# RUN: not llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx90a -simplify-mir -start-before=greedy,2 -stress-regalloc=4 -stop-before=virtregrewriter,2 -o - -verify-regalloc %s 2> %t.err | FileCheck %s
# RUN: FileCheck -check-prefix=ERR %s < %t.err

# To allocate the vreg_512_align2, the allocation will attempt to
# inflate the register class to av_512_align2. This will ultimately
# not work, and the allocation will fail. There is an unproductive
# live range split, and we end up with a snippet copy of an
# unspillable register. Recursive assignment of interfering ranges
# during last chance recoloring would delete the unspillable snippet
# live range. Make sure there's no use after free when rolling back
# the last chance assignment.

# ERR: error: <unknown>:0:0: ran out of registers during register allocation in function 'inflated_reg_class_copy_use_after_free'
# ERR: error: <unknown>:0:0: ran out of registers during register allocation in function 'inflated_reg_class_copy_use_after_free_lane_subset'

--- |
  define amdgpu_kernel void @inflated_reg_class_copy_use_after_free() {
    ret void
  }

  define amdgpu_kernel void @inflated_reg_class_copy_use_after_free_lane_subset() {
    ret void
  }

...

# CHECK-LABEL: name: inflated_reg_class_copy_use_after_free
# CHECK: S_NOP 0, implicit-def [[ORIG_REG:%[0-9]+]].sub0_sub1_sub2_sub3
# CHECK-NEXT: SI_SPILL_AV512_SAVE [[ORIG_REG]], %stack.0, $sgpr32, 0, implicit $exec :: (store (s512) into %stack.0, align 4, addrspace 5)
# CHECK-NEXT: [[RESTORE0:%[0-9]+]]:vreg_512_align2 = SI_SPILL_AV512_RESTORE %stack.0, $sgpr32, 0, implicit $exec :: (load (s512) from %stack.0, align 4, addrspace 5)
# CHECK-NEXT: early-clobber $vgpr0_vgpr1_vgpr2_vgpr3_vgpr4_vgpr5_vgpr6_vgpr7_vgpr8_vgpr9_vgpr10_vgpr11_vgpr12_vgpr13_vgpr14_vgpr15 = V_MFMA_F32_16X16X1F32_vgprcd_e64 undef %3:vgpr_32, undef %3:vgpr_32, [[RESTORE0]], 0, 0, 0, implicit $mode, implicit $exec, implicit $mode, implicit $exec
# CHECK-NEXT: undef [[SPLIT0:%[0-9]+]].sub2_sub3:av_512_align2 = COPY undef $vgpr2_vgpr3 {
# CHECK-NEXT: internal [[SPLIT0]].sub0:av_512_align2 = COPY undef $vgpr0
# CHECK-NEXT: }
# CHECK-NEXT: undef [[SPLIT2:%[0-9]+]].sub2_sub3:av_512_align2 = COPY [[SPLIT0]].sub2_sub3 {
# CHECK-NEXT: internal [[SPLIT2]].sub0:av_512_align2 = COPY [[SPLIT0]].sub0
# CHECK-NEXT: }
# CHECK-NEXT: [[RESTORE2:%[0-9]+]]:av_512_align2 = SI_SPILL_AV512_RESTORE %stack.0, $sgpr32, 0, implicit $exec :: (load (s512) from %stack.0, align 4, addrspace 5)
# CHECK-NEXT: [[MFMA_USE1:%[0-9]+]].sub0_sub1:vreg_512_align2 = COPY [[RESTORE2]].sub0_sub1
# CHECK-NEXT: [[MFMA_USE1]].sub2:vreg_512_align2 = COPY [[SPLIT2]].sub3 
# CHECK-NEXT: [[MFMA_USE1]].sub3:vreg_512_align2 = COPY [[SPLIT2]].sub2
# CHECK-NEXT: [[MFMA_USE1]].sub4:vreg_512_align2 = COPY [[SPLIT2]].sub0
# CHECK-NEXT: [[MFMA_USE1]].sub5:vreg_512_align2 = V_MOV_B32_e32 0, implicit $exec
# CHECK-NEXT: [[MFMA_USE1]].sub6:vreg_512_align2 = V_MOV_B32_e32 0, implicit $exec
# CHECK-NEXT: [[MFMA_USE1]].sub7:vreg_512_align2 = V_MOV_B32_e32 0, implicit $exec
# CHECK-NEXT: [[MFMA_USE1]].sub8:vreg_512_align2 = V_MOV_B32_e32 0, implicit $exec
# CHECK-NEXT: [[MFMA_USE1]].sub9:vreg_512_align2 = V_MOV_B32_e32 0, implicit $exec
# CHECK-NEXT: [[MFMA_USE1]].sub10:vreg_512_align2 = V_MOV_B32_e32 0, implicit $exec
# CHECK-NEXT: [[MFMA_USE1]].sub11:vreg_512_align2 = V_MOV_B32_e32 0, implicit $exec
# CHECK-NEXT: [[MFMA_USE1]].sub12:vreg_512_align2 = V_MOV_B32_e32 0, implicit $exec
# CHECK-NEXT: [[MFMA_USE1]].sub13:vreg_512_align2 = V_MOV_B32_e32 0, implicit $exec
# CHECK-NEXT: [[MFMA_USE1]].sub14:vreg_512_align2 = V_MOV_B32_e32 0, implicit $exec
# CHECK-NEXT: [[MFMA_USE1]].sub15:vreg_512_align2 = V_MOV_B32_e32 0, implicit $exec
# CHECK-NEXT: [[MFMA_USE1]]:vreg_512_align2 = V_MFMA_F32_16X16X1F32_mac_vgprcd_e64 undef %3:vgpr_32, undef %3:vgpr_32, [[MFMA_USE1]], 0, 0, 0, implicit $mode, implicit $exec

