The range +- 2**63 - 2**64 was returning the wrong truncated
result. We also incorrectly signaled overflow for -2**63.
Reported-by: Al Viro <v...@zeniv.linux.org.uk>
Signed-off-by: Richard Henderson <r...@twiddle.net>
---
target-alpha/fpu_helper.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/target-alpha/fpu_helper.c b/target-alpha/fpu_helper.c
index 132b5a2..9449c57 100644
--- a/target-alpha/fpu_helper.c
+++ b/target-alpha/fpu_helper.c
@@ -453,12 +453,12 @@ static uint64_t do_cvttq(CPUAlphaState *env, uint64_t a,
int roundmode)
if (shift >= 0) {
/* In this case the number is so large that we must shift
the fraction left. There is no rounding to do. */
- exc = FPCR_IOV | FPCR_INE;
- if (shift < 63) {
+ if (shift < 64) {
ret = frac << shift;
- if ((ret >> shift) == frac) {
- exc = 0;
- }
+ }
+ /* Check for overflow. Note the special case of -0x1p63. */
+ if (shift >= 11 && a != 0xC3E0000000000000ull) {
+ exc = FPCR_IOV | FPCR_INE;
}
} else {
uint64_t round;
--
2.1.0
