diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index d991115892ad..eee53ac0bd85 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -6,6 +6,9 @@
 	* tree-ssa-dom.c (record_equivalences_from_phis): Add a
 	comment.
 
+	* defaults.h, stmt.c, tree-cfg.c, tree-ssa-dce.c: Fix comment
+	typos.
+
 2004-12-13  Kazuhiro Inaoka <inaoka.kazuhiro@renesas.com>
 
 	* config/m32r/t-linux (SHLIB_MAPFILES): Add libgcc-glibc.ver to
diff --git a/gcc/defaults.h b/gcc/defaults.h
index a60d2a2b0ff0..1c95c6a19cde 100644
--- a/gcc/defaults.h
+++ b/gcc/defaults.h
@@ -339,7 +339,7 @@ do { fputs (integer_asm_op (POINTER_SIZE / BITS_PER_UNIT, TRUE), FILE); \
 #endif
 #endif
 
-/* This decision to use a .jcr section can be overriden by defining
+/* This decision to use a .jcr section can be overridden by defining
    USE_JCR_SECTION to 0 in target file.  This is necessary if target
    can define JCR_SECTION_NAME but does not have crtstuff or
    linker support for .jcr section.  */
diff --git a/gcc/stmt.c b/gcc/stmt.c
index 5e3f3649fb3d..6e21b540aa4f 100644
--- a/gcc/stmt.c
+++ b/gcc/stmt.c
@@ -3041,11 +3041,12 @@ emit_case_nodes (rtx index, case_node_ptr node, rtx default_label,
 
       else if (node->right != 0 && node->left == 0)
 	{
-	  /* Here we have a right child but no left so we issue conditional
+	  /* Here we have a right child but no left so we issue a conditional
 	     branch to default and process the right child.
 
-	     Omit the conditional branch to default if we it avoid only one
-	     right child; it costs too much space to save so little time.  */
+	     Omit the conditional branch to default if the right child
+	     does not have any children and is single valued; it would
+	     cost too much space to save so little time.  */
 
 	  if (node->right->right || node->right->left
 	      || !tree_int_cst_equal (node->right->low, node->right->high))
diff --git a/gcc/tree-cfg.c b/gcc/tree-cfg.c
index a7d24410169b..457ad9ced598 100644
--- a/gcc/tree-cfg.c
+++ b/gcc/tree-cfg.c
@@ -450,7 +450,7 @@ make_edges (void)
      statements in it.  */
   make_edge (ENTRY_BLOCK_PTR, BASIC_BLOCK (0), EDGE_FALLTHRU);
 
-  /* Traverse basic block array placing edges.  */
+  /* Traverse the basic block array placing edges.  */
   FOR_EACH_BB (bb)
     {
       tree first = first_stmt (bb);
@@ -3087,8 +3087,8 @@ bsi_insert_on_edge (edge e, tree stmt)
   append_to_statement_list (stmt, &PENDING_STMT (e));
 }
 
-/* Similar to bsi_insert_on_edge+bsi_commit_edge_inserts.  If new block has to
-   be created, it is returned.  */
+/* Similar to bsi_insert_on_edge+bsi_commit_edge_inserts.  If a new
+   block has to be created, it is returned.  */
 
 basic_block
 bsi_insert_on_edge_immediate (edge e, tree stmt)
@@ -3941,7 +3941,7 @@ has_abnormal_incoming_edge_p (basic_block bb)
   return false;
 }
 
-/* Removes forwarder block BB.  Returns false if this failed.  If new
+/* Removes forwarder block BB.  Returns false if this failed.  If a new
    forwarder block is created due to redirection of edges, it is
    stored to worklist.  */
 
diff --git a/gcc/tree-ssa-dce.c b/gcc/tree-ssa-dce.c
index 502117c2e1c9..f37430d3299f 100644
--- a/gcc/tree-ssa-dce.c
+++ b/gcc/tree-ssa-dce.c
@@ -264,7 +264,7 @@ mark_operand_necessary (tree op, bool phionly)
 }
 
 
-/* Mark STMT as necessary if it is obviously is.  Add it to the worklist if
+/* Mark STMT as necessary if it obviously is.  Add it to the worklist if
    it can make other statements necessary.
 
    If AGGRESSIVE is false, control statements are conservatively marked as