From: Max Kazantsev <mkazantsev@azul.com>
Date: Wed, 25 Jan 2023 07:06:08 +0000 (+0700)
Subject: [IndVars] Expand icmp in preheader rather than in loop
X-Git-Tag: upstream/17.0.6~19703
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=f3e2f26378400dbc785691ec38158ef4019208f8;p=platform%2Fupstream%2Fllvm.git

[IndVars] Expand icmp in preheader rather than in loop

The motivation is that 'createInvariantCond' unconditionally
builds icmp in the loop block,  while it could always do it
in preheader. Build it in preheader instead.

Patch by Aleksandr Popov!

Differential Revision: https://reviews.llvm.org/D141994
Reviewed By: nikic
---

diff --git a/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp b/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp
index c834e51..0c21ae2 100644
--- a/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp
+++ b/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp
@@ -1359,14 +1359,16 @@ createInvariantCond(const Loop *L, BasicBlock *ExitingBB,
                     const ScalarEvolution::LoopInvariantPredicate &LIP,
                     SCEVExpander &Rewriter) {
   ICmpInst::Predicate InvariantPred = LIP.Pred;
-  BranchInst *BI = cast<BranchInst>(ExitingBB->getTerminator());
-  Rewriter.setInsertPoint(BI);
+  BasicBlock *Preheader = L->getLoopPreheader();
+  assert(Preheader && "Preheader doesn't exist");
+  Rewriter.setInsertPoint(Preheader->getTerminator());
   auto *LHSV = Rewriter.expandCodeFor(LIP.LHS);
   auto *RHSV = Rewriter.expandCodeFor(LIP.RHS);
   bool ExitIfTrue = !L->contains(*succ_begin(ExitingBB));
   if (ExitIfTrue)
     InvariantPred = ICmpInst::getInversePredicate(InvariantPred);
-  IRBuilder<> Builder(BI);
+  IRBuilder<> Builder(Preheader->getTerminator());
+  BranchInst *BI = cast<BranchInst>(ExitingBB->getTerminator());
   return Builder.CreateICmp(InvariantPred, LHSV, RHSV,
                             BI->getCondition()->getName());
 }
@@ -1519,7 +1521,6 @@ static bool optimizeLoopExitWithUnknownExitCount(
       auto *NewCond = *Replaced;
       if (auto *NCI = dyn_cast<Instruction>(NewCond)) {
         NCI->setName(OldCond->getName() + ".first_iter");
-        NCI->moveBefore(cast<Instruction>(OldCond));
       }
       LLVM_DEBUG(dbgs() << "Unknown exit count: Replacing " << *OldCond
                         << " with " << *NewCond << "\n");
diff --git a/llvm/test/Transforms/IndVarSimplify/AArch64/widen-loop-comp.ll b/llvm/test/Transforms/IndVarSimplify/AArch64/widen-loop-comp.ll
index ca34685..61fdc4a 100644
--- a/llvm/test/Transforms/IndVarSimplify/AArch64/widen-loop-comp.ll
+++ b/llvm/test/Transforms/IndVarSimplify/AArch64/widen-loop-comp.ll
@@ -856,6 +856,7 @@ define i32 @test16_unsigned_pos1(i32 %start, ptr %p, ptr %q, i32 %x) {
 ; CHECK-NEXT:    [[TMP0:%.*]] = zext i32 [[START:%.*]] to i64
 ; CHECK-NEXT:    [[TMP1:%.*]] = add nsw i64 [[TMP0]], -1
 ; CHECK-NEXT:    [[TMP2:%.*]] = zext i32 [[X:%.*]] to i64
+; CHECK-NEXT:    [[ICMP_USER_WIDE5:%.*]] = icmp ult i64 [[TMP1]], [[TMP2]]
 ; CHECK-NEXT:    br label [[LOOP:%.*]]
 ; CHECK:       loop:
 ; CHECK-NEXT:    [[INDVARS_IV:%.*]] = phi i64 [ [[INDVARS_IV_NEXT:%.*]], [[BACKEDGE:%.*]] ], [ [[TMP0]], [[ENTRY:%.*]] ]
@@ -863,7 +864,6 @@ define i32 @test16_unsigned_pos1(i32 %start, ptr %p, ptr %q, i32 %x) {
 ; CHECK-NEXT:    [[TMP3:%.*]] = add nsw i64 [[INDVARS_IV]], -1
 ; CHECK-NEXT:    br i1 [[COND]], label [[EXIT:%.*]], label [[GUARDED:%.*]]
 ; CHECK:       guarded:
-; CHECK-NEXT:    [[ICMP_USER_WIDE5:%.*]] = icmp ult i64 [[TMP1]], [[TMP2]]
 ; CHECK-NEXT:    br i1 [[ICMP_USER_WIDE5]], label [[BACKEDGE]], label [[SIDE_EXIT:%.*]]
 ; CHECK:       backedge:
 ; CHECK-NEXT:    [[STORE_ADDR:%.*]] = getelementptr i32, ptr [[P:%.*]], i64 [[TMP3]]