---
name:            inflated_reg_class_copy_use_after_free
tracksRegLiveness: true
machineFunctionInfo:
  isEntryFunction: true
  scratchRSrcReg:  '$sgpr72_sgpr73_sgpr74_sgpr75'
  stackPtrOffsetReg: '$sgpr32'
  occupancy:       7
  vgprForAGPRCopy: '$vgpr255'
  sgprForEXECCopy: '$sgpr74_sgpr75'
body:             |
  bb.0:
    liveins: $vgpr0, $sgpr4_sgpr5

    %0:vgpr_32 = IMPLICIT_DEF
    renamable $sgpr0_sgpr1 = S_LOAD_DWORDX2_IMM killed undef renamable $sgpr4_sgpr5, 0, 0 :: (load (s64), addrspace 4)
    S_NOP 0, implicit-def undef %1.sub12_sub13_sub14_sub15:vreg_512_align2
    S_NOP 0, implicit-def %1.sub8_sub9_sub10_sub11:vreg_512_align2
    S_NOP 0, implicit-def %1.sub4_sub5_sub6_sub7:vreg_512_align2
    S_NOP 0, implicit-def %1.sub0_sub1_sub2_sub3:vreg_512_align2
    early-clobber %2:vreg_512_align2 = V_MFMA_F32_16X16X1F32_vgprcd_e64 undef %3:vgpr_32, undef %3:vgpr_32, %1, 0, 0, 0, implicit $mode, implicit $exec, implicit $mode, implicit $exec
    %1.sub2:vreg_512_align2 = COPY %2.sub3
    %1.sub3:vreg_512_align2 = COPY %2.sub2
    %1.sub4:vreg_512_align2 = COPY %2.sub0
    %1.sub5:vreg_512_align2 = V_MOV_B32_e32 0, implicit $exec
    %1.sub6:vreg_512_align2 = V_MOV_B32_e32 0, implicit $exec
    %1.sub7:vreg_512_align2 = V_MOV_B32_e32 0, implicit $exec
    %1.sub8:vreg_512_align2 = V_MOV_B32_e32 0, implicit $exec
    %1.sub9:vreg_512_align2 = V_MOV_B32_e32 0, implicit $exec
    %1.sub10:vreg_512_align2 = V_MOV_B32_e32 0, implicit $exec
    %1.sub11:vreg_512_align2 = V_MOV_B32_e32 0, implicit $exec
    %1.sub12:vreg_512_align2 = V_MOV_B32_e32 0, implicit $exec
    %1.sub13:vreg_512_align2 = V_MOV_B32_e32 0, implicit $exec
    %1.sub14:vreg_512_align2 = V_MOV_B32_e32 0, implicit $exec
    %1.sub15:vreg_512_align2 = V_MOV_B32_e32 0, implicit $exec
    %1:vreg_512_align2 = V_MFMA_F32_16X16X1F32_mac_vgprcd_e64 undef %3:vgpr_32, undef %3:vgpr_32, %1, 0, 0, 0, implicit $mode, implicit $exec
    GLOBAL_STORE_DWORDX4_SADDR undef %3:vgpr_32, %1.sub12_sub13_sub14_sub15, undef renamable $sgpr0_sgpr1, 96, 0, implicit $exec :: (store (s128), addrspace 1)
    S_ENDPGM 0

