From c344a3ff3dbde3db05edb802d8951924689d1d65 Mon Sep 17 00:00:00 2001
From: Tokarak <63452145+Tokarak@users.noreply.github.com>
Date: Tue, 13 Jun 2023 11:35:45 +0100
Subject: [PATCH 01/17] Apply cpu-optimisation to Rust projects (hardcoded)

---
 Library/Homebrew/formula.rb | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/Library/Homebrew/formula.rb b/Library/Homebrew/formula.rb
index a80ff7ac25a4b..14c710ff3127e 100644
--- a/Library/Homebrew/formula.rb
+++ b/Library/Homebrew/formula.rb
@@ -1543,7 +1543,11 @@ def std_configure_args
   # Standard parameters for cargo builds.
   sig { params(root: T.any(String, Pathname), path: String).returns(T::Array[T.any(String, Pathname)]) }
   def std_cargo_args(root: prefix, path: ".")
-    ["--locked", "--root", root, "--path", path]
+    ["--locked", "--root", root, "--path", path,
+     "--config", "target.x86_64-apple-darwin.rustflags=['-Ctarget-cpu=nehalem']",
+     "--config", "target.aarch64-apple-darwin.rustflags=['-Ctarget-cpu=apple-m1']",
+    # Default target-cpu is apple-m1 since Rust 1.71.0
+     ]
   end
 
   # Standard parameters for CMake builds.

From a0725083f10ab39ed4ddc0a7c2f61be94a999d93 Mon Sep 17 00:00:00 2001
From: Tokarak <63452145+Tokarak@users.noreply.github.com>
Date: Tue, 13 Jun 2023 19:17:28 +0100
Subject: [PATCH 02/17] Revert "Apply cpu-optimisation to Rust projects
 (hardcoded)"

This reverts commit c344a3ff3dbde3db05edb802d8951924689d1d65.
---
 Library/Homebrew/formula.rb | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/Library/Homebrew/formula.rb b/Library/Homebrew/formula.rb
index 14c710ff3127e..a80ff7ac25a4b 100644
--- a/Library/Homebrew/formula.rb
+++ b/Library/Homebrew/formula.rb
@@ -1543,11 +1543,7 @@ def std_configure_args
   # Standard parameters for cargo builds.
   sig { params(root: T.any(String, Pathname), path: String).returns(T::Array[T.any(String, Pathname)]) }
   def std_cargo_args(root: prefix, path: ".")
-    ["--locked", "--root", root, "--path", path,
-     "--config", "target.x86_64-apple-darwin.rustflags=['-Ctarget-cpu=nehalem']",
-     "--config", "target.aarch64-apple-darwin.rustflags=['-Ctarget-cpu=apple-m1']",
-    # Default target-cpu is apple-m1 since Rust 1.71.0
-     ]
+    ["--locked", "--root", root, "--path", path]
   end
 
   # Standard parameters for CMake builds.

From 066a88855ba817aefce3ddf79264a963a84a0bb1 Mon Sep 17 00:00:00 2001
From: Tokarak <63452145+Tokarak@users.noreply.github.com>
Date: Tue, 13 Jun 2023 19:22:12 +0100
Subject: [PATCH 03/17] Add rustflags_target_cpu method

---
 Library/Homebrew/extend/os/mac/hardware.rb | 16 ++++++++++++++++
 Library/Homebrew/hardware.rb               | 12 ++++++++++++
 2 files changed, 28 insertions(+)

