Add support for mcpu

In case of arm , mcpu can be specified instead
of 'march' and 'mtune'.

Change-Id: I8318f6dfaf02beb2dad40dec59fc73a263e7d04f
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>

2 files changed, 19 insertions, 10 deletions

diff --git a/chromium/build/config/arm.gni b/chromium/build/config/arm.gni
index ddd1c5df823..eb7731337f1 100644
--- a/chromium/build/config/arm.gni
+++ b/chromium/build/config/arm.gni
@@ -36,6 +36,9 @@ if (current_cpu == "arm" || v8_current_cpu == "arm") {
     # Thumb is a reduced instruction set available on some ARM processors that
     # has increased code density.
     arm_use_thumb = true
+
+    # arch + tune
+    arm_cpu = ""
   }
 
   if (current_os == "android" || target_os == "android") {
@@ -61,7 +64,7 @@ if (current_cpu == "arm" || v8_current_cpu == "arm") {
   }
 
   if (arm_version == 6) {
-    if (arm_arch == "") {
+    if (arm_arch == "" && arm_cpu == "") {
       arm_arch = "armv6"
     }
     if (arm_tune != "") {
@@ -76,10 +79,10 @@ if (current_cpu == "arm" || v8_current_cpu == "arm") {
     arm_use_thumb = false
     arm_use_neon = false
   } else if (arm_version == 7) {
-    if (arm_arch == "") {
+    if (arm_arch == "" && arm_cpu == "") {
       arm_arch = "armv7-a"
     }
-    if (arm_tune == "") {
+    if (arm_tune == "" && arm_cpu == "") {
       arm_tune = "generic-armv7-a"
     }
 
@@ -100,10 +103,10 @@ if (current_cpu == "arm" || v8_current_cpu == "arm") {
       }
     }
   } else if (arm_version == 8) {
-    if (arm_arch == "") {
+    if (arm_arch == "" && arm_cpu == "") {
       arm_arch = "armv8-a"
     }
-    if (arm_tune == "") {
+    if (arm_tune == "" && arm_cpu == "") {
       arm_tune = "generic-armv8-a"
     }
 
diff --git a/chromium/build/config/compiler/BUILD.gn b/chromium/build/config/compiler/BUILD.gn
index cda452e8a8b..33abfc46b81 100644
--- a/chromium/build/config/compiler/BUILD.gn
+++ b/chromium/build/config/compiler/BUILD.gn
@@ -753,9 +753,12 @@ config("compiler") {
     # unless the architecture revision in .ARM.attributes is sufficiently new.
     # TODO(pcc): The contents of .ARM.attributes should be based on the
     # -march flag passed at compile time (see llvm.org/pr36291).
-    if (current_cpu == "arm") {
+    if (current_cpu == "arm" && arm_arch != "") {
       ldflags += [ "-march=$arm_arch" ]
     }
+    if (current_cpu == "arm" && arm_cpu != "") {
+      ldflags += [ "-mcpu=$arm_cpu" ]
+    }
   }
 
   if (compiler_timing) {
@@ -892,10 +895,13 @@ config("compiler_cpu_abi") {
         ldflags += [ "--target=arm-linux-gnueabihf" ]
       }
       if (!is_nacl) {
-        cflags += [
-          "-march=$arm_arch",
-          "-mfloat-abi=$arm_float_abi",
-        ]
+        cflags += ["-mfloat-abi=$arm_float_abi"]
+        if (arm_arch != "") {
+          cflags += [ "-march=$arm_arch"]
+        }
+        if (arm_cpu != "") {
+          cflags += [ "-mcpu=$arm_cpu"]
+        }
       }
       if (arm_tune != "") {
         cflags += [ "-mtune=$arm_tune" ]