fpu/softfloat: Don't set Invalid for float-to-int(MAXINT)

In float-to-integer conversion, if the floating point input
converts exactly to the largest or smallest integer that
fits in to the result type, this is not an overflow.
In this situation we were producing the correct result value,
but were incorrectly setting the Invalid flag.
For example for Arm A64, "FCVTAS w0, d0" on an input of
0x41dfffffffc00000 should produce 0x7fffffff and set no flags.

Fix the boundary case to take the right half of the if()
statements.

This fixes a regression from 2.11 introduced by the softfloat
refactoring.

Cc: qemu-stable@nongnu.org
Fixes: ab52f973a50
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20180510140141.12120-1-peter.maydell@linaro.org

diff --git a/fpu/softfloat.c b/fpu/softfloat.c
index b39c0c6fbb7145c7559628f4fd986c26ce6ac2b1..bc0f52fa54706644785a9229c8efe93b297fbc0b 100644 (file)
--- a/fpu/softfloat.c
+++ b/fpu/softfloat.c
@@ -1368,14 +1368,14 @@ static int64_t round_to_int_and_pack(FloatParts in, int rmode,
             r = UINT64_MAX;
         }
         if (p.sign) {
-            if (r < -(uint64_t) min) {
+            if (r <= -(uint64_t) min) {
                 return -r;
             } else {
                 s->float_exception_flags = orig_flags | float_flag_invalid;
                 return min;
             }
         } else {
-            if (r < max) {
+            if (r <= max) {
                 return r;
             } else {
                 s->float_exception_flags = orig_flags | float_flag_invalid;