Revert b19ec1eb3d

Summary: This reverts commit b19ec1eb3d as it fails powerpc tests

Subscribers: llvm-commits

llvm/include/llvm/Analysis/BranchProbabilityInfo.h

@@ -34,7 +34,6 @@ namespace llvm {
 class Function;
 class LoopInfo;
 class raw_ostream;
-class PostDominatorTree;
 class TargetLibraryInfo;
 class Value;
 
@@ -188,10 +187,8 @@ private:
   /// Track the set of blocks that always lead to a cold call.
   SmallPtrSet<const BasicBlock *, 16> PostDominatedByColdCall;
 
-  void computePostDominatedByUnreachable(const Function &F,
+  void updatePostDominatedByUnreachable(const BasicBlock *BB);
-                                         PostDominatorTree *PDT);
+  void updatePostDominatedByColdCall(const BasicBlock *BB);
-  void computePostDominatedByColdCall(const Function &F,
-                                      PostDominatorTree *PDT);
   bool calcUnreachableHeuristics(const BasicBlock *BB);
   bool calcMetadataWeights(const BasicBlock *BB);
   bool calcColdCallHeuristics(const BasicBlock *BB);

llvm/lib/Analysis/BranchProbabilityInfo.cpp

@@ -16,7 +16,6 @@
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/Analysis/LoopInfo.h"
-#include "llvm/Analysis/PostDominators.h"
 #include "llvm/Analysis/TargetLibraryInfo.h"
 #include "llvm/IR/Attributes.h"
 #include "llvm/IR/BasicBlock.h"
@@ -147,82 +146,68 @@ static const uint32_t IH_TAKEN_WEIGHT = 1024 * 1024 - 1;
 /// instruction. This is essentially never taken.
 static const uint32_t IH_NONTAKEN_WEIGHT = 1;
 
-static void UpdatePDTWorklist(const BasicBlock *BB, PostDominatorTree *PDT,
+/// Add \p BB to PostDominatedByUnreachable set if applicable.
-                              SmallVectorImpl<const BasicBlock *> &WorkList,
+void
-                              SmallPtrSetImpl<const BasicBlock *> &TargetSet) {
+BranchProbabilityInfo::updatePostDominatedByUnreachable(const BasicBlock *BB) {
-  SmallVector<BasicBlock *, 8> Descendants;
+  const Instruction *TI = BB->getTerminator();
-  SmallPtrSet<const BasicBlock *, 16> NewItems;
-
-  PDT->getDescendants(const_cast<BasicBlock *>(BB), Descendants);
-  for (auto *BB : Descendants)
-    if (TargetSet.insert(BB).second)
-      for (pred_iterator PI = pred_begin(BB), E = pred_end(BB); PI != E; ++PI)
-        if (!TargetSet.count(*PI))
-          NewItems.insert(*PI);
-  WorkList.insert(WorkList.end(), NewItems.begin(), NewItems.end());
-}
-
-/// Compute a set of basic blocks that are post-dominated by unreachables.
-void BranchProbabilityInfo::computePostDominatedByUnreachable(
-    const Function &F, PostDominatorTree *PDT) {
-  SmallVector<const BasicBlock *, 8> WorkList;
-  for (auto &BB : F) {
-    const Instruction *TI = BB.getTerminator();
   if (TI->getNumSuccessors() == 0) {
     if (isa<UnreachableInst>(TI) ||
         // If this block is terminated by a call to
-          // @llvm.experimental.deoptimize then treat it like an unreachable
+        // @llvm.experimental.deoptimize then treat it like an unreachable since
-          // since the @llvm.experimental.deoptimize call is expected to
+        // the @llvm.experimental.deoptimize call is expected to practically
-          // practically never execute.
+        // never execute.
-          BB.getTerminatingDeoptimizeCall())
+        BB->getTerminatingDeoptimizeCall())
-        UpdatePDTWorklist(&BB, PDT, WorkList, PostDominatedByUnreachable);
+      PostDominatedByUnreachable.insert(BB);
-    }
+    return;
   }
 
