From: Roman Lebedev <lebedev.ri@gmail.com>
Date: Tue, 13 Aug 2019 12:49:28 +0000 (+0000)
Subject: [InstCombine] Non-canonical clamp-like pattern handling
X-Git-Tag: llvmorg-11-init~12036
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=73f702ff192475b27039325a7428ce037771a5de;p=platform%2Fupstream%2Fllvm.git

[InstCombine] Non-canonical clamp-like pattern handling

Summary:
Given a pattern like:
```
%old_cmp1 = icmp slt i32 %x, C2
%old_replacement = select i1 %old_cmp1, i32 %target_low, i32 %target_high
%old_x_offseted = add i32 %x, C1
%old_cmp0 = icmp ult i32 %old_x_offseted, C0
%r = select i1 %old_cmp0, i32 %x, i32 %old_replacement
```
it can be rewritten as more canonical pattern:
```
%new_cmp1 = icmp slt i32 %x, -C1
%new_cmp2 = icmp sge i32 %x, C0-C1
%new_clamped_low = select i1 %new_cmp1, i32 %target_low, i32 %x
%r = select i1 %new_cmp2, i32 %target_high, i32 %new_clamped_low
```
Iff `-C1 s<= C2 s<= C0-C1`
Also, `ULT` predicate can also be `UGE`; or `UGT` iff `C0 != -1` (+invert result)
Also, `SLT` predicate can also be `SGE`; or `SGT` iff `C2 != INT_MAX` (+invert result)

If `C1 == 0`, then all 3 instructions must be one-use; else at most either `%old_cmp1` or `%old_x_offseted` can have extra uses.
NOTE: if we could reuse `%old_cmp1` as one of the comparisons we'll have to build, this could be less limiting.

So there are two icmp's, each one with 3 predicate variants, so there are 9 fold variants:

|     | ULT                            | UGE                             | UGT                             |
| SLT | https://rise4fun.com/Alive/yIJ | https://rise4fun.com/Alive/5BfN | https://rise4fun.com/Alive/INH  |
| SGE | https://rise4fun.com/Alive/hd8 | https://rise4fun.com/Alive/Abk  | https://rise4fun.com/Alive/PlzS |
| SGT | https://rise4fun.com/Alive/VYG | https://rise4fun.com/Alive/oMY  | https://rise4fun.com/Alive/KrzC |
{F9730206}

This fold was brought up in https://reviews.llvm.org/D65148#1603922 by @dmgreen, and is needed to unblock that patch.
This patch requires D65530.

Reviewers: spatel, nikic, xbolva00, dmgreen

Reviewed By: spatel

Subscribers: hiraditya, llvm-commits, dmgreen

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D65765

llvm-svn: 368687
---

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
index 8950d92..45c0f4e 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
@@ -1118,6 +1118,149 @@ static Value *foldSelectValueEquivalence(SelectInst &Sel, ICmpInst &Cmp,
   return nullptr;
 }
 
+// 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
+//   %old_x_offseted = add i32 %x, C1
+//   %old_cmp0 = icmp ult i32 %old_x_offseted, C0
+//   %r = select i1 %old_cmp0, i32 %x, i32 %old_replacement
+// This can be rewritten as more canonical pattern:
+//   %new_cmp1 = icmp slt i32 %x, -C1
+//   %new_cmp2 = icmp sge i32 %x, C0-C1
+//   %new_clamped_low = select i1 %new_cmp1, i32 %target_low, i32 %x
+//   %r = select i1 %new_cmp2, i32 %target_high, i32 %new_clamped_low
+// Iff -C1 s<= C2 s<= C0-C1
+// Also ULT predicate can also be UGT iff C0 != -1 (+invert result)
+//      SLT predicate can also be SGT iff C2 != INT_MAX (+invert res.)
+static Instruction *canonicalizeClampLike(SelectInst &Sel0, ICmpInst &Cmp0,
+                                          InstCombiner::BuilderTy &Builder) {
+  Value *X = Sel0.getTrueValue();
+  Value *Sel1 = Sel0.getFalseValue();
+
+  // First match the condition of the outermost select.
+  // Said condition must be one-use.
+  if (!Cmp0.hasOneUse())
+    return nullptr;
+  Value *Cmp00 = Cmp0.getOperand(0);
+  Constant *C0;
+  if (!match(Cmp0.getOperand(1),
+             m_CombineAnd(m_AnyIntegralConstant(), m_Constant(C0))))
+    return nullptr;
+  // Canonicalize Cmp0 into the form we expect.
+  // FIXME: we shouldn't care about lanes that are 'undef' in the end?
+  switch (Cmp0.getPredicate()) {
+  case ICmpInst::Predicate::ICMP_ULT:
+    break; // Great!
+  case ICmpInst::Predicate::ICMP_ULE:
+    // We'd have to increment C0 by one, and for that it must not have all-ones
+    // element, but then it would have been canonicalized to 'ult' before
+    // we get here. So we can't do anything useful with 'ule'.
+    return nullptr;
+  case ICmpInst::Predicate::ICMP_UGT:
+    // We want to canonicalize it to 'ult', so we'll need to increment C0,
+    // which again means it must not have any all-ones elements.
+    if (!match(C0,
+               m_SpecificInt_ICMP(ICmpInst::Predicate::ICMP_NE,
+                                  APInt::getAllOnesValue(
+                                      C0->getType()->getScalarSizeInBits()))))
+      return nullptr; // Can't do, have all-ones element[s].
+    C0 = AddOne(C0);
+    std::swap(X, Sel1);
+    break;
+  case ICmpInst::Predicate::ICMP_UGE:
+    // The only way we'd get this predicate if this `icmp` has extra uses,
+    // but then we won't be able to do this fold.
+    return nullptr;
+  default:
+    return nullptr; // Unknown predicate.
+  }
+
+  // Now that we've canonicalized the ICmp, we know the X we expect;
+  // the select in other hand should be one-use.
+  if (!Sel1->hasOneUse())
+    return nullptr;
+
+  // We now can finish matching the condition of the outermost select:
+  // it should either be the X itself, or an addition of some constant to X.
+  Constant *C1;
+  if (Cmp00 == X)
+    C1 = ConstantInt::getNullValue(Sel0.getType());
+  else if (!match(Cmp00,
+                  m_Add(m_Specific(X),
+                        m_CombineAnd(m_AnyIntegralConstant(), m_Constant(C1)))))
+    return nullptr;
+
+  Value *Cmp1;
+  ICmpInst::Predicate Pred1;
+  Constant *C2;
+  Value *ReplacementLow, *ReplacementHigh;
+  if (!match(Sel1, m_Select(m_Value(Cmp1), m_Value(ReplacementLow),
+                            m_Value(ReplacementHigh))) ||
+      !match(Cmp1,
+             m_ICmp(Pred1, m_Specific(X),
+                    m_CombineAnd(m_AnyIntegralConstant(), m_Constant(C2)))))
+    return nullptr;
+
+  if (!Cmp1->hasOneUse() && (Cmp00 == X || !Cmp00->hasOneUse()))
+    return nullptr; // Not enough one-use instructions for the fold.
+  // FIXME: this restriction could be relaxed if Cmp1 can be reused as one of
+  //        two comparisons we'll need to build.
+
+  // Canonicalize Cmp1 into the form we expect.
+  // FIXME: we shouldn't care about lanes that are 'undef' in the end?
+  switch (Pred1) {
+  case ICmpInst::Predicate::ICMP_SLT:
+    break;
+  case ICmpInst::Predicate::ICMP_SLE:
+    // We'd have to increment C2 by one, and for that it must not have signed
+    // max element, but then it would have been canonicalized to 'slt' before
+    // we get here. So we can't do anything useful with 'sle'.
+    return nullptr;
+  case ICmpInst::Predicate::ICMP_SGT:
+    // We want to canonicalize it to 'slt', so we'll need to increment C2,
+    // which again means it must not have any signed max elements.
+    if (!match(C2,
+               m_SpecificInt_ICMP(ICmpInst::Predicate::ICMP_NE,
+                                  APInt::getSignedMaxValue(
+                                      C2->getType()->getScalarSizeInBits()))))
+      return nullptr; // Can't do, have signed max element[s].
+    C2 = AddOne(C2);
+    LLVM_FALLTHROUGH;
+  case ICmpInst::Predicate::ICMP_SGE:
+    // Also non-canonical, but here we don't need to change C2,
+    // so we don't have any restrictions on C2, so we can just handle it.
+    std::swap(ReplacementLow, ReplacementHigh);
+    break;
+  default:
+    return nullptr; // Unknown predicate.
+  }
+
+  // The thresholds of this clamp-like pattern.
+  auto *ThresholdLowIncl = ConstantExpr::getNeg(C1);
+  auto *ThresholdHighExcl = ConstantExpr::getSub(C0, C1);
+
+  // The fold has a precondition 1: C2 s>= ThresholdLow
+  auto *Precond1 = ConstantExpr::getICmp(ICmpInst::Predicate::ICMP_SGE, C2,
+                                         ThresholdLowIncl);
+  if (!match(Precond1, m_One()))
+    return nullptr;
+  // The fold has a precondition 2: C2 s<= ThresholdHigh
+  auto *Precond2 = ConstantExpr::getICmp(ICmpInst::Predicate::ICMP_SLE, C2,
+                                         ThresholdHighExcl);
+  if (!match(Precond2, m_One()))
+    return nullptr;
+
+  // All good, finally emit the new pattern.
+  Value *ShouldReplaceLow = Builder.CreateICmpSLT(X, ThresholdLowIncl);
+  Value *ShouldReplaceHigh = Builder.CreateICmpSGE(X, ThresholdHighExcl);
+  Value *MaybeReplacedLow =
+      Builder.CreateSelect(ShouldReplaceLow, ReplacementLow, X);
+  Instruction *MaybeReplacedHigh =
+      SelectInst::Create(ShouldReplaceHigh, ReplacementHigh, MaybeReplacedLow);
+
+  return MaybeReplacedHigh;
+}
+
 /// Visit a SelectInst that has an ICmpInst as its first operand.
 Instruction *InstCombiner::foldSelectInstWithICmp(SelectInst &SI,
                                                   ICmpInst *ICI) {
@@ -1130,6 +1273,9 @@ Instruction *InstCombiner::foldSelectInstWithICmp(SelectInst &SI,
   if (Instruction *NewAbs = canonicalizeAbsNabs(SI, *ICI, Builder))
     return NewAbs;
 
