Allow anonymous arguments to be passed partly in registers (only ABI-HS)

Author: Claudiu Zissulescu

gcc/ChangeLog.ARC

@@ -1,3 +1,14 @@
+2013-07-29 Claudiu Zissulescu <[email protected]>
+
+	* config/arc/arc.c (arc_setup_incoming_varargs): Pass
+          anonymous arguments in registers (ABI HS).
+	  (arc_function_args_impl): Likewise.
+	* config/arc/arc.h (CUMULATIVE_ARGS.last_reg): New member.
+	* testsuite/gcc.target/arc/abitest.S: New file.
+	* testsuite/gcc.target/arc/va_args-1.c: Likewise.
+	* testsuite/gcc.target/arc/va_args-2.c: Likewise.
+	* testsuite/gcc.target/arc/va_args-3.c: Likewise.
+
 2013-07-23 Claudiu Zissulescu <[email protected]>
 
 	* config/arc/arc-opts.h (arc_abi_type): Define.

gcc/config/arc/arc.c

@@ -1862,17 +1862,11 @@ arc_setup_incoming_varargs (cumulative_args_t args_so_far,
   int first_anon_arg;
   CUMULATIVE_ARGS next_cum;
 
-  if (TARGET_HS)
-    {
-      *pretend_size = 0;
-      return;
-    }
-
   /* We must treat `__builtin_va_alist' as an anonymous arg.  */
 
   next_cum = *get_cumulative_args (args_so_far);
   arc_function_arg_advance (pack_cumulative_args (&next_cum), mode, type, true);
-  first_anon_arg = next_cum.arg_num;
+  first_anon_arg = TARGET_HS ? next_cum.last_reg : next_cum.arg_num;
 
   if (FUNCTION_ARG_REGNO_P (first_anon_arg))
     {
@@ -5215,6 +5209,7 @@ void arc_init_cumulative_args (CUMULATIVE_ARGS *cum,
   int i;
 
   cum->arg_num = 0;
+  cum->last_reg = 0;
   for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
     {
       cum->avail[i] = true;
@@ -5261,7 +5256,30 @@ arc_function_args_impl (CUMULATIVE_ARGS *cum,
     return const0_rtx;
 
   if (!named && TARGET_HS)
-    return NULL_RTX; /* all unamed arguments are passed on stack. */
+    {
+      reg_idx = cum->last_reg; /* for unamed args don't try fill up the reg-holes. */
+      nregs = arc_hard_regno_nregs (0, mode, type); /* only interested in the number of regs. */
+      if ((nregs == 2)
+	  && (mode != BLKmode) /* Only DI-like modes are interesting for us. */
+	  && (reg_idx & 1) /* Only for "non-aligned" registers. */
+	  && FUNCTION_ARG_REGNO_P (reg_idx + nregs - 1))
+	{
+	  rtx reg1 = gen_rtx_REG (SImode, reg_idx);
+	  rtx reg2 = gen_rtx_REG (SImode, reg_idx + 1);
+	  rtvec vec = gen_rtvec (2, gen_rtx_EXPR_LIST (VOIDmode, reg1, const0_rtx),
+				 gen_rtx_EXPR_LIST (VOIDmode, reg2, GEN_INT (4)));
+
+	  if (advance)
+	    {
+	      cum->arg_num           += nregs;
+	      cum->avail[reg_idx]     = false;
+	      cum->avail[reg_idx + 1] = false;
+	      cum->last_reg          += nregs;
+	    }
+
+	  return gen_rtx_PARALLEL (mode, vec);
+	}
+    }
 
   while (FUNCTION_ARG_REGNO_P (reg_idx))
     {
@@ -5302,6 +5320,7 @@ arc_function_args_impl (CUMULATIVE_ARGS *cum,
 	    {
 	      cum->avail[reg_idx] = false;
 	    }
+	  cum->last_reg = reg_idx;
 	  cum->arg_num += nregs;
 	}
       return gen_rtx_REG (mode, reg_location);

gcc/config/arc/arc.h

@@ -924,6 +924,9 @@ typedef struct arc_args
 {
   /* Registers that are still available for parameter passing. */
   bool avail[FIRST_PSEUDO_REGISTER];
+  /* HS-ABI: last set register. It is needed for passing the first
+     anonymous arguments in regs. */
+  unsigned int last_reg;
   /* Backwards compatibility: total number of used registers.  */
   int arg_num;
 } CUMULATIVE_ARGS;

gcc/testsuite/gcc.target/arc/abitest.S

@@ -0,0 +1,31 @@
+/* { dg-do assemble } */
+#ifndef ENTRY
+#define ENTRY(nm)               \
+        .text `                 \
+        .align 4 `              \
+        .globl nm `             \
+        .type nm,@function `    \
+nm:
+#endif
+
+#ifndef END
+#define END(name)       .size name,.-name
+#endif
+
+ENTRY(tsyscall)
+ENTRY(clone)
+	add	r0,r0,r1
+	add	r0,r0,r2
+	add	r0,r0,r3
+	add	r0,r0,r4
+	add	r0,r0,r5
+	j_s.d	[blink]
+	add	r0,r0,r6
+END(tsyscall)
+END(clone)
+
+ENTRY(abidi)
+	add.f r0,r1,1
+        j_s.d [blink]
+        adc r1,r2,0
+END(abidi)

gcc/testsuite/gcc.target/arc/va_args-1.c

@@ -0,0 +1,16 @@
+/* { dg-do run } */
+/* { dg-options "-O2" } */
+/* { dg-additional-sources "abitest.S" } */
+
+extern long tsyscall (long int sysnum, ...);
+
+int main (void)
+{
+  long a;
+
+  a = tsyscall (1, 2, 3, 4, 5, 6, 7);
+
+  if (a != 28)
+    return 1;
+  return 0;
+}

gcc/testsuite/gcc.target/arc/va_args-2.c

@@ -0,0 +1,14 @@
+/* { dg-do run } */
+/* { dg-options "-O2" } */
+/* { dg-additional-sources "abitest.S" } */
+
+extern int clone(int (*fn)(void *), void *child_stack,
+		 int flags, void *arg, ...);
+
+int main (void)
+{
+  int a = clone ((void *) 1, (void *)2, 3, (void *) 4, 5, 6, 7);
+  if (a != 28)
+    return 1;
+  return 0;
+}

gcc/testsuite/gcc.target/arc/va_args-3.c

@@ -0,0 +1,15 @@
+/* { dg-do run } */
+/* { dg-options "-O2" } */
+/* { dg-additional-sources "abitest.S" } */
+
+extern long long abidi (int a, ...);
+
+int main (void)
+{
+  long long a = 1;
+  a = abidi (10, a);
+
+  if (a != 2)
+    return 1;
+  return 0;
+}