[PATCH 1/6] host-utils: fix ssub32/64_saturate return type and clamp direction

Brian Cain <[email protected]> Wed, 5 Aug 2026 09:52:20 -0700
Newsgroups gmane.comp.emulators.qemu
Message-ID <[email protected]>
ssub32_saturate() and ssub64_saturate() were declared to return bool
instead of int32_t/int64_t, and clamped to the wrong bound on overflow.

Signed-off-by: Brian Cain <[email protected]>
---
 include/qemu/host-utils.h | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/include/qemu/host-utils.h b/include/qemu/host-utils.h
index 2e8da7fb3d0..291bb198b65 100644
--- a/include/qemu/host-utils.h
+++ b/include/qemu/host-utils.h
@@ -610,7 +610,7 @@ static inline bool umul64_overflow(uint64_t x, uint64_t y, uint64_t *ret)
  * sadd32_saturate - addition with saturation
  * @x, @y: addends
  *
- * Computes @x + @y, and saturates rathern than truncating the result.
+ * Computes @x + @y, and saturates rather than truncating the result.
  */
 static inline int32_t sadd32_saturate(int32_t x, int32_t y)
 {
@@ -625,7 +625,7 @@ static inline int32_t sadd32_saturate(int32_t x, int32_t y)
  * sadd64_saturate - addition with saturation
  * @x, @y: addends
  *
- * Computes @x + @y, and saturates rathern than truncating the result.
+ * Computes @x + @y, and saturates rather than truncating the result.
  */
 static inline int64_t sadd64_saturate(int64_t x, int64_t y)
 {
@@ -638,30 +638,30 @@ static inline int64_t sadd64_saturate(int64_t x, int64_t y)
 
 /**
  * ssub32_saturate - subtraction with saturation
- * @x, @y: addends
+ * @x, @y: minuend and subtrahend
  *
- * Computes @x + @y, and saturates rathern than truncating the result.
+ * Computes @x - @y, and saturates rather than truncating the result.
  */
-static inline bool ssub32_saturate(int32_t x, int32_t y)
+static inline int32_t ssub32_saturate(int32_t x, int32_t y)
 {
     int32_t ret;
     if (ssub32_overflow(x, y, &ret)) {
-        ret = x < 0 ? INT32_MAX : INT32_MIN;
+        ret = x < 0 ? INT32_MIN : INT32_MAX;
     }
     return ret;
 }
 
 /**
  * ssub64_saturate - subtraction with saturation
- * @x, @y: addends
+ * @x, @y: minuend and subtrahend
  *
- * Computes @x + @y, and saturates rathern than truncating the result.
+ * Computes @x - @y, and saturates rather than truncating the result.
  */
-static inline bool ssub64_saturate(int64_t x, int64_t y)
+static inline int64_t ssub64_saturate(int64_t x, int64_t y)
 {
     int64_t ret;
     if (ssub64_overflow(x, y, &ret)) {
-        ret = x < 0 ? INT64_MAX : INT64_MIN;
+        ret = x < 0 ? INT64_MIN : INT64_MAX;
     }
     return ret;
 }
-- 
2.34.1