From 2d4f2c38672b057168a4c2401b007f9c5a342aae Mon Sep 17 00:00:00 2001
From: David Carlier <devnexen@gmail.com>
Date: Fri, 13 Mar 2020 00:04:56 +0000
Subject: [PATCH] AAL, basic arm implementation proposal.

---
 CMakeLists.txt      |  3 ++-
 src/aal/aal.h       |  8 ++++++-
 src/aal/aal_arm.h   | 53 +++++++++++++++++++++++++++++++++++++++++++++
 src/ds/bits.h       |  1 +
 src/pal/pal_posix.h |  1 +
 5 files changed, 64 insertions(+), 2 deletions(-)
 create mode 100644 src/aal/aal_arm.h

diff --git a/CMakeLists.txt b/CMakeLists.txt
index e07a06d..d7dc850 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -136,7 +136,8 @@ if(NOT DEFINED SNMALLOC_ONLY_HEADER_LIBRARY)
      add_compile_options(-march=native)
     elseif(${CMAKE_SYSTEM_PROCESSOR} STREQUAL "x86")
      add_compile_options(-march=native)
-    # XXX elseif ARM?
+    elseif(${CMAKE_SYSTEM_PROCESSOR} MATCHES "arm")
+     add_compile_options(-march=native)
     endif()
   endif()
 
diff --git a/src/aal/aal.h b/src/aal/aal.h
index e963250..d323bfd 100644
--- a/src/aal/aal.h
+++ b/src/aal/aal.h
@@ -9,6 +9,10 @@
 #  define PLATFORM_IS_X86
 #endif
 
+#if defined(__arm__) || defined(__aarch64__)
+#  define PLATFORM_IS_ARM
+#endif
+
 namespace snmalloc
 {
   /**
@@ -70,8 +74,10 @@ namespace snmalloc
 
 } // namespace snmalloc
 
-#ifdef PLATFORM_IS_X86
+#if defined(PLATFORM_IS_X86)
 #  include "aal_x86.h"
+#elif defined(PLATFORM_IS_ARM)
+#  include "aal_arm.h"
 #endif
 
 namespace snmalloc
diff --git a/src/aal/aal_arm.h b/src/aal/aal_arm.h
new file mode 100644
index 0000000..52bb0d0
--- /dev/null
+++ b/src/aal/aal_arm.h
@@ -0,0 +1,53 @@
+#pragma once
+
+#if defined(__arch64__)
+#  define SNMALLOC_VA_BITS_64
+#else
+#  define SNMALLOC_VA_BITS_32
+#endif
+
+#include <iostream>
+namespace snmalloc
+{
+  /**
+   * ARM-specific architecture abstraction layer.
+   */
+  class AAL_arm
+  {
+  public:
+    /**
+     * Bitmap of AalFeature flags
+     */
+    static constexpr uint64_t aal_features = IntegerPointers;
+    /**
+     * On pipelined processors, notify the core that we are in a spin loop and
+     * that speculative execution past this point may not be a performance gain.
+     */
+    static inline void pause()
+    {
+      __asm__ volatile("yield");
+    }
+
+    /**
+     * Issue a prefetch hint at the specified address.
+     */
+    static inline void prefetch(void* ptr)
+    {
+      __builtin_prefetch(ptr, 0, 1);
+    }
+
+    /**
+     * Return a cycle counter value.
+     * on ARM cpu counters are accessible only in privileged mode
+     */
+    static inline uint64_t tick()
+    {
+      struct timespec n = {0, 0ul};
+      clock_gettime(CLOCK_MONOTONIC, &n);
+
+      return static_cast<uint64_t>((n.tv_sec) * (1000000000ul * n.tv_nsec));
+    }
+  };
+
+  using AAL_Arch = AAL_arm;
+} // namespace snmalloc
diff --git a/src/ds/bits.h b/src/ds/bits.h
index 9dc05b0..6f3621e 100644
--- a/src/ds/bits.h
+++ b/src/ds/bits.h
@@ -1,6 +1,7 @@
 #pragma once
 
 #include <limits>
+#include <cstddef>
 
 // #define USE_LZCNT
 
diff --git a/src/pal/pal_posix.h b/src/pal/pal_posix.h
index 57d76ac..4344ad4 100644
--- a/src/pal/pal_posix.h
+++ b/src/pal/pal_posix.h
@@ -4,6 +4,7 @@
 #include "../mem/allocconfig.h"
 
 #include <string.h>
+#include <stdlib.h>
 #include <sys/mman.h>
 
 extern "C" int puts(const char* str);