http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56077
Bug #: 56077
Summary: volatile ignored when function inlined
Classification: Unclassified
Product: gcc
Version: 4.7.2
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
AssignedTo: [email protected]
ReportedBy: [email protected]
The following code snipit produces incorrect code with -fno-schedule-insns2.
The volatile assignments are incorrectly condensed, but only when the function
is inlined.
I observed similar behavior with the RX port of gcc (KPIT 12.02).
brad
---------------------------
DRACK-1$ cat x.c
static inline void
foo(volatile int *p)
{
asm("#BEGIN");
*p = 86;
*p = 87;
*p = 88;
asm("#END");
}
void
bar(void)
{
volatile int *p = (volatile int *)1234567;
foo(p);
}
DRACK-1$ gcc -Wall -Wextra -fno-schedule-insns2 -O -c -save-temps /tmp/x.c &&
sed -n '/BEGIN/,/END/p' /tmp/x.s
#BEGIN
# 0 "" 2
#NO_APP
movl $86, 1234567
movl $87, 1234567
movl $88, 1234567
#APP
# 10 "/tmp/x.c" 1
#END
DRACK-1$ gcc -Wall -Wextra -fschedule-insns2 -O -c -save-temps /tmp/x.c && sed
-n '/BEGIN/,/END/p' /tmp/x.s
#BEGIN
# 0 "" 2
#NO_APP
movl $88, 1234567
#APP
# 10 "/tmp/x.c" 1
#END
DRACK-1$ gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.7/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro
4.7.2-2ubuntu1' --with-bugurl=file:///usr/share/doc/gcc-4.7/README.Bugs
--enable-languages=c,c++,go,fortran,objc,obj-c++ --prefix=/usr
--program-suffix=-4.7 --enable-shared --enable-linker-build-id
--with-system-zlib --libexecdir=/usr/lib --without-included-gettext
--enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.7
--libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu
--enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-gnu-unique-object
--enable-plugin --enable-objc-gc --disable-werror --with-arch-32=i686
--with-tune=generic --enable-checking=release --build=x86_64-linux-gnu
--host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 4.7.2 (Ubuntu/Linaro 4.7.2-2ubuntu1)
DRACK-1$ cat /tmp/x.i
# 1 "/tmp/x.c"
# 1 "<command-line>"
# 1 "/tmp/x.c"
static inline void
foo(volatile int *p)
{
asm("#BEGIN");
*p = 86;
*p = 87;
*p = 88;
asm("#END");
}
void
bar(void)
{
volatile int *p = (volatile int *)1234567;
foo(p);
}
DRACK-1$
