[InstCombine] Bail out on inner disjoint or in foldSelectICmpEq

Author: dtcxzyw

llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp

@@ -1853,12 +1853,13 @@ static Instruction *foldSelectICmpEq(SelectInst &SI, ICmpInst *ICI,
                  XorOps = Instruction::Xor, NoOps = 0;
   enum NotMask { None = 0, NotInner, NotRHS };
 
+  // We cannot refine TrueVal to FalseVal when the inner instruction contains
+  // disjoint or.
   auto matchFalseVal = [&](unsigned OuterOpc, unsigned InnerOpc,
                            unsigned NotMask) {
-    auto matchInner = m_c_BinOp(InnerOpc, m_Specific(X), m_Specific(Y));
-    if (OuterOpc == NoOps)
-      return match(CmpRHS, m_Zero()) && match(FalseVal, matchInner);
-
+    auto matchInner =
+        m_CombineAnd(m_c_BinOp(InnerOpc, m_Specific(X), m_Specific(Y)),
+                     m_Unless(m_DisjointOr(m_Value(), m_Value())));
     if (NotMask == NotInner) {
       return match(FalseVal, m_c_BinOp(OuterOpc, m_NotForbidPoison(matchInner),
                                        m_Specific(CmpRHS)));

llvm/test/Transforms/InstCombine/select.ll

@@ -4567,10 +4567,14 @@ define i32 @src_no_trans_select_xor_eq0_or_xor(i32 %x, i32 %y) {
 define i32 @src_no_trans_select_xor_eqc_and_disjoint_or_and_notc(i32 noundef %x, i32 noundef %y, i32 %c) {
 ; CHECK-LABEL: @src_no_trans_select_xor_eqc_and_disjoint_or_and_notc(
 ; CHECK-NEXT:  entry:
-; CHECK-NEXT:    [[OR:%.*]] = or disjoint i32 [[Y:%.*]], [[X:%.*]]
-; CHECK-NEXT:    [[NOT:%.*]] = xor i32 [[C:%.*]], -1
+; CHECK-NEXT:    [[XOR:%.*]] = xor i32 [[Y:%.*]], [[X:%.*]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i32 [[XOR]], [[C:%.*]]
+; CHECK-NEXT:    [[AND:%.*]] = and i32 [[X]], [[Y]]
+; CHECK-NEXT:    [[OR:%.*]] = or disjoint i32 [[Y]], [[X]]
+; CHECK-NEXT:    [[NOT:%.*]] = xor i32 [[C]], -1
 ; CHECK-NEXT:    [[AND1:%.*]] = and i32 [[OR]], [[NOT]]
-; CHECK-NEXT:    ret i32 [[AND1]]
+; CHECK-NEXT:    [[COND:%.*]] = select i1 [[CMP]], i32 [[AND]], i32 [[AND1]]
+; CHECK-NEXT:    ret i32 [[COND]]
 ;
 entry:
   %xor = xor i32 %y, %x