llvm/test/CodeGen/AMDGPU/loop_exit_with_xor.ll

; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 2
; RUN: llc -mtriple=amdgcn--amdpal -mcpu=gfx803 -verify-machineinstrs < %s | FileCheck -check-prefix=GCN %s

; Where the mask of lanes wanting to exit the loop on this iteration is not
; obviously already masked by exec (in this case, the xor with -1 inserted by
; control flow annotation), then lower control flow must insert an S_AND_B64
; with exec.

define void @needs_and(i32 %arg) {
; GCN-LABEL: needs_and:
; GCN:       ; %bb.0: ; %entry
; GCN-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
; GCN-NEXT:    s_mov_b32 s10, 1
; GCN-NEXT:    s_mov_b64 s[6:7], 0
; GCN-NEXT:    s_branch .LBB0_2
; GCN-NEXT:  .LBB0_1: ; %endif
; GCN-NEXT:    ; in Loop: Header=BB0_2 Depth=1
; GCN-NEXT:    s_or_b64 exec, exec, s[8:9]
; GCN-NEXT:    s_and_b64 s[4:5], exec, vcc
; GCN-NEXT:    s_or_b64 s[6:7], s[4:5], s[6:7]
; GCN-NEXT:    s_add_i32 s10, s10, 1
; GCN-NEXT:    s_andn2_b64 exec, exec, s[6:7]
; GCN-NEXT:    s_cbranch_execz .LBB0_4
; GCN-NEXT:  .LBB0_2: ; %loop
; GCN-NEXT:    ; =>This Inner Loop Header: Depth=1
; GCN-NEXT:    v_cmp_gt_u32_e64 s[4:5], s10, v0
; GCN-NEXT:    v_cmp_le_u32_e32 vcc, s10, v0
; GCN-NEXT:    s_and_saveexec_b64 s[8:9], s[4:5]
; GCN-NEXT:    s_cbranch_execz .LBB0_1
; GCN-NEXT:  ; %bb.3: ; %then
; GCN-NEXT:    ; in Loop: Header=BB0_2 Depth=1
; GCN-NEXT:    s_nop 1
; GCN-NEXT:    buffer_store_dword v0, off, s[4:7], s4
; GCN-NEXT:    s_branch .LBB0_1
; GCN-NEXT:  .LBB0_4: ; %loopexit
; GCN-NEXT:    s_or_b64 exec, exec, s[6:7]
; GCN-NEXT:    s_waitcnt vmcnt(0)
; GCN-NEXT:    s_setpc_b64 s[30:31]
entry:
  br label %loop

loop:
  %tmp23phi = phi i32 [ %tmp23, %endif ], [ 0, %entry ]
  %tmp23 = add nuw i32 %tmp23phi, 1
  %tmp27 = icmp ult i32 %arg, %tmp23
  br i1 %tmp27, label %then, label %endif

then:                                             ; preds = %bb
  call void @llvm.amdgcn.raw.ptr.buffer.store.f32(float undef, ptr addrspace(8) undef, i32 0, i32 undef, i32 0)
  br label %endif

endif:                                             ; preds = %bb28, %bb
  br i1 %tmp27, label %loop, label %loopexit

loopexit:
  ret void
}

; Where the mask of lanes wanting to exit the loop on this iteration is
; obviously already masked by exec (a V_CMP), then lower control flow can omit
; the S_AND_B64 to avoid an unnecessary instruction.

define void @doesnt_need_and(i32 %arg) {
; GCN-LABEL: doesnt_need_and:
; GCN:       ; %bb.0: ; %entry
; GCN-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
; GCN-NEXT:    s_mov_b32 s6, 0
; GCN-NEXT:    s_mov_b64 s[4:5], 0
; GCN-NEXT:  .LBB1_1: ; %loop
; GCN-NEXT:    ; =>This Inner Loop Header: Depth=1
; GCN-NEXT:    s_add_i32 s6, s6, 1
; GCN-NEXT:    v_cmp_le_u32_e32 vcc, s6, v0
; GCN-NEXT:    s_or_b64 s[4:5], vcc, s[4:5]
; GCN-NEXT:    buffer_store_dword v0, off, s[4:7], s4
; GCN-NEXT:    s_andn2_b64 exec, exec, s[4:5]
; GCN-NEXT:    s_cbranch_execnz .LBB1_1
; GCN-NEXT:  ; %bb.2: ; %loopexit
; GCN-NEXT:    s_or_b64 exec, exec, s[4:5]
; GCN-NEXT:    s_waitcnt vmcnt(0)
; GCN-NEXT:    s_setpc_b64 s[30:31]
entry:
  br label %loop

