Files
clang-p2996/llvm/test/CodeGen/AMDGPU/control-flow-fastregalloc.ll
Alexander Timofeev c4d256a590 [AMDGPU] Come back patch for the 'Assign register class for cross block values according to the divergence.'
Detailed description:

    After https://reviews.llvm.org/D59990 submit several issues were discovered.
    Changes in common code were preserved but AMDGPU specific part was reverted to keep the backend working correctly.

    Discovered issues were addressed in the following commits:

    https://reviews.llvm.org/D67662
    https://reviews.llvm.org/D67101
    https://reviews.llvm.org/D63953
    https://reviews.llvm.org/D63731

    This change brings back AMDGPU specific changes.

  Reviewed by: rampitec, arsenm

  Differential Revision: https://reviews.llvm.org/D68635

llvm-svn: 374767
2019-10-14 12:01:10 +00:00

293 lines
13 KiB
LLVM

; RUN: llc -O0 -mtriple=amdgcn--amdhsa -march=amdgcn -amdgpu-spill-sgpr-to-vgpr=0 -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefix=VMEM -check-prefix=GCN %s
; RUN: llc -O0 -mtriple=amdgcn--amdhsa -march=amdgcn -amdgpu-spill-sgpr-to-vgpr=1 -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefix=VGPR -check-prefix=GCN %s
; Verify registers used for tracking exec mask changes when all
; registers are spilled at the end of the block. The SGPR spill
; placement relative to the exec modifications are important.
; FIXME: This checks with SGPR to VGPR spilling disabled, but this may
; not work correctly in cases where no workitems take a branch.
; GCN-LABEL: {{^}}divergent_if_endif:
; VGPR: workitem_private_segment_byte_size = 12{{$}}
; GCN: {{^}}; %bb.0:
; GCN: s_mov_b32 m0, -1
; GCN: ds_read_b32 [[LOAD0:v[0-9]+]]
; GCN: v_cmp_eq_u32_e64 [[CMP0:s\[[0-9]+:[0-9]\]]], s{{[0-9]+}}, v0
; GCN: s_mov_b64 s{{\[}}[[SAVEEXEC_LO:[0-9]+]]:[[SAVEEXEC_HI:[0-9]+]]{{\]}}, exec
; GCN: s_and_b64 s{{\[}}[[ANDEXEC_LO:[0-9]+]]:[[ANDEXEC_HI:[0-9]+]]{{\]}}, s{{\[}}[[SAVEEXEC_LO]]:[[SAVEEXEC_HI]]{{\]}}, [[CMP0]]
; Spill load
; GCN: buffer_store_dword [[LOAD0]], off, s[0:3], s7 offset:[[LOAD0_OFFSET:[0-9]+]] ; 4-byte Folded Spill
; Spill saved exec
; VGPR: v_writelane_b32 [[SPILL_VGPR:v[0-9]+]], s[[SAVEEXEC_LO]], [[SAVEEXEC_LO_LANE:[0-9]+]]
; VGPR: v_writelane_b32 [[SPILL_VGPR]], s[[SAVEEXEC_HI]], [[SAVEEXEC_HI_LANE:[0-9]+]]
