* [PATCH, i386]: Fix target/35504: incorrect code generated on i386 for C++ multiple inheritance, large return structures and regparm or fastcall calling conventions
2008-03-18 5:31 ` Mikulas Patocka
@ 2008-03-18 20:06 ` Uros Bizjak
0 siblings, 0 replies; 3+ messages in thread
From: Uros Bizjak @ 2008-03-18 20:06 UTC (permalink / raw)
To: Mikulas Patocka; +Cc: gcc patches, Richard Guenther
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Mikulas Patocka wrote:
> Hmm, I see, I don't know why. So use the attachment in bugzilla, there is
> also a testcase.
>
> I am not a gcc developer, you can take it and commit it to gcc.
>
Attached patch correctly calculates location of "this" pointer when
regparm or fastcall is in effect.
2008-03-18 Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
PR target/35504
* config/i386/i386.c (x86_this_parameter): Calculate correct "this"
pointer location when "regparm = N" or "fastcall" is in effect.
testsuite/ChangeLog
2008-03-18 Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
PR target/35504
* g++.dg/other/pr35504.C: New test.
The patch was bootstrapped and regression tested on x86_64-pc-linux-gnu
{,-m32}.
Patch is committed to SVN, it will be committed to 4.3 and 4.2 in a
couple of days.
Thanks,
Uros.
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Index: testsuite/g++.dg/other/pr35504.C
===================================================================
--- testsuite/g++.dg/other/pr35504.C (revision 0)
+++ testsuite/g++.dg/other/pr35504.C (revision 0)
@@ -0,0 +1,147 @@
+// { dg-do run { target { { i?86-*-* x86_64-*-* } && ilp32 } } }
+
+#define ATTR0 __attribute__((__regparm__(0)))
+#define ATTR1 __attribute__((__regparm__(1)))
+#define ATTR2 __attribute__((__regparm__(2)))
+#define ATTR3 __attribute__((__regparm__(3)))
+#define ATTR4 __attribute__((__fastcall__))
+#define ATTR5 __attribute__((__stdcall__))
+#define ATTR6 __attribute__((__cdecl__))
+#define ATTR7
+
+extern "C" void abort (void);
+
+struct long_struct
+{
+ int a[3];
+};
+
+struct long_struct ret;
+
+class c3 *this3;
+
+class c1
+{
+ int val1;
+public:
+ virtual void foo () { }
+};
+
+class c2
+{
+public:
+ virtual ATTR0 struct long_struct method0 ()
+ {
+ return ret;
+ }
+
+ virtual ATTR1 struct long_struct method1 ()
+ {
+ return ret;
+ }
+
+ virtual ATTR2 struct long_struct method2 ()
+ {
+ return ret;
+ }
+
+ virtual ATTR3 struct long_struct method3 ()
+ {
+ return ret;
+ }
+
+ virtual ATTR4 struct long_struct method4 ()
+ {
+ return ret;
+ }
+
+ virtual ATTR5 struct long_struct method5 ()
+ {
+ return ret;
+ }
+
+ virtual ATTR6 struct long_struct method6 ()
+ {
+ return ret;
+ }
+
+ virtual ATTR7 struct long_struct method7 ()
+ {
+ return ret;
+ }
+};
+
+class c3:c1, public c2
+{
+public:
+ c3 ()
+ {
+ this3 = this;
+ }
+
+ struct long_struct check_this (int a)
+ {
+ if (this3 != this)
+ abort ();
+
+ return ret;
+ }
+
+ virtual ATTR0 struct long_struct method0 ()
+ {
+ return check_this (0);
+ }
+
+ virtual ATTR1 struct long_struct method1 ()
+ {
+ return check_this (1);
+ }
+
+ virtual ATTR2 struct long_struct method2 ()
+ {
+ return check_this (2);
+ }
+
+ virtual ATTR3 struct long_struct method3 ()
+ {
+ return check_this (3);
+ }
+
+ virtual ATTR4 struct long_struct method4 ()
+ {
+ return check_this (4);
+ }
+
+ virtual ATTR5 struct long_struct method5 ()
+ {
+ return check_this (5);
+ }
+
+ virtual ATTR6 struct long_struct method6 ()
+ {
+ return check_this (6);
+ }
+
+ virtual ATTR7 struct long_struct method7 ()
+ {
+ return check_this (7);
+ }
+};
+
+class c3 c3_instance;
+class c2 *c2_ptr = &c3_instance;
+
+int
+main ()
+{
+ c2_ptr->method0 ();
+ c2_ptr->method1 ();
+ c2_ptr->method2 ();
+ c2_ptr->method3 ();
+ c2_ptr->method4 ();
+ c2_ptr->method5 ();
+ c2_ptr->method6 ();
+ c2_ptr->method7 ();
+
+ return 0;
+}
Index: stor-layout.c
===================================================================
--- stor-layout.c (revision 133318)
+++ stor-layout.c (working copy)
@@ -699,6 +699,9 @@ update_alignment_for_field (record_layou
&& ! integer_zerop (DECL_SIZE (rli->prev_field)))))
{
unsigned int type_align = TYPE_ALIGN (type);
+ unsigned int type_size
+ = tree_low_cst (TYPE_SIZE (type), 1);
+ type_align = MAX (type_align, type_size);
type_align = MAX (type_align, desired_align);
if (maximum_field_alignment != 0)
type_align = MIN (type_align, maximum_field_alignment);
Index: config/i386/i386.c
===================================================================
--- config/i386/i386.c (revision 133318)
+++ config/i386/i386.c (working copy)
@@ -22698,6 +22698,7 @@ x86_this_parameter (tree function)
{
tree type = TREE_TYPE (function);
bool aggr = aggregate_value_p (TREE_TYPE (type), type) != 0;
+ int nregs;
if (TARGET_64BIT)
{
@@ -22710,11 +22711,25 @@ x86_this_parameter (tree function)
return gen_rtx_REG (DImode, parm_regs[aggr]);
}
- if (ix86_function_regparm (type, function) > 0 && !stdarg_p (type))
+ nregs = ix86_function_regparm (type, function);
+
+ if (nregs > 0 && !stdarg_p (type))
{
- int regno = AX_REG;
+ int regno;
+
if (lookup_attribute ("fastcall", TYPE_ATTRIBUTES (type)))
- regno = CX_REG;
+ regno = aggr ? DX_REG : CX_REG;
+ else
+ {
+ regno = AX_REG;
+ if (aggr)
+ {
+ regno = DX_REG;
+ if (nregs == 1)
+ return gen_rtx_MEM (SImode,
+ plus_constant (stack_pointer_rtx, 4));
+ }
+ }
return gen_rtx_REG (SImode, regno);
}
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