[llvm] aadb635 - [SCCP] Remove forcedconstant, go to overdefined instead

Florian Hahn via llvm-commits llvm-commits at lists.llvm.org
Tue Feb 11 07:30:38 PST 2020


Author: Florian Hahn
Date: 2020-02-11T15:24:15Z
New Revision: aadb635e04854220064b77cc10d0e6772f5492fd

URL: https://github.com/llvm/llvm-project/commit/aadb635e04854220064b77cc10d0e6772f5492fd
DIFF: https://github.com/llvm/llvm-project/commit/aadb635e04854220064b77cc10d0e6772f5492fd.diff

LOG: [SCCP] Remove forcedconstant, go to overdefined instead

This patch removes forcedconstant to simplify things for the
move to ValueLattice, which includes constant ranges, but no
forced constants.

This patch removes forcedconstant and changes ResolvedUndefsIn
to mark instructions with unknown operands as overdefined. This
means we do not do simplifications based on undef directly in SCCP
any longer, but this seems to hardly come up in practice (see stats
below), presumably because InstCombine & others take care
of most of the relevant folds already.

It is still beneficial to keep ResolvedUndefIn, as it allows us delaying
going to overdefined until we propagated all known information.

I also built MultiSource, SPEC2000 and SPEC2006 and compared
sccp.IPNumInstRemoved and sccp.NumInstRemoved. It looks like the impact
is quite low:

Tests: 244
Same hash: 238 (filtered out)
Remaining: 6
Metric: sccp.IPNumInstRemoved

Program                                        base     patch    diff
 test-suite...arks/VersaBench/dbms/dbms.test     4.00    3.00  -25.0%
 test-suite...TimberWolfMC/timberwolfmc.test    38.00   34.00  -10.5%
 test-suite...006/453.povray/453.povray.test   158.00  155.00  -1.9%
 test-suite.../CINT2000/176.gcc/176.gcc.test   668.00  668.00   0.0%
 test-suite.../CINT2006/403.gcc/403.gcc.test   1209.00 1209.00  0.0%
 test-suite...arks/mafft/pairlocalalign.test    76.00   76.00   0.0%

Tests: 244
Same hash: 238 (filtered out)
Remaining: 6
Metric: sccp.NumInstRemoved

Program                                        base    patch     diff
 test-suite...arks/mafft/pairlocalalign.test   185.00  175.00  -5.4%
 test-suite.../CINT2006/403.gcc/403.gcc.test   2059.00 2056.00 -0.1%
 test-suite.../CINT2000/176.gcc/176.gcc.test   2358.00 2357.00 -0.0%
 test-suite...006/453.povray/453.povray.test   317.00  317.00   0.0%
 test-suite...TimberWolfMC/timberwolfmc.test    12.00   12.00   0.0%

Reviewers: davide, efriedma, mssimpso

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D61314

Added: 
    

Modified: 
    llvm/lib/Transforms/Scalar/SCCP.cpp
    llvm/test/Transforms/IPConstantProp/PR16052.ll
    llvm/test/Transforms/IPConstantProp/PR26044.ll
    llvm/test/Transforms/SCCP/2006-12-19-UndefBug.ll
    llvm/test/Transforms/SCCP/apint-bigint2.ll
    llvm/test/Transforms/SCCP/apint-ipsccp3.ll
    llvm/test/Transforms/SCCP/apint-select.ll
    llvm/test/Transforms/SCCP/ip-constant-ranges.ll
    llvm/test/Transforms/SCCP/ipsccp-basic.ll
    llvm/test/Transforms/SCCP/logical-nuke.ll
    llvm/test/Transforms/SCCP/switch-multiple-undef.ll
    llvm/test/Transforms/SCCP/ub-shift.ll
    llvm/test/Transforms/SCCP/undef-resolve.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Transforms/Scalar/SCCP.cpp b/llvm/lib/Transforms/Scalar/SCCP.cpp
index 34f18ec7c121..3e6697e91b9e 100644
--- a/llvm/lib/Transforms/Scalar/SCCP.cpp
+++ b/llvm/lib/Transforms/Scalar/SCCP.cpp
@@ -85,19 +85,13 @@ class LatticeVal {
     /// constant - This LLVM Value has a specific constant value.
     constant,
 
-    /// forcedconstant - This LLVM Value was thought to be undef until
-    /// ResolvedUndefsIn.  This is treated just like 'constant', but if merged
-    /// with another (
diff erent) constant, it goes to overdefined, instead of
-    /// asserting.
-    forcedconstant,
-
     /// overdefined - This instruction is not known to be constant, and we know
     /// it has a value.
     overdefined
   };
 
   /// Val: This stores the current lattice value along with the Constant* for
-  /// the constant if this is a 'constant' or 'forcedconstant' value.
+  /// the constant if this is a 'constant' value.
   PointerIntPair<Constant *, 2, LatticeValueTy> Val;
 
   LatticeValueTy getLatticeValue() const {
@@ -109,9 +103,7 @@ class LatticeVal {
 
   bool isUnknown() const { return getLatticeValue() == unknown; }
 
-  bool isConstant() const {
-    return getLatticeValue() == constant || getLatticeValue() == forcedconstant;
-  }
+  bool isConstant() const { return getLatticeValue() == constant; }
 
   bool isOverdefined() const { return getLatticeValue() == overdefined; }
 
@@ -131,26 +123,15 @@ class LatticeVal {
 
   /// markConstant - Return true if this is a change in status.
   bool markConstant(Constant *V) {
-    if (getLatticeValue() == constant) { // Constant but not forcedconstant.
+    if (getLatticeValue() == constant) { // Constant
       assert(getConstant() == V && "Marking constant with 
diff erent value");
       return false;
     }
 
-    if (isUnknown()) {
-      Val.setInt(constant);
-      assert(V && "Marking constant with NULL");
-      Val.setPointer(V);
-    } else {
-      assert(getLatticeValue() == forcedconstant &&
-             "Cannot move from overdefined to constant!");
-      // Stay at forcedconstant if the constant is the same.
-      if (V == getConstant()) return false;
-
-      // Otherwise, we go to overdefined.  Assumptions made based on the
-      // forced value are possibly wrong.  Assuming this is another constant
-      // could expose a contradiction.
-      Val.setInt(overdefined);
-    }
+    assert(isUnknown());
+    Val.setInt(constant);
+    assert(V && "Marking constant with NULL");
+    Val.setPointer(V);
     return true;
   }
 
@@ -170,12 +151,6 @@ class LatticeVal {
     return nullptr;
   }
 
-  void markForcedConstant(Constant *V) {
-    assert(isUnknown() && "Can't force a defined value!");
-    Val.setInt(forcedconstant);
-    Val.setPointer(V);
-  }
-
   ValueLatticeElement toValueLattice() const {
     if (isOverdefined())
       return ValueLatticeElement::getOverdefined();
@@ -421,7 +396,7 @@ class SCCPSolver : public InstVisitor<SCCPSolver> {
   }
 
 private:
-  // pushToWorkList - Helper for markConstant/markForcedConstant/markOverdefined
+  // pushToWorkList - Helper for markConstant/markOverdefined
   void pushToWorkList(LatticeVal &IV, Value *V) {
     if (IV.isOverdefined())
       return OverdefinedInstWorkList.push_back(V);
@@ -443,14 +418,6 @@ class SCCPSolver : public InstVisitor<SCCPSolver> {
     return markConstant(ValueState[V], V, C);
   }
 
