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-rw-r--r--target/i386/tcg/fpu_helper.c12
1 files changed, 12 insertions, 0 deletions
diff --git a/target/i386/tcg/fpu_helper.c b/target/i386/tcg/fpu_helper.c
index 53b49bb297..d0a1e2f3c8 100644
--- a/target/i386/tcg/fpu_helper.c
+++ b/target/i386/tcg/fpu_helper.c
@@ -173,6 +173,18 @@ void cpu_init_fp_statuses(CPUX86State *env)
      */
     set_float_2nan_prop_rule(float_2nan_prop_x87, &env->mmx_status);
     set_float_2nan_prop_rule(float_2nan_prop_x87, &env->sse_status);
+    /*
+     * Only SSE has multiply-add instructions. In the SDM Section 14.5.2
+     * "Fused-Multiply-ADD (FMA) Numeric Behavior" the NaN handling is
+     * specified -- for 0 * inf + NaN the input NaN is selected, and if
+     * there are multiple input NaNs they are selected in the order a, b, c.
+     */
+    set_float_infzeronan_rule(float_infzeronan_dnan_never, &env->sse_status);
+    set_float_3nan_prop_rule(float_3nan_prop_abc, &env->sse_status);
+    /* Default NaN: sign bit set, most significant frac bit set */
+    set_float_default_nan_pattern(0b11000000, &env->fp_status);
+    set_float_default_nan_pattern(0b11000000, &env->mmx_status);
+    set_float_default_nan_pattern(0b11000000, &env->sse_status);
 }
 
 static inline uint8_t save_exception_flags(CPUX86State *env)