llvm/test/CodeGen/AMDGPU/splitkit.mir

# RUN: llc -o - %s -mtriple=amdgcn-- -mcpu=fiji -verify-machineinstrs -run-pass=greedy,virtregrewriter | FileCheck %s
--- |
  define amdgpu_kernel void @func0() #0 { ret void }
  define amdgpu_kernel void @func1() #0 { ret void }
  define amdgpu_kernel void @splitHoist() #0 { ret void }

  attributes #0 = { "amdgpu-num-sgpr"="12" }
...
---
# Make sure we only get a single spill+reload even if liverange splitting
# created a sequence of multiple copy instructions.
# CHECK-LABEL: name: func0
# CHECK: SI_SPILL_S128_SAVE
# CHECK-NOT: SI_SPILL_S128_SAVE
# CHECK: S_NOP 0
# CHECK: SI_SPILL_S128_RESTORE
# CHECK-NOT: SI_SPILL_S128_RESTORE
name: func0
body: |
  bb.0:
    S_NOP 0, implicit-def undef %0.sub0 : sgpr_128
    S_NOP 0, implicit-def %0.sub3 : sgpr_128

    ; Clobber registers
    S_NOP 0, implicit-def dead $sgpr0, implicit-def dead $sgpr1, implicit-def dead $sgpr2, implicit-def dead $sgpr3, implicit-def dead $sgpr4, implicit-def dead $sgpr5, implicit-def dead $sgpr6, implicit-def dead $sgpr7, implicit-def dead $sgpr8, implicit-def dead $sgpr9, implicit-def dead $sgpr10, implicit-def dead $sgpr11

    S_NOP 0, implicit %0.sub0
    S_NOP 0, implicit %0.sub3
    S_NOP 0, implicit %0.sub0
    S_NOP 0, implicit %0.sub3
...
---
# LiveRange splitting should split this into 2 intervals with the second getting
# allocated to sgpr0_sgpr1 and the first to something else so we see two copies
# in between for the two subregisters that are alive.
# CHECK-LABEL: name: func1
# CHECK: [[REG0:\$sgpr[0-9]+]] = COPY $sgpr0
# CHECK: [[REG1:\$sgpr[0-9]+]] = COPY $sgpr2
# CHECK: S_NOP 0
# CHECK: S_NOP 0, implicit renamable [[REG0]]
# CHECK: S_NOP 0, implicit renamable [[REG1]]
# CHECK: $sgpr0 = COPY renamable [[REG0]]
# CHECK: $sgpr2 = COPY renamable [[REG1]]
# CHECK: S_NOP
# CHECK: S_NOP 0, implicit renamable $sgpr0
# CHECK: S_NOP 0, implicit renamable $sgpr2
name: func1
tracksRegLiveness: true
body: |
  bb.0:
    liveins: $sgpr0, $sgpr1, $sgpr2
    undef %0.sub0 : sgpr_128 = COPY $sgpr0
    %0.sub2 = COPY $sgpr2

    S_NOP 0, implicit-def dead $sgpr0, implicit-def dead $sgpr1

    S_NOP 0, implicit %0.sub0
    S_NOP 0, implicit %0.sub2

    ; Clobber everything but sgpr0-sgpr3
    S_NOP 0, implicit-def dead $sgpr4, implicit-def dead $sgpr5, implicit-def dead $sgpr6, implicit-def dead $sgpr7, implicit-def dead $sgpr8, implicit-def dead $sgpr9, implicit-def dead $sgpr10, implicit-def dead $sgpr11, implicit-def dead $sgpr12, implicit-def dead $sgpr13, implicit-def dead $sgpr14, implicit-def dead $sgpr15, implicit-def dead $vcc_lo, implicit-def dead $vcc_hi

    S_NOP 0, implicit %0.sub0
    S_NOP 0, implicit %0.sub2
...
---
# Check that copy hoisting out of loops works. This mainly should not crash the
# compiler when it hoists a subreg copy sequence.
# CHECK-LABEL: name: splitHoist
# CHECK: S_NOP 0, implicit-def renamable $sgpr0
# CHECK: S_NOP 0, implicit-def renamable $sgpr3
# CHECK-NEXT: SI_SPILL_S128_SAVE
name: splitHoist
tracksRegLiveness: true
body: |
  bb.0:
    successors: %bb.1, %bb.2
    S_NOP 0, implicit-def undef %0.sub0 : sgpr_128
    S_NOP 0, implicit-def %0.sub3 : sgpr_128

    S_CBRANCH_VCCNZ %bb.1, implicit undef $vcc
    S_BRANCH %bb.2

  bb.1:
    successors: %bb.1, %bb.3
    S_NOP 0, implicit %0.sub0

    ; Clobber registers
    S_NOP 0, implicit-def dead $sgpr0, implicit-def dead $sgpr1, implicit-def dead $sgpr2, implicit-def dead $sgpr3, implicit-def dead $sgpr4, implicit-def dead $sgpr5, implicit-def dead $sgpr6, implicit-def dead $sgpr7, implicit-def dead $sgpr8, implicit-def dead $sgpr9, implicit-def dead $sgpr10, implicit-def dead $sgpr11

    S_CBRANCH_VCCNZ %bb.1, implicit undef $vcc
    S_BRANCH %bb.3

  bb.2:
    successors: %bb.3
    ; Clobber registers
    S_NOP 0, implicit-def dead $sgpr0, implicit-def dead $sgpr1, implicit-def dead $sgpr2, implicit-def dead $sgpr3, implicit-def dead $sgpr4, implicit-def dead $sgpr5, implicit-def dead $sgpr6, implicit-def dead $sgpr7, implicit-def dead $sgpr8, implicit-def dead $sgpr9, implicit-def dead $sgpr10, implicit-def dead $sgpr11
    S_BRANCH %bb.3

  bb.3:
    S_NOP 0, implicit %0.sub0
    S_NOP 0, implicit %0.sub3
    S_NOP 0, implicit %0.sub0
    S_NOP 0, implicit %0.sub3
...