The fxam instruction returns the wrong result after fdecstp or after an underflow. Check fptags to handle this.
Reported-by: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]> --- target/i386/fpu_helper.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/target/i386/fpu_helper.c b/target/i386/fpu_helper.c index 99f28f2..792a128 100644 --- a/target/i386/fpu_helper.c +++ b/target/i386/fpu_helper.c @@ -991,7 +991,11 @@ void helper_fxam_ST0(CPUX86State *env) env->fpus |= 0x200; /* C1 <-- 1 */ } - /* XXX: test fptags too */ + if (env->fptags[env->fpstt]) { + env->fpus |= 0x4100; /* Empty */ + return; + } + expdif = EXPD(temp); if (expdif == MAXEXPD) { if (MANTD(temp) == 0x8000000000000000ULL) { -- 1.8.3.1
