[pypy-commit] pypy ppc-stacklet: Implementation of slp_switch for PPC

[vaibhavsood12]

Author: Vaibhav Sood <vaibhav_sood at persistent.com>
Branch: ppc-stacklet
Changeset: r80521:64dbe96612e5
Date: 2015-10-28 13:14 +0530
http://bitbucket.org/pypy/pypy/changeset/64dbe96612e5/

Log:	Implementation of slp_switch for PPC

diff --git a/rpython/translator/c/src/stacklet/slp_platformselect.h b/rpython/translator/c/src/stacklet/slp_platformselect.h
--- a/rpython/translator/c/src/stacklet/slp_platformselect.h
+++ b/rpython/translator/c/src/stacklet/slp_platformselect.h
@@ -10,6 +10,8 @@
 #include "switch_x86_gcc.h" /* gcc on X86 */
 #elif defined(__GNUC__) && defined(__arm__)
 #include "switch_arm_gcc.h" /* gcc on arm */
+#elif defined(__GNUC__) && defined(__PPC64__)
+#include "switch_ppc64_gcc.h" /* gcc on ppc64 */
 #elif defined(__GNUC__) && defined(__mips__) && defined(_ABI64)
 #include "switch_mips64_gcc.h" /* gcc on mips64 */
 #else
diff --git a/rpython/translator/c/src/stacklet/switch_ppc64_gcc.h b/rpython/translator/c/src/stacklet/switch_ppc64_gcc.h
new file mode 100644
--- /dev/null
+++ b/rpython/translator/c/src/stacklet/switch_ppc64_gcc.h
@@ -0,0 +1,64 @@
+
+static void __attribute__((optimize("O2"))) *slp_switch(void *(*save_state)(void*, void*),
+                        void *(*restore_state)(void*, void*),
+                        void *extra)
+{
+  void *result;
+  __asm__ volatile (
+     /*Prologue: Save explicitly lr and some non-volatile registers used by compiler in caller code */
+     "mflr 0\n"
+     "std 0, 16(1)\n"
+     "std 31, -8(1)\n"
+     "std 30, -16(1)\n"
+     "std 29, -24(1)\n"
+     "std 28, -32(1)\n"
+     "stdu 1, -176(1)\n"         /* 48(save area) + 64(parameter area) + 64(non-volatile save area) = 176 bytes */
+                                 /* stack is implicitly 16-byte aligned */
+
+     "mr 14, %[restore_state]\n" /* save 'restore_state' for later, r14 marked clobbered */
+     "mr 15, %[extra]\n"         /* save 'extra' for later, r15 marked clobbered */
+     
+     "mtlr %[save_state]\n"    /* save 'save_state' for branching */
+     "mr 3, 1\n"               /* arg 1: current (old) stack pointer */ 
+     "mr 4, %[extra]\n"        /* arg 2: extra                       */
+     "stdu 1, -64(1)\n"        /* create temp stack space for callee to use  */
+     "blrl\n"                  /* call save_state()                  */
+     "nop\n"
+     "addi 1, 1, 64\n"         /* destroy temp stack space */
+
+     "cmpdi 3, 0\n"           /* skip the rest if the return value is null */
+     "bt eq, zero\n"
+
+     "mr 1, 3\n"              /* change the stack pointer */
+       /* From now on, the stack pointer is modified, but the content of the
+        stack is not restored yet.  It contains only garbage here. */
+
+     "mr 5, 14\n"
+     "mtlr 5\n"
+     "mr 4, 15\n"             /* arg 2: extra                       */
+                              /* arg 1: current (new) stack pointer is already in r3*/
+
+     "stdu 1, -64(1)\n"       /* create temp stack space for callee to use  */
+     "blrl\n"                 /* call restore_state()               */
+     "nop\n"
+     "addi 1, 1, 64\n"        /* destroy temp stack space */
+
+     /* The stack's content is now restored. */
+
+     "zero:\n"
+     /* Epilogue: Restore sp, lr and saved non-volatile registers */
+     "ld 1, 0(1)\n"
+     "ld 0, 16(1)\n"
+     "mtlr 0\n"
+     "ld 28, -32(1)\n"
+     "ld 29, -24(1)\n"
+     "ld 30, -16(1)\n"
+     "ld 31, -8(1)\n"
+     : [result]"=r"(result)             /* output variables */
+     : [restore_state]"r"(restore_state),       /* input variables  */
+       [save_state]"r"(save_state),
+       [extra]"r"(extra)
+     : "r0", "r4", "r5", "r14", "r15", "memory"
+  );
+  return result;
+}