[AMDGPU] Turn on the new waitcnt insertion pass. Adjust tests.

[msearles]

Summary

Turn on the new waitcnt insertion pass. Adjust tests.

-enable-si-insert-waitcnts=1 becomes the default
-enable-si-insert-waitcnts=0 to use old pass

[rampitec]

LGTM

[msearles]

There's +1 from a reviewer; the changes were originally part of https://reviews.llvm.org/D33114 and so have been available for comment/testing since May 26; I plan on pushing these changes later today unless I hear feedback to the contrary.

[alekseyshl]

There's a use-of-uninitialized-value in branch-relaxation.ll: http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-bootstrap/builds/1504. Please fix.

[msearles]

I have what I believe is the fix; it's going through testing now.

lib/Target/AMDGPU/AMDGPUTargetMachine.cpp

 static cl::opt<bool> EnableAMDGPUAliasAnalysis("enable-amdgpu-aa", cl::Hidden,
   cl::desc("Enable AMDGPU Alias Analysis"),
   cl::init(true));
 
 // Option to enable new waitcnt insertion pass.
 static cl::opt<bool> EnableSIInsertWaitcntsPass(
   "enable-si-insert-waitcnts",
   cl::desc("Use new waitcnt insertion pass"),
-  cl::init(false));
+  cl::init(true));
 
 // Option to run late CFG structurizer
 static cl::opt<bool> LateCFGStructurize(
   "amdgpu-late-structurize",
   cl::desc("Enable late CFG structurization"),
   cl::init(false),
   cl::Hidden);
 

test/CodeGen/AMDGPU/basic-branch.ll

 
 ; GCN-LABEL: {{^}}test_brcc_i1:
 ; GCN: buffer_load_ubyte
 ; GCN: v_and_b32_e32 v{{[0-9]+}}, 1,
 ; GCN: v_cmp_eq_u32_e32 vcc,
 ; GCN: s_cbranch_vccnz [[END:BB[0-9]+_[0-9]+]]
 
 ; GCN: buffer_store_dword
-; GCNOPT-NEXT: s_waitcnt vmcnt(0) expcnt(0)
-; TODO: This waitcnt can be eliminated
 
 ; GCN: {{^}}[[END]]:
 ; GCN: s_endpgm
 define amdgpu_kernel void @test_brcc_i1(i32 addrspace(1)* noalias %out, i32 addrspace(1)* noalias %in, i1 %val) #0 {
   %cmp0 = icmp ne i1 %val, 0
   br i1 %cmp0, label %store, label %end
 
 store:
   store i32 222, i32 addrspace(1)* %out
   ret void
 
 end:
   ret void
 }
 
 attributes #0 = { nounwind }

test/CodeGen/AMDGPU/branch-condition-and.ll

 ; GCN-DAG: v_cmp_lt_f32_e32 vcc,
 ; GCN: s_and_b64 [[AND:s\[[0-9]+:[0-9]+\]]], vcc, [[OTHERCC]]
 ; GCN: s_and_saveexec_b64 [[SAVED:s\[[0-9]+:[0-9]+\]]], [[AND]]
 ; GCN: s_xor_b64 {{s\[[0-9]+:[0-9]+\]}}, exec, [[SAVED]]
 ; GCN: ; mask branch [[BB5:BB[0-9]+_[0-9]+]]
 
 ; GCN-NEXT: BB{{[0-9]+_[0-9]+}}: ; %bb4
 ; GCN: ds_write_b32
-; GCN: s_waitcnt
 
-; GCN-NEXT: [[BB5]]
+; GCN: [[BB5]]
 ; GCN: s_or_b64 exec, exec
 ; GCN-NEXT: s_endpgm
 ; GCN-NEXT: .Lfunc_end
 define amdgpu_ps void @ham(float %arg, float %arg1) #0 {
 bb:
   %tmp = fcmp ogt float %arg, 0.000000e+00
   %tmp2 = fcmp ogt float %arg1, 0.000000e+00
   %tmp3 = and i1 %tmp, %tmp2

test/CodeGen/AMDGPU/branch-relaxation.ll

 ; GCN-NEXT: s_getpc_b64 vcc
 ; GCN-NEXT: s_add_u32 vcc_lo, vcc_lo, [[BB3:BB[0-9]_[0-9]+]]-([[LONG_JUMP0]]+4)
 ; GCN-NEXT: s_addc_u32 vcc_hi, vcc_hi, 0{{$}}
 ; GCN-NEXT: s_setpc_b64 vcc
 
 ; GCN-NEXT: [[BB2]]: ; %bb2
 ; GCN: v_mov_b32_e32 [[BB2_K:v[0-9]+]], 17
 ; GCN: buffer_store_dword [[BB2_K]]
-; GCN: s_waitcnt vmcnt(0)
 
 ; GCN-NEXT: [[LONG_JUMP1:BB[0-9]+_[0-9]+]]: ; %bb2
 ; GCN-NEXT: s_getpc_b64 vcc
 ; GCN-NEXT: s_add_u32 vcc_lo, vcc_lo, [[BB4:BB[0-9]_[0-9]+]]-([[LONG_JUMP1]]+4)
 ; GCN-NEXT: s_addc_u32 vcc_hi, vcc_hi, 0{{$}}
 ; GCN-NEXT: s_setpc_b64 vcc
 
