Home | History | Annotate | Download | only in config 
      1 # Copyright 2014 The Chromium Authors. All rights reserved.
      2 # Use of this source code is governed by a BSD-style license that can be
      3 # found in the LICENSE file.
      4 
      5 # These are primarily relevant in current_cpu == "arm" contexts, where
      6 # ARM code is being compiled.  But they can also be relevant in the
      7 # host toolchain context when target_cpu == "arm", where a host-side
      8 # build tool being built will change its behavior depending on the
      9 # details of the target configuration.
     10 if (target_cpu == "arm" || current_cpu == "arm") {
     11   declare_args() {
     12     # Version of the ARM processor when compiling on ARM. Ignored on non-ARM
     13     # platforms.
     14     arm_version = 7
     15 
     16     # The ARM floating point mode. This is either the string "hard", "soft", or
     17     # "softfp". An empty string means to use the default one for the
     18     # arm_version.
     19     arm_float_abi = ""
     20 
     21     # The ARM variant-specific tuning mode. This will be a string like "armv6"
     22     # or "cortex-a15". An empty string means to use the default for the
     23     # arm_version.
     24     arm_tune = ""
     25 
     26     # Whether to use the neon FPU instruction set or not.
     27     arm_use_neon = true
     28 
     29     # Whether to enable optional NEON code paths.
     30     arm_optionally_use_neon = false
     31 
     32     # Thumb is a reduced instruction set available on some ARM processors that
     33     # has increased code density.
     34     arm_use_thumb = true
     35   }
     36 
     37   assert(arm_float_abi == "" || arm_float_abi == "hard" ||
     38          arm_float_abi == "soft" || arm_float_abi == "softfp")
     39 
     40   if (arm_version == 6) {
     41     arm_arch = "armv6"
     42     if (arm_tune != "") {
     43       arm_tune = ""
     44     }
     45     if (arm_float_abi == "") {
     46       arm_float_abi = "softfp"
     47     }
     48     arm_fpu = "vfp"
     49     arm_use_thumb = false
     50   } else if (arm_version == 7) {
     51     arm_arch = "armv7-a"
     52     if (arm_tune == "") {
     53       arm_tune = "generic-armv7-a"
     54     }
     55 
     56     if (arm_float_abi == "") {
     57       if (current_os == "android" || target_os == "android") {
     58         arm_float_abi = "softfp"
     59       } else {
     60         arm_float_abi = "hard"
     61       }
     62     }
     63 
     64     if (arm_use_neon) {
     65       arm_fpu = "neon"
     66     } else {
     67       arm_fpu = "vfpv3-d16"
     68     }
     69   } else if (arm_version == 8) {
     70     arm_arch = "armv8-a"
     71     if (arm_tune == "") {
     72       arm_tune = "generic-armv8-a"
     73     }
     74 
     75     if (arm_float_abi == "") {
     76       if (current_os == "android" || target_os == "android") {
     77         arm_float_abi = "softfp"
     78       } else {
     79         arm_float_abi = "hard"
     80       }
     81     }
     82 
     83     if (arm_use_neon) {
     84       arm_fpu = "neon"
     85     } else {
     86       arm_fpu = "vfpv3-d16"
     87     }
     88   }
     89 } else if (current_cpu == "arm64" || target_cpu == "arm64") {
     90   # arm64 supports only "hard".
     91   arm_float_abi = "hard"
     92   arm_use_neon = true
     93   arm_fpu = "cortex-a57+simd+crypto+fp+crc"
     94 }
     95