+  if (Instruction *NewAbs = canonicalizeClampLike(SI, *ICI, Builder))
+    return NewAbs;
+
   bool Changed = adjustMinMax(SI, *ICI);
 
   if (Value *V = foldSelectICmpAnd(SI, ICI, Builder))
diff --git a/llvm/test/Transforms/InstCombine/canonicalize-clamp-like-pattern-between-negative-and-positive-thresholds.ll b/llvm/test/Transforms/InstCombine/canonicalize-clamp-like-pattern-between-negative-and-positive-thresholds.ll
index 141bf66..7daac62 100644
--- a/llvm/test/Transforms/InstCombine/canonicalize-clamp-like-pattern-between-negative-and-positive-thresholds.ll
+++ b/llvm/test/Transforms/InstCombine/canonicalize-clamp-like-pattern-between-negative-and-positive-thresholds.ll
@@ -25,11 +25,10 @@
 
 define i32 @t0_ult_slt_128(i32 %x, i32 %replacement_low, i32 %replacement_high) {
 ; CHECK-LABEL: @t0_ult_slt_128(
-; CHECK-NEXT:    [[T0:%.*]] = icmp slt i32 [[X:%.*]], 128
-; CHECK-NEXT:    [[T1:%.*]] = select i1 [[T0]], i32 [[REPLACEMENT_LOW:%.*]], i32 [[REPLACEMENT_HIGH:%.*]]
-; CHECK-NEXT:    [[T2:%.*]] = add i32 [[X]], 16
-; CHECK-NEXT:    [[T3:%.*]] = icmp ult i32 [[T2]], 144
-; CHECK-NEXT:    [[R:%.*]] = select i1 [[T3]], i32 [[X]], i32 [[T1]]
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp slt i32 [[X:%.*]], -16
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp slt i32 [[X]], 128
+; CHECK-NEXT:    [[TMP3:%.*]] = select i1 [[TMP1]], i32 [[REPLACEMENT_LOW:%.*]], i32 [[X]]
+; CHECK-NEXT:    [[R:%.*]] = select i1 [[TMP2]], i32 [[TMP3]], i32 [[REPLACEMENT_HIGH:%.*]]
 ; CHECK-NEXT:    ret i32 [[R]]
 ;
   %t0 = icmp slt i32 %x, 128
@@ -41,11 +40,10 @@ define i32 @t0_ult_slt_128(i32 %x, i32 %replacement_low, i32 %replacement_high)
 }
 define i32 @t1_ult_slt_0(i32 %x, i32 %replacement_low, i32 %replacement_high) {
 ; CHECK-LABEL: @t1_ult_slt_0(
-; CHECK-NEXT:    [[T0:%.*]] = icmp slt i32 [[X:%.*]], -16
-; CHECK-NEXT:    [[T1:%.*]] = select i1 [[T0]], i32 [[REPLACEMENT_LOW:%.*]], i32 [[REPLACEMENT_HIGH:%.*]]
-; CHECK-NEXT:    [[T2:%.*]] = add i32 [[X]], 16
-; CHECK-NEXT:    [[T3:%.*]] = icmp ult i32 [[T2]], 144
-; CHECK-NEXT:    [[R:%.*]] = select i1 [[T3]], i32 [[X]], i32 [[T1]]
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp slt i32 [[X:%.*]], -16
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp slt i32 [[X]], 128
+; CHECK-NEXT:    [[TMP3:%.*]] = select i1 [[TMP1]], i32 [[REPLACEMENT_LOW:%.*]], i32 [[X]]
+; CHECK-NEXT:    [[R:%.*]] = select i1 [[TMP2]], i32 [[TMP3]], i32 [[REPLACEMENT_HIGH:%.*]]
 ; CHECK-NEXT:    ret i32 [[R]]
 ;
   %t0 = icmp slt i32 %x, -16
@@ -58,11 +56,10 @@ define i32 @t1_ult_slt_0(i32 %x, i32 %replacement_low, i32 %replacement_high) {
 
 define i32 @t2_ult_sgt_128(i32 %x, i32 %replacement_low, i32 %replacement_high) {
 ; CHECK-LABEL: @t2_ult_sgt_128(
-; CHECK-NEXT:    [[T0:%.*]] = icmp sgt i32 [[X:%.*]], 127
-; CHECK-NEXT:    [[T1:%.*]] = select i1 [[T0]], i32 [[REPLACEMENT_HIGH:%.*]], i32 [[REPLACEMENT_LOW:%.*]]
-; CHECK-NEXT:    [[T2:%.*]] = add i32 [[X]], 16
-; CHECK-NEXT:    [[T3:%.*]] = icmp ult i32 [[T2]], 144
-; CHECK-NEXT:    [[R:%.*]] = select i1 [[T3]], i32 [[X]], i32 [[T1]]
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp slt i32 [[X:%.*]], -16
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp slt i32 [[X]], 128
+; CHECK-NEXT:    [[TMP3:%.*]] = select i1 [[TMP1]], i32 [[REPLACEMENT_LOW:%.*]], i32 [[X]]
+; CHECK-NEXT:    [[R:%.*]] = select i1 [[TMP2]], i32 [[TMP3]], i32 [[REPLACEMENT_HIGH:%.*]]
 ; CHECK-NEXT:    ret i32 [[R]]
 ;
   %t0 = icmp sgt i32 %x, 127
@@ -74,11 +71,10 @@ define i32 @t2_ult_sgt_128(i32 %x, i32 %replacement_low, i32 %replacement_high)
 }
 define i32 @t3_ult_sgt_neg1(i32 %x, i32 %replacement_low, i32 %replacement_high) {
 ; CHECK-LABEL: @t3_ult_sgt_neg1(
-; CHECK-NEXT:    [[T0:%.*]] = icmp sgt i32 [[X:%.*]], -17
-; CHECK-NEXT:    [[T1:%.*]] = select i1 [[T0]], i32 [[REPLACEMENT_HIGH:%.*]], i32 [[REPLACEMENT_LOW:%.*]]
-; CHECK-NEXT:    [[T2:%.*]] = add i32 [[X]], 16
-; CHECK-NEXT:    [[T3:%.*]] = icmp ult i32 [[T2]], 144
-; CHECK-NEXT:    [[R:%.*]] = select i1 [[T3]], i32 [[X]], i32 [[T1]]
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp slt i32 [[X:%.*]], -16
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp slt i32 [[X]], 128
+; CHECK-NEXT:    [[TMP3:%.*]] = select i1 [[TMP1]], i32 [[REPLACEMENT_LOW:%.*]], i32 [[X]]
+; CHECK-NEXT:    [[R:%.*]] = select i1 [[TMP2]], i32 [[TMP3]], i32 [[REPLACEMENT_HIGH:%.*]]
 ; CHECK-NEXT:    ret i32 [[R]]
 ;
   %t0 = icmp sgt i32 %x, -17
@@ -91,11 +87,10 @@ define i32 @t3_ult_sgt_neg1(i32 %x, i32 %replacement_low, i32 %replacement_high)
 