@@ -1196,6 +1196,7 @@ define i32 @test16_signed_neg(i32 %start, ptr %p, ptr %q, i32 %x) {
 ; CHECK-LABEL: @test16_signed_neg(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[TMP0:%.*]] = add i32 [[START:%.*]], -1
+; CHECK-NEXT:    [[ICMP_USER3:%.*]] = icmp ult i32 [[TMP0]], [[X:%.*]]
 ; CHECK-NEXT:    br label [[LOOP:%.*]]
 ; CHECK:       loop:
 ; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ [[START]], [[ENTRY:%.*]] ], [ [[IV_NEXT_1:%.*]], [[BACKEDGE:%.*]] ]
@@ -1203,7 +1204,6 @@ define i32 @test16_signed_neg(i32 %start, ptr %p, ptr %q, i32 %x) {
 ; CHECK-NEXT:    [[FOO:%.*]] = add i32 [[IV]], -1
 ; CHECK-NEXT:    br i1 [[COND]], label [[EXIT:%.*]], label [[GUARDED:%.*]]
 ; CHECK:       guarded:
-; CHECK-NEXT:    [[ICMP_USER3:%.*]] = icmp ult i32 [[TMP0]], [[X:%.*]]
 ; CHECK-NEXT:    br i1 [[ICMP_USER3]], label [[BACKEDGE]], label [[SIDE_EXIT:%.*]]
 ; CHECK:       backedge:
 ; CHECK-NEXT:    [[INDEX:%.*]] = sext i32 [[FOO]] to i64
diff --git a/llvm/test/Transforms/IndVarSimplify/X86/widening-vs-and-elimination.ll b/llvm/test/Transforms/IndVarSimplify/X86/widening-vs-and-elimination.ll
index ba8f4f0..f7dc595 100644
--- a/llvm/test/Transforms/IndVarSimplify/X86/widening-vs-and-elimination.ll
+++ b/llvm/test/Transforms/IndVarSimplify/X86/widening-vs-and-elimination.ll
@@ -11,12 +11,12 @@ define void @test_01(i32 %start, i32 %limit) {
 ; WIDENING_ON-NEXT:    [[TMP0:%.*]] = zext i32 [[START:%.*]] to i64
 ; WIDENING_ON-NEXT:    [[TMP1:%.*]] = add nsw i64 [[TMP0]], -1
 ; WIDENING_ON-NEXT:    [[TMP2:%.*]] = zext i32 [[LIMIT:%.*]] to i64
+; WIDENING_ON-NEXT:    [[RANGE_CHECK_WIDE_FIRST_ITER:%.*]] = icmp ult i64 [[TMP1]], [[TMP2]]
 ; WIDENING_ON-NEXT:    br label [[LOOP:%.*]]
 ; WIDENING_ON:       loop:
 ; WIDENING_ON-NEXT:    [[INDVARS_IV:%.*]] = phi i64 [ [[INDVARS_IV_NEXT:%.*]], [[BACKEDGE:%.*]] ], [ [[TMP0]], [[BB:%.*]] ]
 ; WIDENING_ON-NEXT:    [[INDVARS_IV_NEXT]] = add nsw i64 [[INDVARS_IV]], -1
 ; WIDENING_ON-NEXT:    [[NOT_ZERO:%.*]] = icmp ne i64 [[INDVARS_IV]], 0
-; WIDENING_ON-NEXT:    [[RANGE_CHECK_WIDE_FIRST_ITER:%.*]] = icmp ult i64 [[TMP1]], [[TMP2]]
 ; WIDENING_ON-NEXT:    [[AND:%.*]] = and i1 [[NOT_ZERO]], [[RANGE_CHECK_WIDE_FIRST_ITER]]
 ; WIDENING_ON-NEXT:    br i1 [[AND]], label [[BACKEDGE]], label [[EXIT:%.*]]
 ; WIDENING_ON:       backedge:
@@ -27,12 +27,12 @@ define void @test_01(i32 %start, i32 %limit) {
 ; WIDENING_OFF-LABEL: @test_01(
 ; WIDENING_OFF-NEXT:  bb:
 ; WIDENING_OFF-NEXT:    [[TMP0:%.*]] = add i32 [[START:%.*]], -1
+; WIDENING_OFF-NEXT:    [[RANGE_CHECK_FIRST_ITER:%.*]] = icmp ult i32 [[TMP0]], [[LIMIT:%.*]]
 ; WIDENING_OFF-NEXT:    br label [[LOOP:%.*]]
 ; WIDENING_OFF:       loop:
 ; WIDENING_OFF-NEXT:    [[IV:%.*]] = phi i32 [ [[IV_NEXT:%.*]], [[BACKEDGE:%.*]] ], [ [[START]], [[BB:%.*]] ]
 ; WIDENING_OFF-NEXT:    [[IV_NEXT]] = add i32 [[IV]], -1
 ; WIDENING_OFF-NEXT:    [[NOT_ZERO:%.*]] = icmp ne i32 [[IV]], 0
-; WIDENING_OFF-NEXT:    [[RANGE_CHECK_FIRST_ITER:%.*]] = icmp ult i32 [[TMP0]], [[LIMIT:%.*]]
 ; WIDENING_OFF-NEXT:    [[AND:%.*]] = and i1 [[NOT_ZERO]], [[RANGE_CHECK_FIRST_ITER]]
 ; WIDENING_OFF-NEXT:    br i1 [[AND]], label [[BACKEDGE]], label [[EXIT:%.*]]
 ; WIDENING_OFF:       backedge:
diff --git a/llvm/test/Transforms/IndVarSimplify/predicated_ranges.ll b/llvm/test/Transforms/IndVarSimplify/predicated_ranges.ll
index abaf72e..5eef9cb 100644
--- a/llvm/test/Transforms/IndVarSimplify/predicated_ranges.ll
+++ b/llvm/test/Transforms/IndVarSimplify/predicated_ranges.ll
@@ -470,6 +470,7 @@ define void @test_can_predicate_simple_unsigned(ptr %p, ptr %arr) {
 ; CHECK-NEXT:  preheader:
 ; CHECK-NEXT:    [[LEN:%.*]] = load i32, ptr [[P:%.*]], align 4
