From 1aa7f17b566753c4996b425a24270547f7a157ea Mon Sep 17 00:00:00 2001
From: Ryan Macnak <rmacnak@google.com>
Date: Tue, 24 Jan 2023 00:54:29 +0000
Subject: [PATCH] [build] Default to -O2 instead of -O3.

This moderately reduces code size without large regressions on Golem. Going further to -Os still produces noticeable regressions.

TEST=ci
Bug: https://github.com/dart-lang/sdk/issues/38647
Change-Id: I8409908ca37d4a2b18cb989d9748e35a15072df6
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/217504
Reviewed-by: Siva Annamalai <asiva@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>
---
 build/config/compiler/BUILD.gn |  6 +----
 runtime/BUILD.gn               |  2 +-
 runtime/lib/typed_data.cc      | 24 +++++++++++++-----
 runtime/vm/object.h            | 45 ----------------------------------
 4 files changed, 20 insertions(+), 57 deletions(-)

diff --git a/build/config/compiler/BUILD.gn b/build/config/compiler/BUILD.gn
index 1f919ca7ec9..feb13b1af62 100644
--- a/build/config/compiler/BUILD.gn
+++ b/build/config/compiler/BUILD.gn
@@ -815,13 +815,9 @@ if (is_win) {
 # Default "optimization on" config. On Windows, this favors size over speed.
 config("optimize") {
   if (is_win) {
-    # Favor size over speed, /O1 must be before the common flags. The GYP
-    # build also specifies /Os and /GF but these are implied by /O1.
     cflags = [ "/O2" ] + common_optimize_on_cflags + [ "/Oi" ]
-  } else if (is_android) {
-    cflags = [ "-Os" ] + common_optimize_on_cflags  # Favor size over speed.
   } else {
-    cflags = [ "-O3" ] + common_optimize_on_cflags
+    cflags = [ "-O2" ] + common_optimize_on_cflags
   }
   ldflags = common_optimize_on_ldflags
 }
diff --git a/runtime/BUILD.gn b/runtime/BUILD.gn
index 47e96213e42..2b8f56010ed 100644
--- a/runtime/BUILD.gn
+++ b/runtime/BUILD.gn
@@ -245,7 +245,7 @@ config("dart_config") {
     } else if (dart_debug) {
       cflags += [ "-O${dart_debug_optimization_level}" ]
     } else {
-      cflags += [ "-O3" ]
+      cflags += [ "-O2" ]
     }
 
     if (is_fuchsia) {
diff --git a/runtime/lib/typed_data.cc b/runtime/lib/typed_data.cc
index e4d51d70906..d16b345bf4e 100644
--- a/runtime/lib/typed_data.cc
+++ b/runtime/lib/typed_data.cc
@@ -79,12 +79,24 @@ static BoolPtr CopyData(const TypedDataBase& dst_array,
                            src_array.LengthInBytes()));
   ASSERT(Utils::RangeCheck(dst_offset_in_bytes, length_in_bytes,
                            dst_array.LengthInBytes()));
-  if (clamped) {
-    TypedData::ClampedCopy(dst_array, dst_offset_in_bytes, src_array,
-                           src_offset_in_bytes, length_in_bytes);
-  } else {
-    TypedData::Copy(dst_array, dst_offset_in_bytes, src_array,
-                    src_offset_in_bytes, length_in_bytes);
+  if (length_in_bytes > 0) {
+    NoSafepointScope no_safepoint;
+    if (clamped) {
+      uint8_t* dst_data =
+          reinterpret_cast<uint8_t*>(dst_array.DataAddr(dst_offset_in_bytes));
+      int8_t* src_data =
+          reinterpret_cast<int8_t*>(src_array.DataAddr(src_offset_in_bytes));
+      for (intptr_t ix = 0; ix < length_in_bytes; ix++) {
+        int8_t v = *src_data;
+        if (v < 0) v = 0;
+        *dst_data = v;
+        src_data++;
+        dst_data++;
+      }
+    } else {
+      memmove(dst_array.DataAddr(dst_offset_in_bytes),
+              src_array.DataAddr(src_offset_in_bytes), length_in_bytes);
+    }
   }
   return Bool::True().ptr();
 }
diff --git a/runtime/vm/object.h b/runtime/vm/object.h
index 6138ecb11a8..67e88afb139 100644
--- a/runtime/vm/object.h
+++ b/runtime/vm/object.h
@@ -11431,51 +11431,6 @@ class TypedData : public TypedDataBase {
                            intptr_t len,
                            Heap::Space space = Heap::kNew);
 
-  static void Copy(const TypedDataBase& dst,
-                   intptr_t dst_offset_in_bytes,
-                   const TypedDataBase& src,
-                   intptr_t src_offset_in_bytes,
-                   intptr_t length_in_bytes) {
-    ASSERT(Utils::RangeCheck(src_offset_in_bytes, length_in_bytes,
-                             src.LengthInBytes()));
-    ASSERT(Utils::RangeCheck(dst_offset_in_bytes, length_in_bytes,
-                             dst.LengthInBytes()));
-    {
-      NoSafepointScope no_safepoint;
-      if (length_in_bytes > 0) {
-        memmove(dst.DataAddr(dst_offset_in_bytes),
-                src.DataAddr(src_offset_in_bytes), length_in_bytes);
-      }
-    }
-  }
-
-  static void ClampedCopy(const TypedDataBase& dst,
-                          intptr_t dst_offset_in_bytes,
-                          const TypedDataBase& src,
-                          intptr_t src_offset_in_bytes,
-                          intptr_t length_in_bytes) {
-    ASSERT(Utils::RangeCheck(src_offset_in_bytes, length_in_bytes,
-                             src.LengthInBytes()));
-    ASSERT(Utils::RangeCheck(dst_offset_in_bytes, length_in_bytes,
-                             dst.LengthInBytes()));
-    {
-      NoSafepointScope no_safepoint;
-      if (length_in_bytes > 0) {
-        uint8_t* dst_data =
-            reinterpret_cast<uint8_t*>(dst.DataAddr(dst_offset_in_bytes));
-        int8_t* src_data =
-            reinterpret_cast<int8_t*>(src.DataAddr(src_offset_in_bytes));
-        for (intptr_t ix = 0; ix < length_in_bytes; ix++) {
-          int8_t v = *src_data;
-          if (v < 0) v = 0;
-          *dst_data = v;
-          src_data++;
-          dst_data++;
-        }
-      }
-    }
-  }
-
   static bool IsTypedData(const Instance& obj) {
     ASSERT(!obj.IsNull());
     intptr_t cid = obj.ptr()->GetClassId();