Fix x86/ffi64 calls with 6 gp and some sse registers (libffi#848)

* Fix x86/ffi64 calls with 6 gp and some sse registers

* Add test demonstating issue when mixing gp and sse registers

Author: kellda

src/x86/ffi64.c

@@ -651,7 +651,7 @@ ffi_call_int (ffi_cif *cif, void (*fn)(void), void *rvalue,
 		      break;
 		    default:
 		      reg_args->gpr[gprcount] = 0;
-		      memcpy (&reg_args->gpr[gprcount], a, size);
+		      memcpy (&reg_args->gpr[gprcount], a, sizeof(UINT64));
 		    }
 		  gprcount++;
 		  break;

testsuite/libffi.call/struct_int_float.c

@@ -0,0 +1,88 @@
+/* Area:	ffi_call
+   Purpose:	Demonstrate structures with integers corrupting earlier floats
+   Limitations:	none.
+   PR:		#848
+   Originator:	kellda  */
+
+/* { dg-do run } */
+#include "ffitest.h"
+
+typedef struct
+{
+  unsigned long i;
+  float f;
+} test_structure_int_float;
+
+static float ABI_ATTR struct_int_float(test_structure_int_float ts1,
+                                       test_structure_int_float ts2,
+                                       test_structure_int_float ts3,
+                                       test_structure_int_float ts4,
+                                       test_structure_int_float ts5,
+                                       test_structure_int_float ts6)
+{
+  return ts1.f;
+}
+
+int main (void)
+{
+  ffi_cif cif;
+  ffi_type *args[MAX_ARGS];
+  void *values[MAX_ARGS];
+  ffi_type ts_type;
+  ffi_type *ts_type_elements[3];
+  float rfloat;
+
+  test_structure_int_float ts_arg[6];
+
+  ts_type.size = 0;
+  ts_type.alignment = 0;
+  ts_type.type = FFI_TYPE_STRUCT;
+  ts_type.elements = ts_type_elements;
+  ts_type_elements[0] = &ffi_type_ulong;
+  ts_type_elements[1] = &ffi_type_float;
+  ts_type_elements[2] = NULL;
+
+  args[0] = &ts_type;
+  values[0] = &ts_arg[0];
+  args[1] = &ts_type;
+  values[1] = &ts_arg[1];
+  args[2] = &ts_type;
+  values[2] = &ts_arg[2];
+  args[3] = &ts_type;
+  values[3] = &ts_arg[3];
+  args[4] = &ts_type;
+  values[4] = &ts_arg[4];
+  args[5] = &ts_type;
+  values[5] = &ts_arg[5];
+  
+  /* Initialize the cif */
+  CHECK(ffi_prep_cif(&cif, ABI_NUM, 6, &ffi_type_float, args) == FFI_OK);
+  
+  ts_arg[0].i = 1;
+  ts_arg[0].f = 1.11f;
+  ts_arg[1].i = 2;
+  ts_arg[1].f = 2.22f;
+  ts_arg[2].i = 3;
+  ts_arg[2].f = 3.33f;
+  ts_arg[3].i = 4;
+  ts_arg[3].f = 4.44f;
+  ts_arg[4].i = 5;
+  ts_arg[4].f = 5.55f;
+  ts_arg[5].i = 6;
+  ts_arg[5].f = 6.66f;
+  
+  printf ("%g\n", ts_arg[0].f);
+  printf ("%g\n", ts_arg[1].f);
+  printf ("%g\n", ts_arg[2].f);
+  printf ("%g\n", ts_arg[3].f);
+  printf ("%g\n", ts_arg[4].f);
+  printf ("%g\n", ts_arg[5].f);
+  
+  ffi_call(&cif, FFI_FN(struct_int_float), &rfloat, values);
+
+  printf ("%g\n", rfloat);
+  
+  CHECK(rfloat == 1.11f);
+
+  exit(0);
+}