-  while (!WorkList.empty()) {
+  // If the terminator is an InvokeInst, check only the normal destination block
-    const BasicBlock *BB = WorkList.pop_back_val();
+  // as the unwind edge of InvokeInst is also very unlikely taken.
-    if (PostDominatedByUnreachable.count(BB))
+  if (auto *II = dyn_cast<InvokeInst>(TI)) {
-      continue;
-    // If the terminator is an InvokeInst, check only the normal destination
-    // block as the unwind edge of InvokeInst is also very unlikely taken.
-    if (auto *II = dyn_cast<InvokeInst>(BB->getTerminator())) {
     if (PostDominatedByUnreachable.count(II->getNormalDest()))
-        UpdatePDTWorklist(BB, PDT, WorkList, PostDominatedByUnreachable);
+      PostDominatedByUnreachable.insert(BB);
-    }
+    return;
-    // If all the successors are unreachable, BB is unreachable as well.
-    else if (!successors(BB).empty() &&
-             llvm::all_of(successors(BB), [this](const BasicBlock *Succ) {
-               return PostDominatedByUnreachable.count(Succ);
-             }))
-      UpdatePDTWorklist(BB, PDT, WorkList, PostDominatedByUnreachable);
-  }
   }
 
-/// compute a set of basic blocks that are post-dominated by ColdCalls.
+  for (auto *I : successors(BB))
-void BranchProbabilityInfo::computePostDominatedByColdCall(
+    // If any of successor is not post dominated then BB is also not.
-    const Function &F, PostDominatorTree *PDT) {
+    if (!PostDominatedByUnreachable.count(I))
-  SmallVector<const BasicBlock *, 8> WorkList;
+      return;
-  for (auto &BB : F)
-    for (auto &I : BB)
-      if (const CallInst *CI = dyn_cast<CallInst>(&I))
-        if (CI->hasFnAttr(Attribute::Cold))
-          UpdatePDTWorklist(&BB, PDT, WorkList, PostDominatedByColdCall);
 
-  while (!WorkList.empty()) {
+  PostDominatedByUnreachable.insert(BB);
-    const BasicBlock *BB = WorkList.pop_back_val();
+}
+
+/// Add \p BB to PostDominatedByColdCall set if applicable.
+void
+BranchProbabilityInfo::updatePostDominatedByColdCall(const BasicBlock *BB) {
+  assert(!PostDominatedByColdCall.count(BB));
+  const Instruction *TI = BB->getTerminator();
+  if (TI->getNumSuccessors() == 0)
+    return;
+
+  // If all of successor are post dominated then BB is also done.
+  if (llvm::all_of(successors(BB), [&](const BasicBlock *SuccBB) {
+        return PostDominatedByColdCall.count(SuccBB);
+      })) {
+    PostDominatedByColdCall.insert(BB);
+    return;
+  }
 
   // If the terminator is an InvokeInst, check only the normal destination
   // block as the unwind edge of InvokeInst is also very unlikely taken.
-    if (auto *II = dyn_cast<InvokeInst>(BB->getTerminator())) {
+  if (auto *II = dyn_cast<InvokeInst>(TI))
-      if (PostDominatedByColdCall.count(II->getNormalDest()))
+    if (PostDominatedByColdCall.count(II->getNormalDest())) {
-        UpdatePDTWorklist(BB, PDT, WorkList, PostDominatedByColdCall);
+      PostDominatedByColdCall.insert(BB);
+      return;
     }
-    // If all of successor are post dominated then BB is also done.
+
-    else if (!successors(BB).empty() &&
+  // Otherwise, if the block itself contains a cold function, add it to the
-             llvm::all_of(successors(BB), [this](const BasicBlock *Succ) {
+  // set of blocks post-dominated by a cold call.
-               return PostDominatedByColdCall.count(Succ);
+  for (auto &I : *BB)
-             }))
+    if (const CallInst *CI = dyn_cast<CallInst>(&I))
-      UpdatePDTWorklist(BB, PDT, WorkList, PostDominatedByColdCall);
+      if (CI->hasFnAttr(Attribute::Cold)) {
+        PostDominatedByColdCall.insert(BB);
+        return;
       }
 }
 
@@ -998,16 +983,13 @@ void BranchProbabilityInfo::calculate(const Function &F, const LoopInfo &LI,
     LLVM_DEBUG(dbgs() << "\n");
   }
 
-  std::unique_ptr<PostDominatorTree> PDT =
-      std::make_unique<PostDominatorTree>(const_cast<Function &>(F));
-  computePostDominatedByUnreachable(F, PDT.get());
-  computePostDominatedByColdCall(F, PDT.get());
-
   // Walk the basic blocks in post-order so that we can build up state about
   // the successors of a block iteratively.
   for (auto BB : post_order(&F.getEntryBlock())) {
     LLVM_DEBUG(dbgs() << "Computing probabilities for " << BB->getName()
                       << "\n");
+    updatePostDominatedByUnreachable(BB);
+    updatePostDominatedByColdCall(BB);
     // If there is no at least two successors, no sense to set probability.
     if (BB->getTerminator()->getNumSuccessors() < 2)
       continue;