 ; GCN: [[BB3]]: ; %bb3

 
 ; GCN-NEXT: [[IF]]: ; %if
 ; GCN: buffer_store_dword
 ; GCN: s_cmp_lg_u32
 ; GCN: s_cbranch_scc1 [[ENDIF]]
 
 ; GCN-NEXT: ; BB#2: ; %if_uniform
 ; GCN: buffer_store_dword
-; GCN: s_waitcnt vmcnt(0)
 
 ; GCN-NEXT: [[ENDIF]]: ; %endif
 ; GCN-NEXT: s_or_b64 exec, exec, [[MASK]]
 ; GCN-NEXT: s_sleep 5
 ; GCN-NEXT: s_endpgm
 define amdgpu_kernel void @uniform_inside_divergent(i32 addrspace(1)* %out, i32 %cond) #0 {
 entry:
   %tid = call i32 @llvm.amdgcn.workitem.id.x()

test/CodeGen/AMDGPU/control-flow-fastregalloc.ll

 ; 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:8 ; 4-byte Folded Spill
 
 ; Spill load
 ; GCN: buffer_store_dword [[LOAD0]], off, s[0:3], s7 offset:[[LOAD0_OFFSET:[0-9]+]] ; 4-byte Folded Spill
 
 ; GCN: s_mov_b64 exec, s{{\[}}[[ANDEXEC_LO]]:[[ANDEXEC_HI]]{{\]}}
 
-; GCN: s_waitcnt vmcnt(0) expcnt(0)
 ; 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: s_waitcnt lgkmcnt(0)
 ; 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)
 
 ; 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
-; GCN: s_waitcnt vmcnt(0)
 
 ; VMEM: [[ENDIF]]:
 ; Reload and restore exec mask
+; VGPR: s_waitcnt lgkmcnt(0)
 ; 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:4 ; 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: 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: s_waitcnt vmcnt(0) expcnt(0)
 ; 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:4 ; 4-byte Folded Reload
 ; GCN: v_subrev_i32_e32 [[VAL_LOOP:v[0-9]+]], vcc, v{{[0-9]+}}, v[[VAL_LOOP_RELOAD]]
 ; GCN: v_cmp_ne_u32_e32 vcc,
 ; GCN: s_and_b64 vcc, exec, vcc
 ; GCN: buffer_store_dword [[VAL_LOOP]], off, s[0:3], s7 offset:[[VAL_SUB_OFFSET:[0-9]+]] ; 4-byte Folded Spill
-; GCN: s_waitcnt vmcnt(0) expcnt(0)
 ; GCN-NEXT: s_cbranch_vccnz [[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:20 ; 4-byte Folded Reload

 ; 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]]
-; GCN: s_waitcnt vmcnt(0) expcnt(0)
 
 ; 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]]

 
 ; 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: s_waitcnt vmcnt(0) expcnt(0)
 ; 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:4 ; 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: s_waitcnt vmcnt(0) expcnt(0)
 ; 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:4 ; 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: s_waitcnt vmcnt(0) expcnt(0)
 ; 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

test/CodeGen/AMDGPU/indirect-addressing-si.ll

 }
 
 ; GCN-LABEL: {{^}}extract_neg_offset_vgpr:
 ; The offset depends on the register that holds the first element of the vector.
 
 ; FIXME: The waitcnt for the argument load can go after the loop
 ; IDXMODE: s_set_gpr_idx_on 0, src0
 ; GCN: s_mov_b64 s{{\[[0-9]+:[0-9]+\]}}, exec
-; GCN: s_waitcnt lgkmcnt(0)
-
+; GCN: [[LOOPBB:BB[0-9]+_[0-9]+]]:
 ; GCN: v_readfirstlane_b32 [[READLANE:s[0-9]+]], v{{[0-9]+}}
 
 ; MOVREL: s_add_i32 m0, [[READLANE]], 0xfffffe0
 ; MOVREL: s_and_saveexec_b64 vcc, vcc
 ; MOVREL: v_movrels_b32_e32 [[RESULT:v[0-9]+]], v1
 
 ; IDXMODE: s_addk_i32 [[ADD_IDX:s[0-9]+]], 0xfe00
 ; IDXMODE: s_set_gpr_idx_idx [[ADD_IDX]]

 ; The offset depends on the register that holds the first element of the vector.
 
 ; GCN-DAG: v_mov_b32_e32 [[VEC_ELT0:v[0-9]+]], 1{{$}}
 ; GCN-DAG: v_mov_b32_e32 [[VEC_ELT1:v[0-9]+]], 2{{$}}
 ; GCN-DAG: v_mov_b32_e32 [[VEC_ELT2:v[0-9]+]], 3{{$}}
 ; GCN-DAG: v_mov_b32_e32 [[VEC_ELT3:v[0-9]+]], 4{{$}}
 
 ; GCN: s_mov_b64 [[SAVEEXEC:s\[[0-9]+:[0-9]+\]]], exec
-; GCN: s_waitcnt lgkmcnt(0)
-
 ; GCN: [[LOOPBB:BB[0-9]+_[0-9]+]]:
 ; GCN: v_readfirstlane_b32 [[READLANE:s[0-9]+]]
 
 ; MOVREL: s_add_i32 m0, [[READLANE]], 0xfffffe00
 ; MOVREL: s_and_saveexec_b64 vcc, vcc
 ; MOVREL: v_movreld_b32_e32 [[VEC_ELT0]], 5
 