 define i32 @t4_ugt_slt_128(i32 %x, i32 %replacement_low, i32 %replacement_high) {
 ; CHECK-LABEL: @t4_ugt_slt_128(
-; CHECK-NEXT:    [[T0:%.*]] = icmp slt i32 [[X:%.*]], 128
-; CHECK-NEXT:    [[T1:%.*]] = select i1 [[T0]], i32 [[REPLACEMENT_LOW:%.*]], i32 [[REPLACEMENT_HIGH:%.*]]
-; CHECK-NEXT:    [[T2:%.*]] = add i32 [[X]], 16
-; CHECK-NEXT:    [[T3:%.*]] = icmp ugt i32 [[T2]], 143
-; CHECK-NEXT:    [[R:%.*]] = select i1 [[T3]], i32 [[T1]], i32 [[X]]
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp slt i32 [[X:%.*]], -16
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp slt i32 [[X]], 128
+; CHECK-NEXT:    [[TMP3:%.*]] = select i1 [[TMP1]], i32 [[REPLACEMENT_LOW:%.*]], i32 [[X]]
+; CHECK-NEXT:    [[R:%.*]] = select i1 [[TMP2]], i32 [[TMP3]], i32 [[REPLACEMENT_HIGH:%.*]]
 ; CHECK-NEXT:    ret i32 [[R]]
 ;
   %t0 = icmp slt i32 %x, 128
@@ -107,11 +102,10 @@ define i32 @t4_ugt_slt_128(i32 %x, i32 %replacement_low, i32 %replacement_high)
 }
 define i32 @t5_ugt_slt_0(i32 %x, i32 %replacement_low, i32 %replacement_high) {
 ; CHECK-LABEL: @t5_ugt_slt_0(
-; CHECK-NEXT:    [[T0:%.*]] = icmp slt i32 [[X:%.*]], -16
-; CHECK-NEXT:    [[T1:%.*]] = select i1 [[T0]], i32 [[REPLACEMENT_LOW:%.*]], i32 [[REPLACEMENT_HIGH:%.*]]
-; CHECK-NEXT:    [[T2:%.*]] = add i32 [[X]], 16
-; CHECK-NEXT:    [[T3:%.*]] = icmp ugt i32 [[T2]], 143
-; CHECK-NEXT:    [[R:%.*]] = select i1 [[T3]], i32 [[T1]], i32 [[X]]
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp slt i32 [[X:%.*]], -16
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp slt i32 [[X]], 128
+; CHECK-NEXT:    [[TMP3:%.*]] = select i1 [[TMP1]], i32 [[REPLACEMENT_LOW:%.*]], i32 [[X]]
+; CHECK-NEXT:    [[R:%.*]] = select i1 [[TMP2]], i32 [[TMP3]], i32 [[REPLACEMENT_HIGH:%.*]]
 ; CHECK-NEXT:    ret i32 [[R]]
 ;
   %t0 = icmp slt i32 %x, -16
@@ -124,11 +118,10 @@ define i32 @t5_ugt_slt_0(i32 %x, i32 %replacement_low, i32 %replacement_high) {
 
 define i32 @t6_ugt_sgt_128(i32 %x, i32 %replacement_low, i32 %replacement_high) {
 ; CHECK-LABEL: @t6_ugt_sgt_128(
-; CHECK-NEXT:    [[T0:%.*]] = icmp sgt i32 [[X:%.*]], 127
-; CHECK-NEXT:    [[T1:%.*]] = select i1 [[T0]], i32 [[REPLACEMENT_HIGH:%.*]], i32 [[REPLACEMENT_LOW:%.*]]
-; CHECK-NEXT:    [[T2:%.*]] = add i32 [[X]], 16
-; CHECK-NEXT:    [[T3:%.*]] = icmp ugt i32 [[T2]], 143
-; CHECK-NEXT:    [[R:%.*]] = select i1 [[T3]], i32 [[T1]], i32 [[X]]
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp slt i32 [[X:%.*]], -16
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp slt i32 [[X]], 128
+; CHECK-NEXT:    [[TMP3:%.*]] = select i1 [[TMP1]], i32 [[REPLACEMENT_LOW:%.*]], i32 [[X]]
+; CHECK-NEXT:    [[R:%.*]] = select i1 [[TMP2]], i32 [[TMP3]], i32 [[REPLACEMENT_HIGH:%.*]]
 ; CHECK-NEXT:    ret i32 [[R]]
 ;
   %t0 = icmp sgt i32 %x, 127
@@ -140,11 +133,10 @@ define i32 @t6_ugt_sgt_128(i32 %x, i32 %replacement_low, i32 %replacement_high)
 }
 define i32 @t7_ugt_sgt_neg1(i32 %x, i32 %replacement_low, i32 %replacement_high) {
 ; CHECK-LABEL: @t7_ugt_sgt_neg1(
-; CHECK-NEXT:    [[T0:%.*]] = icmp sgt i32 [[X:%.*]], -17
-; CHECK-NEXT:    [[T1:%.*]] = select i1 [[T0]], i32 [[REPLACEMENT_HIGH:%.*]], i32 [[REPLACEMENT_LOW:%.*]]
-; CHECK-NEXT:    [[T2:%.*]] = add i32 [[X]], 16
-; CHECK-NEXT:    [[T3:%.*]] = icmp ugt i32 [[T2]], 143
-; CHECK-NEXT:    [[R:%.*]] = select i1 [[T3]], i32 [[T1]], i32 [[X]]
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp slt i32 [[X:%.*]], -16
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp slt i32 [[X]], 128
+; CHECK-NEXT:    [[TMP3:%.*]] = select i1 [[TMP1]], i32 [[REPLACEMENT_LOW:%.*]], i32 [[X]]
+; CHECK-NEXT:    [[R:%.*]] = select i1 [[TMP2]], i32 [[TMP3]], i32 [[REPLACEMENT_HIGH:%.*]]
 ; CHECK-NEXT:    ret i32 [[R]]
 ;
   %t0 = icmp sgt i32 %x, -17
@@ -205,10 +197,10 @@ define i32 @t10_oneuse0(i32 %x, i32 %replacement_low, i32 %replacement_high) {
 ; CHECK-LABEL: @t10_oneuse0(
 ; CHECK-NEXT:    [[T0:%.*]] = icmp slt i32 [[X:%.*]], 64
 ; CHECK-NEXT:    call void @use1(i1 [[T0]])
-; CHECK-NEXT:    [[T1:%.*]] = select i1 [[T0]], i32 [[REPLACEMENT_LOW:%.*]], i32 [[REPLACEMENT_HIGH:%.*]]
-; CHECK-NEXT:    [[T2:%.*]] = add i32 [[X]], 16
-; CHECK-NEXT:    [[T3:%.*]] = icmp ult i32 [[T2]], 144
-; CHECK-NEXT:    [[R:%.*]] = select i1 [[T3]], i32 [[X]], i32 [[T1]]
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp slt i32 [[X]], -16
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp slt i32 [[X]], 128
+; CHECK-NEXT:    [[TMP3:%.*]] = select i1 [[TMP1]], i32 [[REPLACEMENT_LOW:%.*]], i32 [[X]]
+; CHECK-NEXT:    [[R:%.*]] = select i1 [[TMP2]], i32 [[TMP3]], i32 [[REPLACEMENT_HIGH:%.*]]
 ; CHECK-NEXT:    ret i32 [[R]]
 ;
   %t0 = icmp slt i32 %x, 64
@@ -241,12 +233,12 @@ define i32 @n11_oneuse1(i32 %x, i32 %replacement_low, i32 %replacement_high) {
 ; This one is ok.
 define i32 @t12_oneuse2(i32 %x, i32 %replacement_low, i32 %replacement_high) {
 ; CHECK-LABEL: @t12_oneuse2(
-; CHECK-NEXT:    [[T0:%.*]] = icmp slt i32 [[X:%.*]], 64
-; CHECK-NEXT:    [[T1:%.*]] = select i1 [[T0]], i32 [[REPLACEMENT_LOW:%.*]], i32 [[REPLACEMENT_HIGH:%.*]]
-; CHECK-NEXT:    [[T2:%.*]] = add i32 [[X]], 16
+; CHECK-NEXT:    [[T2:%.*]] = add i32 [[X:%.*]], 16
 ; CHECK-NEXT:    call void @use32(i32 [[T2]])
-; CHECK-NEXT:    [[T3:%.*]] = icmp ult i32 [[T2]], 144
-; CHECK-NEXT:    [[R:%.*]] = select i1 [[T3]], i32 [[X]], i32 [[T1]]
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp slt i32 [[X]], -16
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp slt i32 [[X]], 128
+; CHECK-NEXT:    [[TMP3:%.*]] = select i1 [[TMP1]], i32 [[REPLACEMENT_LOW:%.*]], i32 [[X]]
+; CHECK-NEXT:    [[R:%.*]] = select i1 [[TMP2]], i32 [[TMP3]], i32 [[REPLACEMENT_HIGH:%.*]]
 ; CHECK-NEXT:    ret i32 [[R]]
 ;
   %t0 = icmp slt i32 %x, 64
@@ -414,11 +406,10 @@ define i32 @n19_oneuse9(i32 %x, i32 %replacement_low, i32 %replacement_high) {
 
