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-rw-r--r--mozglue/build/ppc.cpp64
1 files changed, 64 insertions, 0 deletions
diff --git a/mozglue/build/ppc.cpp b/mozglue/build/ppc.cpp
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+++ b/mozglue/build/ppc.cpp
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+/* 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