...

# This test is similar to except it is still broken when the use
# instruction does not read the full set of lanes after one attempted fix.

# CHECK-LABEL: name: inflated_reg_class_copy_use_after_free_lane_subset
# CHECK: S_NOP 0, implicit-def [[ORIG_REG:%[0-9]+]].sub0_sub1_sub2_sub3
# CHECK-NEXT: SI_SPILL_AV512_SAVE [[ORIG_REG]], %stack.0, $sgpr32, 0, implicit $exec :: (store (s512) into %stack.0, align 4, addrspace 5)
# CHECK-NEXT: [[RESTORE_0:%[0-9]+]]:av_512_align2 = SI_SPILL_AV512_RESTORE %stack.0, $sgpr32, 0, implicit $exec :: (load (s512) from %stack.0, align 4, addrspace 5)
# CHECK-NEXT: S_NOP 0, implicit-def early-clobber $vgpr0_vgpr1_vgpr2_vgpr3_vgpr4_vgpr5_vgpr6_vgpr7_vgpr8_vgpr9_vgpr10_vgpr11_vgpr12_vgpr13_vgpr14_vgpr15, implicit [[RESTORE_0]].sub0_sub1_sub2_sub3, implicit [[RESTORE_0]].sub4_sub5_sub6_sub7
# CHECK-NEXT: undef [[SPLIT0:%[0-9]+]].sub2_sub3:av_512_align2 = COPY undef $vgpr2_vgpr3 {
# CHECK-NEXT: internal [[SPLIT0]].sub0:av_512_align2 = COPY undef $vgpr0
# CHECK-NEXT: }
# CHECK-NEXT: undef [[SPLIT1:%[0-9]+]].sub2_sub3:av_512_align2 = COPY [[SPLIT0]].sub2_sub3 {
# CHECK-NEXT: internal [[SPLIT1]].sub0:av_512_align2 = COPY [[SPLIT0]].sub0
# CHECK-NEXT: }
# CHECK-NEXT: undef [[SPLIT2:%[0-9]+]].sub2_sub3:av_512_align2 = COPY [[SPLIT1]].sub2_sub3 {
# CHECK-NEXT: internal [[SPLIT2]].sub0:av_512_align2 = COPY [[SPLIT1]].sub0
# CHECK-NEXT: }
# CHECK-NEXT: SI_SPILL_AV512_SAVE [[SPLIT2]], %stack.1, $sgpr32, 0, implicit $exec :: (store (s512) into %stack.1, align 4, addrspace 5)
# CHECK-NEXT: [[RESTORE_1:%[0-9]+]]:av_512_align2 = SI_SPILL_AV512_RESTORE %stack.0, $sgpr32, 0, implicit $exec :: (load (s512) from %stack.0, align 4, addrspace 5)
# CHECK-NEXT: undef [[SPLIT3:%[0-9]+]].sub0_sub1:av_512_align2 = COPY [[RESTORE_1]].sub0_sub1
# CHECK-NEXT: [[RESTORE_2:%[0-9]+]]:av_512_align2 = SI_SPILL_AV512_RESTORE %stack.1, $sgpr32, 0, implicit $exec :: (load (s512) from %stack.1, align 4, addrspace 5)
# CHECK-NEXT: undef [[SPLIT4:%[0-9]+]].sub2_sub3:av_512_align2 = COPY [[RESTORE_2]].sub2_sub3 {
# CHECK-NEXT: internal [[SPLIT4]].sub0:av_512_align2 = COPY [[RESTORE_2]].sub0
# CHECK-NEXT: }
# CHECK-NEXT: undef [[SPLIT5:%[0-9]+]].sub2_sub3:av_512_align2 = COPY [[SPLIT4]].sub2_sub3 {
# CHECK-NEXT: internal [[SPLIT5]].sub0:av_512_align2 = COPY [[SPLIT4]].sub0
# CHECK-NEXT: }
# CHECK-NEXT: [[SPLIT3]].sub2:av_512_align2 = COPY [[SPLIT5]].sub3
# CHECK-NEXT: undef [[SPLIT6:%[0-9]+]].sub0_sub1_sub2:av_512_align2 = COPY [[SPLIT3]].sub0_sub1_sub2
# CHECK-NEXT: undef [[SPLIT7:%[0-9]+]].sub0_sub1_sub2:av_512_align2 = COPY [[SPLIT6]].sub0_sub1_sub2
# CHECK-NEXT: undef [[SPLIT8:%[0-9]+]].sub0:av_512_align2 = COPY [[SPLIT5]].sub0 {
# CHECK-NEXT: internal [[SPLIT8]].sub2:av_512_align2 = COPY [[SPLIT5]].sub2
# CHECK-NEXT: }
# CHECK-NEXT: [[SPLIT7]].sub3:av_512_align2 = COPY [[SPLIT8]].sub2
# CHECK-NEXT: undef [[SPLIT9:%[0-9]+]].sub0_sub1_sub2_sub3:av_512_align2 = COPY [[SPLIT7]].sub0_sub1_sub2_sub3
# CHECK-NEXT: undef [[LAST_USE:%[0-9]+]].sub0_sub1_sub2_sub3:vreg_512_align2 = COPY [[SPLIT9]].sub0_sub1_sub2_sub3
# CHECK-NEXT: [[LAST_USE]].sub4:vreg_512_align2 = COPY [[SPLIT8]].sub0
# CHECK-NEXT: [[LAST_USE]].sub5:vreg_512_align2 = V_MOV_B32_e32 0, implicit $exec
# CHECK-NEXT: [[LAST_USE]].sub6:vreg_512_align2 = V_MOV_B32_e32 0, implicit $exec
# CHECK-NEXT: [[LAST_USE]].sub7:vreg_512_align2 = V_MOV_B32_e32 0, implicit $exec
# CHECK-NEXT: [[LAST_USE]].sub8:vreg_512_align2 = V_MOV_B32_e32 0, implicit $exec
# CHECK-NEXT: [[LAST_USE]].sub9:vreg_512_align2 = V_MOV_B32_e32 0, implicit $exec
# CHECK-NEXT: [[LAST_USE]].sub10:vreg_512_align2 = V_MOV_B32_e32 0, implicit $exec
# CHECK-NEXT: [[LAST_USE]].sub11:vreg_512_align2 = V_MOV_B32_e32 0, implicit $exec
# CHECK-NEXT: [[LAST_USE]].sub12:vreg_512_align2 = V_MOV_B32_e32 0, implicit $exec
# CHECK-NEXT: [[LAST_USE]].sub13:vreg_512_align2 = V_MOV_B32_e32 0, implicit $exec
# CHECK-NEXT: [[LAST_USE]].sub14:vreg_512_align2 = V_MOV_B32_e32 0, implicit $exec
# CHECK-NEXT: [[LAST_USE]].sub15:vreg_512_align2 = V_MOV_B32_e32 0, implicit $exec
# CHECK-NEXT: S_NOP 0, implicit-def [[LAST_USE]], implicit [[LAST_USE]].sub0_sub1_sub2_sub3, implicit [[LAST_USE]].sub4_sub5_sub6_sub7, implicit [[LAST_USE]].sub8_sub9_sub10_sub11