; VMEM: v_mov_b32_e32 v[[V_SAVEEXEC_LO:[0-9]+]], s[[SAVEEXEC_LO]]
; VMEM: buffer_store_dword v[[V_SAVEEXEC_LO]], off, s[0:3], s7 offset:20 ; 4-byte Folded Spill
; VMEM: v_mov_b32_e32 v[[V_SAVEEXEC_HI:[0-9]+]], s[[SAVEEXEC_HI]]
; VMEM: buffer_store_dword v[[V_SAVEEXEC_HI]], off, s[0:3], s7 offset:24 ; 4-byte Folded Spill
; GCN: s_mov_b64 exec, s{{\[}}[[ANDEXEC_LO]]:[[ANDEXEC_HI]]{{\]}}
; GCN: mask branch [[ENDIF:BB[0-9]+_[0-9]+]]
; GCN: {{^}}BB{{[0-9]+}}_1: ; %if
; GCN: s_mov_b32 m0, -1
; GCN: ds_read_b32 [[LOAD1:v[0-9]+]]
; GCN: buffer_load_dword [[RELOAD_LOAD0:v[0-9]+]], off, s[0:3], s7 offset:[[LOAD0_OFFSET]] ; 4-byte Folded Reload
; GCN: s_waitcnt vmcnt(0) lgkmcnt(0)
; Spill val register
; GCN: v_add_i32_e32 [[VAL:v[0-9]+]], vcc, [[LOAD1]], [[RELOAD_LOAD0]]
; GCN: buffer_store_dword [[VAL]], off, s[0:3], s7 offset:[[VAL_OFFSET:[0-9]+]] ; 4-byte Folded Spill
; VMEM: [[ENDIF]]:
; Reload and restore exec mask
; VGPR: v_readlane_b32 s[[S_RELOAD_SAVEEXEC_LO:[0-9]+]], [[SPILL_VGPR]], [[SAVEEXEC_LO_LANE]]
; VGPR: v_readlane_b32 s[[S_RELOAD_SAVEEXEC_HI:[0-9]+]], [[SPILL_VGPR]], [[SAVEEXEC_HI_LANE]]
; VMEM: buffer_load_dword v[[V_RELOAD_SAVEEXEC_LO:[0-9]+]], off, s[0:3], s7 offset:20 ; 4-byte Folded Reload
; VMEM: s_waitcnt vmcnt(0)
; VMEM: v_readfirstlane_b32 s[[S_RELOAD_SAVEEXEC_LO:[0-9]+]], v[[V_RELOAD_SAVEEXEC_LO]]
; VMEM: buffer_load_dword v[[V_RELOAD_SAVEEXEC_HI:[0-9]+]], off, s[0:3], s7 offset:24 ; 4-byte Folded Reload
; VMEM: s_waitcnt vmcnt(0)
; VMEM: v_readfirstlane_b32 s[[S_RELOAD_SAVEEXEC_HI:[0-9]+]], v[[V_RELOAD_SAVEEXEC_HI]]
; GCN: s_or_b64 exec, exec, s{{\[}}[[S_RELOAD_SAVEEXEC_LO]]:[[S_RELOAD_SAVEEXEC_HI]]{{\]}}
; Restore val
; GCN: buffer_load_dword [[RELOAD_VAL:v[0-9]+]], off, s[0:3], s7 offset:[[VAL_OFFSET]] ; 4-byte Folded Reload
; GCN: flat_store_dword v{{\[[0-9]+:[0-9]+\]}}, [[RELOAD_VAL]]
define amdgpu_kernel void @divergent_if_endif(i32 addrspace(1)* %out) #0 {
entry:
%tid = call i32 @llvm.amdgcn.workitem.id.x()
%load0 = load volatile i32, i32 addrspace(3)* undef
%cmp0 = icmp eq i32 %tid, 0
br i1 %cmp0, label %if, label %endif
if:
%load1 = load volatile i32, i32 addrspace(3)* undef
%val = add i32 %load0, %load1
br label %endif
endif:
%tmp4 = phi i32 [ %val, %if ], [ 0, %entry ]
store i32 %tmp4, i32 addrspace(1)* %out