diff --git a/Library/Homebrew/extend/os/mac/hardware.rb b/Library/Homebrew/extend/os/mac/hardware.rb
index cbe49c842466e..db7b4957b5d1f 100644
--- a/Library/Homebrew/extend/os/mac/hardware.rb
+++ b/Library/Homebrew/extend/os/mac/hardware.rb
@@ -24,4 +24,20 @@ def self.oldest_cpu(version = nil)
       generic_oldest_cpu
     end
   end
+
+  # Override
+  # Mirrors version-dependent logic of oldest_cpu
+  sig { params(version: T.nilable(Version)).returns(String) } # FIXME: Version, String or Symbol?
+  def self.rustflags_target_cpu(version = nil)
+    version = if version
+      MacOSVersion.new(version.to_s)
+    else
+      MacOS.version
+    end
+    if Hardware::CPU.intel? && version >= :mojave
+      "-Ctarget-cpu=nehalem"
+    else
+      generic_rustflags_target_cpu
+    end
+  end
 end
diff --git a/Library/Homebrew/hardware.rb b/Library/Homebrew/hardware.rb
index 22bebf626b9bd..1db819bbecb91 100644
--- a/Library/Homebrew/hardware.rb
+++ b/Library/Homebrew/hardware.rb
@@ -214,6 +214,18 @@ def oldest_cpu(_version = nil)
       end
     end
     alias generic_oldest_cpu oldest_cpu
+
+    # Returns a _full_ rustflag to set target cpu, if necessary;
+    # Falls back to empty string
+    # This mirrors the logic of `oldest_cpu`,
+    # But only where it is version dependent.
+    # Rust already defaults to the oldest supported cpu for the target-triple
+    # Including apple-m1 since 1.71.
+    sig { params(_version: T.nilable(Version)).returns(String) } # FIXME: Version, String or Symbol?
+    def rustflags_target_cpu(_version = nil)
+      ""
+    end
+    alias generic_rustflags_target_cpu rustflags_target_cpu
   end
 end
 

From b4dd6391891b91ce87b67fe8bc44cec2ed05ceca Mon Sep 17 00:00:00 2001
From: Tokarak <63452145+Tokarak@users.noreply.github.com>
Date: Tue, 13 Jun 2023 19:28:53 +0100
Subject: [PATCH 04/17] Use rustflags_target_cpu

---
 Library/Homebrew/formula.rb | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Library/Homebrew/formula.rb b/Library/Homebrew/formula.rb
index a80ff7ac25a4b..d2cea2d606e23 100644
--- a/Library/Homebrew/formula.rb
+++ b/Library/Homebrew/formula.rb
@@ -1543,7 +1543,8 @@ def std_configure_args
   # Standard parameters for cargo builds.
   sig { params(root: T.any(String, Pathname), path: String).returns(T::Array[T.any(String, Pathname)]) }
   def std_cargo_args(root: prefix, path: ".")
-    ["--locked", "--root", root, "--path", path]
+    ["--locked", "--root", root, "--path", path, "--config",
+     "build.rustflags=['#{Hardware::CPU.rustflags_target_cpu}']"]
   end
 
   # Standard parameters for CMake builds.

From d4bfbb1d02706910c312532052f854c20feb123a Mon Sep 17 00:00:00 2001
From: Tokarak <63452145+Tokarak@users.noreply.github.com>
Date: Tue, 13 Jun 2023 19:32:18 +0100
Subject: [PATCH 05/17] Remove FIXMEs

---
 Library/Homebrew/extend/os/mac/hardware.rb | 2 +-
 Library/Homebrew/hardware.rb               | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/Library/Homebrew/extend/os/mac/hardware.rb b/Library/Homebrew/extend/os/mac/hardware.rb
index db7b4957b5d1f..d7c3f76d95326 100644
--- a/Library/Homebrew/extend/os/mac/hardware.rb
+++ b/Library/Homebrew/extend/os/mac/hardware.rb
@@ -27,7 +27,7 @@ def self.oldest_cpu(version = nil)
 
   # Override
   # Mirrors version-dependent logic of oldest_cpu
-  sig { params(version: T.nilable(Version)).returns(String) } # FIXME: Version, String or Symbol?
+  sig { params(version: T.nilable(Version)).returns(String) }
   def self.rustflags_target_cpu(version = nil)
     version = if version
       MacOSVersion.new(version.to_s)
diff --git a/Library/Homebrew/hardware.rb b/Library/Homebrew/hardware.rb
index 1db819bbecb91..e10a548fd038d 100644
--- a/Library/Homebrew/hardware.rb
+++ b/Library/Homebrew/hardware.rb
@@ -221,7 +221,7 @@ def oldest_cpu(_version = nil)
     # But only where it is version dependent.
     # Rust already defaults to the oldest supported cpu for the target-triple
     # Including apple-m1 since 1.71.
-    sig { params(_version: T.nilable(Version)).returns(String) } # FIXME: Version, String or Symbol?
+    sig { params(_version: T.nilable(Version)).returns(String) }
     def rustflags_target_cpu(_version = nil)
       ""
     end

