fpu/softfloat: Fix conversion from uint64 to float128

The significand is passed to normalizeRoundAndPackFloat128() as high
first, low second. The current code passes the integer first, so the
result is incorrectly shifted left by 64 bits.

This bug affects the emulation of s390x instruction CXLGBR (convert
from logical 64-bit binary-integer operand to extended BFP result).

Cc: qemu-stable@nongnu.org
Tested-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Petr Tesarik <ptesarik@suse.com>
Message-Id: <20180511071052.1443-1-ptesarik@suse.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
(cherry picked from commit 6603d50648901e8b9e6d66ec1142accf0b1df1e6)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>

diff --git a/fpu/softfloat.c b/fpu/softfloat.c
index 9bcaaebe4f063a7dc83221debe2624ccdc996813..a926b91864f38ff966c355bf61b5237f8fe75f2d 100644 (file)
--- a/fpu/softfloat.c
+++ b/fpu/softfloat.c
@@ -3147,7 +3147,7 @@ float128 uint64_to_float128(uint64_t a, float_status *status)
     if (a == 0) {
         return float128_zero;
     }
-    return normalizeRoundAndPackFloat128(0, 0x406E, a, 0, status);
+    return normalizeRoundAndPackFloat128(0, 0x406E, 0, a, status);
 }