Do not use floating point registers when compiling with -msoft-float for SPARC

2015-09-28  Daniel Cederman  <cederman@gaisler.com>

Do not use floating point registers when compiling with -msoft-float for SPARC

__builtin_apply* and __builtin_return accesses the floating point registers on
SPARC even when compiling with -msoft-float.

gcc/
	* config/sparc/sparc.c (sparc_function_value_regno_p): Do not return
	true on %f0 for a target without FPU.
	* config/sparc/sparc.md (untyped_call): Do not save %f0 for a target
	without FPU.
	(untyped_return): Do not load %f0 for a target without FPU.

From-SVN: r228183

gcc/ChangeLog

+2015-09-28  Daniel Cederman  <cederman@gaisler.com>
+
+	* config/sparc/sparc.c (sparc_function_value_regno_p): Do not return
+	true on %f0 for a target without FPU.
+	* config/sparc/sparc.md (untyped_call): Do not save %f0 for a target
+	without FPU.
+	(untyped_return): Do not load %f0 for a target without FPU.
+
 2015-09-28  Andrew Pinski  <apinski@cavium.com>    
 
 	* config/aarch64/aarch64.md (prefetch):

gcc/config/sparc/sparc.c

@@ -7395,7 +7395,7 @@ sparc_libcall_value (machine_mode mode,
 static bool
 sparc_function_value_regno_p (const unsigned int regno)
 {
-  return (regno == 8 || regno == 32);
+  return (regno == 8 || (TARGET_FPU && regno == 32));
 }
 
 /* Do what is necessary for `va_start'.  We look at the current function

gcc/config/sparc/sparc.md

@@ -6398,7 +6398,6 @@
   ""
 {
   rtx valreg1 = gen_rtx_REG (DImode, 8);
-  rtx valreg2 = gen_rtx_REG (TARGET_ARCH64 ? TFmode : DFmode, 32);
   rtx result = operands[1];
 
   /* Pass constm1 to indicate that it may expect a structure value, but
@@ -6407,8 +6406,12 @@
 
   /* Save the function value registers.  */
   emit_move_insn (adjust_address (result, DImode, 0), valreg1);
-  emit_move_insn (adjust_address (result, TARGET_ARCH64 ? TFmode : DFmode, 8),
-				  valreg2);
+  if (TARGET_FPU)
+    {
+      rtx valreg2 = gen_rtx_REG (TARGET_ARCH64 ? TFmode : DFmode, 32);
+      emit_move_insn (adjust_address (result, TARGET_ARCH64 ? TFmode : DFmode, 8),
+                      valreg2);
+    }
 
   /* The optimizer does not know that the call sets the function value
      registers we stored in the result block.  We avoid problems by
@@ -6620,7 +6623,6 @@
   ""
 {
   rtx valreg1 = gen_rtx_REG (DImode, 24);
-  rtx valreg2 = gen_rtx_REG (TARGET_ARCH64 ? TFmode : DFmode, 32);
   rtx result = operands[0];
 
   if (! TARGET_ARCH64)
@@ -6637,14 +6639,18 @@
       emit_insn (gen_update_return (rtnreg, value));
     }
 
-  /* Reload the function value registers.  */
+  /* Reload the function value registers.
+     Put USE insns before the return.  */
   emit_move_insn (valreg1, adjust_address (result, DImode, 0));
-  emit_move_insn (valreg2,
-		  adjust_address (result, TARGET_ARCH64 ? TFmode : DFmode, 8));
-
-  /* Put USE insns before the return.  */
   emit_use (valreg1);
-  emit_use (valreg2);
+
+  if (TARGET_FPU)
+    {
+      rtx valreg2 = gen_rtx_REG (TARGET_ARCH64 ? TFmode : DFmode, 32);
+      emit_move_insn (valreg2,
+		      adjust_address (result, TARGET_ARCH64 ? TFmode : DFmode, 8));
+      emit_use (valreg2);
+    }
 
   /* Construct the return.  */
   expand_naked_return ();