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python-greenlet/python-greenlet-aarch64-support.diff
2013-05-13 09:29:45 +00:00

89 lines
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Diff

--- ./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