ret void
}
; GCN-LABEL: {{^}}divergent_loop:
; VGPR: workitem_private_segment_byte_size = 12{{$}}
; GCN: {{^}}; %bb.0:
; GCN: s_mov_b32 m0, -1
; GCN: ds_read_b32 [[LOAD0:v[0-9]+]]
; GCN: v_cmp_eq_u32_e64 [[CMP0:s\[[0-9]+:[0-9]\]]], s{{[0-9]+}}, v0
; GCN: s_mov_b64 s{{\[}}[[SAVEEXEC_LO:[0-9]+]]:[[SAVEEXEC_HI:[0-9]+]]{{\]}}, exec
; GCN: s_and_b64 s{{\[}}[[ANDEXEC_LO:[0-9]+]]:[[ANDEXEC_HI:[0-9]+]]{{\]}}, s{{\[}}[[SAVEEXEC_LO:[0-9]+]]:[[SAVEEXEC_HI:[0-9]+]]{{\]}}, [[CMP0]]
; Spill load
; GCN: buffer_store_dword [[LOAD0]], off, s[0:3], s7 offset:[[LOAD0_OFFSET:[0-9]+]] ; 4-byte Folded Spill
; Spill saved exec
; VGPR: v_writelane_b32 [[SPILL_VGPR:v[0-9]+]], s[[SAVEEXEC_LO]], [[SAVEEXEC_LO_LANE:[0-9]+]]
; VGPR: v_writelane_b32 [[SPILL_VGPR]], s[[SAVEEXEC_HI]], [[SAVEEXEC_HI_LANE:[0-9]+]]
; VMEM: v_mov_b32_e32 v[[V_SAVEEXEC_LO:[0-9]+]], s[[SAVEEXEC_LO]]
; VMEM: buffer_store_dword v[[V_SAVEEXEC_LO]], off, s[0:3], s7 offset:24 ; 4-byte Folded Spill
; VMEM: v_mov_b32_e32 v[[V_SAVEEXEC_HI:[0-9]+]], s[[SAVEEXEC_HI]]
; VMEM: buffer_store_dword v[[V_SAVEEXEC_HI]], off, s[0:3], s7 offset:28 ; 4-byte Folded Spill
; GCN: s_mov_b64 exec, s{{\[}}[[ANDEXEC_LO]]:[[ANDEXEC_HI]]{{\]}}
; GCN-NEXT: ; mask branch [[END:BB[0-9]+_[0-9]+]]
; GCN-NEXT: s_cbranch_execz [[END]]
; GCN: [[LOOP:BB[0-9]+_[0-9]+]]:
; GCN: buffer_load_dword v[[VAL_LOOP_RELOAD:[0-9]+]], off, s[0:3], s7 offset:[[LOAD0_OFFSET]] ; 4-byte Folded Reload
; GCN: v_subrev_i32_e32 [[VAL_LOOP:v[0-9]+]], vcc, v{{[0-9]+}}, v[[VAL_LOOP_RELOAD]]
; GCN: s_cmp_lg_u32
; GCN: buffer_store_dword [[VAL_LOOP]], off, s[0:3], s7 offset:[[VAL_SUB_OFFSET:[0-9]+]] ; 4-byte Folded Spill
; GCN-NEXT: s_cbranch_scc1 [[LOOP]]
; GCN: [[END]]:
; VGPR: v_readlane_b32 s[[S_RELOAD_SAVEEXEC_LO:[0-9]+]], [[SPILL_VGPR]], [[SAVEEXEC_LO_LANE]]
; VGPR: v_readlane_b32 s[[S_RELOAD_SAVEEXEC_HI:[0-9]+]], [[SPILL_VGPR]], [[SAVEEXEC_HI_LANE]]
; VMEM: buffer_load_dword v[[V_RELOAD_SAVEEXEC_LO:[0-9]+]], off, s[0:3], s7 offset:24 ; 4-byte Folded Reload
; VMEM: s_waitcnt vmcnt(0)
; VMEM: v_readfirstlane_b32 s[[S_RELOAD_SAVEEXEC_LO:[0-9]+]], v[[V_RELOAD_SAVEEXEC_LO]]
; VMEM: buffer_load_dword v[[V_RELOAD_SAVEEXEC_HI:[0-9]+]], off, s[0:3], s7 offset:28 ; 4-byte Folded Reload
; VMEM: s_waitcnt vmcnt(0)
; VMEM: v_readfirstlane_b32 s[[S_RELOAD_SAVEEXEC_HI:[0-9]+]], v[[V_RELOAD_SAVEEXEC_HI]]
