Index: llvm/trunk/include/llvm-c/lto.h
===================================================================
--- llvm/trunk/include/llvm-c/lto.h
+++ llvm/trunk/include/llvm-c/lto.h
@@ -757,17 +757,17 @@
  * @ingroup LLVMCTLTO
  *
  * These entry points control the ThinLTO cache. The cache is intended to
- * support incremental build, and thus needs to be persistent accross build.
- * The client enabled the cache by supplying a path to an existing directory.
+ * support incremental builds, and thus needs to be persistent across builds.
+ * The client enables the cache by supplying a path to an existing directory.
  * The code generator will use this to store objects files that may be reused
  * during a subsequent build.
  * To avoid filling the disk space, a few knobs are provided:
- *  - The pruning interval limit the frequency at which the garbage collector
- *    will try to scan the cache directory to prune it from expired entries.
- *    Setting to -1 disable the pruning (default).
+ *  - The pruning interval limits the frequency at which the garbage collector
+ *    will try to scan the cache directory to prune expired entries.
+ *    Setting to a negative number applies the maximum interval.
  *  - The pruning expiration time indicates to the garbage collector how old an
  *    entry needs to be to be removed.
- *  - Finally, the garbage collector can be instructed to prune the cache till
+ *  - Finally, the garbage collector can be instructed to prune the cache until
  *    the occupied space goes below a threshold.
  * @{
  */
@@ -782,9 +782,9 @@
                                           const char *cache_dir);
 
 /**
- * Sets the cache pruning interval (in seconds). A negative value disable the
- * pruning. An unspecified default value will be applied, and a value of 0 will
- * be ignored.
+ * Sets the cache pruning interval (in seconds). A negative value sets the
+ * maximum possible pruning interval. An unspecified default value will be
+ * applied, and a value of 0 will be ignored.
  *
  * \since LTO_API_VERSION=18
  */
Index: llvm/trunk/include/llvm/LTO/legacy/ThinLTOCodeGenerator.h
===================================================================
--- llvm/trunk/include/llvm/LTO/legacy/ThinLTOCodeGenerator.h
+++ llvm/trunk/include/llvm/LTO/legacy/ThinLTOCodeGenerator.h
@@ -148,8 +148,9 @@
   /// incremental build.
   void setCacheDir(std::string Path) { CacheOptions.Path = std::move(Path); }
 
-  /// Cache policy: interval (seconds) between two prune of the cache. Set to a
-  /// negative value (default) to disable pruning. A value of 0 will be ignored.
+  /// Cache policy: interval (seconds) between two prunes of the cache. A
+  /// negative value sets the maximum possible pruning interval. A value
+  /// of 0 will be ignored.
   void setCachePruningInterval(int Interval) {
     static_assert(std::is_same<decltype(CacheOptions.Policy.Interval),
                                std::chrono::seconds>::value,