From 2bd20eaa1534603b119a0ce6ad0b9f766f9c8c80 Mon Sep 17 00:00:00 2001
From: Tokarak <63452145+Tokarak@users.noreply.github.com>
Date: Tue, 13 Jun 2023 19:45:52 +0100
Subject: [PATCH 06/17] Fix

---
 Library/Homebrew/formula.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Library/Homebrew/formula.rb b/Library/Homebrew/formula.rb
index d2cea2d606e23..46a68eb38f601 100644
--- a/Library/Homebrew/formula.rb
+++ b/Library/Homebrew/formula.rb
@@ -1544,7 +1544,7 @@ def std_configure_args
   sig { params(root: T.any(String, Pathname), path: String).returns(T::Array[T.any(String, Pathname)]) }
   def std_cargo_args(root: prefix, path: ".")
     ["--locked", "--root", root, "--path", path, "--config",
-     "build.rustflags=['#{Hardware::CPU.rustflags_target_cpu}']"]
+     "build.rustflags=['#{Hardware.rustflags_target_cpu}']"]
   end
 
   # Standard parameters for CMake builds.

From c69817420028f9610346d2b4600a3da4229fe708 Mon Sep 17 00:00:00 2001
From: Tokarak <63452145+Tokarak@users.noreply.github.com>
Date: Tue, 13 Jun 2023 20:40:23 +0100
Subject: [PATCH 07/17] Fix error on empty target-cpu

---
 Library/Homebrew/extend/os/mac/hardware.rb | 2 +-
 Library/Homebrew/formula.rb                | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/Library/Homebrew/extend/os/mac/hardware.rb b/Library/Homebrew/extend/os/mac/hardware.rb
index d7c3f76d95326..1bfd2feea075c 100644
--- a/Library/Homebrew/extend/os/mac/hardware.rb
+++ b/Library/Homebrew/extend/os/mac/hardware.rb
@@ -35,7 +35,7 @@ def self.rustflags_target_cpu(version = nil)
       MacOS.version
     end
     if Hardware::CPU.intel? && version >= :mojave
-      "-Ctarget-cpu=nehalem"
+      "'-Ctarget-cpu=nehalem'"
     else
       generic_rustflags_target_cpu
     end
diff --git a/Library/Homebrew/formula.rb b/Library/Homebrew/formula.rb
index 46a68eb38f601..0ddd74cc6c442 100644
--- a/Library/Homebrew/formula.rb
+++ b/Library/Homebrew/formula.rb
@@ -1544,7 +1544,7 @@ def std_configure_args
   sig { params(root: T.any(String, Pathname), path: String).returns(T::Array[T.any(String, Pathname)]) }
   def std_cargo_args(root: prefix, path: ".")
     ["--locked", "--root", root, "--path", path, "--config",
-     "build.rustflags=['#{Hardware.rustflags_target_cpu}']"]
+     "build.rustflags=[#{Hardware.rustflags_target_cpu}]"]
   end
 
   # Standard parameters for CMake builds.

From cccad3e7d858e1dd68afa9e033e20b674fd678e1 Mon Sep 17 00:00:00 2001
From: Tokarak <63452145+Tokarak@users.noreply.github.com>
Date: Wed, 14 Jun 2023 16:46:12 +0100
Subject: [PATCH 08/17] Line break

---
 Library/Homebrew/extend/os/mac/hardware.rb | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Library/Homebrew/extend/os/mac/hardware.rb b/Library/Homebrew/extend/os/mac/hardware.rb
index 1bfd2feea075c..3cc0dab17d557 100644
--- a/Library/Homebrew/extend/os/mac/hardware.rb
+++ b/Library/Homebrew/extend/os/mac/hardware.rb
@@ -34,6 +34,7 @@ def self.rustflags_target_cpu(version = nil)
     else
       MacOS.version
     end
+
     if Hardware::CPU.intel? && version >= :mojave
       "'-Ctarget-cpu=nehalem'"
     else

From 261f55a526d23366204ac243c6029564a5ce81c3 Mon Sep 17 00:00:00 2001
From: Tokarak <63452145+Tokarak@users.noreply.github.com>
Date: Wed, 14 Jun 2023 17:14:05 +0100
Subject: [PATCH 09/17] Prepare to migrate to RUSTFLAGS