-  void markForcedConstant(Value *V, Constant *C) {
-    assert(!V->getType()->isStructTy() && "structs should use mergeInValue");
-    LatticeVal &IV = ValueState[V];
-    IV.markForcedConstant(C);
-    LLVM_DEBUG(dbgs() << "markForcedConstant: " << *C << ": " << *V << '\n');
-    pushToWorkList(IV, V);
-  }
-
   // markOverdefined - Make a value be marked as "overdefined". If the
   // value is not already overdefined, add it to the overdefined instruction
   // work list so that the users of the instruction are updated later.
@@ -1032,8 +999,10 @@ void SCCPSolver::visitBinaryOperator(Instruction &I) {
   }
 
   // If something is undef, wait for it to resolve.
-  if (!V1State.isOverdefined() && !V2State.isOverdefined())
+  if (!V1State.isOverdefined() && !V2State.isOverdefined()) {
+
     return;
+  }
 
   // Otherwise, one of our operands is overdefined.  Try to produce something
   // better than overdefined with some tricks.
@@ -1449,10 +1418,8 @@ void SCCPSolver::Solve() {
 /// constraints on the condition of the branch, as that would impact other users
 /// of the value.
 ///
-/// This scan also checks for values that use undefs, whose results are actually
-/// defined.  For example, 'zext i8 undef to i32' should produce all zeros
-/// conservatively, as "(zext i8 X -> i32) & 0xFF00" must always return zero,
-/// even if X isn't defined.
+/// This scan also checks for values that use undefs. It conservatively marks
+/// them as overdefined.
 bool SCCPSolver::ResolvedUndefsIn(Function &F) {
   for (BasicBlock &BB : F) {
     if (!BBExecutable.count(&BB))
@@ -1475,7 +1442,6 @@ bool SCCPSolver::ResolvedUndefsIn(Function &F) {
         // tracked as precisely as their operands.
         if (isa<ExtractValueInst>(I) || isa<InsertValueInst>(I))
           continue;
-
         // Send the results of everything else to overdefined.  We could be
         // more precise than this but it isn't worth bothering.
         for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) {
@@ -1495,195 +1461,13 @@ bool SCCPSolver::ResolvedUndefsIn(Function &F) {
       // 2. It could be constant-foldable.
       // Because of the way we solve return values, tracked calls must
       // never be marked overdefined in ResolvedUndefsIn.
-      if (CallSite CS = CallSite(&I)) {
+      if (CallSite CS = CallSite(&I))
         if (Function *F = CS.getCalledFunction())
           if (TrackedRetVals.count(F))
             continue;
 
-        // If the call is constant-foldable, we mark it overdefined because
-        // we do not know what return values are valid.
-        markOverdefined(&I);
-        return true;
-      }
-
-      // extractvalue is safe; check here because the argument is a struct.
-      if (isa<ExtractValueInst>(I))
-        continue;
-
-      // Compute the operand LatticeVals, for convenience below.
-      // Anything taking a struct is conservatively assumed to require
-      // overdefined markings.
-      if (I.getOperand(0)->getType()->isStructTy()) {
-        markOverdefined(&I);
-        return true;
-      }
-      LatticeVal Op0LV = getValueState(I.getOperand(0));
-      LatticeVal Op1LV;
-      if (I.getNumOperands() == 2) {
-        if (I.getOperand(1)->getType()->isStructTy()) {
-          markOverdefined(&I);
-          return true;
-        }
-
-        Op1LV = getValueState(I.getOperand(1));
-      }
-      // If this is an instructions whose result is defined even if the input is
-      // not fully defined, propagate the information.
-      Type *ITy = I.getType();
-      switch (I.getOpcode()) {
-      case Instruction::Add:
-      case Instruction::Sub:
-      case Instruction::Trunc:
-      case Instruction::FPTrunc:
-      case Instruction::BitCast:
-        break; // Any undef -> undef
-      case Instruction::FSub:
-      case Instruction::FAdd:
-      case Instruction::FMul:
-      case Instruction::FDiv:
-      case Instruction::FRem:
-        // Floating-point binary operation: be conservative.
-        if (Op0LV.isUnknown() && Op1LV.isUnknown())
-          markForcedConstant(&I, Constant::getNullValue(ITy));
-        else
-          markOverdefined(&I);
-        return true;
-      case Instruction::FNeg:
-        break; // fneg undef -> undef
-      case Instruction::ZExt:
-      case Instruction::SExt:
-      case Instruction::FPToUI:
-      case Instruction::FPToSI:
-      case Instruction::FPExt:
-      case Instruction::PtrToInt:
-      case Instruction::IntToPtr:
-      case Instruction::SIToFP:
-      case Instruction::UIToFP:
-        // undef -> 0; some outputs are impossible
-        markForcedConstant(&I, Constant::getNullValue(ITy));
-        return true;
-      case Instruction::Mul:
-      case Instruction::And:
-        // Both operands undef -> undef
-        if (Op0LV.isUnknown() && Op1LV.isUnknown())
-          break;
-        // undef * X -> 0.   X could be zero.
-        // undef & X -> 0.   X could be zero.
-        markForcedConstant(&I, Constant::getNullValue(ITy));
-        return true;
-      case Instruction::Or:
-        // Both operands undef -> undef
-        if (Op0LV.isUnknown() && Op1LV.isUnknown())
-          break;
-        // undef | X -> -1.   X could be -1.
-        markForcedConstant(&I, Constant::getAllOnesValue(ITy));
-        return true;
-      case Instruction::Xor:
-        // undef ^ undef -> 0; strictly speaking, this is not strictly
-        // necessary, but we try to be nice to people who expect this
-        // behavior in simple cases
-        if (Op0LV.isUnknown() && Op1LV.isUnknown()) {
-          markForcedConstant(&I, Constant::getNullValue(ITy));
-          return true;
-        }
-        // undef ^ X -> undef
-        break;
-      case Instruction::SDiv:
-      case Instruction::UDiv:
-      case Instruction::SRem:
-      case Instruction::URem:
-        // X / undef -> undef.  No change.
-        // X % undef -> undef.  No change.
-        if (Op1LV.isUnknown()) break;
-
-        // X / 0 -> undef.  No change.
-        // X % 0 -> undef.  No change.
-        if (Op1LV.isConstant() && Op1LV.getConstant()->isZeroValue())
-          break;
-
-        // undef / X -> 0.   X could be maxint.
-        // undef % X -> 0.   X could be 1.
-        markForcedConstant(&I, Constant::getNullValue(ITy));
-        return true;
-      case Instruction::AShr:
-        // X >>a undef -> undef.
-        if (Op1LV.isUnknown()) break;
-
-        // Shifting by the bitwidth or more is undefined.
-        if (Op1LV.isConstant()) {
-          if (auto *ShiftAmt = Op1LV.getConstantInt())
-            if (ShiftAmt->getLimitedValue() >=
-                ShiftAmt->getType()->getScalarSizeInBits())
-              break;
-        }
-
-        // undef >>a X -> 0
-        markForcedConstant(&I, Constant::getNullValue(ITy));
-        return true;
-      case Instruction::LShr:
-      case Instruction::Shl:
-        // X << undef -> undef.
-        // X >> undef -> undef.
-        if (Op1LV.isUnknown()) break;
-
-        // Shifting by the bitwidth or more is undefined.
-        if (Op1LV.isConstant()) {
-          if (auto *ShiftAmt = Op1LV.getConstantInt())
-            if (ShiftAmt->getLimitedValue() >=
-                ShiftAmt->getType()->getScalarSizeInBits())
-              break;
-        }
-
-        // undef << X -> 0
-        // undef >> X -> 0
-        markForcedConstant(&I, Constant::getNullValue(ITy));
-        return true;
-      case Instruction::Select:
-        Op1LV = getValueState(I.getOperand(1));
-        // undef ? X : Y  -> X or Y.  There could be commonality between X/Y.
-        if (Op0LV.isUnknown()) {
-          if (!Op1LV.isConstant())  // Pick the constant one if there is any.
-            Op1LV = getValueState(I.getOperand(2));
-        } else if (Op1LV.isUnknown()) {
-          // c ? undef : undef -> undef.  No change.
-          Op1LV = getValueState(I.getOperand(2));
-          if (Op1LV.isUnknown())
-            break;
-          // Otherwise, c ? undef : x -> x.
-        } else {
-          // Leave Op1LV as Operand(1)'s LatticeValue.
-        }
-
-        if (Op1LV.isConstant())
-          markForcedConstant(&I, Op1LV.getConstant());
-        else
-          markOverdefined(&I);
-        return true;
-      case Instruction::Load:
-        // A load here means one of two things: a load of undef from a global,
-        // a load from an unknown pointer.  Either way, having it return undef
-        // is okay.
-        break;
-      case Instruction::ICmp:
-        // X == undef -> undef.  Other comparisons get more complicated.
-        Op0LV = getValueState(I.getOperand(0));
-        Op1LV = getValueState(I.getOperand(1));
-
-        if ((Op0LV.isUnknown() || Op1LV.isUnknown()) &&
-            cast<ICmpInst>(&I)->isEquality())
-          break;
-        markOverdefined(&I);
-        return true;
-      case Instruction::Call:
-      case Instruction::Invoke:
-      case Instruction::CallBr:
-        llvm_unreachable("Call-like instructions should have be handled early");
-      default:
-        // If we don't know what should happen here, conservatively mark it
-        // overdefined.
-        markOverdefined(&I);
-        return true;
-      }
+      markOverdefined(&I);
+      return true;
     }
 
