Revert: Random: Use target attribute instead of -march

If the user overrides -march e.g. via BAZEL_CXXOPTS it may conflict with
the -march override for Randen. So instead use a target attribute which
works on clang and gcc.

PiperOrigin-RevId: 728408888
Change-Id: Ie870600a80fb25f95b53f5e87bb9cc7ade53d69d

absl/random/internal/BUILD.bazel

@@ -44,29 +44,16 @@ licenses(["notice"])
 selects.config_setting_group(
     name = "gcc_compatible",
     match_any = [
-        # For some reason compiler:clang does not match when targeting
-        # Android/CrOS but since we only support building with Clang on these we
-        # assume the compiler is Clang if the target OS is one of these.
-        "@platforms//os:android",
-        "@platforms//os:chromiumos",
         "@rules_cc//cc/compiler:clang",
         "@rules_cc//cc/compiler:gcc",
     ],
 )
 
-selects.config_setting_group(
-    name = "aarch32",
-    match_any = [
-        "@platforms//cpu:aarch32",
-        "@platforms//cpu:armv7",
-    ],
-)
-
 selects.config_setting_group(
     name = "gcc_compatible-aarch32",
     match_all = [
-        ":aarch32",
         ":gcc_compatible",
+        "@platforms//cpu:aarch32",
     ],
 )
 
@@ -106,15 +93,15 @@ selects.config_setting_group(
 # Some libraries are compiled with options to generate AES-NI
 # instructions, and runtime dispatch is used to determine if the host
 # microarchitecture supports AES-NI or if a portable fallback library
-# should be called. Most architectures use target attributes to enable
-# the AES intrinsics so no compile flags are needed, but 32-bit ARM and
-# PowerPC have their intrinsics guarded by #ifdef so we need to pass flags.
+# should be called.
 ABSL_RANDOM_RANDEN_COPTS = select({
-    ":gcc_compatible-aarch32": [
-        "-mcpu=cortex-a53",
-        "-mfpu=crypto-neon-fp-armv8",
-    ],
+    ":gcc_compatible-aarch32": ["-mfpu=neon"],
+    ":gcc_compatible-aarch64": ["-march=armv8-a+crypto"],
     ":gcc_compatible-ppc_crypto": ["-mcrypto"],
+    ":gcc_compatible-x86_64": [
+        "-maes",
+        "-msse4.1",
+    ],
     "//conditions:default": [],
 })
 

absl/random/internal/randen_hwaes.cc

@@ -30,20 +30,19 @@
 // ABSL_RANDEN_HWAES_IMPL indicates whether this file will contain
 // a hardware accelerated implementation of randen, or whether it
 // will contain stubs that exit the process.
+#if ABSL_HAVE_ACCELERATED_AES
+// The following platforms have implemented RandenHwAes.
 #if defined(ABSL_ARCH_X86_64) || defined(ABSL_ARCH_X86_32) || \
     defined(ABSL_ARCH_PPC) || defined(ABSL_ARCH_ARM) ||       \
     defined(ABSL_ARCH_AARCH64)
 #define ABSL_RANDEN_HWAES_IMPL 1
 #endif
+#endif
 
 #if !defined(ABSL_RANDEN_HWAES_IMPL)
 // No accelerated implementation is supported.
 // The RandenHwAes functions are stubs that print an error and exit.
 
-#if ABSL_HAVE_ACCELERATED_AES
-#error "Need to update the definition of ABSL_RANDEN_HWAES_IMPL"
-#endif
-
 #include <cstdio>
 #include <cstdlib>
 
@@ -96,15 +95,12 @@ using absl::random_internal::RandenTraits;
 
 // TARGET_CRYPTO defines a crypto attribute for each architecture.
 //
-// We generally prefer to define these unless the architecture forces us to pass
-// a compile flag to get the intrinsics. This is because architecture compile
-// flags can affect the whole program (see HERMETIC NOTE at the top of
-// randen_hwaes.h).
+// NOTE: Evaluate whether we should eliminate ABSL_TARGET_CRYPTO.
 #if (defined(__clang__) || defined(__GNUC__))
 #if defined(ABSL_ARCH_X86_64) || defined(ABSL_ARCH_X86_32)
 #define ABSL_TARGET_CRYPTO __attribute__((target("aes")))
-#elif defined(ABSL_ARCH_AARCH64)
-#define ABSL_TARGET_CRYPTO __attribute__((target("+aes")))
+#elif defined(ABSL_ARCH_PPC)
+#define ABSL_TARGET_CRYPTO __attribute__((target("crypto")))
 #else
 #define ABSL_TARGET_CRYPTO
 #endif
@@ -215,8 +211,7 @@ inline ABSL_TARGET_CRYPTO void SwapEndian(void*) {}
 
 #elif defined(ABSL_ARCH_X86_64) || defined(ABSL_ARCH_X86_32)
 // On x86 we rely on the aesni instructions
-#include <emmintrin.h>
-#include <wmmintrin.h>
+#include <immintrin.h>
 
 namespace {