 define <2 x i32> @t20_ult_slt_vec_splat(<2 x i32> %x, <2 x i32> %replacement_low, <2 x i32> %replacement_high) {
 ; CHECK-LABEL: @t20_ult_slt_vec_splat(
-; CHECK-NEXT:    [[T0:%.*]] = icmp slt <2 x i32> [[X:%.*]], <i32 128, i32 128>
-; CHECK-NEXT:    [[T1:%.*]] = select <2 x i1> [[T0]], <2 x i32> [[REPLACEMENT_LOW:%.*]], <2 x i32> [[REPLACEMENT_HIGH:%.*]]
-; CHECK-NEXT:    [[T2:%.*]] = add <2 x i32> [[X]], <i32 16, i32 16>
-; CHECK-NEXT:    [[T3:%.*]] = icmp ult <2 x i32> [[T2]], <i32 144, i32 144>
-; CHECK-NEXT:    [[R:%.*]] = select <2 x i1> [[T3]], <2 x i32> [[X]], <2 x i32> [[T1]]
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp slt <2 x i32> [[X:%.*]], <i32 -16, i32 -16>
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp slt <2 x i32> [[X]], <i32 128, i32 128>
+; CHECK-NEXT:    [[TMP3:%.*]] = select <2 x i1> [[TMP1]], <2 x i32> [[REPLACEMENT_LOW:%.*]], <2 x i32> [[X]]
+; CHECK-NEXT:    [[R:%.*]] = select <2 x i1> [[TMP2]], <2 x i32> [[TMP3]], <2 x i32> [[REPLACEMENT_HIGH:%.*]]
 ; CHECK-NEXT:    ret <2 x i32> [[R]]
 ;
   %t0 = icmp slt <2 x i32> %x, <i32 128, i32 128>
@@ -430,11 +421,10 @@ define <2 x i32> @t20_ult_slt_vec_splat(<2 x i32> %x, <2 x i32> %replacement_low
 }
 define <2 x i32> @t21_ult_slt_vec_nonsplat(<2 x i32> %x, <2 x i32> %replacement_low, <2 x i32> %replacement_high) {
 ; CHECK-LABEL: @t21_ult_slt_vec_nonsplat(
-; CHECK-NEXT:    [[T0:%.*]] = icmp slt <2 x i32> [[X:%.*]], <i32 128, i32 64>
-; CHECK-NEXT:    [[T1:%.*]] = select <2 x i1> [[T0]], <2 x i32> [[REPLACEMENT_LOW:%.*]], <2 x i32> [[REPLACEMENT_HIGH:%.*]]
-; CHECK-NEXT:    [[T2:%.*]] = add <2 x i32> [[X]], <i32 16, i32 8>
-; CHECK-NEXT:    [[T3:%.*]] = icmp ult <2 x i32> [[T2]], <i32 144, i32 264>
-; CHECK-NEXT:    [[R:%.*]] = select <2 x i1> [[T3]], <2 x i32> [[X]], <2 x i32> [[T1]]
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp slt <2 x i32> [[X:%.*]], <i32 -16, i32 -8>
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp slt <2 x i32> [[X]], <i32 128, i32 256>
+; CHECK-NEXT:    [[TMP3:%.*]] = select <2 x i1> [[TMP1]], <2 x i32> [[REPLACEMENT_LOW:%.*]], <2 x i32> [[X]]
+; CHECK-NEXT:    [[R:%.*]] = select <2 x i1> [[TMP2]], <2 x i32> [[TMP3]], <2 x i32> [[REPLACEMENT_HIGH:%.*]]
 ; CHECK-NEXT:    ret <2 x i32> [[R]]
 ;
   %t0 = icmp slt <2 x i32> %x, <i32 128, i32 64>
@@ -473,10 +463,10 @@ define <2 x i32> @t23_ult_sge(<2 x i32> %x, <2 x i32> %replacement_low, <2 x i32
 ; CHECK-LABEL: @t23_ult_sge(
 ; CHECK-NEXT:    [[T0:%.*]] = icmp sge <2 x i32> [[X:%.*]], <i32 128, i32 -2147483648>
 ; CHECK-NEXT:    call void @use2xi1(<2 x i1> [[T0]])
-; CHECK-NEXT:    [[T1:%.*]] = select <2 x i1> [[T0]], <2 x i32> [[REPLACEMENT_HIGH:%.*]], <2 x i32> [[REPLACEMENT_LOW:%.*]]
-; CHECK-NEXT:    [[T2:%.*]] = add <2 x i32> [[X]], <i32 16, i32 -2147483648>
-; CHECK-NEXT:    [[T3:%.*]] = icmp ult <2 x i32> [[T2]], <i32 144, i32 -1>
-; CHECK-NEXT:    [[R:%.*]] = select <2 x i1> [[T3]], <2 x i32> [[X]], <2 x i32> [[T1]]
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp slt <2 x i32> [[X]], <i32 -16, i32 -2147483648>
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp slt <2 x i32> [[X]], <i32 128, i32 2147483647>
+; CHECK-NEXT:    [[TMP3:%.*]] = select <2 x i1> [[TMP1]], <2 x i32> [[REPLACEMENT_LOW:%.*]], <2 x i32> [[X]]
+; CHECK-NEXT:    [[R:%.*]] = select <2 x i1> [[TMP2]], <2 x i32> [[TMP3]], <2 x i32> [[REPLACEMENT_HIGH:%.*]]
 ; CHECK-NEXT:    ret <2 x i32> [[R]]
 ;
   %t0 = icmp sge <2 x i32> %x, <i32 128, i32 -2147483648>
diff --git a/llvm/test/Transforms/InstCombine/canonicalize-clamp-like-pattern-between-zero-and-positive-threshold.ll b/llvm/test/Transforms/InstCombine/canonicalize-clamp-like-pattern-between-zero-and-positive-threshold.ll
index 103c086..3a35e4c 100644
--- a/llvm/test/Transforms/InstCombine/canonicalize-clamp-like-pattern-between-zero-and-positive-threshold.ll
+++ b/llvm/test/Transforms/InstCombine/canonicalize-clamp-like-pattern-between-zero-and-positive-threshold.ll
@@ -25,10 +25,10 @@
 
