Mesa (master): gallivm: Comment lp_build_insert_new_block().

[Jose Fonseca]

Module: Mesa
Branch: master
Commit: 4dfb43c6a655574a9b59b552d05408c027d8cfaa
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=4dfb43c6a655574a9b59b552d05408c027d8cfaa

Author: José Fonseca <jfonseca at vmware.com>
Date:   Sun Oct 17 13:41:45 2010 -0700

gallivm: Comment lp_build_insert_new_block().

---

 src/gallium/auxiliary/gallivm/lp_bld_flow.c |    8 ++++++++
 1 files changed, 8 insertions(+), 0 deletions(-)

diff --git a/src/gallium/auxiliary/gallivm/lp_bld_flow.c b/src/gallium/auxiliary/gallivm/lp_bld_flow.c
index f9d061f..a2cee19 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_flow.c
+++ b/src/gallium/auxiliary/gallivm/lp_bld_flow.c
@@ -39,6 +39,14 @@
 
 
 /**
+ * Insert a new block, right where builder is pointing to.
+ *
+ * This is useful important not only for aesthetic reasons, but also for
+ * performance reasons, as frequently run blocks should be laid out next to
+ * each other and fall-throughs maximized.
+ *
+ * See also llvm/lib/Transforms/Scalar/BasicBlockPlacement.cpp.
+ *
  * Note: this function has no dependencies on the flow code and could
  * be used elsewhere.
  */