; GCN: s_or_b64 exec, exec, s{{\[}}[[S_RELOAD_SAVEEXEC_LO]]:[[S_RELOAD_SAVEEXEC_HI]]{{\]}}
; GCN: buffer_load_dword v[[VAL_END:[0-9]+]], off, s[0:3], s7 offset:[[VAL_SUB_OFFSET]] ; 4-byte Folded Reload
; GCN: flat_store_dword v{{\[[0-9]+:[0-9]+\]}}, v[[VAL_END]]
define amdgpu_kernel void @divergent_loop(i32 addrspace(1)* %out) #0 {
entry:
%tid = call i32 @llvm.amdgcn.workitem.id.x()
%load0 = load volatile i32, i32 addrspace(3)* undef
%cmp0 = icmp eq i32 %tid, 0
br i1 %cmp0, label %loop, label %end
loop:
%i = phi i32 [ %i.inc, %loop ], [ 0, %entry ]
%val = phi i32 [ %val.sub, %loop ], [ %load0, %entry ]
%load1 = load volatile i32, i32 addrspace(3)* undef
%i.inc = add i32 %i, 1
%val.sub = sub i32 %val, %load1
%cmp1 = icmp ne i32 %i, 256
br i1 %cmp1, label %loop, label %end
end:
%tmp4 = phi i32 [ %val.sub, %loop ], [ 0, %entry ]
store i32 %tmp4, i32 addrspace(1)* %out
ret void
}
; GCN-LABEL: {{^}}divergent_if_else_endif:
; GCN: {{^}}; %bb.0:
; GCN: s_mov_b32 m0, -1
; GCN: ds_read_b32 [[LOAD0:v[0-9]+]]
; GCN: s_mov_b32 [[ZERO:s[0-9]+]], 0
; GCN: v_cmp_ne_u32_e64 [[CMP0:s\[[0-9]+:[0-9]\]]], [[ZERO]], v0
; GCN: s_mov_b64 s{{\[}}[[SAVEEXEC_LO:[0-9]+]]:[[SAVEEXEC_HI:[0-9]+]]{{\]}}, exec
; GCN: s_and_b64 s{{\[}}[[ANDEXEC_LO:[0-9]+]]:[[ANDEXEC_HI:[0-9]+]]{{\]}}, s{{\[}}[[SAVEEXEC_LO:[0-9]+]]:[[SAVEEXEC_HI:[0-9]+]]{{\]}}, [[CMP0]]
; GCN: s_xor_b64 s{{\[}}[[SAVEEXEC_LO]]:[[SAVEEXEC_HI]]{{\]}}, s{{\[}}[[ANDEXEC_LO]]:[[ANDEXEC_HI]]{{\]}}, s{{\[}}[[SAVEEXEC_LO]]:[[SAVEEXEC_HI]]{{\]}}
; Spill load
; GCN: buffer_store_dword [[LOAD0]], off, s[0:3], s7 offset:[[LOAD0_OFFSET:[0-9]+]] ; 4-byte Folded Spill
; Spill saved exec
; VGPR: v_writelane_b32 [[SPILL_VGPR:v[0-9]+]], s[[SAVEEXEC_LO]], [[SAVEEXEC_LO_LANE:[0-9]+]]
; VGPR: v_writelane_b32 [[SPILL_VGPR]], s[[SAVEEXEC_HI]], [[SAVEEXEC_HI_LANE:[0-9]+]]
; VMEM: v_mov_b32_e32 v[[V_SAVEEXEC_LO:[0-9]+]], s[[SAVEEXEC_LO]]
; VMEM: buffer_store_dword v[[V_SAVEEXEC_LO]], off, s[0:3], s7 offset:[[SAVEEXEC_LO_OFFSET:[0-9]+]] ; 4-byte Folded Spill
; VMEM: v_mov_b32_e32 v[[V_SAVEEXEC_HI:[0-9]+]], s[[SAVEEXEC_HI]]
; VMEM: buffer_store_dword v[[V_SAVEEXEC_HI]], off, s[0:3], s7 offset:[[SAVEEXEC_HI_OFFSET:[0-9]+]] ; 4-byte Folded Spill
; GCN: s_mov_b64 exec, [[CMP0]]
; FIXME: It makes no sense to put this skip here
