clarify some node comments

diff --git a/scripts/ir_spec.py b/scripts/ir_spec.py
index b6a6d10..4525974 100755 (executable)
--- a/scripts/ir_spec.py
+++ b/scripts/ir_spec.py
@@ -31,8 +31,10 @@ class Add(Binop):
 
 class Alloc(Op):
        """allocates a block of memory.
-       It can be specified whether the variable should be allocated to the stack
-       or to the heap."""
+       It can be specified whether the memory should be allocated to the stack
+       or to the heap.
+       Allocates memory for one or more objects (depending on value on count input).
+       """
        ins   = [
                ("mem",   "memory dependency" ),
                ("count", "number of objects to allocate" ),
@@ -47,7 +49,7 @@ class Alloc(Op):
                dict(
                        name    = "type",
                        type    = "ir_type*",
-                       comment = "type of the allocated variable",
+                       comment = "type of the objects to allocate",
                ),
                dict(
                        name    = "where",
@@ -425,7 +427,7 @@ class Conv(Unop):
        attr_struct = "conv_attr"
 
 class CopyB(Op):
-       """Copies a block of memory"""
+       """Copies a block of memory with statically known size/type."""
        ins   = [
                ("mem",  "memory dependency"),
                ("dst",  "destination address"),
@@ -503,7 +505,9 @@ class End(Op):
        singleton        = True
 
 class Eor(Binop):
-       """returns the result of a bitwise exclusive or operation of its operands"""
+       """returns the result of a bitwise exclusive or operation of its operands.
+
+       This is also known as the Xor operation."""
        flags    = [ "commutative" ]
 
 class Free(Op):
@@ -531,7 +535,10 @@ class Free(Op):
        attr_struct = "free_attr"
 
 class Id(Op):
-       """Returns its operand unchanged."""
+       """Returns its operand unchanged.
+
+       This is mainly used when exchanging nodes. Usually you shouldn't see Id
+       nodes since the getters/setters for node inputs skip them automatically."""
        ins    = [
           ("pred", "the value which is returned unchanged")
        ]