llvm/test/Analysis/BranchProbabilityInfo/basic.ll

@@ -141,24 +141,6 @@ exit:
   ret i32 %result
 }
 
-define i32 @test_cold_loop(i32 %a, i32 %b) {
-entry:
-  %cond1 = icmp eq i32 %a, 42
-  br i1 %cond1, label %header, label %exit
-
-header:
-  br label %body
-
-body:
-  %cond2 = icmp eq i32 %b, 42
-  br i1 %cond2, label %header, label %exit
-; CHECK: edge body -> header probability is 0x40000000 / 0x80000000 = 50.00%
-
-exit:
-  call void @coldfunc()
-  ret i32 %b
-}
-
 declare i32 @regular_function(i32 %i)
 
 define i32 @test_cold_call_sites_with_prof(i32 %a, i32 %b, i1 %flag, i1 %flag2) {

llvm/test/Analysis/BranchProbabilityInfo/noreturn.ll

@@ -79,32 +79,6 @@ exit:
   ret i32 %b
 }
 
-define i32 @test4(i32 %a, i32 %b) {
-; CHECK: Printing analysis {{.*}} for function 'test4'
-; Make sure we handle loops post-dominated by unreachables.
-entry:
-  %cond1 = icmp eq i32 %a, 42
-  br i1 %cond1, label %header, label %exit
-; CHECK: edge entry -> header probability is 0x00000001 / 0x80000000 = 0.00%
-; CHECK: edge entry -> exit probability is 0x7fffffff / 0x80000000 = 100.00% [HOT edge]
-
-header:
-  br label %body
-
-body:
-  %cond2 = icmp eq i32 %a, 42
-  br i1 %cond2, label %header, label %abort
-; CHECK: edge body -> header probability is 0x40000000 / 0x80000000 = 50.00%
-; CHECK: edge body -> abort probability is 0x40000000 / 0x80000000 = 50.00%
-
-abort:
-  call void @abort() noreturn
-  unreachable
-
-exit:
-  ret i32 %b
-}
-
 @_ZTIi = external global i8*
 
 ; CHECK-LABEL: throwSmallException

llvm/test/CodeGen/X86/block-placement.ll

@@ -358,11 +358,11 @@ define void @unnatural_cfg2(i32* %p0, i32 %a0) {
 ; CHECK: %loop.header
 ; CHECK: %loop.body1
 ; CHECK: %loop.body2
-; CHECK: %loop.body3
-; CHECK: %loop.inner1.begin
 ; CHECK: %loop.body4
 ; CHECK: %loop.inner2.begin
 ; CHECK: %loop.inner2.begin
+; CHECK: %loop.body3
+; CHECK: %loop.inner1.begin
 ; CHECK: %bail
 
 entry:

llvm/test/CodeGen/X86/pr37916.ll

@@ -7,6 +7,7 @@
 define void @fn1() local_unnamed_addr {
 ; CHECK-LABEL: fn1:
 ; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    .p2align 4, 0x90
 ; CHECK-NEXT:  .LBB0_1: # %if.end
 ; CHECK-NEXT:    # =>This Inner Loop Header: Depth=1
 ; CHECK-NEXT:    movl a+4, %eax

