1 files changed, 64 insertions, 0 deletions
diff --git a/mozglue/build/ppc.cpp b/mozglue/build/ppc.cpp
new file mode 100644
index 0000000000..20ef121386
--- /dev/null
+++ b/mozglue/build/ppc.cpp
@@ -0,0 +1,64 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* compile-time and runtime tests for whether to use Power ISA-specific
+ * extensions */
+
+#include "ppc.h"
+#include "mozilla/Unused.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#if defined(XP_LINUX)
+// Use the getauxval() function if available.
+// ARCH_3_00 wasn't defined until glibc 2.23, so include just in case.
+#  include <sys/auxv.h>
+#  ifndef PPC_FEATURE2_ARCH_3_00
+#    define PPC_FEATURE2_ARCH_3_00 0x00800000
+#  endif
+#endif
+
+const unsigned PPC_FLAG_VMX = 1;
+const unsigned PPC_FLAG_VSX = 2;
+const unsigned PPC_FLAG_VSX3 = 4;
+
+static signed get_ppc_cpu_flags(void) {
+  // This could be expensive, so cache the result.
+  static signed cpu_flags = -1;
+
+  if (cpu_flags > -1) {  // already checked
+    return cpu_flags;
+  }
+  cpu_flags = 0;
+
+#if defined(XP_LINUX)
+  // Try getauxval().
+  unsigned long int cap = getauxval(AT_HWCAP);
+  unsigned long int cap2 = getauxval(AT_HWCAP2);
+
+  if (cap & PPC_FEATURE_HAS_ALTIVEC) {
+    cpu_flags |= PPC_FLAG_VMX;
+  }
+  if (cap & PPC_FEATURE_HAS_VSX) {
+    cpu_flags |= PPC_FLAG_VSX;
+  }
+  if (cap2 & PPC_FEATURE2_ARCH_3_00) {
+    cpu_flags |= PPC_FLAG_VSX3;
+  }
+#else
+  // Non-Linux detection here. Currently, on systems other than Linux,
+  // no CPU SIMD features will be detected.
+#endif
+
+  return cpu_flags;
+}
+
+namespace mozilla {
+namespace ppc_private {
+bool vmx_enabled = !!(get_ppc_cpu_flags() & PPC_FLAG_VMX);
+bool vsx_enabled = !!(get_ppc_cpu_flags() & PPC_FLAG_VSX);
+bool vsx3_enabled = !!(get_ppc_cpu_flags() & PPC_FLAG_VSX3);
+}  // namespace ppc_private
+}  // namespace mozilla