Index: lib/Transforms/InstCombine/InstCombineSelect.cpp
===================================================================
--- lib/Transforms/InstCombine/InstCombineSelect.cpp
+++ lib/Transforms/InstCombine/InstCombineSelect.cpp
@@ -911,6 +911,16 @@
   return V;
 }
 
+/// Returns true if all users of @p Val are Select instructions.
+static bool onlySelectAsUser(const Value &Val) {
+  for (const Use &U : Val.uses()) {
+    Instruction *User = cast<Instruction>(U.getUser());
+    if (User->getOpcode() != Instruction::Select)
+      return false;
+  }
+  return true;
+}
+
 Instruction *InstCombiner::visitSelectInst(SelectInst &SI) {
   Value *CondVal = SI.getCondition();
   Value *TrueVal = SI.getTrueValue();
@@ -1214,6 +1224,29 @@
     if (isa<ConstantAggregateZero>(CondVal)) {
       return ReplaceInstUsesWith(SI, FalseVal);
     }
+  } else {
+    // Avoid arithmetic on i1 types if we can express it with a series of
+    // selects this usually results in better target code as C0 and C1
+    // don't need to be materialized in an integer register.
+
+    // select((C0 & C1), a, b) -> select(C0, select(C1, a, b), b)
+    if (const Instruction *And = dyn_cast<Instruction>(CondVal))
+      if (And->getOpcode() == Instruction::And && onlySelectAsUser(*CondVal)) {
+        Value *InnerSelect = Builder->CreateSelect(And->getOperand(1), TrueVal,
+                                                   FalseVal, SI.getName()+".0");
+        SI.setOperand(0, And->getOperand(0));
+        SI.setOperand(1, InnerSelect);
+        return &SI;
+      }
+    // select((C0 | C1), a, b) -> select(C0, a, select(C1, a, b))
+    if (const Instruction *Or = dyn_cast<Instruction>(CondVal))
+      if (Or->getOpcode() == Instruction::Or && onlySelectAsUser(*CondVal)) {
+        Value *InnerSelect = Builder->CreateSelect(Or->getOperand(1), TrueVal,
+                                                   FalseVal, SI.getName()+".0");
+        SI.setOperand(0, Or->getOperand(0));
+        SI.setOperand(2, InnerSelect);
+        return &SI;
+      }
   }
 
   return nullptr;
Index: test/Transforms/InstCombine/select.ll
===================================================================
--- test/Transforms/InstCombine/select.ll
+++ test/Transforms/InstCombine/select.ll
@@ -1492,3 +1492,31 @@
   %v = load i128* %p
   ret i128 %v
 }
+
+define i32 @test_select_and(i32 %a, i32 %r0, i32 %r1, i32 %v1, i32 %v2) {
+  ; CHECK-LABEL: @test_select_and(
+  ; CHECK: %[[C0:.*]] = icmp sge i32 %a, %v1
+  ; CHECK-NEXT: %[[C1:.*]] = icmp slt i32 %a, %v2
+  ; CHECK-NEXT: %[[SEL0:.*]] = select i1 %[[C1]], i32 %r0, i32 %r1
+  ; CHECK-NEXT: %[[SEL1:.*]] = select i1 %[[C0]], i32 %[[SEL0]], i32 %r1
+  ; CHECK-NEXT: ret i32 %[[SEL1]]
+  %c0 = icmp sge i32 %a, %v1
+  %c1 = icmp slt i32 %a, %v2
+  %and = and i1 %c0, %c1
+  %res = select i1 %and, i32 %r0, i32 %r1
+  ret i32 %res
+}
+
+define i32 @test_select_or(i32 %a, i32 %r0, i32 %r1, i32 %v1, i32 %v2) {
+  ; CHECK-LABEL: @test_select_or(
+  ; CHECK: %[[C0:.*]] = icmp sge i32 %a, %v1
+  ; CHECK-NEXT: %[[C1:.*]] = icmp slt i32 %a, %v2
+  ; CHECK-NEXT: %[[SEL0:.*]] = select i1 %[[C1]], i32 %r0, i32 %r1
+  ; CHECK-NEXT: %[[SEL1:.*]] = select i1 %[[C0]], i32 %r0, i32 %[[SEL0]]
+  ; CHECK-NEXT: ret i32 %[[SEL1]]
+  %c0 = icmp sge i32 %a, %v1
+  %c1 = icmp slt i32 %a, %v2
+  %and = or i1 %c0, %c1
+  %res = select i1 %and, i32 %r0, i32 %r1
+  ret i32 %res
+}
Index: test/Transforms/Reassociate/basictest.ll
===================================================================
--- test/Transforms/Reassociate/basictest.ll
+++ test/Transforms/Reassociate/basictest.ll
@@ -212,7 +212,7 @@
   %A = icmp ne i32 %X1, 0
   %B = icmp slt i32 %X2, %X3
   %C = and i1 %A, %B
-  %D = select i1 %C, i32 %X1, i32 0
+  %D = zext i1 %C to i32
   ret i32 %D
 ; CHECK-LABEL: @test15
 ; CHECK: and i1 %A, %B