #[stable(feature = "a", since = "1.0.0")]
+            pub use super::x86::*;
+        }
+    }
+}
 
 #[stable(feature = "simd_arch", since = "1.27.0")]
 pub use core_arch::arch;

[camelid]

Not sure if this is a compiler-caused thing or not, so added both T-compiler and T-libs.

[camelid]

Maybe a lot of monomorphization happening?

[camelid]

Do we know how much of it is metadata, how much is MIR, how much is LLVM IR, and how much is object code? (Actually I'm not sure what things there are in an rlib – there don't seem to be docs on this.)

[jyn514]

I expect this has the same cause as the 40% compile time regression, which is the new avx512 intrinsics. https://hackmd.io/bm8_ygc8SFi64MWKZowhWw?both#Regressions

[camelid]

@jyn514 Is that #79938? I didn't see anything in the HackMD directly about AVX512.

[tmiasko]

Nightly -Zmeta-stats for core crate (items MIR accounts for 45.3 MB out of 72 MB):

	with MIR	without items MIR
dep bytes	0	0
lib feature bytes	10107	10107
lang item bytes	357	357
diagnostic item bytes	359	359
native bytes	0	0
source_map bytes	220553	220553
impl bytes	47150	47150
exp. symbols bytes	3636	3636
def-path table bytes	1193251	1193251
proc-macro-data-bytes	0	0
item bytes	60279879	19469482
table bytes	4545064	4545064
hygiene bytes	5775148	1274523
zero bytes	18454275	8444074
total bytes	72079395	26767993

• Rollup of 11 pull requests #79167 / Enable AVX512 *epi64 variants by updating stdarch #79131 increased size by 22.1 MB
• update stdarch submodule #77259 increased size by 6.4 MB
• Update stdarch submodule #79938 increased size by 5.3 MB
• Update stdarch submodule #80264 reduced size by 8.8 MB

[tmiasko]

Closing in favour of rust-lang/stdarch#248.