diff mbox

[testsuite] Fix a few test cases

Message ID 548B9C31.6060500@qnx.com
State New
Headers show

Commit Message

Ryan Mansfield Dec. 13, 2014, 1:53 a.m. UTC 
On 14-12-12 04:29 PM, Mike Stump wrote:
> On Dec 12, 2014, at 11:38 AM, Ryan Mansfield <RMansfield@qnx.com> wrote:
>>
>> Here are a few test tweaks. In 921202-1.c, if STACK_SIZE is used then VLEN will blow the stack with 64bit longs. e.g. if STACK_SIZE == 512K then 3 arrays of 32767 longs means at a minimum 767K of stack will be used at -O0. In pr51447.c, the rbx global register is clobbering the rbx of main's caller, which can cause test case crashes on return.
>>
>> 2014-12-12  Ryan Mansfield  <rmansfield@qnx.com>
>>
>>         * gcc.c-torture/execute/921202-1.c: Adjust VLEN.
>>         * gcc.c-torture/execute/pr51447.c: Restore rbx for x86-64.
>>         * gcc.dg/cpp/trad/include.c: Exclude QNX targets.
>>
>> OK?
>
> Ok for first and third part.  The second one, I would like an rbx/x86_64 person to review.

Thanks. rbx is callee saved, and it's being clobbered.

e.g. on Linux x86-64

Breakpoint 1, main ()
     at 
/home/ryan/gnu/gcc/trunk/gcc/testsuite/gcc.c-torture/execute/pr51447.c:13
13	{
1: x/i $pc
=> 0x40054e <main>:	push   %rbp
(gdb) info reg rbx
rbx            0x0	0

(gdb) s
26	  return 0;
1: x/i $pc
=> 0x400596 <main+72>:	mov    $0x0,%eax
(gdb) info reg rbx
rbx            0x400586	4195718r

The global register var docs say:

"A function that can alter the value of a global register variable 
cannot safely be called from a function compiled without this variable, 
because it could clobber the value the caller expects to find there on 
return. Therefore, the function that is the entry point into the part of 
the program that uses the global register variable must explicitly save 
and restore the value that belongs to its caller."

The updated diff switches the test to use inline asm to save/restore rbx 
instead of the local reg vars, but maybe there's a better way.

Regards,

Ryan Mansfield
diff mbox

Patch

Index: gcc/testsuite/gcc.c-torture/execute/921202-1.c
===================================================================
--- gcc/testsuite/gcc.c-torture/execute/921202-1.c	(revision 218685)
+++ gcc/testsuite/gcc.c-torture/execute/921202-1.c	(working copy)
@@ -2,7 +2,7 @@ 
 #ifndef STACK_SIZE
 #define	VLEN	2055
 #else
-#define VLEN ((STACK_SIZE/16) - 1)
+#define VLEN ((STACK_SIZE/32) - 1)
 #endif
 main ()
 {
Index: gcc/testsuite/gcc.c-torture/execute/pr51447.c
===================================================================
--- gcc/testsuite/gcc.c-torture/execute/pr51447.c	(revision 218685)
+++ gcc/testsuite/gcc.c-torture/execute/pr51447.c	(working copy)
@@ -14,6 +14,10 @@ 
 main (void)
 {
   __label__ nonlocal_lab;
+#ifdef __x86_64__
+  void *saved_rbx;
+  asm volatile ("movq %%rbx, %0" : "=r" (saved_rbx) : : );
+#endif
   __attribute__((noinline, noclone)) void
     bar (void *func)
       {
@@ -21,9 +25,15 @@ 
 	goto nonlocal_lab;
       }
   bar (&&nonlocal_lab);
+#ifdef __x86_64__
+  asm volatile ("movq %0, %%rbx" : : "r" (saved_rbx) : "rbx" );
+#endif
   return 1;
 nonlocal_lab:
   if (ptr != &&nonlocal_lab)
     abort ();
+#ifdef __x86_64__
+  asm volatile ("movq %0, %%rbx" : : "r" (saved_rbx) : "rbx" );
+#endif
   return 0;
 }
Index: gcc/testsuite/gcc.dg/cpp/trad/include.c
===================================================================
--- gcc/testsuite/gcc.dg/cpp/trad/include.c	(revision 218685)
+++ gcc/testsuite/gcc.dg/cpp/trad/include.c	(working copy)
@@ -1,11 +1,11 @@ 
 /* Copyright (c) 2002 Free Software Foundation Inc.  */
 
-/* Test that macros are not expanded in the <> quotes of #inlcude.  */
+/* Test that macros are not expanded in the <> quotes of #include.  */
 
 /* vxWorksCommon.h uses the "#" operator to construct the name of an
    include file, thus making the file incompatible with -traditional-cpp.
    Newlib uses ## when including stdlib.h as of 2007-09-07.  */
-/* { dg-do preprocess { target { { ! vxworks_kernel } && { ! newlib } } } } */
+/* { dg-do preprocess { target { { ! vxworks_kernel } && { ! newlib } && { ! *-*-qnx* } } } } */
 
 #define __STDC__ 1		/* Stop complaints about non-ISO compilers.  */
 #define stdlib 1