Use mimalloc as the allocator on x86_64-pc-windows-msvc

Zoxc · Zoxc · commit a4378875576e · 2026-04-30T12:34:25.000+02:00
diff --git a/Cargo.lock b/Cargo.lock
@@ -756,7 +756,7 @@ checksum = "af491d569909a7e4dee0ad7db7f5341fef5c614d5b8ec8cf765732aba3cff681"
 dependencies = [
  "serde",
  "termcolor",
- "unicode-width 0.1.14",
+ "unicode-width 0.2.2",
 ]
 
 [[package]]
@@ -977,6 +977,12 @@ dependencies = [
  "windows-sys 0.61.2",
 ]
 
+[[package]]
+name = "cty"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b365fabc795046672053e29c954733ec3b05e4be654ab130fe8f1f94d7051f35"
+
 [[package]]
 name = "curl"
 version = "0.4.49"
@@ -2216,6 +2222,16 @@ version = "0.2.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f9fbbcab51052fe104eb5e5d351cf728d30a5be1fe14d9be8a3b097481fb97de"
 
+[[package]]
+name = "libmimalloc-sys"
+version = "0.1.47"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2d1eacfa31c33ec25e873c136ba5669f00f9866d0688bea7be4d3f7e43067df6"
+dependencies = [
+ "cc",
+ "cty",
+]
+
 [[package]]
 name = "libredox"
 version = "0.1.10"
@@ -2399,6 +2415,15 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "mimalloc"
+version = "0.1.50"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b3627c4272df786b9260cabaa46aec1d59c93ede723d4c3ef646c503816b0640"
+dependencies = [
+ "libmimalloc-sys",
+]
+
 [[package]]
 name = "minifier"
 version = "0.3.6"
@@ -3808,6 +3833,8 @@ dependencies = [
  "ctrlc",
  "jiff",
  "libc",
+ "libmimalloc-sys",
+ "mimalloc",
  "rustc_abi",
  "rustc_ast",
  "rustc_ast_pretty",
diff --git a/compiler/rustc/Cargo.toml b/compiler/rustc/Cargo.toml
@@ -40,6 +40,7 @@ llvm = ['rustc_driver_impl/llvm']
 llvm_enzyme = ['rustc_driver_impl/llvm_enzyme']
 llvm_offload = ['rustc_driver_impl/llvm_offload']
 max_level_info = ['rustc_driver_impl/max_level_info']
+mimalloc = ['rustc_driver_impl/mimalloc']
 rustc_randomized_layouts = ['rustc_driver_impl/rustc_randomized_layouts']
 # tidy-alphabetical-end
 
diff --git a/compiler/rustc_driver_impl/Cargo.toml b/compiler/rustc_driver_impl/Cargo.toml
@@ -55,13 +55,23 @@ features = [
 ctrlc = "3.4.4"
 # tidy-alphabetical-end
 
+[target.'cfg(target_os = "windows")'.dependencies.mimalloc]
+version = "0.1.50"
+optional = true
+
+[target.'cfg(target_os = "windows")'.dependencies.libmimalloc-sys]
+version = "0.1.47"
+optional = true
+features = ["extended"]
+
 [features]
 # tidy-alphabetical-start
 check_only = ['rustc_interface/check_only']
 llvm = ['rustc_interface/llvm']
 llvm_enzyme = ['rustc_interface/llvm_enzyme']
 llvm_offload = ['rustc_interface/llvm_offload']
 max_level_info = ['rustc_log/max_level_info']
+mimalloc = ['dep:mimalloc', 'dep:libmimalloc-sys']
 rustc_randomized_layouts = [
     'rustc_index/rustc_randomized_layouts',
     'rustc_middle/rustc_randomized_layouts'
diff --git a/compiler/rustc_driver_impl/src/alloc.rs b/compiler/rustc_driver_impl/src/alloc.rs
@@ -0,0 +1,54 @@
+#[cfg(all(target_os = "windows", feature = "mimalloc"))]
+#[global_allocator]
+static GLOBAL: mimalloc::MiMalloc = mimalloc::MiMalloc;
+
+#[cfg(all(target_os = "windows", feature = "mimalloc"))]
+pub mod fns {
+    use std::os::raw::{c_char, c_int, c_void};
+
+    #[unsafe(no_mangle)]
+    pub unsafe extern "C" fn calloc(items: usize, size: usize) -> *mut c_void {
+        unsafe { libmimalloc_sys::mi_calloc(items, size) }
+    }
+
+    #[unsafe(no_mangle)]
+    pub unsafe extern "C" fn posix_memalign(
+        ptr: *mut *mut c_void,
+        align: usize,
+        size: usize,
+    ) -> c_int {
+        unsafe { libmimalloc_sys::mi_posix_memalign(ptr, align, size) }
+    }
+
+    #[unsafe(no_mangle)]
+    pub unsafe extern "C" fn strndup(s: *const c_char, n: usize) -> *mut c_char {
+        unsafe { libmimalloc_sys::mi_strndup(s, n) }
+    }
+
+    #[unsafe(no_mangle)]
+    pub unsafe extern "C" fn strdup(s: *const c_char) -> *mut c_char {
+        unsafe { libmimalloc_sys::mi_strdup(s) }
+    }
+
+    #[unsafe(no_mangle)]
+    pub unsafe extern "C" fn aligned_alloc(align: usize, size: usize) -> *mut c_void {
+        unsafe { libmimalloc_sys::mi_aligned_alloc(align, size) }
+    }
+
+    #[unsafe(no_mangle)]
+    pub unsafe extern "C" fn malloc(size: usize) -> *mut c_void {
+        unsafe { libmimalloc_sys::mi_malloc(size) }
+    }
+
+    #[unsafe(no_mangle)]
+    pub unsafe extern "C" fn realloc(ptr: *mut c_void, size: usize) -> *mut c_void {
+        unsafe { libmimalloc_sys::mi_realloc(ptr, size) }
+    }
+
+    #[unsafe(no_mangle)]
+    pub unsafe extern "C" fn free(ptr: *mut c_void) {
+        unsafe {
+            libmimalloc_sys::mi_free(ptr);
+        }
+    }
+}
diff --git a/compiler/rustc_driver_impl/src/lib.rs b/compiler/rustc_driver_impl/src/lib.rs
@@ -63,6 +63,8 @@ use rustc_target::json::ToJson;
 use rustc_target::spec::{Target, TargetTuple};
 use tracing::trace;
 
