Add more haddocks for AST Instructions

src/Text/LLVM/AST.hs

@@ -1196,7 +1196,17 @@ data Instr' lab
 
 
   | ShuffleVector (Typed (Value' lab)) (Value' lab) (Typed (Value' lab))
-
+    {- ^ * Constructs a fixed permutation of two input vectors: the first
+           argument is the input vector V1, the second input vector V2, and
+           the third is the mask,
+           the third is the insert position.
+         * Middle of basic block.
+         * Returns the permuted vector. For each element, the mask selects
+           an element from one of the input vectors to copy to the result:
+            * non-negative mask values represent an index into the concatenated
+              pair of input vectors, and
+            * -1 mask value indicates that the output element is poison.
+    -}
 
   | Jump lab
     {- ^ * Jump to the given basic block.
@@ -1208,6 +1218,16 @@ data Instr' lab
          * Ends basic block. -}
 
   | Invoke Type (Value' lab) [Typed (Value' lab)] lab lab
+    {- ^ * Calls the specified target function, then branches to the success
+           label.  If an exception occurs during the call, the exception unwind
+           handling branches to the second label.
+         * Arguments:
+           1. The FunctionType
+           2. The Function target
+           3. arguments
+           4. onSuccess ret target label
+           5. onException unwind target label
+         * Ends basic block. -}
 
   | Comment String
     -- ^ Comment
@@ -1217,21 +1237,49 @@ data Instr' lab
 
   | Unwind
   | VaArg (Typed (Value' lab)) Type
+    -- ^ Accesses arguments passed through "varargs" areas of a function call.
+    -- The argument is a va_list*; this instruction returns the value of the
+    -- specified type located at the target and increments the pointer.
+
   | IndirectBr (Typed (Value' lab)) [lab]
+    -- ^ Branch via pointer indirection.  The argument is the address of the
+    -- label to jump to.  (All) Possible destination targets are provided.
 
   | Switch (Typed (Value' lab)) lab [(Integer,lab)]
-    {- ^ * Multi-way branch: the first value determines the direction
-           of the branch, the label is a default direction, if the value
-           does not appear in the jump table, the last argument is the
-           jump table.
+    {- ^ * Multi-way branch: the first value determines the target index
+           for the jump, which is looked up in the third argument table
+           (key values are unique).  If the value is not found in the table,
+           the second argument is the default destination if the target is
+           not in the table.
          * Ends basic block. -}
 
   | LandingPad Type (Maybe (Typed (Value' lab))) Bool [Clause' lab]
+    {- ^ Target of an exception (from the Invoke instruction).
+         * Arguments:
+           1. The result type (the values set by the personality function
+              on re-entry to the function).
+           2. the second argument may be the personality function, which defines
+              values on re-entry. This is used in older LLVM versions and is
+              not supplied for recent LLVM versions.
+           3. True if this block is a "cleanup"
+           4. The list of clauses to handle the exception;  The clauses are
+              used to match the exception thrown.
+         * If no clause matches and cleanup not set, continue unwinding up
+           the stack (see Resume).
+         * If cleanup is false, there must be at least one clause
+     -}
 
   | Resume (Typed (Value' lab))
+    {- ^ Resumes propagation of an in-flight exception whose unwinding was
+         interrupted by a LandingPad instruction.
+         * Argument: the value of the exception to propagate.
+    -}
 
   | Freeze (Typed (Value' lab))
     {- ^ * Used to stop propagation of @undef@ and @poison@ values.
+         * If the argument is undef or poison, returns an arbitrary (but fixed)
+           value of that type instead, otherwise a no-op and returns its
+           argument.
          * Middle of basic block. -}
 
     deriving (Data, Eq, Functor, Generic, Ord, Show, Typeable)