     // Check to see if we have a branch or switch on an undefined value.  If so

diff  --git a/llvm/test/Transforms/IPConstantProp/PR16052.ll b/llvm/test/Transforms/IPConstantProp/PR16052.ll
index 451693f1c90c..a16067fe278a 100644
--- a/llvm/test/Transforms/IPConstantProp/PR16052.ll
+++ b/llvm/test/Transforms/IPConstantProp/PR16052.ll
@@ -1,4 +1,4 @@
-; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --function-signature --scrub-attributes 
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --function-signature --scrub-attributes
 ; RUN: opt < %s -S -ipsccp | FileCheck %s
 
 target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
@@ -7,7 +7,9 @@ target triple = "x86_64-unknown-linux-gnu"
 define i64 @fn2() {
 ; CHECK-LABEL: define {{[^@]+}}@fn2()
 ; CHECK-NEXT:  entry:
-; CHECK-NEXT:    [[CALL2:%.*]] = call i64 @fn1(i64 undef)
+; CHECK-NEXT:    [[CONV:%.*]] = sext i32 undef to i64
+; CHECK-NEXT:    [[DIV:%.*]] = sdiv i64 8, [[CONV]]
+; CHECK-NEXT:    [[CALL2:%.*]] = call i64 @fn1(i64 [[DIV]])
 ; CHECK-NEXT:    ret i64 [[CALL2]]
 ;
 entry:
@@ -21,7 +23,8 @@ define internal i64 @fn1(i64 %p1) {
 ; CHECK-LABEL: define {{[^@]+}}@fn1
 ; CHECK-SAME: (i64 [[P1:%.*]])
 ; CHECK-NEXT:  entry:
-; CHECK-NEXT:    [[COND:%.*]] = select i1 undef, i64 undef, i64 undef
+; CHECK-NEXT:    [[TOBOOL:%.*]] = icmp ne i64 [[P1]], 0
+; CHECK-NEXT:    [[COND:%.*]] = select i1 [[TOBOOL]], i64 [[P1]], i64 [[P1]]
 ; CHECK-NEXT:    ret i64 [[COND]]
 ;
 entry:

diff  --git a/llvm/test/Transforms/IPConstantProp/PR26044.ll b/llvm/test/Transforms/IPConstantProp/PR26044.ll
index eeb5b87e0a28..8b4f2590b9f8 100644
--- a/llvm/test/Transforms/IPConstantProp/PR26044.ll
+++ b/llvm/test/Transforms/IPConstantProp/PR26044.ll
@@ -11,7 +11,8 @@ define void @fn2(i32* %P) {
 ; CHECK:       for.cond1:
 ; CHECK-NEXT:    br i1 false, label [[IF_END]], label [[IF_END]]
 ; CHECK:       if.end:
-; CHECK-NEXT:    [[CALL:%.*]] = call i32 @fn1(i32 undef)
+; CHECK-NEXT:    [[TMP0:%.*]] = load i32, i32* null, align 4
+; CHECK-NEXT:    [[CALL:%.*]] = call i32 @fn1(i32 [[TMP0]])
 ; CHECK-NEXT:    store i32 [[CALL]], i32* [[P]]
 ; CHECK-NEXT:    br label [[FOR_COND1:%.*]]
 ;
@@ -33,7 +34,8 @@ define internal i32 @fn1(i32 %p1) {
 ; CHECK-LABEL: define {{[^@]+}}@fn1
 ; CHECK-SAME: (i32 [[P1:%.*]])
 ; CHECK-NEXT:  entry:
-; CHECK-NEXT:    [[COND:%.*]] = select i1 undef, i32 undef, i32 undef
+; CHECK-NEXT:    [[TOBOOL:%.*]] = icmp ne i32 [[P1]], 0
+; CHECK-NEXT:    [[COND:%.*]] = select i1 [[TOBOOL]], i32 [[P1]], i32 [[P1]]
 ; CHECK-NEXT:    ret i32 [[COND]]
 ;
 entry:

diff  --git a/llvm/test/Transforms/SCCP/2006-12-19-UndefBug.ll b/llvm/test/Transforms/SCCP/2006-12-19-UndefBug.ll
index ede1a32c5f7a..4bd096e0a656 100644
--- a/llvm/test/Transforms/SCCP/2006-12-19-UndefBug.ll
+++ b/llvm/test/Transforms/SCCP/2006-12-19-UndefBug.ll
@@ -1,8 +1,12 @@
-; RUN: opt < %s -sccp -S | \
-; RUN:   grep "ret i1 false"
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -sccp -S | FileCheck %s
 
 define i1 @foo() {
-	%X = and i1 false, undef		; <i1> [#uses=1]
-	ret i1 %X
+; CHECK-LABEL: @foo(
+; CHECK-NEXT:    [[X:%.*]] = and i1 false, undef
+; CHECK-NEXT:    ret i1 [[X]]
+;
+  %X = and i1 false, undef		; <i1> [#uses=1]
+  ret i1 %X
 }
 

diff  --git a/llvm/test/Transforms/SCCP/apint-bigint2.ll b/llvm/test/Transforms/SCCP/apint-bigint2.ll
index 5277d9fa5c6e..7d75240a0d8e 100644
--- a/llvm/test/Transforms/SCCP/apint-bigint2.ll
+++ b/llvm/test/Transforms/SCCP/apint-bigint2.ll
@@ -18,7 +18,13 @@ define i101 @array() {
 }
 
