diff --git a/llvm/lib/Transforms/InstCombine/InstCombineInternal.h b/llvm/lib/Transforms/InstCombine/InstCombineInternal.h
index a051a568bfd62ee..9bd06a0abb5e530 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineInternal.h
+++ b/llvm/lib/Transforms/InstCombine/InstCombineInternal.h
@@ -734,6 +734,7 @@ class LLVM_LIBRARY_VISIBILITY InstCombinerImpl final
   Instruction *foldSelectOfBools(SelectInst &SI);
   Instruction *foldSelectToCmp(SelectInst &SI);
   Instruction *foldSelectExtConst(SelectInst &Sel);
+  Instruction *foldSelectEqualityTest(SelectInst &SI);
   Instruction *foldSelectOpOp(SelectInst &SI, Instruction *TI, Instruction *FI);
   Instruction *foldSelectIntoOp(SelectInst &SI, Value *, Value *);
   Instruction *foldSPFofSPF(Instruction *Inner, SelectPatternFlavor SPF1,
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
index 66f7c4592457c20..0598b678f0111e2 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
@@ -1406,6 +1406,48 @@ Instruction *InstCombinerImpl::foldSelectValueEquivalence(SelectInst &Sel,
   return nullptr;
 }
 
+/// Fold the following code sequence:
+/// \code
+///   %XEq = icmp eq i64 %X, %Z
+///   %YEq = icmp eq i64 %Y, %Z
+///   %either = select i1 %XEq, i1 true, i1 %YEq
+///   %both = select i1 %XEq, i1 %YEq, i1 false
+///   %cmp = icmp eq i64 %X, %Y
+///   %equal = select i1 %either, i1 %both, i1 %cmp
+/// \code
+///
+/// into:
+///   %equal = icmp eq i64 %X, %Y
+///
+/// Equivalently:
+///   (X==Z || Y==Z) ? (X==Z && Y==Z) : X==Y --> X==Y
+Instruction *InstCombinerImpl::foldSelectEqualityTest(SelectInst &Sel) {
+  Value *X, *Y, *Z, *XEq, *YEq;
+  Value *Either = Sel.getCondition(), *Both = Sel.getTrueValue(),
+        *Cmp = Sel.getFalseValue();
+
+  if (!match(Either, m_LogicalOr(m_Value(XEq), m_Value(YEq))))
+    return nullptr;
+
+  if (!match(XEq, m_SpecificICmp(ICmpInst::ICMP_EQ, m_Value(X), m_Value(Z))))
+    return nullptr;
+  if (!match(YEq,
+             m_c_SpecificICmp(ICmpInst::ICMP_EQ, m_Value(Y), m_Specific(Z))))
+    std::swap(X, Z);
+  if (!match(YEq,
+             m_c_SpecificICmp(ICmpInst::ICMP_EQ, m_Value(Y), m_Specific(Z))))
+    return nullptr;
+
+  if (!match(Both, m_c_LogicalAnd(m_Specific(XEq), m_Specific(YEq))))
+    return nullptr;
+
+  if (!match(Cmp,
+             m_c_SpecificICmp(ICmpInst::ICMP_EQ, m_Specific(X), m_Specific(Y))))
+    return nullptr;
+
+  return replaceInstUsesWith(Sel, Cmp);
+}
+
 // See if this is a pattern like:
 //   %old_cmp1 = icmp slt i32 %x, C2
 //   %old_replacement = select i1 %old_cmp1, i32 %target_low, i32 %target_high
@@ -4068,6 +4110,11 @@ Instruction *InstCombinerImpl::visitSelectInst(SelectInst &SI) {
   if (Instruction *I = foldSelectOfSymmetricSelect(SI, Builder))
     return I;
 
+  // This needs to happen before foldNestedSelects, as that could break the
+  // patterns that we test for.
