[Qemu-devel] [PATCH 135/147] softfloat: Fix uint64_to_float64

[Richard Henderson]

The interface to normalizeRoundAndPackFloat64 requires that the
high bit be clear.  Perform one shift-right-and-jam if needed.

Signed-off-by: Richard Henderson <address@hidden>
---
 fpu/softfloat.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/fpu/softfloat.c b/fpu/softfloat.c
index b29256a..45f105a 100644
--- a/fpu/softfloat.c
+++ b/fpu/softfloat.c
@@ -1273,9 +1273,14 @@ float64 int64_to_float64( int64 a STATUS_PARAM )
 
 float64 uint64_to_float64( uint64 a STATUS_PARAM )
 {
-    if ( a == 0 ) return float64_zero;
-    return normalizeRoundAndPackFloat64( 0, 0x43C, a STATUS_VAR );
+    int exp =  0x43C;
 
+    if ( a == 0 ) return float64_zero;
+    if ( (int64_t)a < 0 ) {
+        a = (a >> 1) | (a & 1);
+        exp += 1;
+    }
+    return normalizeRoundAndPackFloat64( 0, exp, a STATUS_VAR );
 }
 
 /*----------------------------------------------------------------------------
-- 
1.7.11.4