reference, declarationdefinition
definition → references, declarations, derived classes, virtual overrides
reference to multiple definitions → definitions
unreferenced
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# RUN: llc -mtriple=thumbv8.1m.main -run-pass=arm-low-overhead-loops %s -verify-machineinstrs -o - | FileCheck %s

# CHECK-NOT: DoLoopStart
# CHECK-NOT: DLS
# CHECK: bb.1.for.body:
# CHECK:      $lr = t2SUBri killed renamable $lr, 1, 14, $noreg, def $cpsr
# CHECK-NOT:  t2CMPri $lr
# CHECK:      tBcc %bb.3, 1, $cpsr
# CHECK:      tB %bb.2, 14, $noreg
# CHECK: bb.2.for.cond.cleanup:
# CHECK: bb.3.for.header:

--- |
  target datalayout = "e-m:e-p:32:32-Fi8-i64:64-v128:64:128-a:0:32-n32-S64"
  target triple = "thumbv8.1m.main"
  
  define void @size_limit(i32* nocapture %a, i32* nocapture readonly %b, i32* nocapture readonly %c, i32 %N) {
  entry:
    call void @llvm.set.loop.iterations.i32(i32 %N)
    %scevgep = getelementptr i32, i32* %a, i32 -1
    %scevgep4 = getelementptr i32, i32* %c, i32 -1
    %scevgep8 = getelementptr i32, i32* %b, i32 -1
    br label %for.header
  
  for.body:                                         ; preds = %for.header
    %scevgep11 = getelementptr i32, i32* %lsr.iv9, i32 1
    %ld1 = load i32, i32* %scevgep11, align 4
    %scevgep7 = getelementptr i32, i32* %lsr.iv5, i32 1
    %ld2 = load i32, i32* %scevgep7, align 4
    %mul = mul nsw i32 %ld2, %ld1
    %scevgep3 = getelementptr i32, i32* %lsr.iv1, i32 1
    store i32 %mul, i32* %scevgep3, align 4
    %scevgep2 = getelementptr i32, i32* %lsr.iv1, i32 1
    %scevgep6 = getelementptr i32, i32* %lsr.iv5, i32 1
    %scevgep10 = getelementptr i32, i32* %lsr.iv9, i32 1
    %count.next = call i32 @llvm.loop.decrement.reg.i32.i32.i32(i32 %count, i32 1)
    %cmp = icmp ne i32 %count.next, 0
    br i1 %cmp, label %for.header, label %for.cond.cleanup
  
  for.cond.cleanup:                                 ; preds = %for.body
    ret void
  
  for.header:                                       ; preds = %for.body, %entry
    %lsr.iv9 = phi i32* [ %scevgep8, %entry ], [ %scevgep10, %for.body ]
    %lsr.iv5 = phi i32* [ %scevgep4, %entry ], [ %scevgep6, %for.body ]
    %lsr.iv1 = phi i32* [ %scevgep, %entry ], [ %scevgep2, %for.body ]
    %count = phi i32 [ %N, %entry ], [ %count.next, %for.body ]
    br label %for.body
  }
  
  ; Function Attrs: nounwind
  declare i32 @llvm.arm.space(i32 immarg, i32) #0
  
  ; Function Attrs: noduplicate nounwind
  declare void @llvm.set.loop.iterations.i32(i32) #1
  
  ; Function Attrs: noduplicate nounwind
  declare i32 @llvm.loop.decrement.reg.i32.i32.i32(i32, i32) #1
  