 ; IDXMODE: s_addk_i32 [[ADD_IDX:s[0-9]+]], 0xfe00{{$}}

 ; GCN-DAG: v_mov_b32_e32 [[VEC_ELT1:v[0-9]+]], 2{{$}}
 ; GCN-DAG: v_mov_b32_e32 [[VEC_ELT2:v[0-9]+]], 3{{$}}
 ; GCN-DAG: v_mov_b32_e32 [[VEC_ELT3:v[0-9]+]], 4{{$}}
 ; GCN-DAG: v_mov_b32_e32 [[VAL:v[0-9]+]], 0x1f4{{$}}
 
 ; IDXMODE: s_set_gpr_idx_on 0, dst
 
 ; GCN: s_mov_b64 [[SAVEEXEC:s\[[0-9]+:[0-9]+\]]], exec
-; GCN: s_waitcnt lgkmcnt(0)
 
 ; The offset depends on the register that holds the first element of the vector.
 ; GCN: v_readfirstlane_b32 [[READLANE:s[0-9]+]]
 
 ; MOVREL: s_add_i32 m0, [[READLANE]], -16
 ; MOVREL: v_movreld_b32_e32 [[VEC_ELT0]], [[VAL]]
 
 ; IDXMODE: s_add_i32 [[ADD_IDX:s[0-9]+]], [[READLANE]], -16

 ; GCN-DAG: s_mov_b32 [[S_ELT1:s[0-9]+]], 9
 ; GCN-DAG: s_mov_b32 [[S_ELT0:s[0-9]+]], 7
 ; GCN-DAG: v_mov_b32_e32 [[VEC_ELT0:v[0-9]+]], [[S_ELT0]]
 ; GCN-DAG: v_mov_b32_e32 [[VEC_ELT1:v[0-9]+]], [[S_ELT1]]
 
 ; IDXMODE: s_set_gpr_idx_on 0, src0
 
 ; GCN: s_mov_b64 [[MASK:s\[[0-9]+:[0-9]+\]]], exec
-; GCN: s_waitcnt vmcnt(0)
 
 ; GCN: [[LOOP0:BB[0-9]+_[0-9]+]]:
+; GCN-NEXT: s_waitcnt vmcnt(0)
 ; GCN-NEXT: v_readfirstlane_b32 [[READLANE:s[0-9]+]], [[IDX0]]
 ; GCN: v_cmp_eq_u32_e32 vcc, [[READLANE]], [[IDX0]]
 
 ; MOVREL: s_mov_b32 m0, [[READLANE]]
 ; MOVREL: s_and_saveexec_b64 vcc, vcc
 ; MOVREL: v_movrels_b32_e32 [[MOVREL0:v[0-9]+]], [[VEC_ELT0]]
 
 ; IDXMODE: s_set_gpr_idx_idx [[READLANE]]

 ; GCN-DAG: v_mov_b32_e32 v[[VEC_ELT3:[0-9]+]], s[[S_ELT3]]
 ; GCN: v_mov_b32_e32 v[[VEC_ELT2:[0-9]+]], s{{[0-9]+}}
 ; GCN: v_mov_b32_e32 v[[VEC_ELT1:[0-9]+]], s{{[0-9]+}}
 ; GCN: v_mov_b32_e32 v[[VEC_ELT0:[0-9]+]], s[[S_ELT0]]
 
 ; IDXMODE: s_set_gpr_idx_on 0, dst
 
 ; GCN: [[LOOP0:BB[0-9]+_[0-9]+]]:
+; GCN-NEXT: s_waitcnt vmcnt(0)
 ; GCN-NEXT: v_readfirstlane_b32 [[READLANE:s[0-9]+]], [[IDX0]]
 ; GCN: v_cmp_eq_u32_e32 vcc, [[READLANE]], [[IDX0]]
 
 ; MOVREL: s_mov_b32 m0, [[READLANE]]
 ; MOVREL: s_and_saveexec_b64 vcc, vcc
 ; MOVREL-NEXT: v_movreld_b32_e32 v[[VEC_ELT0]], [[INS0]]
 
 ; IDXMODE: s_set_gpr_idx_idx [[READLANE]]

test/CodeGen/AMDGPU/infinite-loop.ll

 ; RUN: llc -march=amdgcn -verify-machineinstrs < %s | FileCheck -check-prefix=SI %s
 ; RUN: llc -march=amdgcn -mcpu=tonga -mattr=-flat-for-global -verify-machineinstrs < %s | FileCheck -check-prefix=SI %s
 
 ; SI-LABEL: {{^}}infinite_loop:
 ; SI: v_mov_b32_e32 [[REG:v[0-9]+]], 0x3e7
 ; SI: BB0_1:
+; SI: s_waitcnt lgkmcnt(0)
 ; SI: buffer_store_dword [[REG]]
-; SI: s_waitcnt vmcnt(0) expcnt(0)
 ; SI: s_branch BB0_1
 define amdgpu_kernel void @infinite_loop(i32 addrspace(1)* %out) {
 entry:
   br label %for.body
 
 for.body:                                         ; preds = %entry, %for.body
   store i32 999, i32 addrspace(1)* %out, align 4
   br label %for.body
 }
 

test/CodeGen/AMDGPU/llvm.amdgcn.buffer.store.format.ll

main_body:
   call void @llvm.amdgcn.buffer.store.format.v4f32(<4 x float> %1, <4 x i32> %0, i32 %3, i32 %2, i1 0, i1 0)
   ret void
 }
 