 ; CHECK-NEXT:    [[TMP0:%.*]] = add i32 [[LEN]], -1
+; CHECK-NEXT:    [[RANGE_CHECK1:%.*]] = icmp ult i32 [[TMP0]], [[LEN]]
 ; CHECK-NEXT:    br label [[LOOP:%.*]]
 ; CHECK:       loop:
 ; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ [[LEN]], [[PREHEADER:%.*]] ], [ [[IV_NEXT:%.*]], [[BACKEDGE:%.*]] ]
@@ -477,7 +478,6 @@ define void @test_can_predicate_simple_unsigned(ptr %p, ptr %arr) {
 ; CHECK-NEXT:    br i1 [[ZERO_COND]], label [[EXIT:%.*]], label [[RANGE_CHECK_BLOCK:%.*]]
 ; CHECK:       range_check_block:
 ; CHECK-NEXT:    [[IV_NEXT]] = sub i32 [[IV]], 1
-; CHECK-NEXT:    [[RANGE_CHECK1:%.*]] = icmp ult i32 [[TMP0]], [[LEN]]
 ; CHECK-NEXT:    br i1 [[RANGE_CHECK1]], label [[BACKEDGE]], label [[FAIL:%.*]]
 ; CHECK:       backedge:
 ; CHECK-NEXT:    [[EL_PTR:%.*]] = getelementptr i32, ptr [[P]], i32 [[IV]]
@@ -521,6 +521,7 @@ define void @test_can_predicate_simple_unsigned_inverted(ptr %p, ptr %arr) {
 ; CHECK-NEXT:  preheader:
 ; CHECK-NEXT:    [[LEN:%.*]] = load i32, ptr [[P:%.*]], align 4
 ; CHECK-NEXT:    [[TMP0:%.*]] = add i32 [[LEN]], -1
+; CHECK-NEXT:    [[RANGE_CHECK1:%.*]] = icmp uge i32 [[TMP0]], [[LEN]]
 ; CHECK-NEXT:    br label [[LOOP:%.*]]
 ; CHECK:       loop:
 ; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ [[LEN]], [[PREHEADER:%.*]] ], [ [[IV_NEXT:%.*]], [[BACKEDGE:%.*]] ]
@@ -528,7 +529,6 @@ define void @test_can_predicate_simple_unsigned_inverted(ptr %p, ptr %arr) {
 ; CHECK-NEXT:    br i1 [[ZERO_COND]], label [[EXIT:%.*]], label [[RANGE_CHECK_BLOCK:%.*]]
 ; CHECK:       range_check_block:
 ; CHECK-NEXT:    [[IV_NEXT]] = sub i32 [[IV]], 1
-; CHECK-NEXT:    [[RANGE_CHECK1:%.*]] = icmp uge i32 [[TMP0]], [[LEN]]
 ; CHECK-NEXT:    br i1 [[RANGE_CHECK1]], label [[FAIL:%.*]], label [[BACKEDGE]]
 ; CHECK:       backedge:
 ; CHECK-NEXT:    [[EL_PTR:%.*]] = getelementptr i32, ptr [[P]], i32 [[IV]]
@@ -624,6 +624,7 @@ define void @test_can_predicate_trunc_unsigned(ptr %p, ptr %arr) {
 ; CHECK-NEXT:    [[LEN:%.*]] = load i32, ptr [[P:%.*]], align 4
 ; CHECK-NEXT:    [[START:%.*]] = zext i32 [[LEN]] to i64
 ; CHECK-NEXT:    [[TMP0:%.*]] = add i32 [[LEN]], -1
+; CHECK-NEXT:    [[RANGE_CHECK1:%.*]] = icmp ult i32 [[TMP0]], [[LEN]]
 ; CHECK-NEXT:    br label [[LOOP:%.*]]
 ; CHECK:       loop:
 ; CHECK-NEXT:    [[IV:%.*]] = phi i64 [ [[START]], [[PREHEADER:%.*]] ], [ [[IV_NEXT:%.*]], [[BACKEDGE:%.*]] ]
@@ -631,7 +632,6 @@ define void @test_can_predicate_trunc_unsigned(ptr %p, ptr %arr) {
 ; CHECK-NEXT:    br i1 [[ZERO_COND]], label [[EXIT:%.*]], label [[RANGE_CHECK_BLOCK:%.*]]
 ; CHECK:       range_check_block:
 ; CHECK-NEXT:    [[IV_NEXT]] = sub nsw i64 [[IV]], 1
-; CHECK-NEXT:    [[RANGE_CHECK1:%.*]] = icmp ult i32 [[TMP0]], [[LEN]]
 ; CHECK-NEXT:    br i1 [[RANGE_CHECK1]], label [[BACKEDGE]], label [[FAIL:%.*]]
 ; CHECK:       backedge:
 ; CHECK-NEXT:    [[EL_PTR:%.*]] = getelementptr i32, ptr [[ARR:%.*]], i64 [[IV]]
@@ -678,6 +678,7 @@ define void @test_can_predicate_trunc_unsigned_inverted(ptr %p, ptr %arr) {
 ; CHECK-NEXT:    [[LEN:%.*]] = load i32, ptr [[P:%.*]], align 4
 ; CHECK-NEXT:    [[START:%.*]] = zext i32 [[LEN]] to i64
 ; CHECK-NEXT:    [[TMP0:%.*]] = add i32 [[LEN]], -1
+; CHECK-NEXT:    [[RANGE_CHECK1:%.*]] = icmp uge i32 [[TMP0]], [[LEN]]
 ; CHECK-NEXT:    br label [[LOOP:%.*]]
 ; CHECK:       loop:
 ; CHECK-NEXT:    [[IV:%.*]] = phi i64 [ [[START]], [[PREHEADER:%.*]] ], [ [[IV_NEXT:%.*]], [[BACKEDGE:%.*]] ]
@@ -685,7 +686,6 @@ define void @test_can_predicate_trunc_unsigned_inverted(ptr %p, ptr %arr) {
 ; CHECK-NEXT:    br i1 [[ZERO_COND]], label [[EXIT:%.*]], label [[RANGE_CHECK_BLOCK:%.*]]
 ; CHECK:       range_check_block:
 ; CHECK-NEXT:    [[IV_NEXT]] = sub nsw i64 [[IV]], 1
-; CHECK-NEXT:    [[RANGE_CHECK1:%.*]] = icmp uge i32 [[TMP0]], [[LEN]]
