Bypass Slow Divides

* Only apply divide bypass optimization when not optimizing for size. 
* Fixed bug caused by constant for 0 value of type Int32,
  used dividend type to generate the constant instead.
* For atom x86-64 apply the divide bypass to use 16-bit divides instead of
  64-bit divides when operand values are small enough.
* Added lit tests for 64-bit divide bypass.

Patch by Tyler Nowicki!

llvm-svn: 176442

1 files changed, 2 insertions, 2 deletions

diff --git a/llvm/lib/Transforms/Utils/BypassSlowDivision.cpp b/llvm/lib/Transforms/Utils/BypassSlowDivision.cpp
index 00cda8e0346..1f517d038d1 100644
--- a/llvm/lib/Transforms/Utils/BypassSlowDivision.cpp
+++ b/llvm/lib/Transforms/Utils/BypassSlowDivision.cpp
@@ -163,7 +163,7 @@ static bool insertFastDiv(Function &F,
   Value *AndV = MainBuilder.CreateAnd(OrV, BitMask);
 
   // Compare operand values and branch
-  Value *ZeroV = MainBuilder.getInt32(0);
+  Value *ZeroV = ConstantInt::getSigned(Dividend->getType(), 0);
   Value *CmpV = MainBuilder.CreateICmpEQ(AndV, ZeroV);
   MainBuilder.CreateCondBr(CmpV, FastBB, SlowBB);
 
@@ -244,7 +244,7 @@ bool llvm::bypassSlowDivision(Function &F,
 
     // Get bitwidth of div/rem instruction
     IntegerType *T = cast<IntegerType>(J->getType());
-    int bitwidth = T->getBitWidth();
+    unsigned int bitwidth = T->getBitWidth();
 
     // Continue if bitwidth is not bypassed
     DenseMap<unsigned int, unsigned int>::const_iterator BI = BypassWidths.find(bitwidth);