[llvm-commits] [llvm] r160643 - in /llvm/trunk: lib/Support/ConstantRange.cpp unittests/Support/ConstantRangeTest.cpp

[Nuno Lopes]

Author: nlopes
Date: Mon Jul 23 15:33:29 2012
New Revision: 160643

URL: http://llvm.org/viewvc/llvm-project?rev=160643&view=rev
Log:
make ConstantRange::zeroExtend() optimal

Modified:
    llvm/trunk/lib/Support/ConstantRange.cpp
    llvm/trunk/unittests/Support/ConstantRangeTest.cpp

Modified: llvm/trunk/lib/Support/ConstantRange.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Support/ConstantRange.cpp?rev=160643&r1=160642&r2=160643&view=diff
==============================================================================
--- llvm/trunk/lib/Support/ConstantRange.cpp (original)
+++ llvm/trunk/lib/Support/ConstantRange.cpp Mon Jul 23 15:33:29 2012
@@ -427,9 +427,13 @@
 
   unsigned SrcTySize = getBitWidth();
   assert(SrcTySize < DstTySize && "Not a value extension");
-  if (isFullSet() || isWrappedSet())
+  if (isFullSet() || isWrappedSet()) {
     // Change into [0, 1 << src bit width)
-    return ConstantRange(APInt(DstTySize,0), APInt(DstTySize,1).shl(SrcTySize));
+    APInt LowerExt(DstTySize, 0);
+    if (!Upper) // special case: [X, 0) -- not really wrapping around
+      LowerExt = Lower.zext(DstTySize);
+    return ConstantRange(LowerExt, APInt(DstTySize, 1).shl(SrcTySize));
+  }
 
   return ConstantRange(Lower.zext(DstTySize), Upper.zext(DstTySize));
 }

Modified: llvm/trunk/unittests/Support/ConstantRangeTest.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/unittests/Support/ConstantRangeTest.cpp?rev=160643&r1=160642&r2=160643&view=diff
==============================================================================
--- llvm/trunk/unittests/Support/ConstantRangeTest.cpp (original)
+++ llvm/trunk/unittests/Support/ConstantRangeTest.cpp Mon Jul 23 15:33:29 2012
@@ -193,6 +193,10 @@
   EXPECT_EQ(ZSome, ConstantRange(Some.getLower().zext(20),
                                  Some.getUpper().zext(20)));
   EXPECT_EQ(ZWrap, ConstantRange(APInt(20, 0), APInt(20, 0x10000)));
+
+  // zext([5, 0), 3->7) = [5, 8)
+  ConstantRange FiveZero(APInt(3, 5), APInt(3, 0));
+  EXPECT_EQ(FiveZero.zeroExtend(7), ConstantRange(APInt(7, 5), APInt(7, 8)));
 }
 
 TEST_F(ConstantRangeTest, SExt) {