 ; Ideally, the register allocator would avoid the wait here
 ;
 ;CHECK-LABEL: {{^}}buffer_store_wait:
 ;CHECK: buffer_store_format_xyzw v[0:3], v4, s[0:3], 0 idxen
-;CHECK: s_waitcnt vmcnt(0) expcnt(0)
+;CHECK: s_waitcnt expcnt(0)
 ;CHECK: buffer_load_format_xyzw v[0:3], v5, s[0:3], 0 idxen
 ;CHECK: s_waitcnt vmcnt(0)
 ;CHECK: buffer_store_format_xyzw v[0:3], v6, s[0:3], 0 idxen
 define amdgpu_ps void @buffer_store_wait(<4 x i32> inreg, <4 x float>, i32, i32, i32) {
 main_body:
   call void @llvm.amdgcn.buffer.store.format.v4f32(<4 x float> %1, <4 x i32> %0, i32 %2, i32 0, i1 0, i1 0)
   %data = call <4 x float> @llvm.amdgcn.buffer.load.format.v4f32(<4 x i32> %0, i32 %3, i32 0, i1 0, i1 0)
   call void @llvm.amdgcn.buffer.store.format.v4f32(<4 x float> %data, <4 x i32> %0, i32 %4, i32 0, i1 0, i1 0)

test/CodeGen/AMDGPU/llvm.amdgcn.buffer.store.ll

main_body:
   call void @llvm.amdgcn.buffer.store.v4f32(<4 x float> %1, <4 x i32> %0, i32 %3, i32 %2, i1 0, i1 0)
   ret void
 }
 
 ; Ideally, the register allocator would avoid the wait here
 ;
 ;CHECK-LABEL: {{^}}buffer_store_wait:
 ;CHECK: buffer_store_dwordx4 v[0:3], v4, s[0:3], 0 idxen
-;CHECK: s_waitcnt vmcnt(0) expcnt(0)
+;CHECK: s_waitcnt expcnt(0)
 ;CHECK: buffer_load_dwordx4 v[0:3], v5, s[0:3], 0 idxen
 ;CHECK: s_waitcnt vmcnt(0)
 ;CHECK: buffer_store_dwordx4 v[0:3], v6, s[0:3], 0 idxen
 define amdgpu_ps void @buffer_store_wait(<4 x i32> inreg, <4 x float>, i32, i32, i32) {
 main_body:
   call void @llvm.amdgcn.buffer.store.v4f32(<4 x float> %1, <4 x i32> %0, i32 %2, i32 0, i1 0, i1 0)
   %data = call <4 x float> @llvm.amdgcn.buffer.load.v4f32(<4 x i32> %0, i32 %3, i32 0, i1 0, i1 0)
   call void @llvm.amdgcn.buffer.store.v4f32(<4 x float> %data, <4 x i32> %0, i32 %4, i32 0, i1 0, i1 0)

test/CodeGen/AMDGPU/llvm.amdgcn.ds.swizzle.ll

 ; RUN: llc -mtriple=amdgcn--amdhsa -mcpu=hawaii -verify-machineinstrs < %s | FileCheck %s
 ; RUN: llc -mtriple=amdgcn--amdhsa -mcpu=fiji -verify-machineinstrs < %s | FileCheck %s
 
 declare i32 @llvm.amdgcn.ds.swizzle(i32, i32) #0
 
 ; FUNC-LABEL: {{^}}ds_swizzle:
 ; CHECK: ds_swizzle_b32 v{{[0-9]+}}, v{{[0-9]+}} offset:swizzle(BITMASK_PERM,"00p11")
-; CHECK: s_waitcnt lgkmcnt
 define amdgpu_kernel void @ds_swizzle(i32 addrspace(1)* %out, i32 %src) nounwind {
   %swizzle = call i32 @llvm.amdgcn.ds.swizzle(i32 %src, i32 100) #0
   store i32 %swizzle, i32 addrspace(1)* %out, align 4
   ret void
 }
 
 attributes #0 = { nounwind readnone convergent }

test/CodeGen/AMDGPU/llvm.amdgcn.image.ll

main_body:
   call void @llvm.amdgcn.exp.f32(i32 0, i32 15, float %r0, float %r1, float %r2, float %r3, i1 true, i1 true) #0
   ret void
 }
 
