[NDS32] We need to make sure it is NOT a variadic function so that some v3push/v3pop...

  -- The rationale of such avoidance is that the 'pop25' instruction also
     contains return behavior and we have no chance to further adjust stack
     pointer before returning to caller, which is very important to
     variadic function.
  -- So we do not setup v3push/v3pop (push25/pop25) information for a
     variadic function.  It will use normal stack push/pop instead.

	* config/nds32/nds32.c (nds32_compute_stack_frame): Do not use
	v3push/v3pop for variadic function.
	* config/nds32/nds32.md (prologue, epilogue): Likewise.

From-SVN: r214857

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index a8d27bf6ac1b591da139a12e34b978d2c3001638..7d871025608d7385b1b3c71c1b55d8eae1cc9e30 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2014-09-03  Chung-Ju Wu  <jasonwucj@gmail.com>
+
+       * config/nds32/nds32.c (nds32_compute_stack_frame): Do not use
+       v3push/v3pop for variadic function.
+       * config/nds32/nds32.md (prologue, epilogue): Likewise.
+
 2014-09-03  Chung-Ju Wu  <jasonwucj@gmail.com>
 
        * config/nds32/nds32-md-auxiliary.c (nds32_output_stack_push):

diff --git a/gcc/config/nds32/nds32.c b/gcc/config/nds32/nds32.c
index da3087fd85a2e47facb556ddcaf28b69cc60a16b..f54d700f0856ae90724d8ae66f612526d271bacc 100644 (file)
--- a/gcc/config/nds32/nds32.c
+++ b/gcc/config/nds32/nds32.c
@@ -215,7 +215,8 @@ nds32_compute_stack_frame (void)
                     which means we do not have to save
                     any callee-saved registers.
        condition 2: Both $lp and $fp are NOT live in this function,
-                    which means we do not need to save them.
+                    which means we do not need to save them and there
+                    is no outgoing size.
        condition 3: There is no local_size, which means
                     we do not need to adjust $sp.  */
   if (lookup_attribute ("naked", DECL_ATTRIBUTES (current_function_decl))
@@ -225,8 +226,11 @@ nds32_compute_stack_frame (void)
          && !df_regs_ever_live_p (LP_REGNUM)
          && cfun->machine->local_size == 0))
     {
-      /* Set this function 'naked_p' and
-         other functions can check this flag.  */
+      /* Set this function 'naked_p' and other functions can check this flag.
+         Note that in nds32 port, the 'naked_p = 1' JUST means there is no
+         callee-saved, local size, and outgoing size.
+         The varargs space and ret instruction may still present in
+         the prologue/epilogue expanding.  */
       cfun->machine->naked_p = 1;
 
       /* No need to save $fp, $gp, and $lp.
@@ -250,8 +254,11 @@ nds32_compute_stack_frame (void)
      we need to make sure Rb is $r6 and Re is
      located on $r6, $r8, $r10, or $r14.
      Some results above will be discarded and recomputed.
-     Note that it is only available under V3/V3M ISA.  */
-  if (TARGET_V3PUSH)
+     Note that it is only available under V3/V3M ISA and we
+     DO NOT setup following stuff for isr or variadic function.  */
+  if (TARGET_V3PUSH
+      && !nds32_isr_function_p (current_function_decl)
+      && (cfun->machine->va_args_size == 0))
     {
       /* Recompute:
            cfun->machine->fp_size

diff --git a/gcc/config/nds32/nds32.md b/gcc/config/nds32/nds32.md
index ccf33d9861ed52ab6c0801575090e980f69fb2ce..18d6d1b52ef72d7628d7e3d9f8396dcfc98617bb 100644 (file)
--- a/gcc/config/nds32/nds32.md
+++ b/gcc/config/nds32/nds32.md
@@ -1971,8 +1971,12 @@ create_template:
 (define_expand "prologue" [(const_int 0)]
   ""
 {
-  /* Note that only under V3/V3M ISA, we could use v3push prologue.  */
-  if (TARGET_V3PUSH)
+  /* Note that only under V3/V3M ISA, we could use v3push prologue.
+     In addition, we do not want to use v3push for isr function
+     and variadic function.  */
+  if (TARGET_V3PUSH
+      && !nds32_isr_function_p (current_function_decl)
+      && (cfun->machine->va_args_size == 0))
     nds32_expand_prologue_v3push ();
   else
     nds32_expand_prologue ();
@@ -1982,8 +1986,12 @@ create_template:
 (define_expand "epilogue" [(const_int 0)]
   ""
 {
-  /* Note that only under V3/V3M ISA, we could use v3pop epilogue.  */
-  if (TARGET_V3PUSH)
+  /* Note that only under V3/V3M ISA, we could use v3pop epilogue.
+     In addition, we do not want to use v3pop for isr function
+     and variadic function.  */
+  if (TARGET_V3PUSH
+      && !nds32_isr_function_p (current_function_decl)
+      && (cfun->machine->va_args_size == 0))
     nds32_expand_epilogue_v3pop ();
   else
     nds32_expand_epilogue ();