llvm/test/CodeGen/X86/ragreedy-hoist-spill.ll

@@ -29,8 +29,8 @@ define i8* @SyFgets(i8* %line, i64 %length, i64 %fid) {
 ; CHECK-NEXT:    .cfi_def_cfa_offset 48
 ; CHECK-NEXT:    pushq %rbx
 ; CHECK-NEXT:    .cfi_def_cfa_offset 56
-; CHECK-NEXT:    subq $552, %rsp ## imm = 0x228
+; CHECK-NEXT:    subq $536, %rsp ## imm = 0x218
-; CHECK-NEXT:    .cfi_def_cfa_offset 608
+; CHECK-NEXT:    .cfi_def_cfa_offset 592
 ; CHECK-NEXT:    .cfi_offset %rbx, -56
 ; CHECK-NEXT:    .cfi_offset %r12, -48
 ; CHECK-NEXT:    .cfi_offset %r13, -40
@@ -54,7 +54,7 @@ define i8* @SyFgets(i8* %line, i64 %length, i64 %fid) {
 ; CHECK-NEXT:    testb %al, %al
 ; CHECK-NEXT:    je LBB0_55
 ; CHECK-NEXT:  LBB0_4: ## %cleanup
-; CHECK-NEXT:    addq $552, %rsp ## imm = 0x228
+; CHECK-NEXT:    addq $536, %rsp ## imm = 0x218
 ; CHECK-NEXT:    popq %rbx
 ; CHECK-NEXT:    popq %r12
 ; CHECK-NEXT:    popq %r13
@@ -68,7 +68,7 @@ define i8* @SyFgets(i8* %line, i64 %length, i64 %fid) {
 ; CHECK-NEXT:    je LBB0_55
 ; CHECK-NEXT:  ## %bb.6: ## %SyTime.exit2720
 ; CHECK-NEXT:    movq %rdx, %rbx
-; CHECK-NEXT:    movq %rdi, %r14
+; CHECK-NEXT:    movq %rdi, %rbp
 ; CHECK-NEXT:    leaq {{[0-9]+}}(%rsp), %rax
 ; CHECK-NEXT:    leaq {{[0-9]+}}(%rsp), %rcx
 ; CHECK-NEXT:    cmpq %rax, %rcx
@@ -78,10 +78,10 @@ define i8* @SyFgets(i8* %line, i64 %length, i64 %fid) {
 ; CHECK-NEXT:    movl $32, %esi
 ; CHECK-NEXT:    callq _memset
 ; CHECK-NEXT:  LBB0_8: ## %while.body.preheader
+; CHECK-NEXT:    movq %rbp, {{[-0-9]+}}(%r{{[sb]}}p) ## 8-byte Spill
 ; CHECK-NEXT:    imulq $1040, %rbx, %rax ## imm = 0x410
 ; CHECK-NEXT:    movq _syBuf@{{.*}}(%rip), %rcx
-; CHECK-NEXT:    leaq 8(%rcx,%rax), %rax
+; CHECK-NEXT:    leaq 8(%rcx,%rax), %rbx
-; CHECK-NEXT:    movq %rax, {{[-0-9]+}}(%r{{[sb]}}p) ## 8-byte Spill
 ; CHECK-NEXT:    movl $1, %r15d
 ; CHECK-NEXT:    movq _syCTRO@{{.*}}(%rip), %rax
 ; CHECK-NEXT:    movb $1, %cl
@@ -92,70 +92,69 @@ define i8* @SyFgets(i8* %line, i64 %length, i64 %fid) {
 ; CHECK-NEXT:    testb %cl, %cl
 ; CHECK-NEXT:    jne LBB0_9
 ; CHECK-NEXT:  ## %bb.10: ## %do.end
-; CHECK-NEXT:    xorl %ebp, %ebp
+; CHECK-NEXT:    xorl %r14d, %r14d
-; CHECK-NEXT:    testb %bpl, %bpl
+; CHECK-NEXT:    testb %r14b, %r14b
 ; CHECK-NEXT:    jne LBB0_11
 ; CHECK-NEXT:  ## %bb.12: ## %while.body200.preheader
-; CHECK-NEXT:    xorl %ebx, %ebx
+; CHECK-NEXT:    xorl %edx, %edx
-; CHECK-NEXT:    leaq {{.*}}(%rip), %r13
+; CHECK-NEXT:    leaq {{.*}}(%rip), %rsi
-; CHECK-NEXT:    movl $0, {{[-0-9]+}}(%r{{[sb]}}p) ## 4-byte Folded Spill
+; CHECK-NEXT:    leaq {{.*}}(%rip), %rdi
-; CHECK-NEXT:    xorl %r12d, %r12d
+; CHECK-NEXT:    xorl %ebp, %ebp
-; CHECK-NEXT:    movq %r14, {{[-0-9]+}}(%r{{[sb]}}p) ## 8-byte Spill
+; CHECK-NEXT:    xorl %r13d, %r13d
 ; CHECK-NEXT:    jmp LBB0_13