 ; Ideally, the register allocator would avoid the wait here
 ;
 ; GCN-LABEL: {{^}}image_store_wait:
 ; GCN: image_store v[0:3], v4, s[0:7] dmask:0xf unorm
-; GCN: s_waitcnt vmcnt(0) expcnt(0)
+; GCN: s_waitcnt expcnt(0)
 ; GCN: image_load v[0:3], v4, s[8:15] dmask:0xf unorm
 ; GCN: s_waitcnt vmcnt(0)
 ; GCN: image_store v[0:3], v4, s[16:23] dmask:0xf unorm
 define amdgpu_ps void @image_store_wait(<8 x i32> inreg %arg, <8 x i32> inreg %arg1, <8 x i32> inreg %arg2, <4 x float> %arg3, i32 %arg4) #0 {
 main_body:
   call void @llvm.amdgcn.image.store.v4f32.i32.v8i32(<4 x float> %arg3, i32 %arg4, <8 x i32> %arg, i32 15, i1 false, i1 false, i1 false, i1 false)
   %data = call <4 x float> @llvm.amdgcn.image.load.v4f32.i32.v8i32(i32 %arg4, <8 x i32> %arg1, i32 15, i1 false, i1 false, i1 false, i1 false)
   call void @llvm.amdgcn.image.store.v4f32.i32.v8i32(<4 x float> %data, i32 %arg4, <8 x i32> %arg2, i32 15, i1 false, i1 false, i1 false, i1 false)

test/CodeGen/AMDGPU/llvm.amdgcn.s.dcache.inv.ll

 }
 
 ; GCN-LABEL: {{^}}test_s_dcache_inv_insert_wait:
 ; GCN-NEXT: ; BB#0:
 ; GCN: s_dcache_inv
 ; GCN: s_waitcnt lgkmcnt(0) ; encoding
 define amdgpu_kernel void @test_s_dcache_inv_insert_wait() #0 {
   call void @llvm.amdgcn.s.dcache.inv()
-  call void @llvm.amdgcn.s.waitcnt(i32 0)
+  call void @llvm.amdgcn.s.waitcnt(i32 127)
   br label %end
 
 end:
   store volatile i32 3, i32 addrspace(1)* undef
   ret void
 }
 
 attributes #0 = { nounwind }

test/CodeGen/AMDGPU/llvm.amdgcn.s.dcache.inv.vol.ll

 }
 
 ; GCN-LABEL: {{^}}test_s_dcache_inv_vol_insert_wait:
 ; GCN-NEXT: ; BB#0:
 ; GCN-NEXT: s_dcache_inv_vol
 ; GCN: s_waitcnt lgkmcnt(0) ; encoding
 define amdgpu_kernel void @test_s_dcache_inv_vol_insert_wait() #0 {
   call void @llvm.amdgcn.s.dcache.inv.vol()
-  call void @llvm.amdgcn.s.waitcnt(i32 0)
+  call void @llvm.amdgcn.s.waitcnt(i32 127)
   br label %end
 
 end:
   store volatile i32 3, i32 addrspace(1)* undef
   ret void
 }
 
 attributes #0 = { nounwind }

test/CodeGen/AMDGPU/llvm.amdgcn.s.dcache.wb.ll

 }
 
 ; VI-LABEL: {{^}}test_s_dcache_wb_insert_wait:
 ; VI-NEXT: ; BB#0:
 ; VI-NEXT: s_dcache_wb
 ; VI: s_waitcnt lgkmcnt(0) ; encoding
 define amdgpu_kernel void @test_s_dcache_wb_insert_wait() #0 {
   call void @llvm.amdgcn.s.dcache.wb()
-  call void @llvm.amdgcn.s.waitcnt(i32 0)
+  call void @llvm.amdgcn.s.waitcnt(i32 127)
   br label %end
 
 end:
   store volatile i32 3, i32 addrspace(1)* undef
   ret void
 }
 
 attributes #0 = { nounwind }

test/CodeGen/AMDGPU/llvm.amdgcn.s.dcache.wb.vol.ll

 }
 
 ; VI-LABEL: {{^}}test_s_dcache_wb_vol_insert_wait:
 ; VI-NEXT: ; BB#0:
 ; VI-NEXT: s_dcache_wb_vol
 ; VI: s_waitcnt lgkmcnt(0) ; encoding
 define amdgpu_kernel void @test_s_dcache_wb_vol_insert_wait() #0 {
   call void @llvm.amdgcn.s.dcache.wb.vol()
-  call void @llvm.amdgcn.s.waitcnt(i32 0)
+  call void @llvm.amdgcn.s.waitcnt(i32 127)
   br label %end
 
 end:
   store volatile i32 3, i32 addrspace(1)* undef
   ret void
 }
 
 attributes #0 = { nounwind }

test/CodeGen/AMDGPU/llvm.amdgcn.s.waitcnt.ll

define amdgpu_ps void @test1(<8 x i32> inreg %rsrc, <4 x float> %d0, <4 x float> %d1, i32 %c0, i32 %c1) {
   ret void
 }
 
 ; Test that the intrinsic is merged with automatically generated waits and
 ; emitted as late as possible.
 ;
 ; CHECK-LABEL: {{^}}test2:
 ; CHECK: image_load
-; CHECK-NOT: s_waitcnt vmcnt(0){{$}}
-; CHECK: s_waitcnt
+; CHECK-NEXT: s_waitcnt
+; CHECK: s_waitcnt vmcnt(0){{$}}
 ; CHECK-NEXT: image_store
 define amdgpu_ps void @test2(<8 x i32> inreg %rsrc, i32 %c) {
   %t = call <4 x float> @llvm.amdgcn.image.load.v4f32.i32.v8i32(i32 %c, <8 x i32> %rsrc, i32 15, i1 0, i1 0, i1 0, i1 0)
   call void @llvm.amdgcn.s.waitcnt(i32 3840) ; 0xf00
   %c.1 = mul i32 %c, 2
   call void @llvm.amdgcn.image.store.v4f32.i32.v8i32(<4 x float> %t, i32 %c.1, <8 x i32> %rsrc, i32 15, i1 0, i1 0, i1 0, i1 0)
   ret void
 }
 