 ; CHECK-LABEL: @large_aggregate
-; CHECK-NEXT: ret i101 undef
+; CHECK-NEXT:    %B = load i101, i101* undef
+; CHECK-NEXT:    %D = and i101 %B, 1
+; CHECK-NEXT:    %DD = or i101 %D, 1
+; CHECK-NEXT:    %G = getelementptr i101, i101* getelementptr inbounds ([6 x i101], [6 x i101]* @Y, i32 0, i32 5), i101 %DD
+; CHECK-NEXT:    %L3 = load i101, i101* %G
+; CHECK-NEXT:    ret i101 %L3
+;
 define i101 @large_aggregate() {
   %B = load i101, i101* undef
   %D = and i101 %B, 1
@@ -29,6 +35,22 @@ define i101 @large_aggregate() {
   ret i101 %L3
 }
 
+; CHECK-LABEL: define i101 @large_aggregate_2() {
+; CHECK-NEXT:     %D = and i101 undef, 1
+; CHECK-NEXT:     %DD = or i101 %D, 1
+; CHECK-NEXT:     %G = getelementptr i101, i101* getelementptr inbounds ([6 x i101], [6 x i101]* @Y, i32 0, i32 5), i101 %DD
+; CHECK-NEXT:     %L3 = load i101, i101* %G
+; CHECK-NEXT:     ret i101 %L3
+;
+define i101 @large_aggregate_2() {
+  %D = and i101 undef, 1
+  %DD = or i101 %D, 1
+  %F = getelementptr [6 x i101], [6 x i101]* @Y, i32 0, i32 5
+  %G = getelementptr i101, i101* %F, i101 %DD
+  %L3 = load i101, i101* %G
+  ret i101 %L3
+}
+
 ; CHECK-LABEL: @index_too_large
 ; CHECK-NEXT: store i101* getelementptr (i101, i101* getelementptr ([6 x i101], [6 x i101]* @Y, i32 0, i32 -1), i101 9224497936761618431), i101** undef
 ; CHECK-NEXT: ret void

diff  --git a/llvm/test/Transforms/SCCP/apint-ipsccp3.ll b/llvm/test/Transforms/SCCP/apint-ipsccp3.ll
index c99ae5820b2d..4ba1f8db30ba 100644
--- a/llvm/test/Transforms/SCCP/apint-ipsccp3.ll
+++ b/llvm/test/Transforms/SCCP/apint-ipsccp3.ll
@@ -1,23 +1,39 @@
-; RUN: opt < %s -ipsccp -S | not grep global
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -ipsccp -S | FileCheck %s
 
 @G = internal global i66 undef
 
 
-
 define void @foo() {
-	%X = load i66, i66* @G
-	store i66 %X, i66* @G
-	ret void
+; CHECK-LABEL: @foo(
+; CHECK-NEXT:    [[X:%.*]] = load i66, i66* @G
+; CHECK-NEXT:    store i66 [[X]], i66* @G
+; CHECK-NEXT:    ret void
+;
+  %X = load i66, i66* @G
+  store i66 %X, i66* @G
+  ret void
 }
 
 define i66 @bar() {
-	%V = load i66, i66* @G
-	%C = icmp eq i66 %V, 17
-	br i1 %C, label %T, label %F
+; CHECK-LABEL: @bar(
+; CHECK-NEXT:    [[V:%.*]] = load i66, i66* @G
+; CHECK-NEXT:    [[C:%.*]] = icmp eq i66 [[V]], 17
+; CHECK-NEXT:    br i1 [[C]], label [[T:%.*]], label [[F:%.*]]
+; CHECK:       T:
+; CHECK-NEXT:    store i66 17, i66* @G
+; CHECK-NEXT:    ret i66 17
+; CHECK:       F:
+; CHECK-NEXT:    store i66 123, i66* @G
+; CHECK-NEXT:    ret i66 0
+;
+  %V = load i66, i66* @G
+  %C = icmp eq i66 %V, 17
+  br i1 %C, label %T, label %F
 T:
-	store i66 17, i66* @G
-	ret i66 %V
+  store i66 17, i66* @G
+  ret i66 %V
 F:
-	store i66 123, i66* @G
-	ret i66 0
+  store i66 123, i66* @G
+  ret i66 0
 }

diff  --git a/llvm/test/Transforms/SCCP/apint-select.ll b/llvm/test/Transforms/SCCP/apint-select.ll
index 893331ea9867..d797c7a4d43c 100644
--- a/llvm/test/Transforms/SCCP/apint-select.ll
+++ b/llvm/test/Transforms/SCCP/apint-select.ll
@@ -1,21 +1,29 @@
-; RUN: opt < %s -sccp -S | not grep select
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -sccp -S | FileCheck %s
 
 @A = constant i32 10
 
 define i712 @test1() {
-        %P = getelementptr i32, i32* @A, i32 0
-        %B = ptrtoint i32* %P to i64
-        %BB = and i64 %B, undef
-        %C = icmp sge i64 %BB, 0
-	%X = select i1 %C, i712 0, i712 1
-	ret i712 %X
+; CHECK-LABEL: @test1(
+; CHECK-NEXT:    [[BB:%.*]] = and i64 ptrtoint (i32* @A to i64), undef
+; CHECK-NEXT:    [[C:%.*]] = icmp sge i64 [[BB]], 0
+; CHECK-NEXT:    [[X:%.*]] = select i1 [[C]], i712 0, i712 1
+; CHECK-NEXT:    ret i712 [[X]]
+;
+  %P = getelementptr i32, i32* @A, i32 0
+  %B = ptrtoint i32* %P to i64
+  %BB = and i64 %B, undef
+  %C = icmp sge i64 %BB, 0
+  %X = select i1 %C, i712 0, i712 1
+  ret i712 %X
 }
 