+  if (Instruction *I = foldSelectEqualityTest(SI))
+    return I;
+
   if (Instruction *I = foldNestedSelects(SI, Builder))
     return I;
 
diff --git a/llvm/test/Transforms/InstCombine/icmp-equality-test.ll b/llvm/test/Transforms/InstCombine/icmp-equality-test.ll
index c0d14e96552abb6..f822870273801fc 100644
--- a/llvm/test/Transforms/InstCombine/icmp-equality-test.ll
+++ b/llvm/test/Transforms/InstCombine/icmp-equality-test.ll
@@ -4,13 +4,8 @@
 define i1 @icmp_equality_test(i64 %X, i64 %Y, i64 %Z) {
 ; CHECK-LABEL: @icmp_equality_test(
 ; CHECK-NEXT:  entry:
-; CHECK-NEXT:    [[XEQ:%.*]] = icmp eq i64 [[X:%.*]], [[Z:%.*]]
-; CHECK-NEXT:    [[YEQ:%.*]] = icmp eq i64 [[Y:%.*]], [[Z]]
-; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i64 [[X]], [[Y]]
-; CHECK-NEXT:    [[NOT_YEQ:%.*]] = xor i1 [[YEQ]], true
-; CHECK-NEXT:    [[BOTH:%.*]] = select i1 [[NOT_YEQ]], i1 [[CMP]], i1 false
-; CHECK-NEXT:    [[EQUAL:%.*]] = select i1 [[XEQ]], i1 [[YEQ]], i1 [[BOTH]]
-; CHECK-NEXT:    ret i1 [[EQUAL]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i64 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    ret i1 [[CMP]]
 ;
 entry:
   %XEq = icmp eq i64 %X, %Z
@@ -25,13 +20,8 @@ entry:
 define i1 @icmp_equality_test_constant(i42 %X, i42 %Y) {
 ; CHECK-LABEL: @icmp_equality_test_constant(
 ; CHECK-NEXT:  entry:
-; CHECK-NEXT:    [[XEQ:%.*]] = icmp eq i42 [[X:%.*]], -42
-; CHECK-NEXT:    [[YEQ:%.*]] = icmp eq i42 [[Y:%.*]], -42
-; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i42 [[X]], [[Y]]
-; CHECK-NEXT:    [[NOT_YEQ:%.*]] = xor i1 [[YEQ]], true
-; CHECK-NEXT:    [[BOTH:%.*]] = select i1 [[NOT_YEQ]], i1 [[CMP]], i1 false
-; CHECK-NEXT:    [[EQUAL:%.*]] = select i1 [[XEQ]], i1 [[YEQ]], i1 [[BOTH]]
-; CHECK-NEXT:    ret i1 [[EQUAL]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i42 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    ret i1 [[CMP]]
 ;
 entry:
   %XEq = icmp eq i42 %X, -42
@@ -46,13 +36,8 @@ entry:
 define <2 x i1> @icmp_equality_test_vector(<2 x i64> %X, <2 x i64> %Y) {
 ; CHECK-LABEL: @icmp_equality_test_vector(
 ; CHECK-NEXT:  entry:
-; CHECK-NEXT:    [[XEQ:%.*]] = icmp eq <2 x i64> [[X:%.*]], <i64 123, i64 456>
-; CHECK-NEXT:    [[YEQ:%.*]] = icmp eq <2 x i64> [[Y:%.*]], <i64 123, i64 456>
-; CHECK-NEXT:    [[CMP:%.*]] = icmp eq <2 x i64> [[X]], [[Y]]
-; CHECK-NEXT:    [[NOT_YEQ:%.*]] = xor <2 x i1> [[YEQ]], <i1 true, i1 true>
-; CHECK-NEXT:    [[BOTH:%.*]] = select <2 x i1> [[NOT_YEQ]], <2 x i1> [[CMP]], <2 x i1> zeroinitializer
-; CHECK-NEXT:    [[EQUAL:%.*]] = select <2 x i1> [[XEQ]], <2 x i1> [[YEQ]], <2 x i1> [[BOTH]]
-; CHECK-NEXT:    ret <2 x i1> [[EQUAL]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq <2 x i64> [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    ret <2 x i1> [[CMP]]
 ;
 entry:
   %XEq = icmp eq <2 x i64> %X, <i64 123, i64 456>
@@ -67,13 +52,8 @@ entry:
 define i1 @icmp_equality_test_commute_icmp1(i64 %X, i64 %Y, i64 %Z) {