 ; CHECK-NEXT:    .p2align 4, 0x90
 ; CHECK-NEXT:  LBB0_20: ## %sw.bb256
 ; CHECK-NEXT:    ## in Loop: Header=BB0_13 Depth=1
-; CHECK-NEXT:    movl %ebp, %r12d
+; CHECK-NEXT:    movl %r14d, %r13d
 ; CHECK-NEXT:  LBB0_21: ## %while.cond197.backedge
 ; CHECK-NEXT:    ## in Loop: Header=BB0_13 Depth=1
 ; CHECK-NEXT:    decl %r15d
 ; CHECK-NEXT:    testl %r15d, %r15d
-; CHECK-NEXT:    movl %r12d, %ebp
+; CHECK-NEXT:    movl %r13d, %r14d
 ; CHECK-NEXT:    jle LBB0_22
 ; CHECK-NEXT:  LBB0_13: ## %while.body200
 ; CHECK-NEXT:    ## =>This Loop Header: Depth=1
 ; CHECK-NEXT:    ## Child Loop BB0_30 Depth 2
 ; CHECK-NEXT:    ## Child Loop BB0_38 Depth 2
-; CHECK-NEXT:    leal -268(%rbp), %eax
+; CHECK-NEXT:    leal -268(%r14), %eax
 ; CHECK-NEXT:    cmpl $105, %eax
 ; CHECK-NEXT:    ja LBB0_14
 ; CHECK-NEXT:  ## %bb.56: ## %while.body200
 ; CHECK-NEXT:    ## in Loop: Header=BB0_13 Depth=1
-; CHECK-NEXT:    movslq (%r13,%rax,4), %rax
+; CHECK-NEXT:    movslq (%rdi,%rax,4), %rax
-; CHECK-NEXT:    addq %r13, %rax
+; CHECK-NEXT:    addq %rdi, %rax
 ; CHECK-NEXT:    jmpq *%rax
 ; CHECK-NEXT:  LBB0_44: ## %while.cond1037.preheader
 ; CHECK-NEXT:    ## in Loop: Header=BB0_13 Depth=1
-; CHECK-NEXT:    testb %bl, %bl
+; CHECK-NEXT:    testb %dl, %dl
-; CHECK-NEXT:    movl %ebp, %r12d
+; CHECK-NEXT:    movl %r14d, %r13d
 ; CHECK-NEXT:    jne LBB0_21
 ; CHECK-NEXT:    jmp LBB0_55
 ; CHECK-NEXT:    .p2align 4, 0x90
 ; CHECK-NEXT:  LBB0_14: ## %while.body200
 ; CHECK-NEXT:    ## in Loop: Header=BB0_13 Depth=1
-; CHECK-NEXT:    leal 1(%rbp), %eax
+; CHECK-NEXT:    leal 1(%r14), %eax
 ; CHECK-NEXT:    cmpl $21, %eax
 ; CHECK-NEXT:    ja LBB0_20
 ; CHECK-NEXT:  ## %bb.15: ## %while.body200
 ; CHECK-NEXT:    ## in Loop: Header=BB0_13 Depth=1
-; CHECK-NEXT:    movl $-1, %r12d
+; CHECK-NEXT:    movl $-1, %r13d
-; CHECK-NEXT:    leaq {{.*}}(%rip), %rcx
+; CHECK-NEXT:    movslq (%rsi,%rax,4), %rax
-; CHECK-NEXT:    movslq (%rcx,%rax,4), %rax
+; CHECK-NEXT:    addq %rsi, %rax
-; CHECK-NEXT:    addq %rcx, %rax
 ; CHECK-NEXT:    jmpq *%rax
 ; CHECK-NEXT:  LBB0_18: ## %while.cond201.preheader
 ; CHECK-NEXT:    ## in Loop: Header=BB0_13 Depth=1
-; CHECK-NEXT:    movl $1, %r12d
+; CHECK-NEXT:    movl $1, %r13d
 ; CHECK-NEXT:    jmp LBB0_21
 ; CHECK-NEXT:  LBB0_26: ## %sw.bb474
 ; CHECK-NEXT:    ## in Loop: Header=BB0_13 Depth=1
-; CHECK-NEXT:    testb %bl, %bl
+; CHECK-NEXT:    testb %dl, %dl
-; CHECK-NEXT:    ## implicit-def: $r14
+; CHECK-NEXT:    ## implicit-def: $r12
 ; CHECK-NEXT:    jne LBB0_34
 ; CHECK-NEXT:  ## %bb.27: ## %do.body479.preheader
 ; CHECK-NEXT:    ## in Loop: Header=BB0_13 Depth=1
-; CHECK-NEXT:    testb %bl, %bl
+; CHECK-NEXT:    testb %dl, %dl
-; CHECK-NEXT:    ## implicit-def: $r14
+; CHECK-NEXT:    ## implicit-def: $r12