 define i32 @t0_ult_slt_65536(i32 %x, i32 %replacement_low, i32 %replacement_high) {
 ; CHECK-LABEL: @t0_ult_slt_65536(
-; CHECK-NEXT:    [[T0:%.*]] = icmp slt i32 [[X:%.*]], 65536
-; CHECK-NEXT:    [[T1:%.*]] = select i1 [[T0]], i32 [[REPLACEMENT_LOW:%.*]], i32 [[REPLACEMENT_HIGH:%.*]]
-; CHECK-NEXT:    [[T2:%.*]] = icmp ult i32 [[X]], 65536
-; CHECK-NEXT:    [[R:%.*]] = select i1 [[T2]], i32 [[X]], i32 [[T1]]
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp slt i32 [[X:%.*]], 0
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp slt i32 [[X]], 65536
+; CHECK-NEXT:    [[TMP3:%.*]] = select i1 [[TMP1]], i32 [[REPLACEMENT_LOW:%.*]], i32 [[X]]
+; CHECK-NEXT:    [[R:%.*]] = select i1 [[TMP2]], i32 [[TMP3]], i32 [[REPLACEMENT_HIGH:%.*]]
 ; CHECK-NEXT:    ret i32 [[R]]
 ;
   %t0 = icmp slt i32 %x, 65536
@@ -39,10 +39,10 @@ define i32 @t0_ult_slt_65536(i32 %x, i32 %replacement_low, i32 %replacement_high
 }
 define i32 @t1_ult_slt_0(i32 %x, i32 %replacement_low, i32 %replacement_high) {
 ; CHECK-LABEL: @t1_ult_slt_0(
-; CHECK-NEXT:    [[T0:%.*]] = icmp slt i32 [[X:%.*]], 0
-; CHECK-NEXT:    [[T1:%.*]] = select i1 [[T0]], i32 [[REPLACEMENT_LOW:%.*]], i32 [[REPLACEMENT_HIGH:%.*]]
-; CHECK-NEXT:    [[T2:%.*]] = icmp ult i32 [[X]], 65536
-; CHECK-NEXT:    [[R:%.*]] = select i1 [[T2]], i32 [[X]], i32 [[T1]]
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp slt i32 [[X:%.*]], 0
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp slt i32 [[X]], 65536
+; CHECK-NEXT:    [[TMP3:%.*]] = select i1 [[TMP1]], i32 [[REPLACEMENT_LOW:%.*]], i32 [[X]]
+; CHECK-NEXT:    [[R:%.*]] = select i1 [[TMP2]], i32 [[TMP3]], i32 [[REPLACEMENT_HIGH:%.*]]
 ; CHECK-NEXT:    ret i32 [[R]]
 ;
   %t0 = icmp slt i32 %x, 0
@@ -54,10 +54,10 @@ define i32 @t1_ult_slt_0(i32 %x, i32 %replacement_low, i32 %replacement_high) {
 
 define i32 @t2_ult_sgt_65536(i32 %x, i32 %replacement_low, i32 %replacement_high) {
 ; CHECK-LABEL: @t2_ult_sgt_65536(
-; CHECK-NEXT:    [[T0:%.*]] = icmp sgt i32 [[X:%.*]], 65535
-; CHECK-NEXT:    [[T1:%.*]] = select i1 [[T0]], i32 [[REPLACEMENT_HIGH:%.*]], i32 [[REPLACEMENT_LOW:%.*]]
-; CHECK-NEXT:    [[T2:%.*]] = icmp ult i32 [[X]], 65536
-; CHECK-NEXT:    [[R:%.*]] = select i1 [[T2]], i32 [[X]], i32 [[T1]]
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp slt i32 [[X:%.*]], 0
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp slt i32 [[X]], 65536
+; CHECK-NEXT:    [[TMP3:%.*]] = select i1 [[TMP1]], i32 [[REPLACEMENT_LOW:%.*]], i32 [[X]]
+; CHECK-NEXT:    [[R:%.*]] = select i1 [[TMP2]], i32 [[TMP3]], i32 [[REPLACEMENT_HIGH:%.*]]
 ; CHECK-NEXT:    ret i32 [[R]]
 ;
   %t0 = icmp sgt i32 %x, 65535
@@ -68,10 +68,10 @@ define i32 @t2_ult_sgt_65536(i32 %x, i32 %replacement_low, i32 %replacement_high
 }
 define i32 @t3_ult_sgt_neg1(i32 %x, i32 %replacement_low, i32 %replacement_high) {
 ; CHECK-LABEL: @t3_ult_sgt_neg1(
-; CHECK-NEXT:    [[T0:%.*]] = icmp sgt i32 [[X:%.*]], -1
-; CHECK-NEXT:    [[T1:%.*]] = select i1 [[T0]], i32 [[REPLACEMENT_HIGH:%.*]], i32 [[REPLACEMENT_LOW:%.*]]
-; CHECK-NEXT:    [[T2:%.*]] = icmp ult i32 [[X]], 65536
-; CHECK-NEXT:    [[R:%.*]] = select i1 [[T2]], i32 [[X]], i32 [[T1]]
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp slt i32 [[X:%.*]], 0
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp slt i32 [[X]], 65536
+; CHECK-NEXT:    [[TMP3:%.*]] = select i1 [[TMP1]], i32 [[REPLACEMENT_LOW:%.*]], i32 [[X]]
+; CHECK-NEXT:    [[R:%.*]] = select i1 [[TMP2]], i32 [[TMP3]], i32 [[REPLACEMENT_HIGH:%.*]]
 ; CHECK-NEXT:    ret i32 [[R]]
 ;
   %t0 = icmp sgt i32 %x, -1
@@ -83,10 +83,10 @@ define i32 @t3_ult_sgt_neg1(i32 %x, i32 %replacement_low, i32 %replacement_high)
 
 define i32 @t4_ugt_slt_65536(i32 %x, i32 %replacement_low, i32 %replacement_high) {
 ; CHECK-LABEL: @t4_ugt_slt_65536(
-; CHECK-NEXT:    [[T0:%.*]] = icmp slt i32 [[X:%.*]], 65536
-; CHECK-NEXT:    [[T1:%.*]] = select i1 [[T0]], i32 [[REPLACEMENT_LOW:%.*]], i32 [[REPLACEMENT_HIGH:%.*]]
-; CHECK-NEXT:    [[T2:%.*]] = icmp ugt i32 [[X]], 65535
-; CHECK-NEXT:    [[R:%.*]] = select i1 [[T2]], i32 [[T1]], i32 [[X]]
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp slt i32 [[X:%.*]], 0
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp slt i32 [[X]], 65536
+; CHECK-NEXT:    [[TMP3:%.*]] = select i1 [[TMP1]], i32 [[REPLACEMENT_LOW:%.*]], i32 [[X]]
+; CHECK-NEXT:    [[R:%.*]] = select i1 [[TMP2]], i32 [[TMP3]], i32 [[REPLACEMENT_HIGH:%.*]]
 ; CHECK-NEXT:    ret i32 [[R]]
 ;
   %t0 = icmp slt i32 %x, 65536
@@ -97,10 +97,10 @@ define i32 @t4_ugt_slt_65536(i32 %x, i32 %replacement_low, i32 %replacement_high
 }
 define i32 @t5_ugt_slt_0(i32 %x, i32 %replacement_low, i32 %replacement_high) {
 ; CHECK-LABEL: @t5_ugt_slt_0(
-; CHECK-NEXT:    [[T0:%.*]] = icmp slt i32 [[X:%.*]], 0
-; CHECK-NEXT:    [[T1:%.*]] = select i1 [[T0]], i32 [[REPLACEMENT_LOW:%.*]], i32 [[REPLACEMENT_HIGH:%.*]]
-; CHECK-NEXT:    [[T2:%.*]] = icmp ugt i32 [[X]], 65535
-; CHECK-NEXT:    [[R:%.*]] = select i1 [[T2]], i32 [[T1]], i32 [[X]]
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp slt i32 [[X:%.*]], 0
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp slt i32 [[X]], 65536
+; CHECK-NEXT:    [[TMP3:%.*]] = select i1 [[TMP1]], i32 [[REPLACEMENT_LOW:%.*]], i32 [[X]]
+; CHECK-NEXT:    [[R:%.*]] = select i1 [[TMP2]], i32 [[TMP3]], i32 [[REPLACEMENT_HIGH:%.*]]
 ; CHECK-NEXT:    ret i32 [[R]]
 ;
   %t0 = icmp slt i32 %x, 0
@@ -112,10 +112,10 @@ define i32 @t5_ugt_slt_0(i32 %x, i32 %replacement_low, i32 %replacement_high) {
 