---
 Library/Homebrew/extend/os/mac/hardware.rb | 2 +-
 Library/Homebrew/formula.rb                | 3 +--
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/Library/Homebrew/extend/os/mac/hardware.rb b/Library/Homebrew/extend/os/mac/hardware.rb
index 3cc0dab17d557..2cc0d30b7eae4 100644
--- a/Library/Homebrew/extend/os/mac/hardware.rb
+++ b/Library/Homebrew/extend/os/mac/hardware.rb
@@ -36,7 +36,7 @@ def self.rustflags_target_cpu(version = nil)
     end
 
     if Hardware::CPU.intel? && version >= :mojave
-      "'-Ctarget-cpu=nehalem'"
+      "-Ctarget-cpu=nehalem"
     else
       generic_rustflags_target_cpu
     end
diff --git a/Library/Homebrew/formula.rb b/Library/Homebrew/formula.rb
index 0ddd74cc6c442..a80ff7ac25a4b 100644
--- a/Library/Homebrew/formula.rb
+++ b/Library/Homebrew/formula.rb
@@ -1543,8 +1543,7 @@ def std_configure_args
   # Standard parameters for cargo builds.
   sig { params(root: T.any(String, Pathname), path: String).returns(T::Array[T.any(String, Pathname)]) }
   def std_cargo_args(root: prefix, path: ".")
-    ["--locked", "--root", root, "--path", path, "--config",
-     "build.rustflags=[#{Hardware.rustflags_target_cpu}]"]
+    ["--locked", "--root", root, "--path", path]
   end
 
   # Standard parameters for CMake builds.

From 2133da85971c81332a1ca7cbe00661b2134df0bd Mon Sep 17 00:00:00 2001
From: Tokarak <63452145+Tokarak@users.noreply.github.com>
Date: Wed, 14 Jun 2023 17:26:01 +0100
Subject: [PATCH 10/17] Set target-cpu through RUSTFLAGS

---
 Library/Homebrew/extend/ENV/shared.rb | 1 +
 Library/Homebrew/extend/ENV/std.rb    | 1 +
 2 files changed, 2 insertions(+)

diff --git a/Library/Homebrew/extend/ENV/shared.rb b/Library/Homebrew/extend/ENV/shared.rb
index bef56363bc21d..fb25328cf7945 100644
--- a/Library/Homebrew/extend/ENV/shared.rb
+++ b/Library/Homebrew/extend/ENV/shared.rb
@@ -28,6 +28,7 @@ module SharedEnvExtension
     CMAKE_PREFIX_PATH CMAKE_INCLUDE_PATH CMAKE_FRAMEWORK_PATH
     GOBIN GOPATH GOROOT PERL_MB_OPT PERL_MM_OPT
     LIBRARY_PATH LD_LIBRARY_PATH LD_PRELOAD LD_RUN_PATH
+    RUSTFLAGS
   ].freeze
   private_constant :SANITIZED_VARS
 
diff --git a/Library/Homebrew/extend/ENV/std.rb b/Library/Homebrew/extend/ENV/std.rb
index b1bdb5424da55..19cec7ad88e50 100644
--- a/Library/Homebrew/extend/ENV/std.rb
+++ b/Library/Homebrew/extend/ENV/std.rb
@@ -36,6 +36,7 @@ def setup_build_environment(formula: nil, cc: nil, build_bottle: false, bottle_a
     self["PKG_CONFIG_LIBDIR"] = determine_pkg_config_libdir
 
     self["MAKEFLAGS"] = "-j#{make_jobs}"
+    self["RUSTFLAGS"] = Hardware.rustflags_target_cpu
 
     if HOMEBREW_PREFIX.to_s != "/usr/local"
       # /usr/local is already an -isystem and -L directory so we skip it

From 9a99b932e839428dd4b188fd11777ee69f6efc4f Mon Sep 17 00:00:00 2001
From: Tokarak <63452145+Tokarak@users.noreply.github.com>
Date: Sat, 17 Jun 2023 10:16:53 +0100
Subject: [PATCH 11/17] Add RUSTFLAGS to ENV/super

