Auto merge of #100035 - workingjubilee:merge-functions, r=nikic

Enable function merging when opt is for size

It is, of course, natural to want to merge aliasing functions when
optimizing for code size, since that can eliminate several bytes.
And an exhaustive match helps make the code less brittle.

Closes #98215.

1 files changed, 5 insertions, 2 deletions

diff --git a/compiler/rustc_codegen_ssa/src/back/write.rs b/compiler/rustc_codegen_ssa/src/back/write.rs
index 1b5ad87107a..dbd55590e5c 100644
--- a/compiler/rustc_codegen_ssa/src/back/write.rs
+++ b/compiler/rustc_codegen_ssa/src/back/write.rs
@@ -256,8 +256,11 @@ impl ModuleConfig {
             {
                 MergeFunctions::Disabled => false,
                 MergeFunctions::Trampolines | MergeFunctions::Aliases => {
-                    sess.opts.optimize == config::OptLevel::Default
-                        || sess.opts.optimize == config::OptLevel::Aggressive
+                    use config::OptLevel::*;
+                    match sess.opts.optimize {
+                        Aggressive | Default | SizeMin | Size => true,
+                        Less | No => false,
+                    }
                 }
             },