[ValueTracking] Checking haveNoCommonBitsSet for (x & y) and ~(x | y)

This one tries to fix:
https://github.com/llvm/llvm-project/issues/53357.

Simply, this one would check (x & y) and ~(x | y) in
haveNoCommonBitsSet. Since they shouldn't have common bits (we could
traverse the case by enumerating), and we could convert this one to (x &
y) | ~(x | y) . Then the compiler could handle it in
InstCombineAndOrXor.
Further more, since ((x & y) + (~x & ~y)) would be converted to ((x & y)
+ ~(x | y)), this patch would fix it too.

https://alive2.llvm.org/ce/z/qsKzRS

Reviewed By: spatel, xbolva00, RKSimon, lebedev.ri

Differential Revision: https://reviews.llvm.org/D118094

1 files changed, 56 insertions, 0 deletions

diff --git a/llvm/unittests/Analysis/ValueTrackingTest.cpp b/llvm/unittests/Analysis/ValueTrackingTest.cpp
index 277b024..e8148ab 100644
--- a/llvm/unittests/Analysis/ValueTrackingTest.cpp
+++ b/llvm/unittests/Analysis/ValueTrackingTest.cpp
@@ -1745,6 +1745,62 @@ TEST_F(ValueTrackingTest, HaveNoCommonBitsSet) {
     EXPECT_TRUE(haveNoCommonBitsSet(LHS, RHS, DL));
     EXPECT_TRUE(haveNoCommonBitsSet(RHS, LHS, DL));
   }
+  {
+    // Check for (A & B) and ~(A | B)
+    auto M = parseModule(R"(
+  define void @test(i32 %A, i32 %B) {
+    %LHS = and i32 %A, %B
+    %or = or i32 %A, %B
+    %RHS = xor i32 %or, -1
+
+    %LHS2 = and i32 %B, %A
+    %or2 = or i32 %A, %B
+    %RHS2 = xor i32 %or2, -1
+
+    ret void
+  })");
+
+    auto *F = M->getFunction("test");
+    const DataLayout &DL = M->getDataLayout();
+
+    auto *LHS = findInstructionByNameOrNull(F, "LHS");
+    auto *RHS = findInstructionByNameOrNull(F, "RHS");
+    EXPECT_TRUE(haveNoCommonBitsSet(LHS, RHS, DL));
+    EXPECT_TRUE(haveNoCommonBitsSet(RHS, LHS, DL));
+
+    auto *LHS2 = findInstructionByNameOrNull(F, "LHS2");
+    auto *RHS2 = findInstructionByNameOrNull(F, "RHS2");
+    EXPECT_TRUE(haveNoCommonBitsSet(LHS2, RHS2, DL));
+    EXPECT_TRUE(haveNoCommonBitsSet(RHS2, LHS2, DL));
+  }
+  {
+    // Check for (A & B) and ~(A | B) in vector version
+    auto M = parseModule(R"(
+  define void @test(<2 x i32> %A, <2 x i32> %B) {
+    %LHS = and <2 x i32> %A, %B
+    %or = or <2 x i32> %A, %B
+    %RHS = xor <2 x i32> %or, <i32 -1, i32 -1>
+
+    %LHS2 = and <2 x i32> %B, %A
+    %or2 = or <2 x i32> %A, %B
+    %RHS2 = xor <2 x i32> %or2, <i32 -1, i32 -1>
+
+    ret void
+  })");
+
+    auto *F = M->getFunction("test");
+    const DataLayout &DL = M->getDataLayout();
+
+    auto *LHS = findInstructionByNameOrNull(F, "LHS");
+    auto *RHS = findInstructionByNameOrNull(F, "RHS");
+    EXPECT_TRUE(haveNoCommonBitsSet(LHS, RHS, DL));
+    EXPECT_TRUE(haveNoCommonBitsSet(RHS, LHS, DL));
+
+    auto *LHS2 = findInstructionByNameOrNull(F, "LHS2");
+    auto *RHS2 = findInstructionByNameOrNull(F, "RHS2");
+    EXPECT_TRUE(haveNoCommonBitsSet(LHS2, RHS2, DL));
+    EXPECT_TRUE(haveNoCommonBitsSet(RHS2, LHS2, DL));
+  }
 }
 
 class IsBytewiseValueTest : public ValueTrackingTest,