 declare void @llvm.amdgcn.s.waitcnt(i32) #0
 
 declare <4 x float> @llvm.amdgcn.image.load.v4f32.i32.v8i32(i32, <8 x i32>, i32, i1, i1, i1, i1) #1
 declare void @llvm.amdgcn.image.store.v4f32.i32.v8i32(<4 x float>, i32, <8 x i32>, i32, i1, i1, i1, i1) #0
 
 attributes #0 = { nounwind }
 attributes #1 = { nounwind readonly }

test/CodeGen/AMDGPU/multi-divergent-exit-region.ll

 
 ; GCN: v_mov_b32_e32 v0, 2.0
 ; GCN: s_or_b64 exec, exec
 ; GCN: s_and_b64 exec, exec
 ; GCN: v_mov_b32_e32 v0, 1.0
 
 ; GCN: {{^BB[0-9]+_[0-9]+}}: ; %UnifiedReturnBlock
 ; GCN-NEXT: s_or_b64 exec, exec
+; GCN-NEXT: s_waitcnt vmcnt(0) lgkmcnt(0)
 ; GCN-NEXT: ; return
 
 define amdgpu_ps float @uniform_branch_to_multi_divergent_region_exit_ret_ret_return_value(i32 inreg %sgpr, i32 %vgpr) #0 {
 entry:
   %uniform.cond = icmp slt i32 %sgpr, 2
   br i1 %uniform.cond, label %LeafBlock, label %LeafBlock1
 
 LeafBlock:                                        ; preds = %entry

test/CodeGen/AMDGPU/ret_jump.ll

 
 ; GCN: ; BB#{{[0-9]+}}: ; %else
 ; GCN: s_and_saveexec_b64 [[SAVE_EXEC:s\[[0-9]+:[0-9]+\]]], vcc
 ; GCN-NEXT: s_xor_b64 [[XOR_EXEC:s\[[0-9]+:[0-9]+\]]], exec, [[SAVE_EXEC]]
 ; GCN-NEXT: ; mask branch [[FLOW1:BB[0-9]+_[0-9]+]]
 
 ; GCN-NEXT:  ; %unreachable.bb
 ; GCN: ds_write_b32
-; GCN: s_waitcnt
 ; GCN: ; divergent unreachable
 
 ; GCN: ; %ret.bb
 ; GCN: store_dword
 
 ; GCN: ; %UnifiedReturnBlock
 ; GCN-NEXT: s_or_b64 exec, exec
+; GCN-NEXT: s_waitcnt
 ; GCN-NEXT: ; return
 ; GCN-NEXT: .Lfunc_end
 define amdgpu_ps <{ i32, i32, i32, i32, i32, i32, i32, i32, i32, float, float, float, float, float, float, float, float, float, float, float, float, float, float }> @uniform_br_nontrivial_ret_divergent_br_nontrivial_unreachable([9 x <16 x i8>] addrspace(2)* byval %arg, [17 x <16 x i8>] addrspace(2)* byval %arg1, [17 x <8 x i32>] addrspace(2)* byval %arg2, i32 addrspace(2)* byval %arg3, float inreg %arg4, i32 inreg %arg5, <2 x i32> %arg6, <2 x i32> %arg7, <2 x i32> %arg8, <3 x i32> %arg9, <2 x i32> %arg10, <2 x i32> %arg11, <2 x i32> %arg12, float %arg13, float %arg14, float %arg15, float %arg16, float %arg17, i32 inreg %arg18, i32 %arg19, float %arg20, i32 %arg21) #0 {
 main_body:
   %i.i = extractelement <2 x i32> %arg7, i32 0
   %j.i = extractelement <2 x i32> %arg7, i32 1
   %i.f.i = bitcast i32 %i.i to float
   %j.f.i = bitcast i32 %j.i to float

test/CodeGen/AMDGPU/si-lower-control-flow-unreachable-block.ll

 ; RUN: llc -march=amdgcn -verify-machineinstrs < %s | FileCheck -check-prefix=GCN %s
 
 ; GCN-LABEL: {{^}}lower_control_flow_unreachable_terminator:
 ; GCN: v_cmp_eq_u32
 ; GCN: s_and_saveexec_b64
 ; GCN: s_xor_b64
 ; GCN: ; mask branch [[RET:BB[0-9]+_[0-9]+]]
 
 ; GCN-NEXT: BB{{[0-9]+_[0-9]+}}: ; %unreachable
 ; GCN: ds_write_b32
 ; GCN: ; divergent unreachable
-; GCN: s_waitcnt
 
 ; GCN-NEXT: [[RET]]: ; %UnifiedReturnBlock
 ; GCN-NEXT: s_or_b64 exec, exec
 ; GCN: s_endpgm
 
 define amdgpu_kernel void @lower_control_flow_unreachable_terminator() #0 {
 bb:
   %tmp15 = tail call i32 @llvm.amdgcn.workitem.id.y()

 ; GCN: v_cmp_ne_u32
 ; GCN: s_and_saveexec_b64
 ; GCN: s_xor_b64
 ; GCN: ; mask branch [[RETURN:BB[0-9]+_[0-9]+]]
 
