On 14-12-12 04:29 PM, Mike Stump wrote:
On Dec 12, 2014, at 11:38 AM, Ryan Mansfield <rmansfi...@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 <rmansfi...@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
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