 
 
 define i712 @test2(i1 %C) {
-	%X = select i1 %C, i712 0, i712 undef
-	ret i712 %X
+; CHECK-LABEL: @test2(
+; CHECK-NEXT:    ret i712 0
+;
+  %X = select i1 %C, i712 0, i712 undef
+  ret i712 %X
 }
-
-

diff  --git a/llvm/test/Transforms/SCCP/ip-constant-ranges.ll b/llvm/test/Transforms/SCCP/ip-constant-ranges.ll
index 426e3279661f..08de8dba4046 100644
--- a/llvm/test/Transforms/SCCP/ip-constant-ranges.ll
+++ b/llvm/test/Transforms/SCCP/ip-constant-ranges.ll
@@ -141,10 +141,12 @@ define double @test_struct({ double, double } %test) {
 ; Constant range for %x is [47, 302)
 ; CHECK-LABEL: @f5
 ; CHECK-NEXT: entry:
-; CHECK-NEXT: %cmp = icmp sgt i32 %x, undef
-; CHECK-NEXT: %res1 = select i1 %cmp, i32 1, i32 2
-; CHECK-NEXT: %res = add i32 %res1, 3
-; CHECK-NEXT: ret i32 %res
+; CHECK-NEXT:   %cmp = icmp sgt i32 %x, undef
+; CHECK-NEXT:   %cmp2 = icmp ne i32 undef, %x
+; CHECK-NEXT:   %res1 = select i1 %cmp, i32 1, i32 2
+; CHECK-NEXT:   %res2 = select i1 %cmp2, i32 3, i32 4
+; CHECK-NEXT:   %res = add i32 %res1, %res2
+; CHECK-NEXT:   ret i32 %res
 define internal i32 @f5(i32 %x) {
 entry:
   %cmp = icmp sgt i32 %x, undef

diff  --git a/llvm/test/Transforms/SCCP/ipsccp-basic.ll b/llvm/test/Transforms/SCCP/ipsccp-basic.ll
index b1660b545652..795a73f1d907 100644
--- a/llvm/test/Transforms/SCCP/ipsccp-basic.ll
+++ b/llvm/test/Transforms/SCCP/ipsccp-basic.ll
@@ -56,7 +56,9 @@ define void @test3a() {
 	ret void
 }
 ; CHECK-LABEL: define void @test3a(
-; CHECK-NEXT: ret void
+; CHECK-NEXT:    %X = load i32, i32* @G
+; CHECK-NEXT:    store i32 %X, i32* @G
+; CHECK-NEXT:   ret void
 
 
 define i32 @test3b() {
@@ -71,9 +73,17 @@ F:
 	ret i32 0
 }
 ; CHECK-LABEL: define i32 @test3b(
-; CHECK-NOT: store
-; CHECK: ret i32 0
+; CHECK-NEXT:    %V = load i32, i32* @G
+; CHECK-NEXT:    %C = icmp eq i32 %V, 17
+; CHECK-NEXT:    br i1 %C, label %T, label %F
+
+; CHECK-LABEL: T:
+; CHECK-NEXT:   store i32 17, i32* @G
+; CHECK-NEXT:   ret i32 17
 
+; CHECK-LABEL: F:
+; CHECK-NEXT:    store i32 123, i32* @G
+; CHECK-NEXT:    ret i32 0
 
 ;;======================== test4
 
@@ -226,8 +236,11 @@ define i32 @test10a() nounwind {
 entry:
   %call = call i32 @test10b(i32 undef)
   ret i32 %call
+
 ; CHECK-LABEL: define i32 @test10a(
-; CHECK: ret i32 0
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    %call = call i32 @test10b(i32 undef)
+; CHECK-NEXT:    ret i32 %call
 }
 
 define internal i32 @test10b(i32 %x) nounwind {
@@ -235,7 +248,9 @@ entry:
   %r = and i32 %x, 1
   ret i32 %r
 ; CHECK-LABEL: define internal i32 @test10b(
-; CHECK: ret i32 undef
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    %r = and i32 undef, 1
+; CHECK-NEXT:    ret i32 %r
 }
 
 ;;======================== test11
@@ -244,7 +259,8 @@ define i64 @test11a() {
   %xor = xor i64 undef, undef
   ret i64 %xor
 ; CHECK-LABEL: define i64 @test11a
-; CHECK: ret i64 0
+; CHECK-NEXT:    %xor = xor i64 undef, undef
+; CHECK-NEXT:    ret i64 %xor
 }
 
 define i64 @test11b() {
@@ -252,9 +268,9 @@ define i64 @test11b() {
   %call2 = call i64 @llvm.ctpop.i64(i64 %call1)
   ret i64 %call2
 ; CHECK-LABEL: define i64 @test11b
-; CHECK: %[[call1:.*]] = call i64 @test11a()
-; CHECK-NOT: call i64 @llvm.ctpop.i64
-; CHECK-NEXT: ret i64 0
+; CHECK-NEXT:   [[call1:%.*]] = call i64 @test11a()
+; CHECK-NEXT:    [[call2:%.*]] = call i64 @llvm.ctpop.i64(i64 [[call1]])
+; CHECK-NEXT: ret i64 [[call2]]
 }
 
 declare i64 @llvm.ctpop.i64(i64)

diff  --git a/llvm/test/Transforms/SCCP/logical-nuke.ll b/llvm/test/Transforms/SCCP/logical-nuke.ll
index 6ca16de4489b..5152e126e8fa 100644
--- a/llvm/test/Transforms/SCCP/logical-nuke.ll
+++ b/llvm/test/Transforms/SCCP/logical-nuke.ll
@@ -1,39 +1,47 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
 ; RUN: opt < %s -sccp -S | FileCheck %s
 
 ; Test that SCCP has basic knowledge of when and/or/mul nuke overdefined values.
 
-; CHECK-LABEL: test
-; CHECK: ret i32 0
  define i32 @test(i32 %X) {
+; CHECK-LABEL: @test(
+; CHECK-NEXT:    ret i32 0
+;
   %Y = and i32 %X, 0
   ret i32 %Y
 }
 
-; CHECK-LABEL: test2
-; CHECK: ret i32 -1
 define i32 @test2(i32 %X) {
+; CHECK-LABEL: @test2(
+; CHECK-NEXT:    ret i32 -1
+;
   %Y = or i32 -1, %X
   ret i32 %Y
 }
 
-; CHECK-LABEL: test3
-; CHECK: ret i32 0
 define i32 @test3(i32 %X) {
+; CHECK-LABEL: @test3(
+; CHECK-NEXT:    [[Y:%.*]] = and i32 undef, [[X:%.*]]
+; CHECK-NEXT:    ret i32 [[Y]]
+;
   %Y = and i32 undef, %X
   ret i32 %Y
 }
 
-; CHECK-LABEL: test4
-; CHECK: ret i32 -1
 define i32 @test4(i32 %X) {
+; CHECK-LABEL: @test4(
+; CHECK-NEXT:    [[Y:%.*]] = or i32 [[X:%.*]], undef
+; CHECK-NEXT:    ret i32 [[Y]]
+;
   %Y = or i32 %X, undef
   ret i32 %Y
 }
 
