diff --git a/fpu/softfloat.c b/fpu/softfloat.c
index 0638c9f4e0..301ce3b537 100644
--- a/fpu/softfloat.c
+++ b/fpu/softfloat.c
@@ -1920,13 +1920,30 @@ float16 float32_to_float16(float32 a, bool ieee, float_status *s)
     return float16a_round_pack_canonical(pr, s, fmt16);
 }
 
-float64 float32_to_float64(float32 a, float_status *s)
+static float64 QEMU_SOFTFLOAT_ATTR
+soft_float32_to_float64(float32 a, float_status *s)
 {
     FloatParts p = float32_unpack_canonical(a, s);
     FloatParts pr = float_to_float(p, &float64_params, s);
     return float64_round_pack_canonical(pr, s);
 }
 
+float64 float32_to_float64(float32 a, float_status *s)
+{
+    if (likely(float32_is_normal(a))) {
+        /* Widening conversion can never produce inexact results.  */
+        union_float32 uf;
+        union_float64 ud;
+        uf.s = a;
+        ud.h = uf.h;
+        return ud.s;
+    } else if (float32_is_zero(a)) {
+        return float64_set_sign(float64_zero, float32_is_neg(a));
+    } else {
+        return soft_float32_to_float64(a, s);
+    }
+}
+
 float16 float64_to_float16(float64 a, bool ieee, float_status *s)
 {
     const FloatFmt *fmt16 = ieee ? &float16_params : &float16_params_ahp;