Seems like we generate more code than cg_llvm

[antoyo]

Compare the GIMPLE and LLVM IR for my project reproducer-memchr.

The GIMPLE seems to contain more functions than the LLVM IR.

This might be one of the causes of the difference in binary size.

[bjorn3]

Note that the output of --emit llvm-ir is after optimizations unless you pass -Cno-prepopulate-passes.

Also is this with a sysroot compiled by cg_gcc rather than the default sysroot shipped with rustc? And if so did you make sure to enable release mode while compiling the sysroot? Also you probably have to pass -Zinline-mir given that you are building the sysroot with incr comp enabled. Incr comp disables MIR inlining by default. https://github.com/rust-lang/rustc_codegen_cranelift/blob/0335dc131fb35f710668f6e079d39eebbc31edac/build_system/build_sysroot.rs#L233-L236