 ; X * 0 = 0 even if X is overdefined.
-; CHECK-LABEL: test5
-; CHECK: ret i32 0
 define i32 @test5(i32 %foo) {
+; CHECK-LABEL: @test5(
+; CHECK-NEXT:    ret i32 0
+;
   %patatino = mul i32 %foo, 0
   ret i32 %patatino
 }

diff  --git a/llvm/test/Transforms/SCCP/switch-multiple-undef.ll b/llvm/test/Transforms/SCCP/switch-multiple-undef.ll
index 027c9c0c9ba7..df99e4eee7d2 100644
--- a/llvm/test/Transforms/SCCP/switch-multiple-undef.ll
+++ b/llvm/test/Transforms/SCCP/switch-multiple-undef.ll
@@ -1,3 +1,4 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
 ; RUN: opt -S -ipsccp < %s | FileCheck %s
 
 declare void @foo()
@@ -5,9 +6,25 @@ declare void @goo()
 declare void @patatino()
 
 define void @test1(i32 %t) {
+; CHECK-LABEL: @test1(
+; CHECK-NEXT:    [[CHOICE:%.*]] = icmp eq i32 undef, -1
+; CHECK-NEXT:    switch i1 [[CHOICE]], label [[FIRST:%.*]] [
+; CHECK-NEXT:    i1 false, label [[SECOND:%.*]]
+; CHECK-NEXT:    i1 true, label [[THIRD:%.*]]
+; CHECK-NEXT:    ]
+; CHECK:       first:
+; CHECK-NEXT:    call void @foo()
+; CHECK-NEXT:    ret void
+; CHECK:       second:
+; CHECK-NEXT:    call void @goo()
+; CHECK-NEXT:    ret void
+; CHECK:       third:
+; CHECK-NEXT:    call void @patatino()
+; CHECK-NEXT:    ret void
+;
   %choice = icmp eq i32 undef, -1
   switch i1 %choice, label %first [i1 0, label %second
-                                   i1 1, label %third]
+  i1 1, label %third]
 first:
   call void @foo()
   ret void
@@ -18,10 +35,3 @@ third:
   call void @patatino()
   ret void
 }
-
-; CHECK: define void @test1(i32 %t) {
-; CHECK-NEXT:   br label %second
-; CHECK: second:
-; CHECK-NEXT:   call void @goo()
-; CHECK-NEXT:   ret void
-; CHECK-NEXT: }

diff  --git a/llvm/test/Transforms/SCCP/ub-shift.ll b/llvm/test/Transforms/SCCP/ub-shift.ll
index 3fb2d97457d9..6e15d6b2bccd 100644
--- a/llvm/test/Transforms/SCCP/ub-shift.ll
+++ b/llvm/test/Transforms/SCCP/ub-shift.ll
@@ -1,68 +1,89 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
 ; RUN: opt < %s -sccp -S | FileCheck %s
 
-; CHECK-LABEL: shift_undef_64
 define void @shift_undef_64(i64* %p) {
+; CHECK-LABEL: @shift_undef_64(
+; CHECK-NEXT:    [[R1:%.*]] = lshr i64 -1, 4294967296
+; CHECK-NEXT:    store i64 [[R1]], i64* [[P:%.*]]
+; CHECK-NEXT:    [[R2:%.*]] = ashr i64 -1, 4294967297
+; CHECK-NEXT:    store i64 [[R2]], i64* [[P]]
+; CHECK-NEXT:    [[R3:%.*]] = shl i64 -1, 4294967298
+; CHECK-NEXT:    store i64 [[R3]], i64* [[P]]
+; CHECK-NEXT:    ret void
+;
   %r1 = lshr i64 -1, 4294967296 ; 2^32
-  ; CHECK: store i64 undef
   store i64 %r1, i64* %p
 
   %r2 = ashr i64 -1, 4294967297 ; 2^32 + 1
-  ; CHECK: store i64 undef
   store i64 %r2, i64* %p
 
   %r3 = shl i64 -1, 4294967298 ; 2^32 + 2
-  ; CHECK: store i64 undef
   store i64 %r3, i64* %p
 
   ret void
 }
 
-; CHECK-LABEL: shift_undef_65
 define void @shift_undef_65(i65* %p) {
+; CHECK-LABEL: @shift_undef_65(
+; CHECK-NEXT:    [[R1:%.*]] = lshr i65 2, -18446744073709551615
+; CHECK-NEXT:    store i65 [[R1]], i65* [[P:%.*]]
+; CHECK-NEXT:    [[R2:%.*]] = ashr i65 4, -18446744073709551615
+; CHECK-NEXT:    store i65 [[R2]], i65* [[P]]
+; CHECK-NEXT:    [[R3:%.*]] = shl i65 1, -18446744073709551615
+; CHECK-NEXT:    store i65 [[R3]], i65* [[P]]
+; CHECK-NEXT:    ret void
+;
   %r1 = lshr i65 2, 18446744073709551617
-  ; CHECK: store i65 undef
   store i65 %r1, i65* %p
 
   %r2 = ashr i65 4, 18446744073709551617
-  ; CHECK: store i65 undef
   store i65 %r2, i65* %p
 
   %r3 = shl i65 1, 18446744073709551617
-  ; CHECK: store i65 undef
   store i65 %r3, i65* %p
 
   ret void
 }
 
-; CHECK-LABEL: shift_undef_256
 define void @shift_undef_256(i256* %p) {
+; CHECK-LABEL: @shift_undef_256(
+; CHECK-NEXT:    [[R1:%.*]] = lshr i256 2, 18446744073709551617
+; CHECK-NEXT:    store i256 [[R1]], i256* [[P:%.*]]
+; CHECK-NEXT:    [[R2:%.*]] = ashr i256 4, 18446744073709551618
+; CHECK-NEXT:    store i256 [[R2]], i256* [[P]]
+; CHECK-NEXT:    [[R3:%.*]] = shl i256 1, 18446744073709551619
+; CHECK-NEXT:    store i256 [[R3]], i256* [[P]]
+; CHECK-NEXT:    ret void
+;
   %r1 = lshr i256 2, 18446744073709551617
-  ; CHECK: store i256 undef
   store i256 %r1, i256* %p
 
   %r2 = ashr i256 4, 18446744073709551618
-  ; CHECK: store i256 undef
   store i256 %r2, i256* %p
 
   %r3 = shl i256 1, 18446744073709551619
-  ; CHECK: store i256 undef
   store i256 %r3, i256* %p
 
   ret void
 }
 
-; CHECK-LABEL: shift_undef_511
 define void @shift_undef_511(i511* %p) {
+; CHECK-LABEL: @shift_undef_511(
+; CHECK-NEXT:    [[R1:%.*]] = lshr i511 -1, 1208925819614629174706276
+; CHECK-NEXT:    store i511 [[R1]], i511* [[P:%.*]]
+; CHECK-NEXT:    [[R2:%.*]] = ashr i511 -2, 1208925819614629174706200
+; CHECK-NEXT:    store i511 [[R2]], i511* [[P]]
+; CHECK-NEXT:    [[R3:%.*]] = shl i511 -3, 1208925819614629174706180
+; CHECK-NEXT:    store i511 [[R3]], i511* [[P]]
+; CHECK-NEXT:    ret void
+;
   %r1 = lshr i511 -1, 1208925819614629174706276 ; 2^80 + 100
-  ; CHECK: store i511 undef
   store i511 %r1, i511* %p
 
   %r2 = ashr i511 -2, 1208925819614629174706200
-  ; CHECK: store i511 undef
   store i511 %r2, i511* %p
 
