[llvm-commits] [llvm] r61478 - /llvm/trunk/lib/Transforms/IPO/AddReadAttrs.cpp

[Duncan Sands]

Author: baldrick
Date: Mon Dec 29 14:51:17 2008
New Revision: 61478

URL: http://llvm.org/viewvc/llvm-project?rev=61478&view=rev
Log:
Experiments show that looking through phi nodes
and select instructions doesn't buy anything here
except extra complexity: the only difference in
the entire testsuite was that a readonly function
became readnone in MiBench/consumer-typeset.  Add
a comment about this.

Modified:
    llvm/trunk/lib/Transforms/IPO/AddReadAttrs.cpp

Modified: llvm/trunk/lib/Transforms/IPO/AddReadAttrs.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/IPO/AddReadAttrs.cpp?rev=61478&r1=61477&r2=61478&view=diff

==============================================================================
--- llvm/trunk/lib/Transforms/IPO/AddReadAttrs.cpp (original)
+++ llvm/trunk/lib/Transforms/IPO/AddReadAttrs.cpp Mon Dec 29 14:51:17 2008
@@ -64,6 +64,8 @@
   // A global constant counts as local memory for our purposes.
   if (GlobalVariable *GV = dyn_cast<GlobalVariable>(V))
     return GV->isConstant();
+  // Could look through phi nodes and selects here, but it doesn't seem
+  // to be useful in practice.
   return false;
 }