[llvm] 6c1a318 - [UnitTests] Add exhaustive tests for KnownBits shl/lshr/ashr

[Simon Pilgrim via llvm-commits]

Author: Simon Pilgrim
Date: 2020-11-05T10:13:16Z
New Revision: 6c1a31858d0598fb5180fd3deb6bd97621ecd6d8

URL: https://github.com/llvm/llvm-project/commit/6c1a31858d0598fb5180fd3deb6bd97621ecd6d8
DIFF: https://github.com/llvm/llvm-project/commit/6c1a31858d0598fb5180fd3deb6bd97621ecd6d8.diff

LOG: [UnitTests] Add exhaustive tests for KnownBits shl/lshr/ashr

Thanks to @foad for the suggestion.

Added: 
    

Modified: 
    llvm/unittests/Support/KnownBitsTest.cpp

Removed: 
    


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diff  --git a/llvm/unittests/Support/KnownBitsTest.cpp b/llvm/unittests/Support/KnownBitsTest.cpp
index d2f766fb3344..57124cb503bf 100644
--- a/llvm/unittests/Support/KnownBitsTest.cpp
+++ b/llvm/unittests/Support/KnownBitsTest.cpp
@@ -113,6 +113,9 @@ TEST(KnownBitsTest, BinaryExhaustive) {
       KnownBits KnownSMax(KnownAnd);
       KnownBits KnownSMin(KnownAnd);
       KnownBits KnownMul(KnownAnd);
+      KnownBits KnownShl(KnownAnd);
+      KnownBits KnownLShr(KnownAnd);
+      KnownBits KnownAShr(KnownAnd);
 
       ForeachNumInKnownBits(Known1, [&](const APInt &N1) {
         ForeachNumInKnownBits(Known2, [&](const APInt &N2) {
@@ -149,6 +152,24 @@ TEST(KnownBitsTest, BinaryExhaustive) {
           Res = N1 * N2;
           KnownMul.One &= Res;
           KnownMul.Zero &= ~Res;
+
+          if (N2.ult(1ULL << N1.getBitWidth())) {
+            Res = N1.shl(N2);
+            KnownShl.One &= Res;
+            KnownShl.Zero &= ~Res;
+
+            Res = N1.lshr(N2);
+            KnownLShr.One &= Res;
+            KnownLShr.Zero &= ~Res;
+
+            Res = N1.ashr(N2);
+            KnownAShr.One &= Res;
+            KnownAShr.Zero &= ~Res;
+          } else {
+            KnownShl.resetAll();
+            KnownLShr.resetAll();
+            KnownAShr.resetAll();
+          }
         });
       });
 
@@ -185,6 +206,18 @@ TEST(KnownBitsTest, BinaryExhaustive) {
       KnownBits ComputedMul = KnownBits::computeForMul(Known1, Known2);
       EXPECT_TRUE(ComputedMul.Zero.isSubsetOf(KnownMul.Zero));
       EXPECT_TRUE(ComputedMul.One.isSubsetOf(KnownMul.One));
+
+      KnownBits ComputedShl = KnownBits::shl(Known1, Known2);
+      EXPECT_TRUE(ComputedShl.Zero.isSubsetOf(KnownShl.Zero));
+      EXPECT_TRUE(ComputedShl.One.isSubsetOf(KnownShl.One));
+
+      KnownBits ComputedLShr = KnownBits::lshr(Known1, Known2);
+      EXPECT_TRUE(ComputedLShr.Zero.isSubsetOf(KnownLShr.Zero));
+      EXPECT_TRUE(ComputedLShr.One.isSubsetOf(KnownLShr.One));
+
+      KnownBits ComputedAShr = KnownBits::ashr(Known1, Known2);
+      EXPECT_TRUE(ComputedAShr.Zero.isSubsetOf(KnownAShr.Zero));
+      EXPECT_TRUE(ComputedAShr.One.isSubsetOf(KnownAShr.One));
     });
   });
 }