   %r3 = shl i511 -3, 1208925819614629174706180
-  ; CHECK: store i511 undef
   store i511 %r3, i511* %p
 
   ret void

diff  --git a/llvm/test/Transforms/SCCP/undef-resolve.ll b/llvm/test/Transforms/SCCP/undef-resolve.ll
index 7fdcd556dae6..e2a4268596f4 100644
--- a/llvm/test/Transforms/SCCP/undef-resolve.ll
+++ b/llvm/test/Transforms/SCCP/undef-resolve.ll
@@ -1,12 +1,15 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
 ; RUN: opt -sccp -S < %s | FileCheck %s
 
 
 ; PR6940
 define double @test1() {
+; CHECK-LABEL: @test1(
+; CHECK-NEXT:    [[T:%.*]] = sitofp i32 undef to double
+; CHECK-NEXT:    ret double [[T]]
+;
   %t = sitofp i32 undef to double
   ret double %t
-; CHECK-LABEL: @test1(
-; CHECK: ret double 0.0
 }
 
 
@@ -14,6 +17,72 @@ define double @test1() {
 ; Check that lots of stuff doesn't get turned into undef.
 define i32 @test2() nounwind readnone ssp {
 ; CHECK-LABEL: @test2(
+; CHECK-NEXT:  init:
+; CHECK-NEXT:    br label [[CONTROL_OUTER_OUTER:%.*]]
+; CHECK:       control.outer.loopexit.us-lcssa:
+; CHECK-NEXT:    br label [[CONTROL_OUTER_LOOPEXIT:%.*]]
+; CHECK:       control.outer.loopexit:
+; CHECK-NEXT:    br label [[CONTROL_OUTER_OUTER_BACKEDGE:%.*]]
+; CHECK:       control.outer.outer:
+; CHECK-NEXT:    [[SWITCHCOND_0_PH_PH:%.*]] = phi i32 [ 2, [[INIT:%.*]] ], [ 3, [[CONTROL_OUTER_OUTER_BACKEDGE]] ]
+; CHECK-NEXT:    [[I_0_PH_PH:%.*]] = phi i32 [ undef, [[INIT]] ], [ [[I_0_PH_PH_BE:%.*]], [[CONTROL_OUTER_OUTER_BACKEDGE]] ]
+; CHECK-NEXT:    [[TMP4:%.*]] = icmp eq i32 [[I_0_PH_PH]], 0
+; CHECK-NEXT:    br i1 [[TMP4]], label [[CONTROL_OUTER_OUTER_SPLIT_US:%.*]], label [[CONTROL_OUTER_OUTER_CONTROL_OUTER_OUTER_SPLIT_CRIT_EDGE:%.*]]
+; CHECK:       control.outer.outer.control.outer.outer.split_crit_edge:
+; CHECK-NEXT:    br label [[CONTROL_OUTER:%.*]]
+; CHECK:       control.outer.outer.split.us:
+; CHECK-NEXT:    br label [[CONTROL_OUTER_US:%.*]]
+; CHECK:       control.outer.us:
+; CHECK-NEXT:    [[A_0_PH_US:%.*]] = phi i32 [ [[SWITCHCOND_0_US:%.*]], [[BB3_US:%.*]] ], [ 4, [[CONTROL_OUTER_OUTER_SPLIT_US]] ]
+; CHECK-NEXT:    [[SWITCHCOND_0_PH_US:%.*]] = phi i32 [ [[A_0_PH_US]], [[BB3_US]] ], [ [[SWITCHCOND_0_PH_PH]], [[CONTROL_OUTER_OUTER_SPLIT_US]] ]
+; CHECK-NEXT:    br label [[CONTROL_US:%.*]]
+; CHECK:       bb3.us:
+; CHECK-NEXT:    br label [[CONTROL_OUTER_US]]
+; CHECK:       bb0.us:
+; CHECK-NEXT:    br label [[CONTROL_US]]
+; CHECK:       control.us:
+; CHECK-NEXT:    [[SWITCHCOND_0_US]] = phi i32 [ [[A_0_PH_US]], [[BB0_US:%.*]] ], [ [[SWITCHCOND_0_PH_US]], [[CONTROL_OUTER_US]] ]
+; CHECK-NEXT:    switch i32 [[SWITCHCOND_0_US]], label [[CONTROL_OUTER_LOOPEXIT_US_LCSSA_US:%.*]] [
+; CHECK-NEXT:    i32 0, label [[BB0_US]]
+; CHECK-NEXT:    i32 1, label [[BB1_US_LCSSA_US:%.*]]
+; CHECK-NEXT:    i32 3, label [[BB3_US]]
+; CHECK-NEXT:    i32 4, label [[BB4_US_LCSSA_US:%.*]]
+; CHECK-NEXT:    ]
+; CHECK:       control.outer.loopexit.us-lcssa.us:
+; CHECK-NEXT:    br label [[CONTROL_OUTER_LOOPEXIT]]
+; CHECK:       bb1.us-lcssa.us:
+; CHECK-NEXT:    br label [[BB1:%.*]]
+; CHECK:       bb4.us-lcssa.us:
+; CHECK-NEXT:    br label [[BB4:%.*]]
+; CHECK:       control.outer:
+; CHECK-NEXT:    [[A_0_PH:%.*]] = phi i32 [ [[NEXTID17:%.*]], [[BB3:%.*]] ], [ 4, [[CONTROL_OUTER_OUTER_CONTROL_OUTER_OUTER_SPLIT_CRIT_EDGE]] ]
+; CHECK-NEXT:    [[SWITCHCOND_0_PH:%.*]] = phi i32 [ 0, [[BB3]] ], [ [[SWITCHCOND_0_PH_PH]], [[CONTROL_OUTER_OUTER_CONTROL_OUTER_OUTER_SPLIT_CRIT_EDGE]] ]
+; CHECK-NEXT:    br label [[CONTROL:%.*]]
+; CHECK:       control:
+; CHECK-NEXT:    [[SWITCHCOND_0:%.*]] = phi i32 [ [[A_0_PH]], [[BB0:%.*]] ], [ [[SWITCHCOND_0_PH]], [[CONTROL_OUTER]] ]
+; CHECK-NEXT:    switch i32 [[SWITCHCOND_0]], label [[CONTROL_OUTER_LOOPEXIT_US_LCSSA:%.*]] [
+; CHECK-NEXT:    i32 0, label [[BB0]]
+; CHECK-NEXT:    i32 1, label [[BB1_US_LCSSA:%.*]]
+; CHECK-NEXT:    i32 3, label [[BB3]]
+; CHECK-NEXT:    i32 4, label [[BB4_US_LCSSA:%.*]]
+; CHECK-NEXT:    ]
+; CHECK:       bb4.us-lcssa:
+; CHECK-NEXT:    br label [[BB4]]
+; CHECK:       bb4:
+; CHECK-NEXT:    br label [[CONTROL_OUTER_OUTER_BACKEDGE]]
+; CHECK:       control.outer.outer.backedge:
+; CHECK-NEXT:    [[I_0_PH_PH_BE]] = phi i32 [ 1, [[BB4]] ], [ 0, [[CONTROL_OUTER_LOOPEXIT]] ]
+; CHECK-NEXT:    br label [[CONTROL_OUTER_OUTER]]
+; CHECK:       bb3:
+; CHECK-NEXT:    [[NEXTID17]] = add i32 [[SWITCHCOND_0]], -2
+; CHECK-NEXT:    br label [[CONTROL_OUTER]]
+; CHECK:       bb0:
+; CHECK-NEXT:    br label [[CONTROL]]
+; CHECK:       bb1.us-lcssa:
+; CHECK-NEXT:    br label [[BB1]]
+; CHECK:       bb1:
+; CHECK-NEXT:    ret i32 0
+;
 init:
   br label %control.outer.outer
 