---
name:            inflated_reg_class_copy_use_after_free_lane_subset
tracksRegLiveness: true
machineFunctionInfo:
  isEntryFunction: true
  scratchRSrcReg:  '$sgpr72_sgpr73_sgpr74_sgpr75'
  stackPtrOffsetReg: '$sgpr32'
  occupancy:       7
  vgprForAGPRCopy: '$vgpr255'
  sgprForEXECCopy: '$sgpr74_sgpr75'
body:             |
  bb.0:
    liveins: $vgpr0, $sgpr4_sgpr5

    %0:vgpr_32 = IMPLICIT_DEF
    renamable $sgpr0_sgpr1 = S_LOAD_DWORDX2_IMM killed undef renamable $sgpr4_sgpr5, 0, 0 :: (load (s64), addrspace 4)
    S_NOP 0, implicit-def undef %1.sub12_sub13_sub14_sub15:vreg_512_align2
    S_NOP 0, implicit-def %1.sub8_sub9_sub10_sub11:vreg_512_align2
    S_NOP 0, implicit-def %1.sub4_sub5_sub6_sub7:vreg_512_align2
    S_NOP 0, implicit-def %1.sub0_sub1_sub2_sub3:vreg_512_align2
    S_NOP 0, implicit-def early-clobber %2:vreg_512_align2, implicit %1.sub0_sub1_sub2_sub3, implicit %1.sub4_sub5_sub6_sub7
    %1.sub2:vreg_512_align2 = COPY %2.sub3
    %1.sub3:vreg_512_align2 = COPY %2.sub2
    %1.sub4:vreg_512_align2 = COPY %2.sub0
    %1.sub5:vreg_512_align2 = V_MOV_B32_e32 0, implicit $exec
    %1.sub6:vreg_512_align2 = V_MOV_B32_e32 0, implicit $exec
    %1.sub7:vreg_512_align2 = V_MOV_B32_e32 0, implicit $exec
    %1.sub8:vreg_512_align2 = V_MOV_B32_e32 0, implicit $exec
    %1.sub9:vreg_512_align2 = V_MOV_B32_e32 0, implicit $exec
    %1.sub10:vreg_512_align2 = V_MOV_B32_e32 0, implicit $exec
    %1.sub11:vreg_512_align2 = V_MOV_B32_e32 0, implicit $exec
    %1.sub12:vreg_512_align2 = V_MOV_B32_e32 0, implicit $exec
    %1.sub13:vreg_512_align2 = V_MOV_B32_e32 0, implicit $exec
    %1.sub14:vreg_512_align2 = V_MOV_B32_e32 0, implicit $exec
    %1.sub15:vreg_512_align2 = V_MOV_B32_e32 0, implicit $exec
    S_NOP 0, implicit-def %1:vreg_512_align2, implicit %1.sub0_sub1_sub2_sub3, implicit %1.sub4_sub5_sub6_sub7, implicit %1.sub8_sub9_sub10_sub11
    GLOBAL_STORE_DWORDX4_SADDR undef %3:vgpr_32, %1.sub12_sub13_sub14_sub15, undef renamable $sgpr0_sgpr1, 96, 0, implicit $exec :: (store (s128), addrspace 1)
    S_ENDPGM 0

...