Index: llvm/trunk/lib/Transforms/InstCombine/InstCombineCasts.cpp
===================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineCasts.cpp
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineCasts.cpp
@@ -185,8 +185,14 @@
   case Instruction::Shl:
   case Instruction::UDiv:
   case Instruction::URem: {
-    Value *LHS = EvaluateInDifferentType(I->getOperand(0), Ty, isSigned);
-    Value *RHS = EvaluateInDifferentType(I->getOperand(1), Ty, isSigned);
+    Value *LHS, *RHS;
+    if (I->getOperand(0) == I->getOperand(1)) {
+      // Don't create an unnecessary value if the operands are repeated.
+      LHS = RHS = EvaluateInDifferentType(I->getOperand(0), Ty, isSigned);
+    } else {
+      LHS = EvaluateInDifferentType(I->getOperand(0), Ty, isSigned);
+      RHS = EvaluateInDifferentType(I->getOperand(1), Ty, isSigned);
+    }
     Res = BinaryOperator::Create((Instruction::BinaryOps)Opc, LHS, RHS);
     break;
   }
@@ -320,10 +326,12 @@
   assert(!isa<Constant>(V) && "Constant should already be handled.");
   if (!isa<Instruction>(V))
     return true;
-  // We can't extend or shrink something that has multiple uses: doing so would
-  // require duplicating the instruction in general, which isn't profitable.
+  // We can't extend or shrink something that has multiple uses -- unless those
+  // multiple uses are all in the same instruction -- doing so would require
+  // duplicating the instruction which isn't profitable.
   if (!V->hasOneUse())
-    return true;
+    if (any_of(V->users(), [&](User *U) { return U != V->user_back(); }))
+      return true;
 
   return false;
 }
Index: llvm/trunk/test/Transforms/InstCombine/cast-mul-select.ll
===================================================================
--- llvm/trunk/test/Transforms/InstCombine/cast-mul-select.ll
+++ llvm/trunk/test/Transforms/InstCombine/cast-mul-select.ll
@@ -49,11 +49,9 @@
 
 define i32 @eval_trunc_multi_use_in_one_inst(i32 %x) {
 ; CHECK-LABEL: @eval_trunc_multi_use_in_one_inst(
-; CHECK-NEXT:    [[Z:%.*]] = zext i32 [[X:%.*]] to i64
-; CHECK-NEXT:    [[A:%.*]] = add nuw nsw i64 [[Z]], 15
-; CHECK-NEXT:    [[M:%.*]] = mul i64 [[A]], [[A]]
-; CHECK-NEXT:    [[T:%.*]] = trunc i64 [[M]] to i32
-; CHECK-NEXT:    ret i32 [[T]]
+; CHECK-NEXT:    [[A:%.*]] = add i32 [[X:%.*]], 15
+; CHECK-NEXT:    [[M:%.*]] = mul i32 [[A]], [[A]]
+; CHECK-NEXT:    ret i32 [[M]]
 ;
   %z = zext i32 %x to i64
   %a = add nsw nuw i64 %z, 15
@@ -64,11 +62,9 @@
 
 define i32 @eval_zext_multi_use_in_one_inst(i32 %x) {
 ; CHECK-LABEL: @eval_zext_multi_use_in_one_inst(
-; CHECK-NEXT:    [[T:%.*]] = trunc i32 [[X:%.*]] to i16
-; CHECK-NEXT:    [[A:%.*]] = and i16 [[T]], 5
-; CHECK-NEXT:    [[M:%.*]] = mul nuw nsw i16 [[A]], [[A]]
-; CHECK-NEXT:    [[R:%.*]] = zext i16 [[M]] to i32
-; CHECK-NEXT:    ret i32 [[R]]
+; CHECK-NEXT:    [[A:%.*]] = and i32 [[X:%.*]], 5
+; CHECK-NEXT:    [[M:%.*]] = mul nuw nsw i32 [[A]], [[A]]
+; CHECK-NEXT:    ret i32 [[M]]
 ;
   %t = trunc i32 %x to i16
   %a = and i16 %t, 5
@@ -79,12 +75,10 @@
 
 define i32 @eval_sext_multi_use_in_one_inst(i32 %x) {
 ; CHECK-LABEL: @eval_sext_multi_use_in_one_inst(
-; CHECK-NEXT:    [[T:%.*]] = trunc i32 [[X:%.*]] to i16
-; CHECK-NEXT:    [[A:%.*]] = and i16 [[T]], 14
-; CHECK-NEXT:    [[M:%.*]] = mul nuw nsw i16 [[A]], [[A]]
-; CHECK-NEXT:    [[O:%.*]] = or i16 [[M]], -32768
-; CHECK-NEXT:    [[R:%.*]] = sext i16 [[O]] to i32
-; CHECK-NEXT:    ret i32 [[R]]
+; CHECK-NEXT:    [[A:%.*]] = and i32 [[X:%.*]], 14
+; CHECK-NEXT:    [[M:%.*]] = mul nuw nsw i32 [[A]], [[A]]
+; CHECK-NEXT:    [[O:%.*]] = or i32 [[M]], -32768
+; CHECK-NEXT:    ret i32 [[O]]
 ;
   %t = trunc i32 %x to i16
   %a = and i16 %t, 14
Index: llvm/trunk/test/Transforms/InstCombine/icmp-mul-zext.ll
===================================================================
--- llvm/trunk/test/Transforms/InstCombine/icmp-mul-zext.ll
+++ llvm/trunk/test/Transforms/InstCombine/icmp-mul-zext.ll
@@ -55,13 +55,12 @@
 
 define void @PR33765(i8 %beth) {
 ; CHECK-LABEL: @PR33765(
-; CHECK-NEXT:    [[CONV:%.*]] = zext i8 [[BETH:%.*]] to i32
+; CHECK-NEXT:    [[CONV:%.*]] = zext i8 [[BETH:%.*]] to i16
 ; CHECK-NEXT:    br i1 false, label [[IF_THEN9:%.*]], label [[IF_THEN9]]
 ; CHECK:       if.then9:
-; CHECK-NEXT:    [[MUL:%.*]] = mul nuw nsw i32 [[CONV]], [[CONV]]
+; CHECK-NEXT:    [[MUL:%.*]] = mul nuw i16 [[CONV]], [[CONV]]
 ; CHECK-NEXT:    [[TINKY:%.*]] = load i16, i16* @glob, align 2
-; CHECK-NEXT:    [[TMP1:%.*]] = trunc i32 [[MUL]] to i16
-; CHECK-NEXT:    [[CONV14:%.*]] = and i16 [[TINKY]], [[TMP1]]
+; CHECK-NEXT:    [[CONV14:%.*]] = and i16 [[TINKY]], [[MUL]]
 ; CHECK-NEXT:    store i16 [[CONV14]], i16* @glob, align 2
 ; CHECK-NEXT:    ret void
 ;