 define i32 @t6_ugt_sgt_65536(i32 %x, i32 %replacement_low, i32 %replacement_high) {
 ; CHECK-LABEL: @t6_ugt_sgt_65536(
-; CHECK-NEXT:    [[T0:%.*]] = icmp sgt i32 [[X:%.*]], 65535
-; CHECK-NEXT:    [[T1:%.*]] = select i1 [[T0]], i32 [[REPLACEMENT_HIGH:%.*]], i32 [[REPLACEMENT_LOW:%.*]]
-; CHECK-NEXT:    [[T2:%.*]] = icmp ugt i32 [[X]], 65535
-; CHECK-NEXT:    [[R:%.*]] = select i1 [[T2]], i32 [[T1]], i32 [[X]]
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp slt i32 [[X:%.*]], 0
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp slt i32 [[X]], 65536
+; CHECK-NEXT:    [[TMP3:%.*]] = select i1 [[TMP1]], i32 [[REPLACEMENT_LOW:%.*]], i32 [[X]]
+; CHECK-NEXT:    [[R:%.*]] = select i1 [[TMP2]], i32 [[TMP3]], i32 [[REPLACEMENT_HIGH:%.*]]
 ; CHECK-NEXT:    ret i32 [[R]]
 ;
   %t0 = icmp sgt i32 %x, 65535
@@ -126,10 +126,10 @@ define i32 @t6_ugt_sgt_65536(i32 %x, i32 %replacement_low, i32 %replacement_high
 }
 define i32 @t7_ugt_sgt_neg1(i32 %x, i32 %replacement_low, i32 %replacement_high) {
 ; CHECK-LABEL: @t7_ugt_sgt_neg1(
-; CHECK-NEXT:    [[T0:%.*]] = icmp sgt i32 [[X:%.*]], -1
-; CHECK-NEXT:    [[T1:%.*]] = select i1 [[T0]], i32 [[REPLACEMENT_HIGH:%.*]], i32 [[REPLACEMENT_LOW:%.*]]
-; CHECK-NEXT:    [[T2:%.*]] = icmp ugt i32 [[X]], 65535
-; CHECK-NEXT:    [[R:%.*]] = select i1 [[T2]], i32 [[T1]], i32 [[X]]
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp slt i32 [[X:%.*]], 0
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp slt i32 [[X]], 65536
+; CHECK-NEXT:    [[TMP3:%.*]] = select i1 [[TMP1]], i32 [[REPLACEMENT_LOW:%.*]], i32 [[X]]
+; CHECK-NEXT:    [[R:%.*]] = select i1 [[TMP2]], i32 [[TMP3]], i32 [[REPLACEMENT_HIGH:%.*]]
 ; CHECK-NEXT:    ret i32 [[R]]
 ;
   %t0 = icmp sgt i32 %x, -1
@@ -311,10 +311,10 @@ define i32 @n16_oneuse6(i32 %x, i32 %replacement_low, i32 %replacement_high) {
 
 define <2 x i32> @t17_ult_slt_vec_splat(<2 x i32> %x, <2 x i32> %replacement_low, <2 x i32> %replacement_high) {
 ; CHECK-LABEL: @t17_ult_slt_vec_splat(
-; CHECK-NEXT:    [[T0:%.*]] = icmp slt <2 x i32> [[X:%.*]], <i32 65536, i32 65536>
-; CHECK-NEXT:    [[T1:%.*]] = select <2 x i1> [[T0]], <2 x i32> [[REPLACEMENT_LOW:%.*]], <2 x i32> [[REPLACEMENT_HIGH:%.*]]
-; CHECK-NEXT:    [[T2:%.*]] = icmp ult <2 x i32> [[X]], <i32 65536, i32 65536>
-; CHECK-NEXT:    [[R:%.*]] = select <2 x i1> [[T2]], <2 x i32> [[X]], <2 x i32> [[T1]]
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp slt <2 x i32> [[X:%.*]], zeroinitializer
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp slt <2 x i32> [[X]], <i32 65536, i32 65536>
+; CHECK-NEXT:    [[TMP3:%.*]] = select <2 x i1> [[TMP1]], <2 x i32> [[REPLACEMENT_LOW:%.*]], <2 x i32> [[X]]
+; CHECK-NEXT:    [[R:%.*]] = select <2 x i1> [[TMP2]], <2 x i32> [[TMP3]], <2 x i32> [[REPLACEMENT_HIGH:%.*]]
 ; CHECK-NEXT:    ret <2 x i32> [[R]]
 ;
   %t0 = icmp slt <2 x i32> %x, <i32 65536, i32 65536>
@@ -325,10 +325,10 @@ define <2 x i32> @t17_ult_slt_vec_splat(<2 x i32> %x, <2 x i32> %replacement_low
 }
 define <2 x i32> @t18_ult_slt_vec_nonsplat(<2 x i32> %x, <2 x i32> %replacement_low, <2 x i32> %replacement_high) {
 ; CHECK-LABEL: @t18_ult_slt_vec_nonsplat(
-; CHECK-NEXT:    [[T0:%.*]] = icmp slt <2 x i32> [[X:%.*]], <i32 65536, i32 32768>
-; CHECK-NEXT:    [[T1:%.*]] = select <2 x i1> [[T0]], <2 x i32> [[REPLACEMENT_LOW:%.*]], <2 x i32> [[REPLACEMENT_HIGH:%.*]]
-; CHECK-NEXT:    [[T2:%.*]] = icmp ult <2 x i32> [[X]], <i32 65536, i32 32768>
-; CHECK-NEXT:    [[R:%.*]] = select <2 x i1> [[T2]], <2 x i32> [[X]], <2 x i32> [[T1]]
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp slt <2 x i32> [[X:%.*]], zeroinitializer
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp slt <2 x i32> [[X]], <i32 65536, i32 32768>
+; CHECK-NEXT:    [[TMP3:%.*]] = select <2 x i1> [[TMP1]], <2 x i32> [[REPLACEMENT_LOW:%.*]], <2 x i32> [[X]]
+; CHECK-NEXT:    [[R:%.*]] = select <2 x i1> [[TMP2]], <2 x i32> [[TMP3]], <2 x i32> [[REPLACEMENT_HIGH:%.*]]
 ; CHECK-NEXT:    ret <2 x i32> [[R]]
 ;
   %t0 = icmp slt <2 x i32> %x, <i32 65536, i32 32768>
@@ -340,10 +340,10 @@ define <2 x i32> @t18_ult_slt_vec_nonsplat(<2 x i32> %x, <2 x i32> %replacement_
 