 ; CHECK-LABEL: @icmp_equality_test_commute_icmp1(
 ; CHECK-NEXT:  entry:
-; CHECK-NEXT:    [[XEQ:%.*]] = icmp eq i64 [[Z:%.*]], [[X:%.*]]
-; CHECK-NEXT:    [[YEQ:%.*]] = icmp eq i64 [[Z]], [[Y:%.*]]
-; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i64 [[Y]], [[X]]
-; CHECK-NEXT:    [[NOT_YEQ:%.*]] = xor i1 [[YEQ]], true
-; CHECK-NEXT:    [[BOTH:%.*]] = select i1 [[NOT_YEQ]], i1 [[CMP]], i1 false
-; CHECK-NEXT:    [[EQUAL:%.*]] = select i1 [[XEQ]], i1 [[YEQ]], i1 [[BOTH]]
-; CHECK-NEXT:    ret i1 [[EQUAL]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i64 [[Y:%.*]], [[X:%.*]]
+; CHECK-NEXT:    ret i1 [[CMP]]
 ;
 entry:
   %XEq = icmp eq i64 %Z, %X
@@ -88,13 +68,8 @@ entry:
 define i1 @icmp_equality_test_commute_icmp2(i64 %X, i64 %Y, i64 %Z) {
 ; CHECK-LABEL: @icmp_equality_test_commute_icmp2(
 ; CHECK-NEXT:  entry:
-; CHECK-NEXT:    [[XEQ:%.*]] = icmp eq i64 [[Z:%.*]], [[X:%.*]]
-; CHECK-NEXT:    [[YEQ:%.*]] = icmp eq i64 [[Y:%.*]], [[Z]]
-; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i64 [[Y]], [[X]]
-; CHECK-NEXT:    [[NOT_YEQ:%.*]] = xor i1 [[YEQ]], true
-; CHECK-NEXT:    [[BOTH:%.*]] = select i1 [[NOT_YEQ]], i1 [[CMP]], i1 false
-; CHECK-NEXT:    [[EQUAL:%.*]] = select i1 [[XEQ]], i1 [[YEQ]], i1 [[BOTH]]
-; CHECK-NEXT:    ret i1 [[EQUAL]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i64 [[Y:%.*]], [[X:%.*]]
+; CHECK-NEXT:    ret i1 [[CMP]]
 ;
 entry:
   %XEq = icmp eq i64 %Z, %X
@@ -109,13 +84,8 @@ entry:
 define i1 @icmp_equality_test_commute_select1(i64 %X, i64 %Y) {
 ; CHECK-LABEL: @icmp_equality_test_commute_select1(
 ; CHECK-NEXT:  entry:
-; CHECK-NEXT:    [[XEQ:%.*]] = icmp eq i64 [[X:%.*]], 0
-; CHECK-NEXT:    [[YEQ:%.*]] = icmp eq i64 [[Y:%.*]], 0
-; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i64 [[X]], [[Y]]
-; CHECK-NEXT:    [[NOT_YEQ:%.*]] = xor i1 [[YEQ]], true
-; CHECK-NEXT:    [[BOTH:%.*]] = select i1 [[NOT_YEQ]], i1 [[CMP]], i1 false
-; CHECK-NEXT:    [[EQUAL:%.*]] = select i1 [[XEQ]], i1 [[YEQ]], i1 [[BOTH]]
-; CHECK-NEXT:    ret i1 [[EQUAL]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i64 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    ret i1 [[CMP]]
 ;
 entry:
   %XEq = icmp eq i64 %X, 0
@@ -130,13 +100,8 @@ entry:
 define i1 @icmp_equality_test_commute_select2(i64 %X, i64 %Y) {
 ; CHECK-LABEL: @icmp_equality_test_commute_select2(
 ; CHECK-NEXT:  entry:
-; CHECK-NEXT:    [[XEQ:%.*]] = icmp eq i64 [[X:%.*]], 0
-; CHECK-NEXT:    [[YEQ:%.*]] = icmp eq i64 [[Y:%.*]], 0
-; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i64 [[X]], [[Y]]
-; CHECK-NEXT:    [[NOT_XEQ:%.*]] = xor i1 [[XEQ]], true
-; CHECK-NEXT:    [[BOTH:%.*]] = select i1 [[NOT_XEQ]], i1 [[CMP]], i1 false
-; CHECK-NEXT:    [[EQUAL:%.*]] = select i1 [[YEQ]], i1 [[XEQ]], i1 [[BOTH]]
-; CHECK-NEXT:    ret i1 [[EQUAL]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i64 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    ret i1 [[CMP]]
 ;
 entry:
   %XEq = icmp eq i64 %X, 0