File python-greenlet-aarch64-support.diff of Package python-greenlet

Overview Repositories Revisions Requests Users Attributes Meta

File python-greenlet-aarch64-support.diff of Package python-greenlet (Revision 06e8243135142543f8908a6fb5179d57)

Currently displaying revision 06e8243135142543f8908a6fb5179d57 , Show latest

--- ./slp_platformselect.h.mm	2012-05-12 22:56:32.000000000 +0000
+++ ./slp_platformselect.h	2013-04-08 11:28:47.000000000 +0000
@@ -32,4 +32,6 @@
 #include "platform/switch_arm32_gcc.h" /* gcc using arm32 */
 #elif defined(__GNUC__) && defined(__mips__) && defined(__linux__)
 #include "platform/switch_mips_unix.h" /* Linux/MIPS */
+#elif defined(__GNUC__) && defined(__aarch64__)
+#include "platform/switch_aarch64_gcc.h" /* Aarch64 ABI */
 #endif
--- ./platform/switch_aarch64_gcc.h.mm	2013-04-13 21:40:23.000000000 +0000
+++ ./platform/switch_aarch64_gcc.h	2013-04-13 21:41:39.000000000 +0000
@@ -0,0 +1,76 @@
+/*
+ * this is the internal transfer function.
+ *
+ * HISTORY
+ * 13-Apr-13 Add support for strange GCC caller-save decisions
+ * 08-Apr-13 File creation. Michael Matz
+ *
+ * NOTES
+ *
+ * Simply save all callee saved registers
+ *
+ */
+
+#define STACK_REFPLUS 1
+
+#ifdef SLP_EVAL
+#define STACK_MAGIC 0
+#define REGS_TO_SAVE "r19", "r20", "r21", "r22", "r23", "r24", "r25", "r26", \
+                     "r27", "r28", "r30" /* aka lr */, \
+                     "v8", "v9", "v10", "v11", \
+                     "v12", "v13", "v14", "v15"
+
+/* See below for the purpose of this function.  */
+__attribute__((noinline, noclone)) int fancy_return_zero(void);
+__attribute__((noinline, noclone)) int
+fancy_return_zero(void)
+{
+  return 0;
+}
+
+static int
+slp_switch(void)
+{
+	int err = 0;
+	void *fp;
+        register long *stackref, stsizediff;
+        __asm__ volatile ("" : : : REGS_TO_SAVE);
+	__asm__ volatile ("str x29, %0" : "=m"(fp) : : );
+        __asm__ ("mov %0, sp" : "=r" (stackref));
+        {
+                SLP_SAVE_STATE(stackref, stsizediff);
+                __asm__ volatile (
+                    "add sp,sp,%0\n"
+		    "add x29,x29,%0\n"
+                    :
+                    : "r" (stsizediff)
+                    );
+		SLP_RESTORE_STATE();
+		/* SLP_SAVE_STATE macro contains some return statements
+		   (of -1 and 1).  It falls through only when
+		   the return value of slp_save_state() is zero, which
+		   is placed in x0.
+		   In that case we (slp_switch) also want to return zero
+		   (also in x0 of course).
+		   Now, some GCC versions (seen with 4.8) think it's a
+		   good idea to save/restore x0 around the call to
+		   slp_restore_state(), instead of simply zeroing it
+		   at the return below.  But slp_restore_state
+		   writes random values to the stack slot used for this
+		   save/restore (from when it once was saved above in
+		   SLP_SAVE_STATE, when it was still uninitialized), so
+		   "restoring" that precious zero actually makes us
+		   return random values.  There are some ways to make
+		   GCC not use that zero value in the normal return path
+		   (e.g. making err volatile, but that costs a little
+		   stack space), and the simplest is to call a function
+		   that returns an unknown value (which happens to be zero),
+		   so the saved/restored value is unused.  */
+		err = fancy_return_zero();
+        }
+	__asm__ volatile ("ldr x29, %0" : : "m" (fp) :);
+        __asm__ volatile ("" : : : REGS_TO_SAVE);
+        return err;
+}
+
+#endif

Places

File python-greenlet-aarch64-support.diff of Package python-greenlet (Revision 06e8243135142543f8908a6fb5179d57)

Places