 ; CHECK-NEXT:    jne LBB0_34
 ; CHECK-NEXT:  ## %bb.28: ## %land.rhs485.preheader
 ; CHECK-NEXT:    ## in Loop: Header=BB0_13 Depth=1
@@ -166,8 +165,8 @@ define i8* @SyFgets(i8* %line, i64 %length, i64 %fid) {
 ; CHECK-NEXT:    .p2align 4, 0x90
 ; CHECK-NEXT:  LBB0_32: ## %do.body479.backedge
 ; CHECK-NEXT:    ## in Loop: Header=BB0_30 Depth=2
-; CHECK-NEXT:    leaq 1(%r14), %rax
+; CHECK-NEXT:    leaq 1(%r12), %rax
-; CHECK-NEXT:    testb %bl, %bl
+; CHECK-NEXT:    testb %dl, %dl
 ; CHECK-NEXT:    je LBB0_33
 ; CHECK-NEXT:  ## %bb.29: ## %land.rhs485
 ; CHECK-NEXT:    ## in Loop: Header=BB0_30 Depth=2
@@ -176,14 +175,15 @@ define i8* @SyFgets(i8* %line, i64 %length, i64 %fid) {
 ; CHECK-NEXT:  LBB0_30: ## %cond.true.i.i2780
 ; CHECK-NEXT:    ## Parent Loop BB0_13 Depth=1
 ; CHECK-NEXT:    ## => This Inner Loop Header: Depth=2
-; CHECK-NEXT:    movq %rax, %r14
+; CHECK-NEXT:    movq %rax, %r12
-; CHECK-NEXT:    testb %bl, %bl
+; CHECK-NEXT:    testb %dl, %dl
 ; CHECK-NEXT:    jne LBB0_32
 ; CHECK-NEXT:  ## %bb.31: ## %lor.rhs500
 ; CHECK-NEXT:    ## in Loop: Header=BB0_30 Depth=2
 ; CHECK-NEXT:    movl $256, %esi ## imm = 0x100
 ; CHECK-NEXT:    callq ___maskrune
-; CHECK-NEXT:    testb %bl, %bl
+; CHECK-NEXT:    xorl %edx, %edx
+; CHECK-NEXT:    testb %dl, %dl
 ; CHECK-NEXT:    jne LBB0_32
 ; CHECK-NEXT:    jmp LBB0_34
 ; CHECK-NEXT:  LBB0_45: ## %sw.bb1134
@@ -193,23 +193,23 @@ define i8* @SyFgets(i8* %line, i64 %length, i64 %fid) {
 ; CHECK-NEXT:    cmpq %rax, %rcx
 ; CHECK-NEXT:    jb LBB0_55
 ; CHECK-NEXT:  ## %bb.46: ## in Loop: Header=BB0_13 Depth=1
-; CHECK-NEXT:    movl $0, {{[-0-9]+}}(%r{{[sb]}}p) ## 4-byte Folded Spill
+; CHECK-NEXT:    xorl %ebp, %ebp
-; CHECK-NEXT:    movl $268, %r12d ## imm = 0x10C
+; CHECK-NEXT:    movl $268, %r13d ## imm = 0x10C
-; CHECK-NEXT:    jmp LBB0_21
-; CHECK-NEXT:  LBB0_40: ## %sw.bb566
-; CHECK-NEXT:    ## in Loop: Header=BB0_13 Depth=1
-; CHECK-NEXT:    movl $20, %r12d
 ; CHECK-NEXT:    jmp LBB0_21
 ; CHECK-NEXT:  LBB0_19: ## %sw.bb243
 ; CHECK-NEXT:    ## in Loop: Header=BB0_13 Depth=1
-; CHECK-NEXT:    movl $2, %r12d
+; CHECK-NEXT:    movl $2, %r13d
+; CHECK-NEXT:    jmp LBB0_21
+; CHECK-NEXT:  LBB0_40: ## %sw.bb566
+; CHECK-NEXT:    ## in Loop: Header=BB0_13 Depth=1
+; CHECK-NEXT:    movl $20, %r13d
 ; CHECK-NEXT:    jmp LBB0_21
 ; CHECK-NEXT:  LBB0_33: ## %if.end517.loopexitsplit
 ; CHECK-NEXT:    ## in Loop: Header=BB0_13 Depth=1
-; CHECK-NEXT:    incq %r14
+; CHECK-NEXT:    incq %r12
 ; CHECK-NEXT:  LBB0_34: ## %if.end517
 ; CHECK-NEXT:    ## in Loop: Header=BB0_13 Depth=1
-; CHECK-NEXT:    leal -324(%r12), %eax
+; CHECK-NEXT:    leal -324(%r13), %eax
 ; CHECK-NEXT:    cmpl $59, %eax
 ; CHECK-NEXT:    ja LBB0_35
 ; CHECK-NEXT:  ## %bb.57: ## %if.end517
