Upgrade stacklet

Author: saghul

src/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(__mips__) && defined(_ABI64)
+#include "switch_mips64_gcc.h" /* gcc on mips64 */
 #else
 #error "Unsupported platform!"
 #endif

src/switch_arm_gcc.h

@@ -1,3 +1,9 @@
+#if defined(__ARM_ARCH_4__) || defined (__ARM_ARCH_4T__)
+# define call_reg(x) "mov lr, pc ; bx " #x "\n"
+#else
+/* ARM >= 5 */
+# define call_reg(x) "blx " #x "\n"
+#endif
 
 static void __attribute__((optimize("O3"))) *slp_switch(void *(*save_state)(void*, void*),
                         void *(*restore_state)(void*, void*),
@@ -11,7 +17,7 @@ static void __attribute__((optimize("O3"))) *slp_switch(void *(*save_state)(void
     "mov r5, %[extra]\n"
     "mov r0, sp\n"        	/* arg 1: current (old) stack pointer */
     "mov r1, r5\n"        	/* arg 2: extra                       */
-    "blx r3\n"				/* call save_state()                  */
+    call_reg(r3)		/* call save_state()                  */
 
     /* skip the rest if the return value is null */
     "cmp r0, #0\n"
@@ -23,7 +29,7 @@ static void __attribute__((optimize("O3"))) *slp_switch(void *(*save_state)(void
 	stack is not restored yet.  It contains only garbage here. */
     "mov r1, r5\n"       	/* arg 2: extra                       */
    	 						/* arg 1: current (new) stack pointer is already in r0*/
-    "blx r4\n"           	/* call restore_state()               */
+    call_reg(r4)		/* call restore_state()               */
 
     /* The stack's content is now restored. */
     "zero:\n"

src/switch_mips64_gcc.h

@@ -0,0 +1,63 @@
+static void *slp_switch(void *(*save_state)(void*, void*),
+                        void *(*restore_state)(void*, void*),
+                        void *extra)
+{
+  void *result;
+  __asm__ volatile (
+     "daddiu $sp, $sp, -0x50\n"
+     "sd $s0, 0x0($sp)\n" /* push the registers specified as caller-save */
+     "sd $s1, 0x8($sp)\n"
+     "sd $s2, 0x10($sp)\n"
+     "sd $s3, 0x18($sp)\n"
+     "sd $s4, 0x20($sp)\n"
+     "sd $s5, 0x28($sp)\n"
+     "sd $s6, 0x30($sp)\n"
+     "sd $s7, 0x38($sp)\n"
+     "sd $fp, 0x40($sp)\n"
+     "sd $ra, 0x48($sp)\n"
+
+     "move $s0, %[rstate]\n" /* save 'restore_state' for later */
+     "move $s1, %[extra]\n" /* save 'extra' for later */
+
+     "move $a1, %[extra]\n"/* arg 2: extra */
+     "move $a0, $sp\n" /* arg 1: current (old) stack pointer */
+                           
+     "move $t9, %[sstate]\n"
+     "jalr $t9\n" /* call save_state() */
+
+     "beqz $v0, 0f\n" /* skip the rest if the return value is null */
+
+     "move $sp, $v0\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. */
+
+     "move $a1, $s1\n" /* arg 2: extra */
+     "move $a0, $v0\n" /* arg 1: current (new) stack pointer */
+     "move $t9, $s0\n"
+     "jalr $t9\n" /* call restore_state() */
+
+     /* The stack's content is now restored. */
+
+     "0:\n"
+     "move %[result], $v0\n"
+     "ld $s0, 0x0($sp)\n"
+     "ld $s1, 0x8($sp)\n"
+     "ld $s2, 0x10($sp)\n"
+     "ld $s3, 0x18($sp)\n"
+     "ld $s4, 0x20($sp)\n"
+     "ld $s5, 0x28($sp)\n"
+     "ld $s6, 0x30($sp)\n"
+     "ld $s7, 0x38($sp)\n"
+     "ld $fp, 0x40($sp)\n"
+     "ld $ra, 0x48($sp)\n"
+     "daddiu $sp, $sp, 0x50\n"
+
+     : [result]"=&r"(result)
+     : [sstate]"r"(save_state),
+       [rstate]"r"(restore_state),
+       [extra]"r"(extra)
+     : "memory", "v0", "a0", "a1", "t9"
+     );
+  return result;
+}

src/switch_x86_64_gcc.h

@@ -10,7 +10,10 @@ static void *slp_switch(void *(*save_state)(void*, void*),
      "pushq %%r12\n"
      "pushq %%r13\n"
      "pushq %%r14\n"
+     "movq %%rsp, %%rbp\n"
+     "andq $-16, %%rsp\n"   /* <= align the stack here... */
      "pushq %%r15\n"
+     "pushq %%rbp\n"       /* ...so that rsp is now a multiple of 16 */
 
      "movq %%rax, %%r12\n" /* save 'restore_state' for later */
      "movq %%rsi, %%r13\n" /* save 'extra' for later         */
@@ -34,7 +37,9 @@ static void *slp_switch(void *(*save_state)(void*, void*),
      /* The stack's content is now restored. */
 
      "0:\n"
+     "popq %%rbp\n"
      "popq %%r15\n"
+     "movq %%rbp, %%rsp\n"
      "popq %%r14\n"
      "popq %%r13\n"
      "popq %%r12\n"

src/switch_x86_gcc.h

@@ -8,7 +8,10 @@ static void *slp_switch(void *(*save_state)(void*, void*),
      "pushl %%ebp\n"
      "pushl %%ebx\n"       /* push some registers that may contain */
      "pushl %%esi\n"       /* some value that is meant to be saved */
+     "movl %%esp, %%ebp\n"
+     "andl $-16, %%esp\n"  /* <= align the stack here, for the calls */
      "pushl %%edi\n"
+     "pushl %%ebp\n"
 
      "movl %%eax, %%esi\n" /* save 'restore_state' for later */
      "movl %%edx, %%edi\n" /* save 'extra' for later         */
@@ -35,7 +38,9 @@ static void *slp_switch(void *(*save_state)(void*, void*),
 
      "0:\n"
      "addl $8, %%esp\n"
+     "popl %%ebp\n"
      "popl %%edi\n"
+     "movl %%ebp, %%esp\n"
      "popl %%esi\n"
      "popl %%ebx\n"
      "popl %%ebp\n"