  attributes #0 = { nounwind }
  attributes #1 = { noduplicate nounwind }

...
---
name:            size_limit
alignment:       2
exposesReturnsTwice: false
legalized:       false
regBankSelected: false
selected:        false
failedISel:      false
tracksRegLiveness: true
hasWinCFI:       false
registers:       []
liveins:
  - { reg: '$r0', virtual-reg: '' }
  - { reg: '$r1', virtual-reg: '' }
  - { reg: '$r2', virtual-reg: '' }
  - { reg: '$r3', virtual-reg: '' }
frameInfo:
  isFrameAddressTaken: false
  isReturnAddressTaken: false
  hasStackMap:     false
  hasPatchPoint:   false
  stackSize:       40
  offsetAdjustment: 0
  maxAlignment:    4
  adjustsStack:    false
  hasCalls:        false
  stackProtector:  ''
  maxCallFrameSize: 0
  cvBytesOfCalleeSavedRegisters: 0
  hasOpaqueSPAdjustment: false
  hasVAStart:      false
  hasMustTailInVarArgFunc: false
  localFrameSize:  0
  savePoint:       ''
  restorePoint:    ''
fixedStack:      []
stack:
  - { id: 0, name: '', type: spill-slot, offset: -12, size: 4, alignment: 4, 
      stack-id: default, callee-saved-register: '', callee-saved-restored: true, 
      debug-info-variable: '', debug-info-expression: '', debug-info-location: '' }
  - { id: 1, name: '', type: spill-slot, offset: -16, size: 4, alignment: 4, 
      stack-id: default, callee-saved-register: '', callee-saved-restored: true, 
      debug-info-variable: '', debug-info-expression: '', debug-info-location: '' }
  - { id: 2, name: '', type: spill-slot, offset: -20, size: 4, alignment: 4, 
      stack-id: default, callee-saved-register: '', callee-saved-restored: true, 
      debug-info-variable: '', debug-info-expression: '', debug-info-location: '' }
  - { id: 3, name: '', type: spill-slot, offset: -24, size: 4, alignment: 4, 
      stack-id: default, callee-saved-register: '', callee-saved-restored: true, 
      debug-info-variable: '', debug-info-expression: '', debug-info-location: '' }
  - { id: 4, name: '', type: spill-slot, offset: -28, size: 4, alignment: 4, 
      stack-id: default, callee-saved-register: '', callee-saved-restored: true, 
      debug-info-variable: '', debug-info-expression: '', debug-info-location: '' }
  - { id: 5, name: '', type: spill-slot, offset: -32, size: 4, alignment: 4, 
      stack-id: default, callee-saved-register: '', callee-saved-restored: true, 
      debug-info-variable: '', debug-info-expression: '', debug-info-location: '' }
  - { id: 6, name: '', type: spill-slot, offset: -36, size: 4, alignment: 4, 
      stack-id: default, callee-saved-register: '', callee-saved-restored: true, 
      debug-info-variable: '', debug-info-expression: '', debug-info-location: '' }
  - { id: 7, name: '', type: spill-slot, offset: -40, size: 4, alignment: 4, 
      stack-id: default, callee-saved-register: '', callee-saved-restored: true, 
      debug-info-variable: '', debug-info-expression: '', debug-info-location: '' }
  - { id: 8, name: '', type: spill-slot, offset: -4, size: 4, alignment: 4, 
      stack-id: default, callee-saved-register: '$lr', callee-saved-restored: false, 
      debug-info-variable: '', debug-info-expression: '', debug-info-location: '' }
  - { id: 9, name: '', type: spill-slot, offset: -8, size: 4, alignment: 4, 
      stack-id: default, callee-saved-register: '$r7', callee-saved-restored: true, 
      debug-info-variable: '', debug-info-expression: '', debug-info-location: '' }
callSites:       []
constants:       []
machineFunctionInfo: {}
body:             |
  bb.0.entry:
    successors: %bb.3(0x80000000)
    liveins: $r0, $r1, $r2, $r3, $r7, $lr
  