+pub mod alloc;
+
 #[allow(unused_macros)]
 macro do_not_use_print($($t:tt)*) {
     std::compile_error!(
diff --git a/src/bootstrap/src/core/config/mod.rs b/src/bootstrap/src/core/config/mod.rs
@@ -254,12 +254,14 @@ impl<'de> Deserialize<'de> for CompilerBuiltins {
 #[derive(Copy, Clone, Debug, PartialEq, Eq)]
 pub enum OverrideAllocator {
     Jemalloc,
+    Mimalloc,
 }
 
 impl OverrideAllocator {
     pub fn feature_name(self) -> &'static str {
         match self {
             OverrideAllocator::Jemalloc => "jemalloc",
+            OverrideAllocator::Mimalloc => "mimalloc",
         }
     }
 }
@@ -272,7 +274,8 @@ impl<'de> Deserialize<'de> for OverrideAllocator {
         let name = String::deserialize(deserializer)?;
         match name.as_str() {
             "jemalloc" => Ok(Self::Jemalloc),
-            other => Err(serde::de::Error::unknown_variant(other, &["jemalloc"])),
+            "mimalloc" => Ok(Self::Mimalloc),
+            other => Err(serde::de::Error::unknown_variant(other, &["jemalloc", "mimalloc"])),
         }
     }
 }
diff --git a/src/ci/github-actions/jobs.yml b/src/ci/github-actions/jobs.yml
@@ -659,6 +659,7 @@ auto:
         --target=x86_64-pc-windows-msvc
         --enable-full-tools
         --enable-profiler
+        --set rust.override-allocator=mimalloc
         --set rust.codegen-units=1
       SCRIPT: python x.py build --set rust.debug=true opt-dist && PGO_HOST=x86_64-pc-windows-msvc ./build/x86_64-pc-windows-msvc/stage1-tools-bin/opt-dist windows-ci -- python x.py dist bootstrap --include-default-paths
       DIST_REQUIRE_ALL_TOOLS: 1
diff --git a/src/tools/tidy/src/deps.rs b/src/tools/tidy/src/deps.rs
@@ -304,6 +304,7 @@ const PERMITTED_RUSTC_DEPENDENCIES: &[&str] = &[
     "crossbeam-utils",
     "crypto-common",
     "ctrlc",
+    "cty",
     "darling",
     "darling_core",
     "darling_macro",
@@ -356,6 +357,7 @@ const PERMITTED_RUSTC_DEPENDENCIES: &[&str] = &[
     "leb128",
     "libc",
     "libloading",
+    "libmimalloc-sys",
     "linux-raw-sys",
     "litemap",
     "lock_api",
@@ -365,6 +367,7 @@ const PERMITTED_RUSTC_DEPENDENCIES: &[&str] = &[
     "measureme",
     "memchr",
     "memmap2",
+    "mimalloc",
     "miniz_oxide",
     "nix",
     "nu-ansi-term",

Original file line number	Diff line number	Diff line change
`@@ -254,12 +254,14 @@ impl<'de> Deserialize<'de> for CompilerBuiltins {`
`254`	`254`	`#[derive(Copy, Clone, Debug, PartialEq, Eq)]`
`255`	`255`	`pub enum OverrideAllocator {`
`256`	`256`	`Jemalloc,`
	`257`	`+ Mimalloc,`
`257`	`258`	`}`
`258`	`259`
`259`	`260`	`impl OverrideAllocator {`
`260`	`261`	`pub fn feature_name(self) -> &'static str {`
`261`	`262`	`match self {`
`262`	`263`	`OverrideAllocator::Jemalloc => "jemalloc",`
	`264`	`+ OverrideAllocator::Mimalloc => "mimalloc",`
`263`	`265`	`}`
`264`	`266`	`}`
`265`	`267`	`}`
`@@ -272,7 +274,8 @@ impl<'de> Deserialize<'de> for OverrideAllocator {`
`272`	`274`	`let name = String::deserialize(deserializer)?;`
`273`	`275`	`match name.as_str() {`
`274`	`276`	`"jemalloc" => Ok(Self::Jemalloc),`
`275`		`- other => Err(serde::de::Error::unknown_variant(other, &["jemalloc"])),`
	`277`	`+ "mimalloc" => Ok(Self::Mimalloc),`
	`278`	`+ other => Err(serde::de::Error::unknown_variant(other, &["jemalloc", "mimalloc"])),`
`276`	`279`	`}`
`277`	`280`	`}`
`278`	`281`	`}`