@@ -219,11 +219,11 @@ define i8* @SyFgets(i8* %line, i64 %length, i64 %fid) {
 ; CHECK-NEXT:    jb LBB0_38
 ; CHECK-NEXT:  LBB0_35: ## %if.end517
 ; CHECK-NEXT:    ## in Loop: Header=BB0_13 Depth=1
-; CHECK-NEXT:    cmpl $11, %r12d
+; CHECK-NEXT:    cmpl $11, %r13d
 ; CHECK-NEXT:    je LBB0_38
 ; CHECK-NEXT:  ## %bb.36: ## %if.end517
 ; CHECK-NEXT:    ## in Loop: Header=BB0_13 Depth=1
-; CHECK-NEXT:    cmpl $24, %r12d
+; CHECK-NEXT:    cmpl $24, %r13d
 ; CHECK-NEXT:    je LBB0_38
 ; CHECK-NEXT:  ## %bb.37: ## %if.then532
 ; CHECK-NEXT:    ## in Loop: Header=BB0_13 Depth=1
@@ -233,14 +233,15 @@ define i8* @SyFgets(i8* %line, i64 %length, i64 %fid) {
 ; CHECK-NEXT:  LBB0_38: ## %for.cond534
 ; CHECK-NEXT:    ## Parent Loop BB0_13 Depth=1
 ; CHECK-NEXT:    ## => This Inner Loop Header: Depth=2
-; CHECK-NEXT:    testb %bl, %bl
+; CHECK-NEXT:    testb %dl, %dl
 ; CHECK-NEXT:    jne LBB0_38
 ; CHECK-NEXT:  ## %bb.39: ## %for.cond542.preheader
 ; CHECK-NEXT:    ## in Loop: Header=BB0_13 Depth=1
-; CHECK-NEXT:    testb %bl, %bl
+; CHECK-NEXT:    testb %dl, %dl
-; CHECK-NEXT:    movb $0, (%r14)
+; CHECK-NEXT:    movb $0, (%r12)
-; CHECK-NEXT:    movl %ebp, %r12d
+; CHECK-NEXT:    movl %r14d, %r13d
-; CHECK-NEXT:    movq {{[-0-9]+}}(%r{{[sb]}}p), %r14 ## 8-byte Reload
+; CHECK-NEXT:    leaq {{.*}}(%rip), %rsi
+; CHECK-NEXT:    leaq {{.*}}(%rip), %rdi
 ; CHECK-NEXT:    jmp LBB0_21
 ; CHECK-NEXT:    .p2align 4, 0x90
 ; CHECK-NEXT:  LBB0_42: ## %while.cond864
@@ -255,31 +256,57 @@ define i8* @SyFgets(i8* %line, i64 %length, i64 %fid) {
 ; CHECK-NEXT:    ## =>This Inner Loop Header: Depth=1
 ; CHECK-NEXT:    jmp LBB0_25
 ; CHECK-NEXT:  LBB0_11:
-; CHECK-NEXT:    movl $0, {{[-0-9]+}}(%r{{[sb]}}p) ## 4-byte Folded Spill
+; CHECK-NEXT:    xorl %ebp, %ebp
-; CHECK-NEXT:    xorl %r12d, %r12d
+; CHECK-NEXT:    xorl %r13d, %r13d
 ; CHECK-NEXT:  LBB0_22: ## %while.end1465
-; CHECK-NEXT:    incl %r12d
+; CHECK-NEXT:    incl %r13d
-; CHECK-NEXT:    cmpl $16, %r12d
+; CHECK-NEXT:    cmpl $16, %r13d
 ; CHECK-NEXT:    ja LBB0_50
 ; CHECK-NEXT:  ## %bb.23: ## %while.end1465
 ; CHECK-NEXT:    movl $83969, %eax ## imm = 0x14801
-; CHECK-NEXT:    btl %r12d, %eax
+; CHECK-NEXT:    btl %r13d, %eax
 ; CHECK-NEXT:    jae LBB0_50
 ; CHECK-NEXT:  ## %bb.24:
-; CHECK-NEXT:    xorl %ebx, %ebx
+; CHECK-NEXT:    xorl %ebp, %ebp
+; CHECK-NEXT:    movq {{[-0-9]+}}(%r{{[sb]}}p), %rbx ## 8-byte Reload
 ; CHECK-NEXT:  LBB0_48: ## %if.then1477
 ; CHECK-NEXT:    movl $1, %edx
 ; CHECK-NEXT:    callq _write
-; CHECK-NEXT:    subq %rbx, %r14
+; CHECK-NEXT:    subq %rbp, %rbx
 ; CHECK-NEXT:    movq _syHistory@{{.*}}(%rip), %rax
-; CHECK-NEXT:    leaq 8189(%r14,%rax), %rax
+; CHECK-NEXT:    leaq 8189(%rbx,%rax), %rax
 ; CHECK-NEXT:    .p2align 4, 0x90
 ; CHECK-NEXT:  LBB0_49: ## %for.body1723