; GCN-NEXT: ; mask branch [[FLOW:BB[0-9]+_[0-9]+]]
; GCN: s_cbranch_execz [[FLOW]]
; GCN-NEXT: s_branch [[ELSE:BB[0-9]+_[0-9]+]]
; GCN: [[FLOW]]: ; %Flow
; VGPR: v_readlane_b32 s[[FLOW_S_RELOAD_SAVEEXEC_LO:[0-9]+]], [[SPILL_VGPR]], [[SAVEEXEC_LO_LANE]]
; VGPR: v_readlane_b32 s[[FLOW_S_RELOAD_SAVEEXEC_HI:[0-9]+]], [[SPILL_VGPR]], [[SAVEEXEC_HI_LANE]]
; VMEM: buffer_load_dword v[[FLOW_V_RELOAD_SAVEEXEC_LO:[0-9]+]], off, s[0:3], s7 offset:[[SAVEEXEC_LO_OFFSET]]
; VMEM: s_waitcnt vmcnt(0)
; VMEM: v_readfirstlane_b32 s[[FLOW_S_RELOAD_SAVEEXEC_LO:[0-9]+]], v[[FLOW_V_RELOAD_SAVEEXEC_LO]]
; VMEM: buffer_load_dword v[[FLOW_V_RELOAD_SAVEEXEC_HI:[0-9]+]], off, s[0:3], s7 offset:[[SAVEEXEC_HI_OFFSET]] ; 4-byte Folded Reload
; VMEM: s_waitcnt vmcnt(0)
; VMEM: v_readfirstlane_b32 s[[FLOW_S_RELOAD_SAVEEXEC_HI:[0-9]+]], v[[FLOW_V_RELOAD_SAVEEXEC_HI]]
; GCN: s_or_saveexec_b64 s{{\[}}[[FLOW_S_RELOAD_SAVEEXEC_LO]]:[[FLOW_S_RELOAD_SAVEEXEC_HI]]{{\]}}, s{{\[}}[[FLOW_S_RELOAD_SAVEEXEC_LO]]:[[FLOW_S_RELOAD_SAVEEXEC_HI]]{{\]}}
; Regular spill value restored after exec modification
; GCN: buffer_load_dword [[FLOW_VAL:v[0-9]+]], off, s[0:3], s7 offset:[[FLOW_VAL_OFFSET:[0-9]+]] ; 4-byte Folded Reload
; Spill saved exec
; VGPR: v_writelane_b32 [[SPILL_VGPR]], s[[FLOW_S_RELOAD_SAVEEXEC_LO]], [[FLOW_SAVEEXEC_LO_LANE:[0-9]+]]
; VGPR: v_writelane_b32 [[SPILL_VGPR]], s[[FLOW_S_RELOAD_SAVEEXEC_HI]], [[FLOW_SAVEEXEC_HI_LANE:[0-9]+]]
; VMEM: v_mov_b32_e32 v[[FLOW_V_SAVEEXEC_LO:[0-9]+]], s[[FLOW_S_RELOAD_SAVEEXEC_LO]]
; VMEM: buffer_store_dword v[[FLOW_V_SAVEEXEC_LO]], off, s[0:3], s7 offset:[[FLOW_SAVEEXEC_LO_OFFSET:[0-9]+]] ; 4-byte Folded Spill
; VMEM: v_mov_b32_e32 v[[FLOW_V_SAVEEXEC_HI:[0-9]+]], s[[FLOW_S_RELOAD_SAVEEXEC_HI]]
; VMEM: buffer_store_dword v[[FLOW_V_SAVEEXEC_HI]], off, s[0:3], s7 offset:[[FLOW_SAVEEXEC_HI_OFFSET:[0-9]+]] ; 4-byte Folded Spill
; GCN: buffer_store_dword [[FLOW_VAL]], off, s[0:3], s7 offset:[[RESULT_OFFSET:[0-9]+]] ; 4-byte Folded Spill
; GCN: s_xor_b64 exec, exec, s{{\[}}[[FLOW_S_RELOAD_SAVEEXEC_LO]]:[[FLOW_S_RELOAD_SAVEEXEC_HI]]{{\]}}
; GCN-NEXT: ; mask branch [[ENDIF:BB[0-9]+_[0-9]+]]
; GCN-NEXT: s_cbranch_execz [[ENDIF]]
; GCN: BB{{[0-9]+}}_2: ; %if
; GCN: ds_read_b32
