[PATCH] D57983: [ConstantRange] Shl of ConstantRanges considers full-set shifting to last bit position

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This revision was automatically updated to reflect the committed changes.
Closed by commit rL357854: [ConstantRange] Shl considers full-set shifting to last bit position. (authored by mggm, committed by ).

Changed prior to commit:
  https://reviews.llvm.org/D57983?vs=193892&id=194053#toc

Repository:
  rL LLVM

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D57983/new/

https://reviews.llvm.org/D57983

Files:
  llvm/trunk/lib/IR/ConstantRange.cpp
  llvm/trunk/unittests/IR/ConstantRangeTest.cpp


Index: llvm/trunk/lib/IR/ConstantRange.cpp
===================================================================
--- llvm/trunk/lib/IR/ConstantRange.cpp
+++ llvm/trunk/lib/IR/ConstantRange.cpp
@@ -1006,8 +1006,12 @@
   APInt max = getUnsignedMax();
   APInt Other_umax = Other.getUnsignedMax();
 
+  // If we are shifting by maximum amount of
+  // zero return return the original range.
+  if (Other_umax.isNullValue())
+    return *this;
   // there's overflow!
-  if (Other_umax.uge(max.countLeadingZeros()))
+  if (Other_umax.ugt(max.countLeadingZeros()))
     return getFull();
 
   // FIXME: implement the other tricky cases
Index: llvm/trunk/unittests/IR/ConstantRangeTest.cpp
===================================================================
--- llvm/trunk/unittests/IR/ConstantRangeTest.cpp
+++ llvm/trunk/unittests/IR/ConstantRangeTest.cpp
@@ -704,6 +704,8 @@
 }
 
 TEST_F(ConstantRangeTest, Shl) {
+  ConstantRange Some2(APInt(16, 0xfff), APInt(16, 0x8000));
+  ConstantRange WrapNullMax(APInt(16, 0x1), APInt(16, 0x0));
   EXPECT_EQ(Full.shl(Full), Full);
   EXPECT_EQ(Full.shl(Empty), Empty);
   EXPECT_EQ(Full.shl(One), Full);    // TODO: [0, (-1 << 0xa) + 1)
@@ -720,6 +722,10 @@
   EXPECT_EQ(Some.shl(Some), Full);   // TODO: [0xa << 0xa, 0xfc01)
   EXPECT_EQ(Some.shl(Wrap), Full);   // TODO: [0xa, 0x7ff << 0x5 + 1)
   EXPECT_EQ(Wrap.shl(Wrap), Full);
+  EXPECT_EQ(
+      Some2.shl(ConstantRange(APInt(16, 0x1))),
+      ConstantRange(APInt(16, 0xfff << 0x1), APInt(16, 0x7fff << 0x1) + 1));
+  EXPECT_EQ(One.shl(WrapNullMax), Full);
 }
 
 TEST_F(ConstantRangeTest, Lshr) {


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