loop:
  %tmp23phi = phi i32 [ %tmp23, %loop ], [ 0, %entry ]
  %tmp23 = add nuw i32 %tmp23phi, 1
  %tmp27 = icmp ult i32 %arg, %tmp23
  call void @llvm.amdgcn.raw.ptr.buffer.store.f32(float undef, ptr addrspace(8) undef, i32 0, i32 undef, i32 0)
  br i1 %tmp27, label %loop, label %loopexit

loopexit:
  ret void
}

; Another case where the mask of lanes wanting to exit the loop is not masked
; by exec, because it is a function parameter.

define void @break_cond_is_arg(i32 %arg, i1 %breakcond) {
; GCN-LABEL: break_cond_is_arg:
; GCN:       ; %bb.0: ; %entry
; GCN-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
; GCN-NEXT:    v_and_b32_e32 v1, 1, v1
; GCN-NEXT:    v_cmp_eq_u32_e32 vcc, 1, v1
; GCN-NEXT:    s_xor_b64 s[4:5], vcc, -1
; GCN-NEXT:    s_mov_b32 s10, 1
; GCN-NEXT:    s_mov_b64 s[6:7], 0
; GCN-NEXT:    s_branch .LBB2_2
; GCN-NEXT:  .LBB2_1: ; %endif
; GCN-NEXT:    ; in Loop: Header=BB2_2 Depth=1
; GCN-NEXT:    s_or_b64 exec, exec, s[8:9]
; GCN-NEXT:    s_and_b64 s[8:9], exec, s[4:5]
; GCN-NEXT:    s_or_b64 s[6:7], s[8:9], s[6:7]
; GCN-NEXT:    s_add_i32 s10, s10, 1
; GCN-NEXT:    s_andn2_b64 exec, exec, s[6:7]
; GCN-NEXT:    s_cbranch_execz .LBB2_4
; GCN-NEXT:  .LBB2_2: ; %loop
; GCN-NEXT:    ; =>This Inner Loop Header: Depth=1
; GCN-NEXT:    v_cmp_gt_u32_e32 vcc, s10, v0
; GCN-NEXT:    s_and_saveexec_b64 s[8:9], vcc
; GCN-NEXT:    s_cbranch_execz .LBB2_1
; GCN-NEXT:  ; %bb.3: ; %then
; GCN-NEXT:    ; in Loop: Header=BB2_2 Depth=1
; GCN-NEXT:    buffer_store_dword v0, off, s[4:7], s4
; GCN-NEXT:    s_branch .LBB2_1
; GCN-NEXT:  .LBB2_4: ; %loopexit
; GCN-NEXT:    s_or_b64 exec, exec, s[6:7]
; GCN-NEXT:    s_waitcnt vmcnt(0)
; GCN-NEXT:    s_setpc_b64 s[30:31]
entry:
  br label %loop

loop:
  %tmp23phi = phi i32 [ %tmp23, %endif ], [ 0, %entry ]
  %tmp23 = add nuw i32 %tmp23phi, 1
  %tmp27 = icmp ult i32 %arg, %tmp23
  br i1 %tmp27, label %then, label %endif

then:                                             ; preds = %bb
  call void @llvm.amdgcn.raw.ptr.buffer.store.f32(float undef, ptr addrspace(8) undef, i32 0, i32 undef, i32 0)
  br label %endif

endif:                                             ; preds = %bb28, %bb
  br i1 %breakcond, label %loop, label %loopexit

loopexit:
  ret void
}

declare void @llvm.amdgcn.raw.ptr.buffer.store.f32(float, ptr addrspace(8), i32, i32, i32 immarg) #0

attributes #0 = { nounwind writeonly }