[llvm-commits] [llvm] r165126 - /llvm/trunk/lib/Transforms/Utils/BypassSlowDivision.cpp

[Preston Gurd]

Author: pgurd
Date: Wed Oct  3 11:11:44 2012
New Revision: 165126

URL: http://llvm.org/viewvc/llvm-project?rev=165126&view=rev
Log:
This Patch corrects a problem whereby the optimization to use a faster divide
instruction (for Intel Atom) was not being done by Clang, because
the type context used by Clang is not the default context.

It fixes the problem by getting the global context types for each div/rem
instruction in order to compare them against the types in the BypassTypeMap.

Tests for this will be done as a separate patch to Clang.

Patch by Tyler Nowicki.


Modified:
    llvm/trunk/lib/Transforms/Utils/BypassSlowDivision.cpp

Modified: llvm/trunk/lib/Transforms/Utils/BypassSlowDivision.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/BypassSlowDivision.cpp?rev=165126&r1=165125&r2=165126&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/BypassSlowDivision.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/BypassSlowDivision.cpp Wed Oct  3 11:11:44 2012
@@ -238,14 +238,24 @@
     if (!UseDivOp && !UseRemOp)
       continue;
 
+    // Skip division on vector types, only optimize integer instructions
+    if (!J->getType()->isIntegerTy())
+      continue;
+
+    // Get same type in global context
+    IntegerType *T = cast<IntegerType>(J->getType());
+    IntegerType *GT = IntegerType::get(getGlobalContext(), T->getBitWidth());
+
     // Continue if div/rem type is not bypassed
-    DenseMap<Type *, Type *>::const_iterator BT =
-      BypassTypeMap.find(J->getType());
-    if (BT == BypassTypeMap.end())
+    DenseMap<Type *, Type *>::const_iterator BI = BypassTypeMap.find(GT);
+    if (BI == BypassTypeMap.end())
       continue;
 
-    IntegerType *BypassType = cast<IntegerType>(BT->second);
-    MadeChange |= reuseOrInsertFastDiv(F, I, J, BypassType, UseDivOp,
+    // Get the bypass type in the original context
+    IntegerType *GBT = cast<IntegerType>(BI->second);
+    IntegerType *BT = IntegerType::get(J->getContext(), GBT->getBitWidth());
+
+    MadeChange |= reuseOrInsertFastDiv(F, I, J, BT, UseDivOp,
                                        UseSignedOp, DivCache);
   }