 ; CHECK-NEXT:    ## =>This Inner Loop Header: Depth=1
 ; CHECK-NEXT:    decq %rax
 ; CHECK-NEXT:    jmp LBB0_49
+; CHECK-NEXT:  LBB0_50: ## %for.cond1480.preheader
+; CHECK-NEXT:    movl $512, %eax ## imm = 0x200
+; CHECK-NEXT:    cmpq %rax, %rax
+; CHECK-NEXT:    jae LBB0_55
+; CHECK-NEXT:  ## %bb.51: ## %for.body1664.lr.ph
+; CHECK-NEXT:    xorl %eax, %eax
+; CHECK-NEXT:    testb %al, %al
+; CHECK-NEXT:    jne LBB0_54
+; CHECK-NEXT:  ## %bb.52: ## %while.body1679.preheader
+; CHECK-NEXT:    incl %ebp
+; CHECK-NEXT:    .p2align 4, 0x90
+; CHECK-NEXT:  LBB0_53: ## %while.body1679
+; CHECK-NEXT:    ## =>This Inner Loop Header: Depth=1
+; CHECK-NEXT:    movq (%rbx), %rdi
+; CHECK-NEXT:    callq _fileno
+; CHECK-NEXT:    movslq %ebp, %rax
+; CHECK-NEXT:    leal 1(%rax), %ebp
+; CHECK-NEXT:    cmpq %rax, %rax
+; CHECK-NEXT:    jl LBB0_53
+; CHECK-NEXT:  LBB0_54: ## %while.cond1683.preheader
+; CHECK-NEXT:    xorl %eax, %eax
+; CHECK-NEXT:    testb %al, %al
+; CHECK-NEXT:  LBB0_55: ## %if.then.i
+; CHECK-NEXT:    ud2
 ; CHECK-NEXT:  LBB0_47: ## %if.then1477.loopexit
-; CHECK-NEXT:    movq %r14, %rbx
+; CHECK-NEXT:    movq {{[-0-9]+}}(%r{{[sb]}}p), %rbx ## 8-byte Reload
+; CHECK-NEXT:    movq %rbx, %rbp
 ; CHECK-NEXT:    jmp LBB0_48
 ; CHECK-NEXT:  LBB0_16: ## %while.cond635.preheader
 ; CHECK-NEXT:    xorl %eax, %eax
@@ -293,31 +320,6 @@ define i8* @SyFgets(i8* %line, i64 %length, i64 %fid) {
 ; CHECK-NEXT:  LBB0_41: ## %while.cond661
 ; CHECK-NEXT:    ## =>This Inner Loop Header: Depth=1
 ; CHECK-NEXT:    jmp LBB0_41
-; CHECK-NEXT:  LBB0_50: ## %for.cond1480.preheader
-; CHECK-NEXT:    movl $512, %eax ## imm = 0x200
-; CHECK-NEXT:    cmpq %rax, %rax
-; CHECK-NEXT:    jae LBB0_55
-; CHECK-NEXT:  ## %bb.51: ## %for.body1664.lr.ph
-; CHECK-NEXT:    xorl %eax, %eax
-; CHECK-NEXT:    testb %al, %al
-; CHECK-NEXT:    jne LBB0_54
-; CHECK-NEXT:  ## %bb.52: ## %while.body1679.preheader
-; CHECK-NEXT:    incl {{[-0-9]+}}(%r{{[sb]}}p) ## 4-byte Folded Spill
-; CHECK-NEXT:  LBB0_53: ## %while.body1679
-; CHECK-NEXT:    ## =>This Inner Loop Header: Depth=1
-; CHECK-NEXT:    movq {{[-0-9]+}}(%r{{[sb]}}p), %rax ## 8-byte Reload
-; CHECK-NEXT:    movq (%rax), %rdi
-; CHECK-NEXT:    callq _fileno
-; CHECK-NEXT:    movslq {{[-0-9]+}}(%r{{[sb]}}p), %rax ## 4-byte Folded Reload
-; CHECK-NEXT:    leal 1(%rax), %ecx
-; CHECK-NEXT:    movl %ecx, {{[-0-9]+}}(%r{{[sb]}}p) ## 4-byte Spill
-; CHECK-NEXT:    cmpq %rax, %rax
-; CHECK-NEXT:    jl LBB0_53
-; CHECK-NEXT:  LBB0_54: ## %while.cond1683.preheader
-; CHECK-NEXT:    xorl %eax, %eax
-; CHECK-NEXT:    testb %al, %al
-; CHECK-NEXT:  LBB0_55: ## %if.then.i
-; CHECK-NEXT:    ud2
 entry:
   %sub.ptr.rhs.cast646 = ptrtoint i8* %line to i64
   %old = alloca [512 x i8], align 16