---
 Library/Homebrew/extend/ENV/super.rb | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Library/Homebrew/extend/ENV/super.rb b/Library/Homebrew/extend/ENV/super.rb
index 734eccb95d266..c5bbe02caecb8 100644
--- a/Library/Homebrew/extend/ENV/super.rb
+++ b/Library/Homebrew/extend/ENV/super.rb
@@ -63,6 +63,7 @@ def setup_build_environment(formula: nil, cc: nil, build_bottle: false, bottle_a
 
     self["HOMEBREW_ENV"] = "super"
     self["MAKEFLAGS"] ||= "-j#{determine_make_jobs}"
+    self["RUSTFLAGS"] = Hardware.rustflags_target_cpu
     self["PATH"] = determine_path
     self["PKG_CONFIG_PATH"] = determine_pkg_config_path
     self["PKG_CONFIG_LIBDIR"] = determine_pkg_config_libdir

From 9a19f5bcd2a352446868ac51873b3ddc1becf2a1 Mon Sep 17 00:00:00 2001
From: Tokarak <63452145+Tokarak@users.noreply.github.com>
Date: Sat, 17 Jun 2023 10:38:32 +0100
Subject: [PATCH 12/17] Refactor to use oldest_cpu

---
 Library/Homebrew/extend/os/mac/hardware.rb | 17 -----------------
 Library/Homebrew/hardware.rb               | 15 +++++++++++----
 2 files changed, 11 insertions(+), 21 deletions(-)

diff --git a/Library/Homebrew/extend/os/mac/hardware.rb b/Library/Homebrew/extend/os/mac/hardware.rb
index 2cc0d30b7eae4..cbe49c842466e 100644
--- a/Library/Homebrew/extend/os/mac/hardware.rb
+++ b/Library/Homebrew/extend/os/mac/hardware.rb
@@ -24,21 +24,4 @@ def self.oldest_cpu(version = nil)
       generic_oldest_cpu
     end
   end
-
-  # Override
-  # Mirrors version-dependent logic of oldest_cpu
-  sig { params(version: T.nilable(Version)).returns(String) }
-  def self.rustflags_target_cpu(version = nil)
-    version = if version
-      MacOSVersion.new(version.to_s)
-    else
-      MacOS.version
-    end
-
-    if Hardware::CPU.intel? && version >= :mojave
-      "-Ctarget-cpu=nehalem"
-    else
-      generic_rustflags_target_cpu
-    end
-  end
 end
diff --git a/Library/Homebrew/hardware.rb b/Library/Homebrew/hardware.rb
index e10a548fd038d..6033f92aa5b1f 100644
--- a/Library/Homebrew/hardware.rb
+++ b/Library/Homebrew/hardware.rb
@@ -41,6 +41,14 @@ def optimization_flags
       end
       alias generic_optimization_flags optimization_flags
 
+      def rust_optimisation_flags
+        # Only give values where it is an improvement over rust cpu defaults
+        @rust_optimisation_flags ||= {
+          native:  "-Ctarget-cpu=native",
+          nehalem: "-Ctarget-cpu=nehalem",
+        }.freeze
+      end
+
       sig { returns(Symbol) }
       def arch_32_bit
         if arm?
@@ -221,11 +229,10 @@ def oldest_cpu(_version = nil)
     # But only where it is version dependent.
     # Rust already defaults to the oldest supported cpu for the target-triple
     # Including apple-m1 since 1.71.
-    sig { params(_version: T.nilable(Version)).returns(String) }
-    def rustflags_target_cpu(_version = nil)
-      ""
+    sig { returns(String) }
+    def rustflags_target_cpu
+      CPU.rust_optimisation_flags.fetch(oldest_cpu, "")
     end
-    alias generic_rustflags_target_cpu rustflags_target_cpu
   end
 end
 

From 73c339d82b2e7b43843f6b3f1b94ac610bbfda04 Mon Sep 17 00:00:00 2001
From: Tokarak <63452145+Tokarak@users.noreply.github.com>
Date: Sat, 17 Jun 2023 10:51:48 +0100
Subject: [PATCH 13/17] Style changes

