gecko/build/autoconf/gcc-pr49911.m4
Rafael Ávila de Espíndola be6ade2240 Bug 678558 - Detect broken vrp and disable it.
Test if the gcc we are using has PR49911 and if so disable value range
propagation to avoid.

--HG--
extra : rebase_source : d539914fa66a44f69399f2964740315f0723378f
2011-08-26 15:39:34 -04:00

68 lines
1.3 KiB
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dnl Check if the compiler is gcc and has PR49911. If so
dnl disable vrp.
AC_DEFUN([MOZ_GCC_PR49911],
[
if test "$GNU_CC"; then
AC_MSG_CHECKING(for gcc PR49911)
ac_have_gcc_pr49911="no"
AC_LANG_SAVE
AC_LANG_CPLUSPLUS
_SAVE_CXXFLAGS=$CXXFLAGS
CXXFLAGS="-O2"
AC_TRY_RUN([
extern "C" void abort(void);
typedef enum {
eax, ecx, edx, ebx, esp, ebp,
esi, edi }
RegisterID;
union StateRemat {
RegisterID reg_;
int offset_;
};
static StateRemat FromRegister(RegisterID reg) {
StateRemat sr;
sr.reg_ = reg;
return sr;
}
static StateRemat FromAddress3(int address) {
StateRemat sr;
sr.offset_ = address;
if (address < 46 && address >= 0) {
abort();
}
return sr;
}
struct FrameState {
StateRemat dataRematInfo2(bool y, int z) {
if (y) return FromRegister(RegisterID(1));
return FromAddress3(z);
}
};
FrameState frame;
StateRemat x;
__attribute__((noinline)) void jsop_setelem(bool y, int z) {
x = frame.dataRematInfo2(y, z);
}
int main(void) {
jsop_setelem(0, 47);
}
], true,
ac_have_gcc_pr49911="yes",
true)
CXXFLAGS="$_SAVE_CXXFLAGS"
AC_LANG_RESTORE
if test "$ac_have_gcc_pr49911" == "yes"; then
AC_MSG_RESULT(yes)
CFLAGS="$CFLAGS -fno-tree-vrp"
CXXFLAGS="$CXXFLAGS -fno-tree-vrp"
else
AC_MSG_RESULT(no)
fi
fi
])