From ef9f33a345aa135de8a14498e15967edda3983e3 Mon Sep 17 00:00:00 2001 From: Aleksandar Markovic Date: Sat, 24 Feb 2018 20:41:44 -0500 Subject: [PATCH] target-mips: Activate IEEE 754-2008 signaling NaN bit meaning for MSA Function msa_reset() is updated so that flag snan_bit_is_one is properly set to 0. By applying this patch, a number of incorrect MSA behaviors that require IEEE 754-2008 compliance will be fixed. Those are behaviors that (up to the moment of applying this patch) did not get the desired functionality from SoftFloat library with respect to distinguishing between quiet and signaling NaN, getting default NaN values (both quiet and signaling), establishing if a floating point number is NaN or not, etc. Two examples: * FMAX, FMIN will now correctly detect and propagate NaNs. * FCLASS.D ans FCLASS.S will now correcty detect NaN flavors Backports commit 40bd6dd456e61a36e454fb9dd2cc739b67c224cf from qemu --- qemu/target-mips/translate_init.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/qemu/target-mips/translate_init.c b/qemu/target-mips/translate_init.c index 4d344c24..69f3f4df 100644 --- a/qemu/target-mips/translate_init.c +++ b/qemu/target-mips/translate_init.c @@ -1143,5 +1143,6 @@ static void msa_reset(CPUMIPSState *env) /* clear float_status nan mode */ set_default_nan_mode(0, &env->active_tc.msa_fp_status); - set_snan_bit_is_one(1, &env->active_tc.msa_fp_status); + /* set proper signanling bit meaning ("1" means "quiet") */ + set_snan_bit_is_one(0, &env->active_tc.msa_fp_status); }