; GCN: buffer_load_dword v[[LOAD0_RELOAD:[0-9]+]], off, s[0:3], s7 offset:[[LOAD0_OFFSET]] ; 4-byte Folded Reload
; GCN: v_add_i32_e32 [[ADD:v[0-9]+]], vcc, v{{[0-9]+}}, v[[LOAD0_RELOAD]]
; GCN: buffer_store_dword [[ADD]], off, s[0:3], s7 offset:[[RESULT_OFFSET]] ; 4-byte Folded Spill
; GCN-NEXT: s_branch [[ENDIF:BB[0-9]+_[0-9]+]]
; GCN: [[ELSE]]: ; %else
; GCN: buffer_load_dword v[[LOAD0_RELOAD:[0-9]+]], off, s[0:3], s7 offset:[[LOAD0_OFFSET]] ; 4-byte Folded Reload
; GCN: v_subrev_i32_e32 [[SUB:v[0-9]+]], vcc, v{{[0-9]+}}, v[[LOAD0_RELOAD]]
; GCN: buffer_store_dword [[ADD]], off, s[0:3], s7 offset:[[FLOW_RESULT_OFFSET:[0-9]+]] ; 4-byte Folded Spill
; GCN-NEXT: s_branch [[FLOW]]
; GCN: [[ENDIF]]:
; VGPR: v_readlane_b32 s[[S_RELOAD_SAVEEXEC_LO:[0-9]+]], [[SPILL_VGPR]], [[FLOW_SAVEEXEC_LO_LANE]]
; VGPR: v_readlane_b32 s[[S_RELOAD_SAVEEXEC_HI:[0-9]+]], [[SPILL_VGPR]], [[FLOW_SAVEEXEC_HI_LANE]]
; VMEM: buffer_load_dword v[[V_RELOAD_SAVEEXEC_LO:[0-9]+]], off, s[0:3], s7 offset:[[FLOW_SAVEEXEC_LO_OFFSET]] ; 4-byte Folded Reload
; VMEM: s_waitcnt vmcnt(0)
; VMEM: v_readfirstlane_b32 s[[S_RELOAD_SAVEEXEC_LO:[0-9]+]], v[[V_RELOAD_SAVEEXEC_LO]]
; VMEM: buffer_load_dword v[[V_RELOAD_SAVEEXEC_HI:[0-9]+]], off, s[0:3], s7 offset:[[FLOW_SAVEEXEC_HI_OFFSET]] ; 4-byte Folded Reload
; VMEM: s_waitcnt vmcnt(0)
; VMEM: v_readfirstlane_b32 s[[S_RELOAD_SAVEEXEC_HI:[0-9]+]], v[[V_RELOAD_SAVEEXEC_HI]]
; GCN: s_or_b64 exec, exec, s{{\[}}[[S_RELOAD_SAVEEXEC_LO]]:[[S_RELOAD_SAVEEXEC_HI]]{{\]}}
; GCN: buffer_load_dword v[[RESULT:[0-9]+]], off, s[0:3], s7 offset:[[RESULT_OFFSET]] ; 4-byte Folded Reload
; GCN: flat_store_dword v{{\[[0-9]+:[0-9]+\]}}, v[[RESULT]]
define amdgpu_kernel void @divergent_if_else_endif(i32 addrspace(1)* %out) #0 {
entry:
%tid = call i32 @llvm.amdgcn.workitem.id.x()
%load0 = load volatile i32, i32 addrspace(3)* undef
%cmp0 = icmp eq i32 %tid, 0
br i1 %cmp0, label %if, label %else
if:
%load1 = load volatile i32, i32 addrspace(3)* undef
%val0 = add i32 %load0, %load1
br label %endif
else:
%load2 = load volatile i32, i32 addrspace(3)* undef
%val1 = sub i32 %load0, %load2
br label %endif
endif:
%result = phi i32 [ %val0, %if ], [ %val1, %else ]
store i32 %result, i32 addrspace(1)* %out
ret void
}
declare i32 @llvm.amdgcn.workitem.id.x() #1
attributes #0 = { nounwind }
attributes #1 = { nounwind readnone }