--- a/build/config/compiler/BUILD.gn
+++ b/build/config/compiler/BUILD.gn
@@ -236,7 +236,6 @@ config("compiler") {
 
   configs += [
     # See the definitions below.
-    ":clang_revision",
     ":compiler_cpu_abi",
     ":compiler_codegen",
   ]
@@ -765,7 +764,6 @@ config("compiler_cpu_abi") {
     if (current_cpu == "x64") {
       cflags += [
         "-m64",
-        "-march=x86-64",
       ]
       ldflags += [ "-m64" ]
     } else if (current_cpu == "x86") {
@@ -1959,7 +1957,7 @@ config("optimize") {
       cflags = [ "-Os" ] + common_optimize_on_cflags
     }
   } else {
-    cflags = [ "-O2" ] + common_optimize_on_cflags
+    cflags = common_optimize_on_cflags
   }
   ldflags = common_optimize_on_ldflags
 }
@@ -1982,7 +1980,7 @@ config("optimize_no_wpo") {
   } else if (optimize_for_fuzzing) {
     cflags = [ "-O1" ] + common_optimize_on_cflags
   } else {
-    cflags = [ "-O2" ] + common_optimize_on_cflags
+    cflags = common_optimize_on_cflags
   }
   ldflags = common_optimize_on_ldflags
 }
@@ -2047,7 +2045,7 @@ config("optimize_max") {
     } else if (optimize_for_fuzzing) {
       cflags = [ "-O1" ] + common_optimize_on_cflags
     } else {
-      cflags = [ "-O2" ] + common_optimize_on_cflags
+      cflags = common_optimize_on_cflags
     }
   }
 }
@@ -2092,7 +2090,7 @@ config("optimize_speed") {
     } else if (optimize_for_fuzzing) {
       cflags = [ "-O1" ] + common_optimize_on_cflags
     } else {
-      cflags = [ "-O3" ] + common_optimize_on_cflags
+      cflags = common_optimize_on_cflags
     }
   }
 }