multiblock-massive.mir 6.07 KB
# RUN: llc -mtriple=armv8.1m.main -mattr=+lob -run-pass=arm-low-overhead-loops --verify-machineinstrs %s -o - | FileCheck %s
# CHECK: for.body:
# CHECK-NOT: t2DLS
# CHECK-NOT: t2LEUpdate

--- |
  ; ModuleID = 'multiblock-massive.ll'
  source_filename = "multiblock-massive.ll"
  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:
    %cmp8 = icmp eq i32 %N, 0
    br i1 %cmp8, label %for.cond.cleanup, label %for.body.preheader
  
  for.body.preheader:                               ; preds = %entry
    call void @llvm.set.loop.iterations.i32(i32 %N)
    br label %for.body
  
  for.cond.cleanup:                                 ; preds = %for.end, %entry
    ret void
  
  for.body:                                         ; preds = %for.end, %for.body.preheader
    %lsr.iv4 = phi i32* [ %b, %for.body.preheader ], [ %scevgep5, %for.end ]
    %lsr.iv2 = phi i32* [ %c, %for.body.preheader ], [ %scevgep3, %for.end ]
    %lsr.iv1 = phi i32* [ %a, %for.body.preheader ], [ %scevgep, %for.end ]
    %lsr.iv = phi i32 [ %N, %for.body.preheader ], [ %lsr.iv.next, %for.end ]
    %size = call i32 @llvm.arm.space(i32 3072, i32 undef)
    %0 = load i32, i32* %lsr.iv4, align 4
    %1 = load i32, i32* %lsr.iv2, align 4
    %mul = mul nsw i32 %1, %0
    store i32 %mul, i32* %lsr.iv1, align 4
    %cmp = icmp ne i32 %0, 0
    br i1 %cmp, label %middle.block, label %for.end
  
  middle.block:                                     ; preds = %for.body
    %div = udiv i32 %1, %0
    store i32 %div, i32* %lsr.iv1, align 4
    %size.1 = call i32 @llvm.arm.space(i32 1024, i32 undef)
    br label %for.end
  
  for.end:                                          ; preds = %middle.block, %for.body
    %scevgep = getelementptr i32, i32* %lsr.iv1, i32 1
    %scevgep3 = getelementptr i32, i32* %lsr.iv2, i32 1
    %scevgep5 = getelementptr i32, i32* %lsr.iv4, i32 1
    %lsr.iv.next = call i32 @llvm.loop.decrement.reg.i32.i32.i32(i32 %lsr.iv, i32 1)
    %exitcond = icmp eq i32 %lsr.iv.next, 0
    br i1 %exitcond, label %for.cond.cleanup, 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
  
  ; Function Attrs: nounwind
  declare void @llvm.stackprotector(i8*, i8**) #0
  
  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:       8
  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: -4, size: 4, alignment: 4, 
      stack-id: default, callee-saved-register: '$lr', callee-saved-restored: false, 
      debug-info-variable: '', debug-info-expression: '', debug-info-location: '' }
  - { id: 1, name: '', type: spill-slot, offset: -8, size: 4, alignment: 4, 
      stack-id: default, callee-saved-register: '$r4', callee-saved-restored: true, 
      debug-info-variable: '', debug-info-expression: '', debug-info-location: '' }
callSites:       []
constants:       []
machineFunctionInfo: {}
body:             |
  bb.0.entry:
    successors: %bb.2(0x80000000)
    liveins: $r0, $r1, $r2, $r3, $r4, $lr
  
    frame-setup tPUSH 14, $noreg, killed $r4, 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 $r4, -8
    tCMPi8 $r3, 0, 14, $noreg, implicit-def $cpsr
    t2IT 0, 8, implicit-def $itstate
    tPOP_RET 0, killed $cpsr, def $r4, def $pc, implicit killed $itstate
    $lr = tMOVr $r3, 14, $noreg
    t2DoLoopStart killed $r3
    tB %bb.2, 14, $noreg
  
  bb.1.for.end:
    successors: %bb.4(0x04000000), %bb.2(0x7c000000)
    liveins: $lr, $r0, $r1, $r2
  
    renamable $r1, dead $cpsr = tADDi8 killed renamable $r1, 4, 14, $noreg
    renamable $r2, dead $cpsr = tADDi8 killed renamable $r2, 4, 14, $noreg
    renamable $r0, dead $cpsr = tADDi8 killed renamable $r0, 4, 14, $noreg
    renamable $lr = t2LoopDec killed renamable $lr, 1
    t2LoopEnd renamable $lr, %bb.2, implicit-def dead $cpsr
    t2B %bb.4, 14, $noreg
  
  bb.2.for.body:
    successors: %bb.3(0x50000000), %bb.1(0x30000000)
    liveins: $lr, $r0, $r1, $r2
  
    dead renamable $r3 = SPACE 3072, undef renamable $r0
    renamable $r3 = tLDRi renamable $r1, 0, 14, $noreg :: (load 4 from %ir.lsr.iv4)
    renamable $r12 = t2LDRi12 renamable $r2, 0, 14, $noreg :: (load 4 from %ir.lsr.iv2)
    tCMPi8 renamable $r3, 0, 14, $noreg, implicit-def $cpsr
    renamable $r4 = nsw t2MUL renamable $r12, renamable $r3, 14, $noreg
    tSTRi killed renamable $r4, renamable $r0, 0, 14, $noreg :: (store 4 into %ir.lsr.iv1)
    t2Bcc %bb.1, 0, killed $cpsr
  
  bb.3.middle.block:
    successors: %bb.1(0x80000000)
    liveins: $lr, $r0, $r1, $r2, $r3, $r12
  
    renamable $r3 = t2UDIV killed renamable $r12, killed renamable $r3, 14, $noreg
    tSTRi killed renamable $r3, renamable $r0, 0, 14, $noreg :: (store 4 into %ir.lsr.iv1)
    dead renamable $r3 = SPACE 1024, undef renamable $r0
    t2B %bb.1, 14, $noreg
  
  bb.4.for.cond.cleanup:
    tPOP_RET 14, $noreg, def $r4, def $pc

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