 ; GCN-NEXT: {{^BB[0-9]+_[0-9]+}}: ; %unreachable
 ; GCN: ds_write_b32
 ; GCN: ; divergent unreachable
-; GCN: s_waitcnt
 
 ; GCN: [[RETURN]]:
 ; GCN-NEXT: s_or_b64 exec, exec
 ; GCN-NEXT: s_endpgm
 define amdgpu_kernel void @lower_control_flow_unreachable_terminator_swap_block_order() #0 {
 bb:
   %tmp15 = tail call i32 @llvm.amdgcn.workitem.id.y()
   %tmp63 = icmp eq i32 %tmp15, 32

 ; GCN: s_cmp_lg_u32
 ; GCN: s_cbranch_scc0 [[UNREACHABLE:BB[0-9]+_[0-9]+]]
 
 ; GCN-NEXT: BB#{{[0-9]+}}: ; %ret
 ; GCN-NEXT: s_endpgm
 
 ; GCN: [[UNREACHABLE]]:
 ; GCN: ds_write_b32
-; GCN: s_waitcnt
 define amdgpu_kernel void @uniform_lower_control_flow_unreachable_terminator(i32 %arg0) #0 {
 bb:
   %tmp63 = icmp eq i32 %arg0, 32
   br i1 %tmp63, label %unreachable, label %ret
 
 unreachable:
   store volatile i32 0, i32 addrspace(3)* undef, align 4
   unreachable

test/CodeGen/AMDGPU/smrd-vccz-bug.ll

 ; RUN: llc -march=amdgcn -mcpu=verde -verify-machineinstrs < %s | FileCheck -check-prefix=GCN -check-prefix=VCCZ-BUG %s
 ; RUN: llc -march=amdgcn -mcpu=bonaire -verify-machineinstrs < %s | FileCheck -check-prefix=GCN -check-prefix=VCCZ-BUG %s
 ; RUN: llc -march=amdgcn -mcpu=tonga -mattr=-flat-for-global -verify-machineinstrs < %s | FileCheck -check-prefix=GCN -check-prefix=NOVCCZ-BUG %s
 
 ; GCN-FUNC: {{^}}vccz_workaround:
 ; GCN: s_load_dword s{{[0-9]+}}, s[{{[0-9]+:[0-9]+}}], 0x0
 ; GCN: v_cmp_neq_f32_e64 vcc, s{{[0-9]+}}, 0{{$}}
-; GCN: s_waitcnt lgkmcnt(0)
+; VCCZ-BUG: s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
 ; VCCZ-BUG: s_mov_b64 vcc, vcc
 ; NOVCCZ-BUG-NOT: s_mov_b64 vcc, vcc
 ; GCN: s_cbranch_vccnz [[EXIT:[0-9A-Za-z_]+]]
 ; GCN: buffer_store_dword
 ; GCN: [[EXIT]]:
 ; GCN: s_endpgm
 define amdgpu_kernel void @vccz_workaround(i32 addrspace(2)* %in, i32 addrspace(1)* %out, float %cond) {
 entry:

test/CodeGen/AMDGPU/spill-m0.ll

 ; GCN-DAG: s_cmp_lg_u32
 
 ; TOVGPR-DAG: s_mov_b32 [[M0_COPY:s[0-9]+]], m0
 ; TOVGPR: v_writelane_b32 [[SPILL_VREG:v[0-9]+]], [[M0_COPY]], 0
 
 ; TOVMEM-DAG: s_mov_b32 [[M0_COPY:s[0-9]+]], m0
 ; TOVMEM-DAG: v_mov_b32_e32 [[SPILL_VREG:v[0-9]+]], [[M0_COPY]]
 ; TOVMEM: buffer_store_dword [[SPILL_VREG]], off, s{{\[[0-9]+:[0-9]+\]}}, s{{[0-9]+}} offset:4 ; 4-byte Folded Spill
-; TOVMEM: s_waitcnt vmcnt(0)
 
 ; TOSMEM-DAG: s_mov_b32 [[M0_COPY:s[0-9]+]], m0
 ; TOSMEM: s_add_u32 m0, s3, 0x100{{$}}
 ; TOSMEM-NOT: [[M0_COPY]]
 ; TOSMEM: s_buffer_store_dword [[M0_COPY]], s{{\[}}[[LO]]:[[HI]]], m0 ; 4-byte Folded Spill
-; TOSMEM: s_waitcnt lgkmcnt(0)
 
 ; GCN: s_cbranch_scc1 [[ENDIF:BB[0-9]+_[0-9]+]]
 
 ; GCN: [[ENDIF]]:
 ; TOVGPR: v_readlane_b32 [[M0_RESTORE:s[0-9]+]], [[SPILL_VREG]], 0
 ; TOVGPR: s_mov_b32 m0, [[M0_RESTORE]]
 
 ; TOVMEM: buffer_load_dword [[RELOAD_VREG:v[0-9]+]], off, s{{\[[0-9]+:[0-9]+\]}}, s{{[0-9]+}} offset:4 ; 4-byte Folded Reload

test/CodeGen/AMDGPU/valu-i1.ll

 ; RUN: llc -march=amdgcn -verify-machineinstrs -enable-misched -asm-verbose < %s | FileCheck -check-prefix=SI %s
 
 declare i32 @llvm.amdgcn.workitem.id.x() nounwind readnone
 
 ; SI-LABEL: {{^}}test_if:
 ; Make sure the i1 values created by the cfg structurizer pass are
 ; moved using VALU instructions
 