 define <3 x i32> @t19_ult_slt_vec_undef0(<3 x i32> %x, <3 x i32> %replacement_low, <3 x i32> %replacement_high) {
 ; CHECK-LABEL: @t19_ult_slt_vec_undef0(
-; CHECK-NEXT:    [[T0:%.*]] = icmp slt <3 x i32> [[X:%.*]], <i32 65536, i32 undef, i32 65536>
-; CHECK-NEXT:    [[T1:%.*]] = select <3 x i1> [[T0]], <3 x i32> [[REPLACEMENT_LOW:%.*]], <3 x i32> [[REPLACEMENT_HIGH:%.*]]
-; CHECK-NEXT:    [[T2:%.*]] = icmp ult <3 x i32> [[X]], <i32 65536, i32 65536, i32 65536>
-; CHECK-NEXT:    [[R:%.*]] = select <3 x i1> [[T2]], <3 x i32> [[X]], <3 x i32> [[T1]]
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp slt <3 x i32> [[X:%.*]], zeroinitializer
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp slt <3 x i32> [[X]], <i32 65536, i32 65536, i32 65536>
+; CHECK-NEXT:    [[TMP3:%.*]] = select <3 x i1> [[TMP1]], <3 x i32> [[REPLACEMENT_LOW:%.*]], <3 x i32> [[X]]
+; CHECK-NEXT:    [[R:%.*]] = select <3 x i1> [[TMP2]], <3 x i32> [[TMP3]], <3 x i32> [[REPLACEMENT_HIGH:%.*]]
 ; CHECK-NEXT:    ret <3 x i32> [[R]]
 ;
   %t0 = icmp slt <3 x i32> %x, <i32 65536, i32 undef, i32 65536>
@@ -354,10 +354,10 @@ define <3 x i32> @t19_ult_slt_vec_undef0(<3 x i32> %x, <3 x i32> %replacement_lo
 }
 define <3 x i32> @t20_ult_slt_vec_undef1(<3 x i32> %x, <3 x i32> %replacement_low, <3 x i32> %replacement_high) {
 ; CHECK-LABEL: @t20_ult_slt_vec_undef1(
-; CHECK-NEXT:    [[T0:%.*]] = icmp slt <3 x i32> [[X:%.*]], <i32 65536, i32 65537, i32 65536>
-; CHECK-NEXT:    [[T1:%.*]] = select <3 x i1> [[T0]], <3 x i32> [[REPLACEMENT_LOW:%.*]], <3 x i32> [[REPLACEMENT_HIGH:%.*]]
-; CHECK-NEXT:    [[T2:%.*]] = icmp ult <3 x i32> [[X]], <i32 65536, i32 undef, i32 65536>
-; CHECK-NEXT:    [[R:%.*]] = select <3 x i1> [[T2]], <3 x i32> [[X]], <3 x i32> [[T1]]
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp slt <3 x i32> [[X:%.*]], zeroinitializer
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp slt <3 x i32> [[X]], <i32 65536, i32 undef, i32 65536>
+; CHECK-NEXT:    [[TMP3:%.*]] = select <3 x i1> [[TMP1]], <3 x i32> [[REPLACEMENT_LOW:%.*]], <3 x i32> [[X]]
+; CHECK-NEXT:    [[R:%.*]] = select <3 x i1> [[TMP2]], <3 x i32> [[TMP3]], <3 x i32> [[REPLACEMENT_HIGH:%.*]]
 ; CHECK-NEXT:    ret <3 x i32> [[R]]
 ;
   %t0 = icmp slt <3 x i32> %x, <i32 65536, i32 65537, i32 65536>
@@ -368,10 +368,10 @@ define <3 x i32> @t20_ult_slt_vec_undef1(<3 x i32> %x, <3 x i32> %replacement_lo
 }
 define <3 x i32> @t21_ult_slt_vec_undef2(<3 x i32> %x, <3 x i32> %replacement_low, <3 x i32> %replacement_high) {
 ; CHECK-LABEL: @t21_ult_slt_vec_undef2(
-; CHECK-NEXT:    [[T0:%.*]] = icmp slt <3 x i32> [[X:%.*]], <i32 65536, i32 undef, i32 65536>
-; CHECK-NEXT:    [[T1:%.*]] = select <3 x i1> [[T0]], <3 x i32> [[REPLACEMENT_LOW:%.*]], <3 x i32> [[REPLACEMENT_HIGH:%.*]]
-; CHECK-NEXT:    [[T2:%.*]] = icmp ult <3 x i32> [[X]], <i32 65536, i32 undef, i32 65536>
-; CHECK-NEXT:    [[R:%.*]] = select <3 x i1> [[T2]], <3 x i32> [[X]], <3 x i32> [[T1]]
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp slt <3 x i32> [[X:%.*]], zeroinitializer
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp slt <3 x i32> [[X]], <i32 65536, i32 undef, i32 65536>
+; CHECK-NEXT:    [[TMP3:%.*]] = select <3 x i1> [[TMP1]], <3 x i32> [[REPLACEMENT_LOW:%.*]], <3 x i32> [[X]]
+; CHECK-NEXT:    [[R:%.*]] = select <3 x i1> [[TMP2]], <3 x i32> [[TMP3]], <3 x i32> [[REPLACEMENT_HIGH:%.*]]
 ; CHECK-NEXT:    ret <3 x i32> [[R]]
 ;
   %t0 = icmp slt <3 x i32> %x, <i32 65536, i32 undef, i32 65536>
@@ -380,3 +380,20 @@ define <3 x i32> @t21_ult_slt_vec_undef2(<3 x i32> %x, <3 x i32> %replacement_lo
   %r = select <3 x i1> %t2, <3 x i32> %x, <3 x i32> %t1
   ret <3 x i32> %r
 }
+
+;-------------------------------------------------------------------------------
+
+define i32* @t22_pointers(i32* %x, i32* %replacement_low, i32* %replacement_high) {
+; CHECK-LABEL: @t22_pointers(
+; CHECK-NEXT:    [[T0:%.*]] = icmp slt i32* [[X:%.*]], inttoptr (i64 65536 to i32*)
+; CHECK-NEXT:    [[T1:%.*]] = select i1 [[T0]], i32* [[REPLACEMENT_LOW:%.*]], i32* [[REPLACEMENT_HIGH:%.*]]
+; CHECK-NEXT:    [[T2:%.*]] = icmp ult i32* [[X]], inttoptr (i64 65536 to i32*)
+; CHECK-NEXT:    [[R:%.*]] = select i1 [[T2]], i32* [[X]], i32* [[T1]]
+; CHECK-NEXT:    ret i32* [[R]]
+;
+  %t0 = icmp slt i32* %x, inttoptr (i64 65536 to i32*)
+  %t1 = select i1 %t0, i32* %replacement_low, i32* %replacement_high
+  %t2 = icmp ult i32* %x, inttoptr (i64 65536 to i32*)
+  %r = select i1 %t2, i32* %x, i32* %t1
+  ret i32* %r
+}
diff --git a/llvm/test/Transforms/InstCombine/canonicalize-clamp-with-select-of-constant-threshold-pattern.ll b/llvm/test/Transforms/InstCombine/canonicalize-clamp-with-select-of-constant-threshold-pattern.ll
index 74f57eb..da6522f 100644
--- a/llvm/test/Transforms/InstCombine/canonicalize-clamp-with-select-of-constant-threshold-pattern.ll
+++ b/llvm/test/Transforms/InstCombine/canonicalize-clamp-with-select-of-constant-threshold-pattern.ll
@@ -7,11 +7,10 @@
 
 define i32 @t0_select_cond_and_v0(i32 %X) {
 ; CHECK-LABEL: @t0_select_cond_and_v0(
-; CHECK-NEXT:    [[DONT_NEED_TO_CLAMP_POSITIVE:%.*]] = icmp slt i32 [[X:%.*]], 32768
-; CHECK-NEXT:    [[CLAMP_LIMIT:%.*]] = select i1 [[DONT_NEED_TO_CLAMP_POSITIVE]], i32 -32768, i32 32767
-; CHECK-NEXT:    [[X_OFF:%.*]] = add i32 [[X]], 32768
-; CHECK-NEXT:    [[TMP1:%.*]] = icmp ult i32 [[X_OFF]], 65536
-; CHECK-NEXT:    [[R:%.*]] = select i1 [[TMP1]], i32 [[X]], i32 [[CLAMP_LIMIT]]
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp slt i32 [[X:%.*]], 32768
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp sgt i32 [[X]], -32768
+; CHECK-NEXT:    [[TMP3:%.*]] = select i1 [[TMP2]], i32 [[X]], i32 -32768
+; CHECK-NEXT:    [[R:%.*]] = select i1 [[TMP1]], i32 [[TMP3]], i32 32767
 ; CHECK-NEXT:    ret i32 [[R]]
 ;
   %dont_need_to_clamp_positive = icmp sle i32 %X, 32767
@@ -23,11 +22,10 @@ define i32 @t0_select_cond_and_v0(i32 %X) {
 }
 define i32 @t1_select_cond_and_v1(i32 %X) {
 ; CHECK-LABEL: @t1_select_cond_and_v1(
-; CHECK-NEXT:    [[DONT_NEED_TO_CLAMP_NEGATIVE:%.*]] = icmp sgt i32 [[X:%.*]], -32769
-; CHECK-NEXT:    [[CLAMP_LIMIT:%.*]] = select i1 [[DONT_NEED_TO_CLAMP_NEGATIVE]], i32 32767, i32 -32768
-; CHECK-NEXT:    [[X_OFF:%.*]] = add i32 [[X]], 32768
-; CHECK-NEXT:    [[TMP1:%.*]] = icmp ult i32 [[X_OFF]], 65536
-; CHECK-NEXT:    [[R:%.*]] = select i1 [[TMP1]], i32 [[X]], i32 [[CLAMP_LIMIT]]
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp slt i32 [[X:%.*]], 32768
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp sgt i32 [[X]], -32768
+; CHECK-NEXT:    [[TMP3:%.*]] = select i1 [[TMP2]], i32 [[X]], i32 -32768
+; CHECK-NEXT:    [[R:%.*]] = select i1 [[TMP1]], i32 [[TMP3]], i32 32767
 ; CHECK-NEXT:    ret i32 [[R]]
 ;
   %dont_need_to_clamp_positive = icmp sle i32 %X, 32767
@@ -42,11 +40,10 @@ define i32 @t1_select_cond_and_v1(i32 %X) {
 