    frame-setup tPUSH 14, $noreg, killed $r7, killed $lr, implicit-def $sp, implicit $sp
    frame-setup CFI_INSTRUCTION def_cfa_offset 8
    frame-setup CFI_INSTRUCTION offset $lr, -4
    frame-setup CFI_INSTRUCTION offset $r7, -8
    $sp = frame-setup tSUBspi $sp, 8, 14, $noreg
    frame-setup CFI_INSTRUCTION def_cfa_offset 40
    t2DoLoopStart renamable $r3
    renamable $r0, dead $cpsr = tSUBi8 killed renamable $r0, 4, 14, $noreg
    renamable $r2, dead $cpsr = tSUBi8 killed renamable $r2, 4, 14, $noreg
    renamable $r1, dead $cpsr = tSUBi8 killed renamable $r1, 4, 14, $noreg
    tSTRspi killed $r1, $sp, 7, 14, $noreg :: (store 4 into %stack.0)
    tSTRspi killed $r2, $sp, 6, 14, $noreg :: (store 4 into %stack.1)
    tSTRspi killed $r0, $sp, 5, 14, $noreg :: (store 4 into %stack.2)
    tSTRspi killed $r3, $sp, 4, 14, $noreg :: (store 4 into %stack.3)
    tB %bb.3, 14, $noreg
  
  bb.1.for.body:
    successors: %bb.3(0x40000000), %bb.2(0x40000000)
  
    $r0 = tLDRspi $sp, 3, 14, $noreg :: (load 4 from %stack.4)
    renamable $r1, renamable $r0 = t2LDR_PRE renamable $r0, 4, 14, $noreg :: (load 4 from %ir.scevgep11)
    $r2 = tLDRspi $sp, 2, 14, $noreg :: (load 4 from %stack.5)
    renamable $r3, renamable $r2 = t2LDR_PRE renamable $r2, 4, 14, $noreg :: (load 4 from %ir.scevgep7)
    renamable $r1, dead $cpsr = nsw tMUL killed renamable $r3, killed renamable $r1, 14, $noreg
    $r3 = tLDRspi $sp, 1, 14, $noreg :: (load 4 from %stack.6)
    early-clobber renamable $r3 = t2STR_PRE killed renamable $r1, renamable $r3, 4, 14, $noreg :: (store 4 into %ir.scevgep3)
    $r1 = tLDRspi $sp, 0, 14, $noreg :: (load 4 from %stack.7)
    $lr = tMOVr killed $r1, 14, $noreg
    renamable $lr = t2LoopDec killed renamable $lr, 1
    $r12 = tMOVr $lr, 14, $noreg
    tSTRspi killed $r0, $sp, 7, 14, $noreg :: (store 4 into %stack.0)
    tSTRspi killed $r2, $sp, 6, 14, $noreg :: (store 4 into %stack.1)
    tSTRspi killed $r3, $sp, 5, 14, $noreg :: (store 4 into %stack.2)
    t2STRi12 killed $r12, $sp, 16, 14, $noreg :: (store 4 into %stack.3)
    t2LoopEnd killed renamable $lr, %bb.3, implicit-def dead $cpsr
    tB %bb.2, 14, $noreg
  
  bb.2.for.cond.cleanup:
    $sp = tADDspi $sp, 8, 14, $noreg
    tPOP_RET 14, $noreg, def $r7, def $pc
  
  bb.3.for.header:
    successors: %bb.1(0x80000000)
  
    $r0 = tLDRspi $sp, 4, 14, $noreg :: (load 4 from %stack.3)
    $r1 = tLDRspi $sp, 5, 14, $noreg :: (load 4 from %stack.2)
    $r2 = tLDRspi $sp, 6, 14, $noreg :: (load 4 from %stack.1)
    $r3 = tLDRspi $sp, 7, 14, $noreg :: (load 4 from %stack.0)
    tSTRspi killed $r0, $sp, 0, 14, $noreg :: (store 4 into %stack.7)
    tSTRspi killed $r1, $sp, 1, 14, $noreg :: (store 4 into %stack.6)
    tSTRspi killed $r2, $sp, 2, 14, $noreg :: (store 4 into %stack.5)
    tSTRspi killed $r3, $sp, 3, 14, $noreg :: (store 4 into %stack.4)
    tB %bb.1, 14, $noreg

...