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authorDavid Hildenbrand <david@redhat.com>2019-02-18 13:27:09 +0100
committerCornelia Huck <cohuck@redhat.com>2019-03-04 11:49:31 +0100
commitb12b103ecdfa0a5a7466a57fc1e55fc00afcd0db (patch)
treed81ddf25a43aa6b639fca202df8b87399f53d1ef
parentbdcfcd445dd4f07e4df5345f1cdd0da5a5e6ba5f (diff)
downloadfocaccia-qemu-b12b103ecdfa0a5a7466a57fc1e55fc00afcd0db.tar.gz
focaccia-qemu-b12b103ecdfa0a5a7466a57fc1e55fc00afcd0db.zip
s390x/tcg: Handle all rounding modes overwritten by BFP instructions
"round to nearest with ties away from 0" maps to float_round_ties_away.
"round to prepare for shorter precision" maps to float_round_to_odd.

As all instructions properly check for valid rounding modes in translate.c
we can add an assert. Fix one missing empty line.

Cc: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20190218122710.23639-15-david@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
-rw-r--r--target/s390x/fpu_helper.c13
1 files changed, 11 insertions, 2 deletions
diff --git a/target/s390x/fpu_helper.c b/target/s390x/fpu_helper.c
index e258f20aa9..1be68bafea 100644
--- a/target/s390x/fpu_helper.c
+++ b/target/s390x/fpu_helper.c
@@ -397,14 +397,21 @@ uint32_t HELPER(cxb)(CPUS390XState *env, uint64_t ah, uint64_t al,
 int s390_swap_bfp_rounding_mode(CPUS390XState *env, int m3)
 {
     int ret = env->fpu_status.float_rounding_mode;
+
     switch (m3) {
     case 0:
         /* current mode */
         break;
     case 1:
-        /* biased round no nearest */
+        /* round to nearest with ties away from 0 */
+        set_float_rounding_mode(float_round_ties_away, &env->fpu_status);
+        break;
+    case 3:
+        /* round to prepare for shorter precision */
+        set_float_rounding_mode(float_round_to_odd, &env->fpu_status);
+        break;
     case 4:
-        /* round to nearest */
+        /* round to nearest with ties to even */
         set_float_rounding_mode(float_round_nearest_even, &env->fpu_status);
         break;
     case 5:
@@ -419,6 +426,8 @@ int s390_swap_bfp_rounding_mode(CPUS390XState *env, int m3)
         /* round to -inf */
         set_float_rounding_mode(float_round_down, &env->fpu_status);
         break;
+    default:
+        g_assert_not_reached();
     }
     return ret;
 }