---
 Library/Homebrew/hardware.rb | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/Library/Homebrew/hardware.rb b/Library/Homebrew/hardware.rb
index 6033f92aa5b1f..3ec3e3599da6b 100644
--- a/Library/Homebrew/hardware.rb
+++ b/Library/Homebrew/hardware.rb
@@ -41,8 +41,10 @@ def optimization_flags
       end
       alias generic_optimization_flags optimization_flags
 
+      # Only give values where it is an improvement over rust cpu defaults
+      # Rust already defaults to the oldest supported cpu for each target-triple
+      # Including apple-m1 since Rust 1.71 for aarch64-apple-darwin.
       def rust_optimisation_flags
-        # Only give values where it is an improvement over rust cpu defaults
         @rust_optimisation_flags ||= {
           native:  "-Ctarget-cpu=native",
           nehalem: "-Ctarget-cpu=nehalem",
@@ -224,11 +226,7 @@ def oldest_cpu(_version = nil)
     alias generic_oldest_cpu oldest_cpu
 
     # Returns a _full_ rustflag to set target cpu, if necessary;
-    # Falls back to empty string
-    # This mirrors the logic of `oldest_cpu`,
-    # But only where it is version dependent.
-    # Rust already defaults to the oldest supported cpu for the target-triple
-    # Including apple-m1 since 1.71.
+    # Defaults to empty string
     sig { returns(String) }
     def rustflags_target_cpu
       CPU.rust_optimisation_flags.fetch(oldest_cpu, "")

From 40aa41929f33ce7f6172b82315e6687fa5c93406 Mon Sep 17 00:00:00 2001
From: Tokarak <63452145+Tokarak@users.noreply.github.com>
Date: Sat, 17 Jun 2023 12:14:21 +0100
Subject: [PATCH 14/17] More cpus in rust_optimisation_flags

---
 Library/Homebrew/hardware.rb | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/Library/Homebrew/hardware.rb b/Library/Homebrew/hardware.rb
index 3ec3e3599da6b..43ecb7268d056 100644
--- a/Library/Homebrew/hardware.rb
+++ b/Library/Homebrew/hardware.rb
@@ -41,13 +41,17 @@ def optimization_flags
       end
       alias generic_optimization_flags optimization_flags
 
-      # Only give values where it is an improvement over rust cpu defaults
       # Rust already defaults to the oldest supported cpu for each target-triple
-      # Including apple-m1 since Rust 1.71 for aarch64-apple-darwin.
+      # so it's safe to ignore generic archs such as :armv6, etc., here.
+      # Rust defaults to apple-m1 since Rust 1.71 for aarch64-apple-darwin.
       def rust_optimisation_flags
         @rust_optimisation_flags ||= {
-          native:  "-Ctarget-cpu=native",
-          nehalem: "-Ctarget-cpu=nehalem",
+          native:      "--codegen target-cpu=native",
+          ivybridge:   "--codegen target-cpu=ivybridge",
+          sandybridge: "--codegen target-cpu=sandybridge",
+          nehalem:     "--codegen target-cpu=nehalem",
+          core2:       "--codegen target-cpu=core2",
+          core:        "--codegen target-cpu=prescott",
         }.freeze
       end
 
@@ -227,9 +231,9 @@ def oldest_cpu(_version = nil)
 
     # Returns a _full_ rustflag to set target cpu, if necessary;
     # Defaults to empty string
-    sig { returns(String) }
+    sig { returns(T.nilable(String)) }
     def rustflags_target_cpu
-      CPU.rust_optimisation_flags.fetch(oldest_cpu, "")
+      CPU.rust_optimisation_flags.fetch(oldest_cpu, nil)
     end
   end
 end

From 87158acfe0e72b30c0e55124a72668c08e0bcc93 Mon Sep 17 00:00:00 2001
From: Nazar <63452145+Tokarak@users.noreply.github.com>
Date: Tue, 20 Jun 2023 23:44:25 +0100
Subject: [PATCH 15/17] Improve logic (code review)

Co-authored-by: Mike McQuaid <mike@mikemcquaid.com>
---
 Library/Homebrew/hardware.rb | 31 ++++++++++++++-----------------
 1 file changed, 14 insertions(+), 17 deletions(-)

diff --git a/Library/Homebrew/hardware.rb b/Library/Homebrew/hardware.rb
index 43ecb7268d056..942915bd15b6c 100644
--- a/Library/Homebrew/hardware.rb
+++ b/Library/Homebrew/hardware.rb
@@ -41,20 +41,6 @@ def optimization_flags
       end
       alias generic_optimization_flags optimization_flags
 
