[llvm-commits] [llvm] r113187 - in /llvm/trunk: include/llvm/Support/ConstantRange.h lib/Support/ConstantRange.cpp unittests/Support/ConstantRangeTest.cpp

[Nick Lewycky]

Author: nicholas
Date: Mon Sep  6 18:52:49 2010
New Revision: 113187

URL: http://llvm.org/viewvc/llvm-project?rev=113187&view=rev
Log:
Add a new isSignWrappedSet() method to ConstantRange.

Fix zeroExtend and signExtend to support empty sets, and to return the smallest
possible result set which contains the extension of each element in their
inputs. For example zext i8 [100, 10) to i16 is now [0, 256), not i16 [100, 10)
which contains 63446 members.

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

Modified: llvm/trunk/include/llvm/Support/ConstantRange.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Support/ConstantRange.h?rev=113187&r1=113186&r2=113187&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Support/ConstantRange.h (original)
+++ llvm/trunk/include/llvm/Support/ConstantRange.h Mon Sep  6 18:52:49 2010
@@ -92,6 +92,11 @@
   ///
   bool isWrappedSet() const;
 
+  /// isSignWrappedSet - Return true if this set wraps around the INT_MIN of
+  /// its bitwidth, for example: i8 [120, 140).
+  ///
+  bool isSignWrappedSet() const;
+
   /// contains - Return true if the specified value is in the set.
   ///
   bool contains(const APInt &Val) const;

Modified: llvm/trunk/lib/Support/ConstantRange.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Support/ConstantRange.cpp?rev=113187&r1=113186&r2=113187&view=diff
==============================================================================
--- llvm/trunk/lib/Support/ConstantRange.cpp (original)
+++ llvm/trunk/lib/Support/ConstantRange.cpp Mon Sep  6 18:52:49 2010
@@ -115,6 +115,14 @@
   return Lower.ugt(Upper);
 }
 
+/// isSignWrappedSet - Return true if this set wraps around the INT_MIN of
+/// its bitwidth, for example: i8 [120, 140).
+///
+bool ConstantRange::isSignWrappedSet() const {
+  return contains(APInt::getSignedMaxValue(getBitWidth())) &&
+         contains(APInt::getSignedMinValue(getBitWidth()));
+}
+
 /// getSetSize - Return the number of elements in this set.
 ///
 APInt ConstantRange::getSetSize() const {
@@ -408,10 +416,12 @@
 /// correspond to the possible range of values as if the source range had been
 /// zero extended.
 ConstantRange ConstantRange::zeroExtend(uint32_t DstTySize) const {
+  if (isEmptySet()) return ConstantRange(DstTySize, /*isFullSet=*/false);
+
   unsigned SrcTySize = getBitWidth();
   assert(SrcTySize < DstTySize && "Not a value extension");
-  if (isFullSet())
-    // Change a source full set into [0, 1 << 8*numbytes)
+  if (isFullSet() || isWrappedSet())
+    // Change into [0, 1 << src bit width)
     return ConstantRange(APInt(DstTySize,0), APInt(DstTySize,1).shl(SrcTySize));
 
   APInt L = Lower; L.zext(DstTySize);
@@ -424,9 +434,11 @@
 /// correspond to the possible range of values as if the source range had been
 /// sign extended.
 ConstantRange ConstantRange::signExtend(uint32_t DstTySize) const {
+  if (isEmptySet()) return ConstantRange(DstTySize, /*isFullSet=*/false);
+
   unsigned SrcTySize = getBitWidth();
   assert(SrcTySize < DstTySize && "Not a value extension");
-  if (isFullSet()) {
+  if (isFullSet() || isSignWrappedSet()) {
     return ConstantRange(APInt::getHighBitsSet(DstTySize,DstTySize-SrcTySize+1),
                          APInt::getLowBitsSet(DstTySize, SrcTySize-1) + 1);
   }

Modified: llvm/trunk/unittests/Support/ConstantRangeTest.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/unittests/Support/ConstantRangeTest.cpp?rev=113187&r1=113186&r2=113187&view=diff
==============================================================================
--- llvm/trunk/unittests/Support/ConstantRangeTest.cpp (original)
+++ llvm/trunk/unittests/Support/ConstantRangeTest.cpp Mon Sep  6 18:52:49 2010
@@ -146,6 +146,22 @@
             APInt(4, 7));
 }
 
+TEST_F(ConstantRangeTest, SignWrapped) {
+  EXPECT_TRUE(Full.isSignWrappedSet());
+  EXPECT_FALSE(Empty.isSignWrappedSet());
+  EXPECT_FALSE(One.isSignWrappedSet());
+  EXPECT_FALSE(Some.isSignWrappedSet());
+  EXPECT_TRUE(Wrap.isSignWrappedSet());
+
+  EXPECT_FALSE(ConstantRange(APInt(8, 127), APInt(8, 128)).isSignWrappedSet());
+  EXPECT_TRUE(ConstantRange(APInt(8, 127), APInt(8, 129)).isSignWrappedSet());
+  EXPECT_FALSE(ConstantRange(APInt(8, 128), APInt(8, 129)).isSignWrappedSet());
+  EXPECT_TRUE(ConstantRange(APInt(8, 10), APInt(8, 9)).isSignWrappedSet());
+  EXPECT_TRUE(ConstantRange(APInt(8, 10), APInt(8, 250)).isSignWrappedSet());
+  EXPECT_FALSE(ConstantRange(APInt(8, 250), APInt(8, 10)).isSignWrappedSet());
+  EXPECT_FALSE(ConstantRange(APInt(8, 250), APInt(8, 251)).isSignWrappedSet());
+}
+
 TEST_F(ConstantRangeTest, Trunc) {
   ConstantRange TFull = Full.truncate(10);
   ConstantRange TEmpty = Empty.truncate(10);
@@ -171,8 +187,7 @@
                                 APInt(One.getUpper()).zext(20)));
   EXPECT_EQ(ZSome, ConstantRange(APInt(Some.getLower()).zext(20),
                                  APInt(Some.getUpper()).zext(20)));
-  EXPECT_EQ(ZWrap, ConstantRange(APInt(Wrap.getLower()).zext(20),
-                                 APInt(Wrap.getUpper()).zext(20)));
+  EXPECT_EQ(ZWrap, ConstantRange(APInt(20, 0), APInt(20, 0x10000)));
 }
 
 TEST_F(ConstantRangeTest, SExt) {
@@ -188,8 +203,11 @@
                                 APInt(One.getUpper()).sext(20)));
   EXPECT_EQ(SSome, ConstantRange(APInt(Some.getLower()).sext(20),
                                  APInt(Some.getUpper()).sext(20)));
-  EXPECT_EQ(SWrap, ConstantRange(APInt(Wrap.getLower()).sext(20),
-                                 APInt(Wrap.getUpper()).sext(20)));
+  EXPECT_EQ(SWrap, ConstantRange(APInt(20, (uint64_t)INT16_MIN, true),
+                                 APInt(20, INT16_MAX + 1, true)));
+
+  EXPECT_EQ(ConstantRange(APInt(8, 120), APInt(8, 140)).signExtend(16),
+            ConstantRange(APInt(16, -128), APInt(16, 128)));
 }
 
 TEST_F(ConstantRangeTest, IntersectWith) {