 ; CHECK-NEXT:    br i1 [[RANGE_CHECK1]], label [[FAIL:%.*]], label [[BACKEDGE]]
 ; CHECK:       backedge:
 ; CHECK-NEXT:    [[EL_PTR:%.*]] = getelementptr i32, ptr [[ARR:%.*]], i64 [[IV]]
@@ -835,6 +835,7 @@ define void @test_can_predicate_simple_unsigned_different_start(i32 %start, ptr
 ; CHECK-NEXT:  preheader:
 ; CHECK-NEXT:    [[LEN:%.*]] = load i32, ptr [[P:%.*]], align 4
 ; CHECK-NEXT:    [[TMP0:%.*]] = add i32 [[START:%.*]], -1
+; CHECK-NEXT:    [[RANGE_CHECK1:%.*]] = icmp ult i32 [[TMP0]], [[LEN]]
 ; CHECK-NEXT:    br label [[LOOP:%.*]]
 ; CHECK:       loop:
 ; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ [[START]], [[PREHEADER:%.*]] ], [ [[IV_NEXT:%.*]], [[BACKEDGE:%.*]] ]
@@ -842,7 +843,6 @@ define void @test_can_predicate_simple_unsigned_different_start(i32 %start, ptr
 ; CHECK-NEXT:    br i1 [[ZERO_COND]], label [[EXIT:%.*]], label [[RANGE_CHECK_BLOCK:%.*]]
 ; CHECK:       range_check_block:
 ; CHECK-NEXT:    [[IV_NEXT]] = sub i32 [[IV]], 1
-; CHECK-NEXT:    [[RANGE_CHECK1:%.*]] = icmp ult i32 [[TMP0]], [[LEN]]
 ; CHECK-NEXT:    br i1 [[RANGE_CHECK1]], label [[BACKEDGE]], label [[FAIL:%.*]]
 ; CHECK:       backedge:
 ; CHECK-NEXT:    [[EL_PTR:%.*]] = getelementptr i32, ptr [[P]], i32 [[IV]]
@@ -886,6 +886,7 @@ define void @test_can_predicate_simple_unsigned_inverted_different_start(i32 %st
 ; CHECK-NEXT:  preheader:
 ; CHECK-NEXT:    [[LEN:%.*]] = load i32, ptr [[P:%.*]], align 4
 ; CHECK-NEXT:    [[TMP0:%.*]] = add i32 [[START:%.*]], -1
+; CHECK-NEXT:    [[RANGE_CHECK1:%.*]] = icmp uge i32 [[TMP0]], [[LEN]]
 ; CHECK-NEXT:    br label [[LOOP:%.*]]
 ; CHECK:       loop:
 ; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ [[START]], [[PREHEADER:%.*]] ], [ [[IV_NEXT:%.*]], [[BACKEDGE:%.*]] ]
@@ -893,7 +894,6 @@ define void @test_can_predicate_simple_unsigned_inverted_different_start(i32 %st
 ; CHECK-NEXT:    br i1 [[ZERO_COND]], label [[EXIT:%.*]], label [[RANGE_CHECK_BLOCK:%.*]]
 ; CHECK:       range_check_block:
 ; CHECK-NEXT:    [[IV_NEXT]] = sub i32 [[IV]], 1
-; CHECK-NEXT:    [[RANGE_CHECK1:%.*]] = icmp uge i32 [[TMP0]], [[LEN]]
 ; CHECK-NEXT:    br i1 [[RANGE_CHECK1]], label [[FAIL:%.*]], label [[BACKEDGE]]
 ; CHECK:       backedge:
 ; CHECK-NEXT:    [[EL_PTR:%.*]] = getelementptr i32, ptr [[P]], i32 [[IV]]
diff --git a/llvm/test/Transforms/IndVarSimplify/turn-to-invariant.ll b/llvm/test/Transforms/IndVarSimplify/turn-to-invariant.ll
index bd5b17a..ff22545 100644
--- a/llvm/test/Transforms/IndVarSimplify/turn-to-invariant.ll
+++ b/llvm/test/Transforms/IndVarSimplify/turn-to-invariant.ll
@@ -8,13 +8,13 @@ define i32 @test_simple_case(i32 %start, i32 %len) {
 ; CHECK-LABEL: @test_simple_case(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[TMP0:%.*]] = add i32 [[START:%.*]], -1
+; CHECK-NEXT:    [[RANGE_CHECK_FIRST_ITER:%.*]] = icmp ult i32 [[TMP0]], [[LEN:%.*]]
 ; CHECK-NEXT:    br label [[LOOP:%.*]]
 ; CHECK:       loop:
 ; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ [[START]], [[ENTRY:%.*]] ], [ [[IV_NEXT:%.*]], [[BACKEDGE:%.*]] ]
 ; CHECK-NEXT:    [[ZERO_CHECK:%.*]] = icmp ne i32 [[IV]], 0
 ; CHECK-NEXT:    br i1 [[ZERO_CHECK]], label [[RANGE_CHECK_BLOCK:%.*]], label [[FAILED_1:%.*]]
 ; CHECK:       range_check_block:
-; CHECK-NEXT:    [[RANGE_CHECK_FIRST_ITER:%.*]] = icmp ult i32 [[TMP0]], [[LEN:%.*]]
 ; CHECK-NEXT:    br i1 [[RANGE_CHECK_FIRST_ITER]], label [[BACKEDGE]], label [[FAILED_2:%.*]]
 ; CHECK:       backedge:
 ; CHECK-NEXT:    [[IV_NEXT]] = add i32 [[IV]], -1
@@ -64,6 +64,7 @@ define i32 @test_litter_conditions(i32 %start, i32 %len) {
 ; CHECK-LABEL: @test_litter_conditions(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[TMP0:%.*]] = add i32 [[START:%.*]], -1
