4 files changed, 91 insertions, 0 deletions
diff --git a/absl/copts/GENERATED_AbseilCopts.cmake b/absl/copts/GENERATED_AbseilCopts.cmake
index c4948d42..88400e98 100644
--- a/absl/copts/GENERATED_AbseilCopts.cmake
+++ b/absl/copts/GENERATED_AbseilCopts.cmake
@@ -218,3 +218,21 @@ list(APPEND ABSL_MSVC_TEST_FLAGS
     "/wd4996"
     "/DNOMINMAX"
 )
+
+list(APPEND ABSL_RANDOM_HWAES_ARM32_FLAGS
+    "-mfpu=neon"
+)
+
+list(APPEND ABSL_RANDOM_HWAES_ARM64_FLAGS
+    "-march=armv8-a+crypto"
+)
+
+list(APPEND ABSL_RANDOM_HWAES_MSVC_X64_FLAGS
+    "/O2"
+    "/Ob2"
+)
+
+list(APPEND ABSL_RANDOM_HWAES_X64_FLAGS
+    "-maes"
+    "-msse4.1"
+)
diff --git a/absl/copts/GENERATED_copts.bzl b/absl/copts/GENERATED_copts.bzl
index 422b3a9b..d7edc936 100644
--- a/absl/copts/GENERATED_copts.bzl
+++ b/absl/copts/GENERATED_copts.bzl
@@ -219,3 +219,21 @@ ABSL_MSVC_TEST_FLAGS = [
     "/wd4996",
     "/DNOMINMAX",
 ]
+
+ABSL_RANDOM_HWAES_ARM32_FLAGS = [
+    "-mfpu=neon",
+]
+
+ABSL_RANDOM_HWAES_ARM64_FLAGS = [
+    "-march=armv8-a+crypto",
+]
+
+ABSL_RANDOM_HWAES_MSVC_X64_FLAGS = [
+    "/O2",
+    "/Ob2",
+]
+
+ABSL_RANDOM_HWAES_X64_FLAGS = [
+    "-maes",
+    "-msse4.1",
+]
diff --git a/absl/copts/configure_copts.bzl b/absl/copts/configure_copts.bzl
index 00159317..8c4efe77 100644
--- a/absl/copts/configure_copts.bzl
+++ b/absl/copts/configure_copts.bzl
@@ -16,6 +16,10 @@ load(
     "ABSL_MSVC_FLAGS",
     "ABSL_MSVC_LINKOPTS",
     "ABSL_MSVC_TEST_FLAGS",
+    "ABSL_RANDOM_HWAES_ARM32_FLAGS",
+    "ABSL_RANDOM_HWAES_ARM64_FLAGS",
+    "ABSL_RANDOM_HWAES_MSVC_X64_FLAGS",
+    "ABSL_RANDOM_HWAES_X64_FLAGS",
 )
 
 ABSL_DEFAULT_COPTS = select({
@@ -46,3 +50,40 @@ ABSL_DEFAULT_LINKOPTS = select({
     "//absl:windows": ABSL_MSVC_LINKOPTS,
     "//conditions:default": [],
 })
+
+# ABSL_RANDOM_RANDEN_COPTS blaze copts flags which are required by each
+# environment to build an accelerated RandenHwAes library.
+ABSL_RANDOM_RANDEN_COPTS = select({
+    # APPLE
+    ":cpu_darwin_x86_64": ABSL_RANDOM_HWAES_X64_FLAGS,
+    ":cpu_darwin": ABSL_RANDOM_HWAES_X64_FLAGS,
+    ":cpu_x64_windows_msvc": ABSL_RANDOM_HWAES_MSVC_X64_FLAGS,
+    ":cpu_x64_windows": ABSL_RANDOM_HWAES_MSVC_X64_FLAGS,
+    ":cpu_haswell": ABSL_RANDOM_HWAES_X64_FLAGS,
+    ":cpu_ppc": ["-mcrypto"],
+
+    # Supported by default or unsupported.
+    "//conditions:default": [],
+})
+
+# absl_random_randen_copts_init:
+#  Initialize the config targets based on cpu, os, etc. used to select
+#  the required values for ABSL_RANDOM_RANDEN_COPTS
+def absl_random_randen_copts_init():
+    """Initialize the config_settings used by ABSL_RANDOM_RANDEN_COPTS."""
+
+    # CPU configs.
+    # These configs have consistent flags to enable HWAES intsructions.
+    cpu_configs = [
+        "ppc",
+        "haswell",
+        "darwin_x86_64",
+        "darwin",
+        "x64_windows_msvc",
+        "x64_windows",
+    ]
+    for cpu in cpu_configs:
+        native.config_setting(
+            name = "cpu_%s" % cpu,
+            values = {"cpu": cpu},
+        )
diff --git a/absl/copts/copts.py b/absl/copts/copts.py
index 5bede34c..d850bb4f 100644
--- a/absl/copts/copts.py
+++ b/absl/copts/copts.py
@@ -199,4 +199,18 @@ COPT_VARS = {
         # Object file doesn't export any previously undefined symbols
         "-ignore:4221",
     ],
+    # "HWAES" is an abbreviation for "hardware AES" (AES - Advanced Encryption
+    # Standard). These flags are used for detecting whether or not the target
+    # architecture has hardware support for AES instructions which can be used
+    # to improve performance of some random bit generators.
+    "ABSL_RANDOM_HWAES_ARM64_FLAGS": ["-march=armv8-a+crypto"],
+    "ABSL_RANDOM_HWAES_ARM32_FLAGS": ["-mfpu=neon"],
+    "ABSL_RANDOM_HWAES_X64_FLAGS": [
+        "-maes",
+        "-msse4.1",
+    ],
+    "ABSL_RANDOM_HWAES_MSVC_X64_FLAGS": [
+        "/O2",  # Maximize speed
+        "/Ob2",  # Aggressive inlining
+    ],
 }