-      # Rust already defaults to the oldest supported cpu for each target-triple
-      # so it's safe to ignore generic archs such as :armv6, etc., here.
-      # Rust defaults to apple-m1 since Rust 1.71 for aarch64-apple-darwin.
-      def rust_optimisation_flags
-        @rust_optimisation_flags ||= {
-          native:      "--codegen target-cpu=native",
-          ivybridge:   "--codegen target-cpu=ivybridge",
-          sandybridge: "--codegen target-cpu=sandybridge",
-          nehalem:     "--codegen target-cpu=nehalem",
-          core2:       "--codegen target-cpu=core2",
-          core:        "--codegen target-cpu=prescott",
-        }.freeze
-      end
-
       sig { returns(Symbol) }
       def arch_32_bit
         if arm?
@@ -229,11 +215,22 @@ def oldest_cpu(_version = nil)
     end
     alias generic_oldest_cpu oldest_cpu
 
-    # Returns a _full_ rustflag to set target cpu, if necessary;
-    # Defaults to empty string
+    # Returns a Rust flag to set the target CPU if necessary.
+    # Defaults to nil.
     sig { returns(T.nilable(String)) }
     def rustflags_target_cpu
-      CPU.rust_optimisation_flags.fetch(oldest_cpu, nil)
+      # Rust already defaults to the oldest supported cpu for each target-triple
+      # so it's safe to ignore generic archs such as :armv6, etc., here.
+      # Rust defaults to apple-m1 since Rust 1.71 for aarch64-apple-darwin.
+      @target_cpu ||= case (cpu = oldest_cpu)
+      when :core
+        :prescott
+      when :native, :ivybridge, :sandybridge, :nehalem, :core2
+        cpu
+      end
+      return if @target_cpu.blank?
+      
+      "--codegen target-cpu=#{@target_cpu}"
     end
   end
 end

From 55bdbabaae8b8abd1db7670ab661795c122d888e Mon Sep 17 00:00:00 2001
From: Tokarak <63452145+Tokarak@users.noreply.github.com>
Date: Tue, 20 Jun 2023 23:48:10 +0100
Subject: [PATCH 16/17] brew style --fix

---
 Library/Homebrew/hardware.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Library/Homebrew/hardware.rb b/Library/Homebrew/hardware.rb
index 942915bd15b6c..13920d61dad3d 100644
--- a/Library/Homebrew/hardware.rb
+++ b/Library/Homebrew/hardware.rb
@@ -229,7 +229,7 @@ def rustflags_target_cpu
         cpu
       end
       return if @target_cpu.blank?
-      
+
       "--codegen target-cpu=#{@target_cpu}"
     end
   end

From 521fdcb506118d34a03c8d377def2ad6cb045abf Mon Sep 17 00:00:00 2001
From: Nazar <63452145+Tokarak@users.noreply.github.com>
Date: Sat, 24 Jun 2023 11:09:28 +0100
Subject: [PATCH 17/17] Wording

Co-authored-by: Alexander Bayandin <alexander@bayandin.dev>
---
 Library/Homebrew/hardware.rb | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Library/Homebrew/hardware.rb b/Library/Homebrew/hardware.rb
index 13920d61dad3d..ed4034c48ad43 100644
--- a/Library/Homebrew/hardware.rb
+++ b/Library/Homebrew/hardware.rb
@@ -219,8 +219,8 @@ def oldest_cpu(_version = nil)
     # Defaults to nil.
     sig { returns(T.nilable(String)) }
     def rustflags_target_cpu
-      # Rust already defaults to the oldest supported cpu for each target-triple
-      # so it's safe to ignore generic archs such as :armv6, etc., here.
+      # Rust already defaults to the oldest supported cpu for each target-triplet
+      # so it's safe to ignore generic archs such as :armv6 here.
       # Rust defaults to apple-m1 since Rust 1.71 for aarch64-apple-darwin.
       @target_cpu ||= case (cpu = oldest_cpu)
       when :core