+; CHECK-NEXT:    [[RANGE_CHECK_FIRST_ITER:%.*]] = icmp ult i32 [[TMP0]], [[LEN:%.*]]
 ; CHECK-NEXT:    br label [[LOOP:%.*]]
 ; CHECK:       loop:
 ; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ [[START]], [[ENTRY:%.*]] ], [ [[IV_NEXT:%.*]], [[BACKEDGE:%.*]] ]
@@ -72,7 +73,6 @@ define i32 @test_litter_conditions(i32 %start, i32 %len) {
 ; CHECK-NEXT:    [[AND_1:%.*]] = and i1 [[ZERO_CHECK]], [[FAKE_1]]
 ; CHECK-NEXT:    br i1 [[AND_1]], label [[RANGE_CHECK_BLOCK:%.*]], label [[FAILED_1:%.*]]
 ; CHECK:       range_check_block:
-; CHECK-NEXT:    [[RANGE_CHECK_FIRST_ITER:%.*]] = icmp ult i32 [[TMP0]], [[LEN:%.*]]
 ; CHECK-NEXT:    [[FAKE_2:%.*]] = call i1 @cond()
 ; CHECK-NEXT:    [[AND_2:%.*]] = and i1 [[RANGE_CHECK_FIRST_ITER]], [[FAKE_2]]
 ; CHECK-NEXT:    br i1 [[AND_2]], label [[BACKEDGE]], label [[FAILED_2:%.*]]
@@ -126,6 +126,7 @@ define i32 @test_litter_conditions_inverse(i32 %start, i32 %len) {
 ; CHECK-LABEL: @test_litter_conditions_inverse(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[TMP0:%.*]] = add i32 [[START:%.*]], -1
+; CHECK-NEXT:    [[RANGE_CHECK_FAILED_FIRST_ITER:%.*]] = icmp uge i32 [[TMP0]], [[LEN:%.*]]
 ; CHECK-NEXT:    br label [[LOOP:%.*]]
 ; CHECK:       loop:
 ; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ [[START]], [[ENTRY:%.*]] ], [ [[IV_NEXT:%.*]], [[BACKEDGE:%.*]] ]
@@ -134,7 +135,6 @@ define i32 @test_litter_conditions_inverse(i32 %start, i32 %len) {
 ; CHECK-NEXT:    [[AND_1:%.*]] = and i1 [[ZERO_CHECK]], [[FAKE_1]]
 ; CHECK-NEXT:    br i1 [[AND_1]], label [[RANGE_CHECK_BLOCK:%.*]], label [[FAILED_1:%.*]]
 ; CHECK:       range_check_block:
-; CHECK-NEXT:    [[RANGE_CHECK_FAILED_FIRST_ITER:%.*]] = icmp uge i32 [[TMP0]], [[LEN:%.*]]
 ; CHECK-NEXT:    [[FAKE_2:%.*]] = call i1 @cond()
 ; CHECK-NEXT:    [[OR_2:%.*]] = or i1 [[RANGE_CHECK_FAILED_FIRST_ITER]], [[FAKE_2]]
 ; CHECK-NEXT:    br i1 [[OR_2]], label [[FAILED_2:%.*]], label [[BACKEDGE]]
@@ -186,6 +186,7 @@ define i32 @test_litter_conditions_01(i32 %start, i32 %len) {
 ; CHECK-LABEL: @test_litter_conditions_01(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[TMP0:%.*]] = add i32 [[START:%.*]], -1
+; CHECK-NEXT:    [[RANGE_CHECK_FIRST_ITER:%.*]] = icmp ult i32 [[TMP0]], [[LEN:%.*]]
 ; CHECK-NEXT:    br label [[LOOP:%.*]]
 ; CHECK:       loop:
 ; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ [[START]], [[ENTRY:%.*]] ], [ [[IV_NEXT:%.*]], [[BACKEDGE:%.*]] ]
@@ -194,7 +195,6 @@ define i32 @test_litter_conditions_01(i32 %start, i32 %len) {
 ; CHECK-NEXT:    [[AND_1:%.*]] = and i1 [[ZERO_CHECK]], [[FAKE_1]]
 ; CHECK-NEXT:    br i1 [[AND_1]], label [[RANGE_CHECK_BLOCK:%.*]], label [[FAILED_1:%.*]]
 ; CHECK:       range_check_block:
-; CHECK-NEXT:    [[RANGE_CHECK_FIRST_ITER:%.*]] = icmp ult i32 [[TMP0]], [[LEN:%.*]]
 ; CHECK-NEXT:    br i1 [[RANGE_CHECK_FIRST_ITER]], label [[BACKEDGE]], label [[FAILED_2:%.*]]
 ; CHECK:       backedge:
 ; CHECK-NEXT:    [[IV_NEXT]] = add i32 [[IV]], -1
@@ -244,6 +244,7 @@ define i32 @test_litter_conditions_01_inverse(i32 %start, i32 %len) {
 ; CHECK-LABEL: @test_litter_conditions_01_inverse(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[TMP0:%.*]] = add i32 [[START:%.*]], -1
+; CHECK-NEXT:    [[RANGE_CHECK_FAILED_FIRST_ITER:%.*]] = icmp uge i32 [[TMP0]], [[LEN:%.*]]
 ; CHECK-NEXT:    br label [[LOOP:%.*]]
 ; CHECK:       loop:
 ; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ [[START]], [[ENTRY:%.*]] ], [ [[IV_NEXT:%.*]], [[BACKEDGE:%.*]] ]
@@ -252,7 +253,6 @@ define i32 @test_litter_conditions_01_inverse(i32 %start, i32 %len) {
 ; CHECK-NEXT:    [[AND_1:%.*]] = and i1 [[ZERO_CHECK]], [[FAKE_1]]
 ; CHECK-NEXT:    br i1 [[AND_1]], label [[RANGE_CHECK_BLOCK:%.*]], label [[FAILED_1:%.*]]