@@ -46,16 +115,13 @@ bb3.us:                                           ; preds = %control.us
 bb0.us:                                           ; preds = %control.us
   br label %control.us
 
-; CHECK: control.us:                                       ; preds = %bb0.us, %control.outer.us
-; CHECK-NEXT:  %switchCond.0.us = phi i32
-; CHECK-NEXT:  switch i32 %switchCond.0.us
 control.us:                                       ; preds = %bb0.us, %control.outer.us
   %switchCond.0.us = phi i32 [ %A.0.ph.us, %bb0.us ], [ %switchCond.0.ph.us, %control.outer.us ] ; <i32> [#uses=2]
   switch i32 %switchCond.0.us, label %control.outer.loopexit.us-lcssa.us [
-    i32 0, label %bb0.us
-    i32 1, label %bb1.us-lcssa.us
-    i32 3, label %bb3.us
-    i32 4, label %bb4.us-lcssa.us
+  i32 0, label %bb0.us
+  i32 1, label %bb1.us-lcssa.us
+  i32 3, label %bb3.us
+  i32 4, label %bb4.us-lcssa.us
   ]
 
 control.outer.loopexit.us-lcssa.us:               ; preds = %control.us
@@ -75,10 +141,10 @@ control.outer:                                    ; preds = %bb3, %control.outer
 control:                                          ; preds = %bb0, %control.outer
   %switchCond.0 = phi i32 [ %A.0.ph, %bb0 ], [ %switchCond.0.ph, %control.outer ] ; <i32> [#uses=2]
   switch i32 %switchCond.0, label %control.outer.loopexit.us-lcssa [
-    i32 0, label %bb0
-    i32 1, label %bb1.us-lcssa
-    i32 3, label %bb3
-    i32 4, label %bb4.us-lcssa
+  i32 0, label %bb0
+  i32 1, label %bb1.us-lcssa
+  i32 3, label %bb3
+  i32 4, label %bb4.us-lcssa
   ]
 
 bb4.us-lcssa:                                     ; preds = %control
@@ -108,83 +174,105 @@ bb1:                                              ; preds = %bb1.us-lcssa, %bb1.
 ; Make sure SCCP honors the xor "idiom"
 ; rdar://9956541
 define i32 @test3() {
+; CHECK-LABEL: @test3(
+; CHECK-NEXT:    [[T:%.*]] = xor i32 undef, undef
+; CHECK-NEXT:    ret i32 [[T]]
+;
   %t = xor i32 undef, undef
   ret i32 %t
-; CHECK-LABEL: @test3(
-; CHECK: ret i32 0
 }
 
 ; Be conservative with FP ops
 define double @test4(double %x) {
+; CHECK-LABEL: @test4(
+; CHECK-NEXT:    [[T:%.*]] = fadd double [[X:%.*]], undef
+; CHECK-NEXT:    ret double [[T]]
+;
   %t = fadd double %x, undef
   ret double %t
-; CHECK-LABEL: @test4(
-; CHECK: fadd double %x, undef
 }
 
 ; Make sure casts produce a possible value
 define i32 @test5() {
+; CHECK-LABEL: @test5(
+; CHECK-NEXT:    [[T:%.*]] = sext i8 undef to i32
+; CHECK-NEXT:    ret i32 [[T]]
+;
   %t = sext i8 undef to i32
   ret i32 %t
-; CHECK-LABEL: @test5(
-; CHECK: ret i32 0
 }
 
 ; Make sure ashr produces a possible value
 define i32 @test6() {
+; CHECK-LABEL: @test6(
+; CHECK-NEXT:    [[T:%.*]] = ashr i32 undef, 31
+; CHECK-NEXT:    ret i32 [[T]]
+;
   %t = ashr i32 undef, 31
   ret i32 %t
-; CHECK-LABEL: @test6(
-; CHECK: ret i32 0
 }
 
 ; Make sure lshr produces a possible value
 define i32 @test7() {
+; CHECK-LABEL: @test7(
+; CHECK-NEXT:    [[T:%.*]] = lshr i32 undef, 31
+; CHECK-NEXT:    ret i32 [[T]]
+;
   %t = lshr i32 undef, 31
   ret i32 %t
-; CHECK-LABEL: @test7(
-; CHECK: ret i32 0
 }
 
 ; icmp eq with undef simplifies to undef
 define i1 @test8() {
+; CHECK-LABEL: @test8(
+; CHECK-NEXT:    [[T:%.*]] = icmp eq i32 undef, -1
+; CHECK-NEXT:    ret i1 [[T]]
+;
   %t = icmp eq i32 undef, -1
   ret i1 %t
-; CHECK-LABEL: @test8(
-; CHECK: ret i1 undef
 }
 
 ; Make sure we don't conclude that relational comparisons simplify to undef
 define i1 @test9() {
+; CHECK-LABEL: @test9(
+; CHECK-NEXT:    [[T:%.*]] = icmp ugt i32 undef, -1
+; CHECK-NEXT:    ret i1 [[T]]
+;
   %t = icmp ugt i32 undef, -1
   ret i1 %t
-; CHECK-LABEL: @test9(
-; CHECK: icmp ugt
 }
 
 ; Make sure we handle extractvalue
-define i64 @test10() { 
+define i64 @test10() {
+; CHECK-LABEL: @test10(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[E:%.*]] = extractvalue { i64, i64 } undef, 1
+; CHECK-NEXT:    ret i64 [[E]]
+;
 entry:
   %e = extractvalue { i64, i64 } undef, 1
   ret i64 %e
-; CHECK-LABEL: @test10(
-; CHECK: ret i64 undef
 }
 
 @GV = external global i32
 
 define i32 @test11(i1 %tobool) {
+; CHECK-LABEL: @test11(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[SHR4:%.*]] = ashr i32 undef, zext (i1 icmp eq (i32* bitcast (i32 (i1)* @test11 to i32*), i32* @GV) to i32)
+; CHECK-NEXT:    ret i32 [[SHR4]]
+;
 entry:
   %shr4 = ashr i32 undef, zext (i1 icmp eq (i32* bitcast (i32 (i1)* @test11 to i32*), i32* @GV) to i32)
   ret i32 %shr4
-; CHECK-LABEL: @test11(
-; CHECK: ret i32 0
 }
 
 ; Test unary ops
 define double @test12(double %x) {
+; CHECK-LABEL: @test12(
+; CHECK-NEXT:    [[T:%.*]] = fneg double undef
+; CHECK-NEXT:    ret double [[T]]
+;
   %t = fneg double undef
   ret double %t
-; CHECK-LABEL: @test12(
-; CHECK: double undef
 }


        


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