 
 ; waitcnt should be inserted after exec modification
 ; SI: v_cmp_lt_i32_e32 vcc, 0,
 ; SI-NEXT: s_and_saveexec_b64 [[SAVE1:s\[[0-9]+:[0-9]+\]]], vcc
 ; SI-NEXT: s_xor_b64 [[SAVE2:s\[[0-9]+:[0-9]+\]]], exec, [[SAVE1]]
-; SI-NEXT: s_waitcnt lgkmcnt(0)
 ; SI-NEXT: ; mask branch [[FLOW_BB:BB[0-9]+_[0-9]+]]
 ; SI-NEXT: s_cbranch_execz [[FLOW_BB]]
 
 ; SI-NEXT: BB{{[0-9]+}}_1: ; %LeafBlock3
 ; SI-NOT: s_mov_b64 s[{{[0-9]:[0-9]}}], -1
 ; SI: v_mov_b32_e32 v{{[0-9]}}, -1
 ; SI: s_and_saveexec_b64
 ; SI-NEXT: s_xor_b64

 ; SI-LABEL: {{^}}simple_test_v_if:
 ; SI: v_cmp_ne_u32_e32 vcc, 0, v{{[0-9]+}}
 ; SI: s_and_saveexec_b64 [[BR_SREG:s\[[0-9]+:[0-9]+\]]], vcc
 ; SI: s_xor_b64 [[BR_SREG]], exec, [[BR_SREG]]
 ; SI: ; mask branch [[EXIT:BB[0-9]+_[0-9]+]]
 
 ; SI-NEXT: BB{{[0-9]+_[0-9]+}}:
 ; SI: buffer_store_dword
-; SI-NEXT: s_waitcnt
 
 ; SI-NEXT: {{^}}[[EXIT]]:
 ; SI: s_or_b64 exec, exec, [[BR_SREG]]
 ; SI: s_endpgm
 define amdgpu_kernel void @simple_test_v_if(i32 addrspace(1)* %dst, i32 addrspace(1)* %src) #1 {
   %tid = call i32 @llvm.amdgcn.workitem.id.x() nounwind readnone
   %is.0 = icmp ne i32 %tid, 0
   br i1 %is.0, label %then, label %exit

 ; SI-LABEL: {{^}}simple_test_v_if_ret_else_ret:
 ; SI: v_cmp_ne_u32_e32 vcc, 0, v{{[0-9]+}}
 ; SI: s_and_saveexec_b64 [[BR_SREG:s\[[0-9]+:[0-9]+\]]], vcc
 ; SI: s_xor_b64 [[BR_SREG]], exec, [[BR_SREG]]
 ; SI: ; mask branch [[EXIT:BB[0-9]+_[0-9]+]]
 
 ; SI-NEXT: BB{{[0-9]+_[0-9]+}}:
 ; SI: buffer_store_dword
-; SI-NEXT: s_waitcnt
 
 ; SI-NEXT: {{^}}[[EXIT]]:
 ; SI: s_or_b64 exec, exec, [[BR_SREG]]
 ; SI: s_endpgm
 define amdgpu_kernel void @simple_test_v_if_ret_else_ret(i32 addrspace(1)* %dst, i32 addrspace(1)* %src) #1 {
   %tid = call i32 @llvm.amdgcn.workitem.id.x()
   %is.0 = icmp ne i32 %tid, 0
   br i1 %is.0, label %then, label %exit

 ; SI-LABEL: {{^}}simple_test_v_if_ret_else_code_ret:
 ; SI: v_cmp_eq_u32_e32 vcc, 0, v{{[0-9]+}}
 ; SI: s_and_saveexec_b64 [[BR_SREG:s\[[0-9]+:[0-9]+\]]], vcc
 ; SI: s_xor_b64 [[BR_SREG]], exec, [[BR_SREG]]
 ; SI: ; mask branch [[FLOW:BB[0-9]+_[0-9]+]]
 
 ; SI-NEXT: {{^BB[0-9]+_[0-9]+}}: ; %exit
 ; SI: ds_write_b32
-; SI: s_waitcnt
 
 ; SI-NEXT: {{^}}[[FLOW]]:
 ; SI-NEXT: s_or_saveexec_b64
 ; SI-NEXT: s_xor_b64 exec, exec
 ; SI-NEXT: ; mask branch [[UNIFIED_RETURN:BB[0-9]+_[0-9]+]]
 
 ; SI-NEXT: {{^BB[0-9]+_[0-9]+}}: ; %then
-; SI: buffer_store_dword
-; SI-NEXT: s_waitcnt
+; SI: s_waitcnt
+; SI-NEXT: buffer_store_dword
 
 ; SI-NEXT: {{^}}[[UNIFIED_RETURN]]: ; %UnifiedReturnBlock
 ; SI: s_or_b64 exec, exec
 ; SI: s_endpgm
 define amdgpu_kernel void @simple_test_v_if_ret_else_code_ret(i32 addrspace(1)* %dst, i32 addrspace(1)* %src) #1 {
   %tid = call i32 @llvm.amdgcn.workitem.id.x()
   %is.0 = icmp ne i32 %tid, 0
   br i1 %is.0, label %then, label %exit