 define i32 @t2_select_cond_or_v0(i32 %X) {
 ; CHECK-LABEL: @t2_select_cond_or_v0(
-; CHECK-NEXT:    [[NEED_TO_CLAMP_POSITIVE:%.*]] = icmp sgt i32 [[X:%.*]], 32767
-; CHECK-NEXT:    [[CLAMP_LIMIT:%.*]] = select i1 [[NEED_TO_CLAMP_POSITIVE]], i32 32767, i32 -32768
-; CHECK-NEXT:    [[X_OFF:%.*]] = add i32 [[X]], 32768
-; CHECK-NEXT:    [[TMP1:%.*]] = icmp ugt i32 [[X_OFF]], 65535
-; CHECK-NEXT:    [[R:%.*]] = select i1 [[TMP1]], i32 [[CLAMP_LIMIT]], i32 [[X]]
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp slt i32 [[X:%.*]], 32768
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp sgt i32 [[X]], -32768
+; CHECK-NEXT:    [[TMP3:%.*]] = select i1 [[TMP2]], i32 [[X]], i32 -32768
+; CHECK-NEXT:    [[R:%.*]] = select i1 [[TMP1]], i32 [[TMP3]], i32 32767
 ; CHECK-NEXT:    ret i32 [[R]]
 ;
   %need_to_clamp_positive = icmp sgt i32 %X, 32767
@@ -58,11 +55,10 @@ define i32 @t2_select_cond_or_v0(i32 %X) {
 }
 define i32 @t3_select_cond_or_v1(i32 %X) {
 ; CHECK-LABEL: @t3_select_cond_or_v1(
-; CHECK-NEXT:    [[NEED_TO_CLAMP_NEGATIVE:%.*]] = icmp slt i32 [[X:%.*]], -32768
-; CHECK-NEXT:    [[CLAMP_LIMIT:%.*]] = select i1 [[NEED_TO_CLAMP_NEGATIVE]], i32 -32768, i32 32767
-; CHECK-NEXT:    [[X_OFF:%.*]] = add i32 [[X]], 32768
-; CHECK-NEXT:    [[TMP1:%.*]] = icmp ugt i32 [[X_OFF]], 65535
-; CHECK-NEXT:    [[R:%.*]] = select i1 [[TMP1]], i32 [[CLAMP_LIMIT]], i32 [[X]]
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp slt i32 [[X:%.*]], 32768
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp sgt i32 [[X]], -32768
+; CHECK-NEXT:    [[TMP3:%.*]] = select i1 [[TMP2]], i32 [[X]], i32 -32768
+; CHECK-NEXT:    [[R:%.*]] = select i1 [[TMP1]], i32 [[TMP3]], i32 32767
 ; CHECK-NEXT:    ret i32 [[R]]
 ;
   %need_to_clamp_positive = icmp sgt i32 %X, 32767
@@ -77,11 +73,10 @@ define i32 @t3_select_cond_or_v1(i32 %X) {
 
 define i32 @t4_select_cond_xor_v0(i32 %X) {
 ; CHECK-LABEL: @t4_select_cond_xor_v0(
-; CHECK-NEXT:    [[NEED_TO_CLAMP_POSITIVE:%.*]] = icmp slt i32 [[X:%.*]], 32768
-; CHECK-NEXT:    [[CLAMP_LIMIT:%.*]] = select i1 [[NEED_TO_CLAMP_POSITIVE]], i32 -32768, i32 32767
-; CHECK-NEXT:    [[X_OFF:%.*]] = add i32 [[X]], 32767
-; CHECK-NEXT:    [[TMP1:%.*]] = icmp ult i32 [[X_OFF]], 65535
-; CHECK-NEXT:    [[R:%.*]] = select i1 [[TMP1]], i32 [[X]], i32 [[CLAMP_LIMIT]]
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp slt i32 [[X:%.*]], 32768
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp sgt i32 [[X]], -32768
+; CHECK-NEXT:    [[TMP3:%.*]] = select i1 [[TMP2]], i32 [[X]], i32 -32768
+; CHECK-NEXT:    [[R:%.*]] = select i1 [[TMP1]], i32 [[TMP3]], i32 32767
 ; CHECK-NEXT:    ret i32 [[R]]
 ;
   %need_to_clamp_positive = icmp sgt i32 %X, 32767
@@ -93,11 +88,10 @@ define i32 @t4_select_cond_xor_v0(i32 %X) {
 }
 define i32 @t4_select_cond_xor_v1(i32 %X) {
 ; CHECK-LABEL: @t4_select_cond_xor_v1(
-; CHECK-NEXT:    [[DONT_NEED_TO_CLAMP_NEGATIVE:%.*]] = icmp sgt i32 [[X:%.*]], -32768
-; CHECK-NEXT:    [[CLAMP_LIMIT:%.*]] = select i1 [[DONT_NEED_TO_CLAMP_NEGATIVE]], i32 32767, i32 -32768
-; CHECK-NEXT:    [[X_OFF:%.*]] = add i32 [[X]], 32767
-; CHECK-NEXT:    [[TMP1:%.*]] = icmp ult i32 [[X_OFF]], 65535
-; CHECK-NEXT:    [[R:%.*]] = select i1 [[TMP1]], i32 [[X]], i32 [[CLAMP_LIMIT]]
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp slt i32 [[X:%.*]], 32768
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp sgt i32 [[X]], -32768
+; CHECK-NEXT:    [[TMP3:%.*]] = select i1 [[TMP2]], i32 [[X]], i32 -32768
+; CHECK-NEXT:    [[R:%.*]] = select i1 [[TMP1]], i32 [[TMP3]], i32 32767
 ; CHECK-NEXT:    ret i32 [[R]]
 ;
   %need_to_clamp_positive = icmp sgt i32 %X, 32767
@@ -110,11 +104,10 @@ define i32 @t4_select_cond_xor_v1(i32 %X) {
 
 define i32 @t5_select_cond_xor_v2(i32 %X) {
 ; CHECK-LABEL: @t5_select_cond_xor_v2(
-; CHECK-NEXT:    [[NEED_TO_CLAMP_NEGATIVE:%.*]] = icmp sgt i32 [[X:%.*]], -32768
-; CHECK-NEXT:    [[CLAMP_LIMIT:%.*]] = select i1 [[NEED_TO_CLAMP_NEGATIVE]], i32 32767, i32 -32768
-; CHECK-NEXT:    [[X_OFF:%.*]] = add i32 [[X]], 32767
-; CHECK-NEXT:    [[TMP1:%.*]] = icmp ult i32 [[X_OFF]], 65535
-; CHECK-NEXT:    [[R:%.*]] = select i1 [[TMP1]], i32 [[X]], i32 [[CLAMP_LIMIT]]
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp slt i32 [[X:%.*]], 32768
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp sgt i32 [[X]], -32768
+; CHECK-NEXT:    [[TMP3:%.*]] = select i1 [[TMP2]], i32 [[X]], i32 -32768
+; CHECK-NEXT:    [[R:%.*]] = select i1 [[TMP1]], i32 [[TMP3]], i32 32767
 ; CHECK-NEXT:    ret i32 [[R]]
 ;
   %dont_need_to_clamp_positive = icmp sle i32 %X, 32767
@@ -126,11 +119,10 @@ define i32 @t5_select_cond_xor_v2(i32 %X) {
 }
 define i32 @t5_select_cond_xor_v3(i32 %X) {
 ; CHECK-LABEL: @t5_select_cond_xor_v3(
-; CHECK-NEXT:    [[DONT_NEED_TO_CLAMP_POSITIVE:%.*]] = icmp slt i32 [[X:%.*]], 32768
-; CHECK-NEXT:    [[CLAMP_LIMIT:%.*]] = select i1 [[DONT_NEED_TO_CLAMP_POSITIVE]], i32 -32768, i32 32767
-; CHECK-NEXT:    [[X_OFF:%.*]] = add i32 [[X]], 32767
-; CHECK-NEXT:    [[TMP1:%.*]] = icmp ult i32 [[X_OFF]], 65535
-; CHECK-NEXT:    [[R:%.*]] = select i1 [[TMP1]], i32 [[X]], i32 [[CLAMP_LIMIT]]
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp slt i32 [[X:%.*]], 32768
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp sgt i32 [[X]], -32768
+; CHECK-NEXT:    [[TMP3:%.*]] = select i1 [[TMP2]], i32 [[X]], i32 -32768
+; CHECK-NEXT:    [[R:%.*]] = select i1 [[TMP1]], i32 [[TMP3]], i32 32767
 ; CHECK-NEXT:    ret i32 [[R]]
 ;
   %dont_need_to_clamp_positive = icmp sle i32 %X, 32767