 ; CHECK:       range_check_block:
-; CHECK-NEXT:    [[RANGE_CHECK_FAILED_FIRST_ITER:%.*]] = icmp uge i32 [[TMP0]], [[LEN:%.*]]
 ; CHECK-NEXT:    br i1 [[RANGE_CHECK_FAILED_FIRST_ITER]], label [[FAILED_2:%.*]], label [[BACKEDGE]]
 ; CHECK:       backedge:
 ; CHECK-NEXT:    [[IV_NEXT]] = add i32 [[IV]], -1
@@ -301,13 +301,13 @@ define i32 @test_litter_conditions_02(i32 %start, i32 %len) {
 ; CHECK-LABEL: @test_litter_conditions_02(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[TMP0:%.*]] = add i32 [[START:%.*]], -1
+; CHECK-NEXT:    [[RANGE_CHECK_FIRST_ITER:%.*]] = icmp ult i32 [[TMP0]], [[LEN:%.*]]
 ; CHECK-NEXT:    br label [[LOOP:%.*]]
 ; CHECK:       loop:
 ; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ [[START]], [[ENTRY:%.*]] ], [ [[IV_NEXT:%.*]], [[BACKEDGE:%.*]] ]
 ; CHECK-NEXT:    [[ZERO_CHECK:%.*]] = icmp ne i32 [[IV]], 0
 ; CHECK-NEXT:    br i1 [[ZERO_CHECK]], label [[RANGE_CHECK_BLOCK:%.*]], label [[FAILED_1:%.*]]
 ; CHECK:       range_check_block:
-; CHECK-NEXT:    [[RANGE_CHECK_FIRST_ITER:%.*]] = icmp ult i32 [[TMP0]], [[LEN:%.*]]
 ; CHECK-NEXT:    [[FAKE_2:%.*]] = call i1 @cond()
 ; CHECK-NEXT:    [[AND_2:%.*]] = and i1 [[RANGE_CHECK_FIRST_ITER]], [[FAKE_2]]
 ; CHECK-NEXT:    br i1 [[AND_2]], label [[BACKEDGE]], label [[FAILED_2:%.*]]
@@ -359,13 +359,13 @@ define i32 @test_litter_conditions_02_inverse(i32 %start, i32 %len) {
 ; CHECK-LABEL: @test_litter_conditions_02_inverse(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[TMP0:%.*]] = add i32 [[START:%.*]], -1
+; CHECK-NEXT:    [[RANGE_CHECK_FAILED_FIRST_ITER:%.*]] = icmp uge i32 [[TMP0]], [[LEN:%.*]]
 ; CHECK-NEXT:    br label [[LOOP:%.*]]
 ; CHECK:       loop:
 ; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ [[START]], [[ENTRY:%.*]] ], [ [[IV_NEXT:%.*]], [[BACKEDGE:%.*]] ]
 ; CHECK-NEXT:    [[ZERO_CHECK:%.*]] = icmp ne i32 [[IV]], 0
 ; CHECK-NEXT:    br i1 [[ZERO_CHECK]], label [[RANGE_CHECK_BLOCK:%.*]], label [[FAILED_1:%.*]]
 ; CHECK:       range_check_block:
-; CHECK-NEXT:    [[RANGE_CHECK_FAILED_FIRST_ITER:%.*]] = icmp uge i32 [[TMP0]], [[LEN:%.*]]
 ; CHECK-NEXT:    [[FAKE_2:%.*]] = call i1 @cond()
 ; CHECK-NEXT:    [[OR_2:%.*]] = or i1 [[RANGE_CHECK_FAILED_FIRST_ITER]], [[FAKE_2]]
 ; CHECK-NEXT:    br i1 [[OR_2]], label [[FAILED_2:%.*]], label [[BACKEDGE]]
@@ -418,13 +418,13 @@ define i32 @test_litter_conditions_bad_context(i32 %start, i32 %len) {
 ; CHECK-LABEL: @test_litter_conditions_bad_context(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[TMP0:%.*]] = add i32 [[START:%.*]], -1
+; CHECK-NEXT:    [[RANGE_CHECK_FIRST_ITER:%.*]] = icmp ult i32 [[TMP0]], [[LEN:%.*]]
 ; CHECK-NEXT:    br label [[LOOP:%.*]]
 ; CHECK:       loop:
 ; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ [[START]], [[ENTRY:%.*]] ], [ [[IV_NEXT:%.*]], [[BACKEDGE:%.*]] ]
 ; CHECK-NEXT:    [[ZERO_CHECK:%.*]] = icmp ne i32 [[IV]], 0
 ; CHECK-NEXT:    [[FAKE_1:%.*]] = call i1 @cond()
 ; CHECK-NEXT:    [[AND_1:%.*]] = and i1 [[ZERO_CHECK]], [[FAKE_1]]
-; CHECK-NEXT:    [[RANGE_CHECK_FIRST_ITER:%.*]] = icmp ult i32 [[TMP0]], [[LEN:%.*]]
 ; CHECK-NEXT:    [[FAKE_2:%.*]] = call i1 @cond()
 ; CHECK-NEXT:    [[AND_2:%.*]] = and i1 [[RANGE_CHECK_FIRST_ITER]], [[FAKE_2]]
 ; CHECK-NEXT:    br i1 [[AND_1]], label [[RANGE_CHECK_BLOCK:%.*]], label [[FAILED_1:%.*]]
@@ -480,13 +480,13 @@ define i32 @test_litter_conditions_bad_context_inverse(i32 %start, i32 %len) {
 ; CHECK-LABEL: @test_litter_conditions_bad_context_inverse(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[TMP0:%.*]] = add i32 [[START:%.*]], -1
+; CHECK-NEXT:    [[RANGE_CHECK_FAILED_FIRST_ITER:%.*]] = icmp uge i32 [[TMP0]], [[LEN:%.*]]
 ; CHECK-NEXT:    br label [[LOOP:%.*]]
 ; CHECK:       loop:
 ; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ [[START]], [[ENTRY:%.*]] ], [ [[IV_NEXT:%.*]], [[BACKEDGE:%.*]] ]
 ; CHECK-NEXT:    [[ZERO_CHECK:%.*]] = icmp ne i32 [[IV]], 0
 ; CHECK-NEXT:    [[FAKE_1:%.*]] = call i1 @cond()
 ; CHECK-NEXT:    [[AND_1:%.*]] = and i1 [[ZERO_CHECK]], [[FAKE_1]]
-; CHECK-NEXT:    [[RANGE_CHECK_FAILED_FIRST_ITER:%.*]] = icmp uge i32 [[TMP0]], [[LEN:%.*]]
 ; CHECK-NEXT:    [[FAKE_2:%.*]] = call i1 @cond()
 ; CHECK-NEXT:    [[OR_2:%.*]] = or i1 [[RANGE_CHECK_FAILED_FIRST_ITER]], [[FAKE_2]]
 ; CHECK-NEXT:    br i1 [[AND_1]], label [[RANGE_CHECK_BLOCK:%.*]], label [[FAILED_1:%.*]]
@@ -544,11 +544,11 @@ define i32 @test_and_conditions(i32 %start, i32 %len) {
 ; CHECK-LABEL: @test_and_conditions(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[TMP0:%.*]] = add i32 [[START:%.*]], -1
+; CHECK-NEXT:    [[RANGE_CHECK_FIRST_ITER:%.*]] = icmp ult i32 [[TMP0]], [[LEN:%.*]]
 ; CHECK-NEXT:    br label [[LOOP:%.*]]
 ; CHECK:       loop:
 ; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ [[START]], [[ENTRY:%.*]] ], [ [[IV_NEXT:%.*]], [[BACKEDGE:%.*]] ]
 ; CHECK-NEXT:    [[ZERO_CHECK:%.*]] = icmp ne i32 [[IV]], 0
-; CHECK-NEXT:    [[RANGE_CHECK_FIRST_ITER:%.*]] = icmp ult i32 [[TMP0]], [[LEN:%.*]]
 ; CHECK-NEXT:    [[BOTH_CHECKS:%.*]] = and i1 [[ZERO_CHECK]], [[RANGE_CHECK_FIRST_ITER]]
 ; CHECK-NEXT:    br i1 [[BOTH_CHECKS]], label [[BACKEDGE]], label [[FAILED:%.*]]
 ; CHECK:       backedge:
@@ -590,11 +590,11 @@ define i32 @test_and_conditions_inverse(i32 %start, i32 %len) {
 ; CHECK-LABEL: @test_and_conditions_inverse(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[TMP0:%.*]] = add i32 [[START:%.*]], -1
+; CHECK-NEXT:    [[RANGE_CHECK_FAILED_FIRST_ITER:%.*]] = icmp uge i32 [[TMP0]], [[LEN:%.*]]
 ; CHECK-NEXT:    br label [[LOOP:%.*]]
 ; CHECK:       loop:
 ; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ [[START]], [[ENTRY:%.*]] ], [ [[IV_NEXT:%.*]], [[BACKEDGE:%.*]] ]
 ; CHECK-NEXT:    [[ZERO_CHECK_FAILED:%.*]] = icmp eq i32 [[IV]], 0
-; CHECK-NEXT:    [[RANGE_CHECK_FAILED_FIRST_ITER:%.*]] = icmp uge i32 [[TMP0]], [[LEN:%.*]]
 ; CHECK-NEXT:    [[EITHER_CHECK:%.*]] = or i1 [[ZERO_CHECK_FAILED]], [[RANGE_CHECK_FAILED_FIRST_ITER]]
 ; CHECK-NEXT:    br i1 [[EITHER_CHECK]], label [[FAILED:%.*]], label [[BACKEDGE]]
 ; CHECK:       backedge:
@@ -635,6 +635,7 @@ define i32 @test_litter_conditions_logical_and(i32 %start, i32 %len) {
 ; CHECK-LABEL: @test_litter_conditions_logical_and(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[TMP0:%.*]] = add i32 [[START:%.*]], -1
+; CHECK-NEXT:    [[RANGE_CHECK_FIRST_ITER:%.*]] = icmp ult i32 [[TMP0]], [[LEN:%.*]]
 ; CHECK-NEXT:    br label [[LOOP:%.*]]
 ; CHECK:       loop:
 ; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ [[START]], [[ENTRY:%.*]] ], [ [[IV_NEXT:%.*]], [[BACKEDGE:%.*]] ]
@@ -643,7 +644,6 @@ define i32 @test_litter_conditions_logical_and(i32 %start, i32 %len) {
 ; CHECK-NEXT:    [[AND_1:%.*]] = and i1 [[ZERO_CHECK]], [[FAKE_1]]
 ; CHECK-NEXT:    br i1 [[AND_1]], label [[RANGE_CHECK_BLOCK:%.*]], label [[FAILED_1:%.*]]
 ; CHECK:       range_check_block:
-; CHECK-NEXT:    [[RANGE_CHECK_FIRST_ITER:%.*]] = icmp ult i32 [[TMP0]], [[LEN:%.*]]
 ; CHECK-NEXT:    [[FAKE_2:%.*]] = call i1 @cond()
 ; CHECK-NEXT:    [[AND_2:%.*]] = select i1 [[RANGE_CHECK_FIRST_ITER]], i1 [[FAKE_2]], i1 false
 ; CHECK-NEXT:    br i1 [[AND_2]], label [[BACKEDGE]], label [[FAILED_2:%.*]]
@@ -696,6 +696,7 @@ define i32 @test_litter_conditions_inverse_logical_or(i32 %start, i32 %len) {
 ; CHECK-LABEL: @test_litter_conditions_inverse_logical_or(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[TMP0:%.*]] = add i32 [[START:%.*]], -1
+; CHECK-NEXT:    [[RANGE_CHECK_FAILED_FIRST_ITER:%.*]] = icmp uge i32 [[TMP0]], [[LEN:%.*]]
 ; CHECK-NEXT:    br label [[LOOP:%.*]]
 ; CHECK:       loop:
 ; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ [[START]], [[ENTRY:%.*]] ], [ [[IV_NEXT:%.*]], [[BACKEDGE:%.*]] ]
@@ -704,7 +705,6 @@ define i32 @test_litter_conditions_inverse_logical_or(i32 %start, i32 %len) {
 ; CHECK-NEXT:    [[AND_1:%.*]] = and i1 [[ZERO_CHECK]], [[FAKE_1]]
 ; CHECK-NEXT:    br i1 [[AND_1]], label [[RANGE_CHECK_BLOCK:%.*]], label [[FAILED_1:%.*]]
 ; CHECK:       range_check_block:
-; CHECK-NEXT:    [[RANGE_CHECK_FAILED_FIRST_ITER:%.*]] = icmp uge i32 [[TMP0]], [[LEN:%.*]]
 ; CHECK-NEXT:    [[FAKE_2:%.*]] = call i1 @cond()
 ; CHECK-NEXT:    [[OR_2:%.*]] = select i1 [[RANGE_CHECK_FAILED_FIRST_ITER]], i1 true, i1 [[FAKE_2]]
 ; CHECK-NEXT:    br i1 [[OR_2]], label [[FAILED_2:%.*]], label [[BACKEDGE]]
@@ -757,11 +757,11 @@ define i32 @test_and_conditions_logical_and(i32 %start, i32 %len) {
 ; CHECK-LABEL: @test_and_conditions_logical_and(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[TMP0:%.*]] = add i32 [[START:%.*]], -1
+; CHECK-NEXT:    [[RANGE_CHECK_FIRST_ITER:%.*]] = icmp ult i32 [[TMP0]], [[LEN:%.*]]
 ; CHECK-NEXT:    br label [[LOOP:%.*]]
 ; CHECK:       loop:
 ; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ [[START]], [[ENTRY:%.*]] ], [ [[IV_NEXT:%.*]], [[BACKEDGE:%.*]] ]
 ; CHECK-NEXT:    [[ZERO_CHECK:%.*]] = icmp ne i32 [[IV]], 0
-; CHECK-NEXT:    [[RANGE_CHECK_FIRST_ITER:%.*]] = icmp ult i32 [[TMP0]], [[LEN:%.*]]
 ; CHECK-NEXT:    [[BOTH_CHECKS:%.*]] = select i1 [[ZERO_CHECK]], i1 [[RANGE_CHECK_FIRST_ITER]], i1 false
 ; CHECK-NEXT:    br i1 [[BOTH_CHECKS]], label [[BACKEDGE]], label [[FAILED:%.*]]
 ; CHECK:       backedge:
@@ -802,11 +802,11 @@ define i32 @test_and_conditions_inverse_logical_or(i32 %start, i32 %len) {
 ; CHECK-LABEL: @test_and_conditions_inverse_logical_or(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[TMP0:%.*]] = add i32 [[START:%.*]], -1
+; CHECK-NEXT:    [[RANGE_CHECK_FAILED_FIRST_ITER:%.*]] = icmp uge i32 [[TMP0]], [[LEN:%.*]]
 ; CHECK-NEXT:    br label [[LOOP:%.*]]
 ; CHECK:       loop:
 ; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ [[START]], [[ENTRY:%.*]] ], [ [[IV_NEXT:%.*]], [[BACKEDGE:%.*]] ]
 ; CHECK-NEXT:    [[ZERO_CHECK_FAILED:%.*]] = icmp eq i32 [[IV]], 0
-; CHECK-NEXT:    [[RANGE_CHECK_FAILED_FIRST_ITER:%.*]] = icmp uge i32 [[TMP0]], [[LEN:%.*]]
 ; CHECK-NEXT:    [[EITHER_CHECK:%.*]] = select i1 [[ZERO_CHECK_FAILED]], i1 true, i1 [[RANGE_CHECK_FAILED_FIRST_ITER]]
 ; CHECK-NEXT:    br i1 [[EITHER_CHECK]], label [[FAILED:%.*]], label [[BACKEDGE]]
 ; CHECK:       backedge:
@@ -847,6 +847,7 @@ define i32 @test_litter_conditions_constant(i32 %start, i32 %len) {
 ; CHECK-LABEL: @test_litter_conditions_constant(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[TMP0:%.*]] = add i32 [[START:%.*]], -1
+; CHECK-NEXT:    [[RANGE_CHECK_FIRST_ITER:%.*]] = icmp ult i32 [[TMP0]], [[LEN:%.*]]
 ; CHECK-NEXT:    br label [[LOOP:%.*]]
 ; CHECK:       loop:
 ; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ [[START]], [[ENTRY:%.*]] ], [ [[IV_NEXT:%.*]], [[BACKEDGE:%.*]] ]
@@ -859,7 +860,6 @@ define i32 @test_litter_conditions_constant(i32 %start, i32 %len) {
 ; CHECK-NEXT:    [[AND_1:%.*]] = and i1 [[ZERO_CHECK]], [[FAKE_1]]
 ; CHECK-NEXT:    br i1 [[AND_1]], label [[RANGE_CHECK_BLOCK:%.*]], label [[FAILED_1:%.*]]
 ; CHECK:       range_check_block:
-; CHECK-NEXT:    [[RANGE_CHECK_FIRST_ITER:%.*]] = icmp ult i32 [[TMP0]], [[LEN:%.*]]
 ; CHECK-NEXT:    [[FAKE_2:%.*]] = call i1 @cond()
 ; CHECK-NEXT:    [[AND_2:%.*]] = and i1 [[RANGE_CHECK_FIRST_ITER]], [[FAKE_2]]
 ; CHECK-NEXT:    br i1 [[AND_2]], label [[BACKEDGE]], label [[FAILED_2:%.*]]