llvm/test/CodeGen/AMDGPU/merge-load-store.mir

# RUN: llc -march=amdgcn -verify-machineinstrs -run-pass si-load-store-opt -o - %s | FileCheck %s

# Check that SILoadStoreOptimizer honors memory dependencies between moved
# instructions.
#
# The following IR snippet would usually be optimized by the peephole optimizer.
# However, an equivalent situation can occur with buffer instructions as well.

# CHECK-LABEL: name: mem_dependency
# CHECK: DS_READ2_B32 %0, 0, 1,
# CHECK: DS_WRITE_B32 %0, killed %1, 64,
# CHECK: DS_READ2_B32 %0, 16, 17,
# CHECK: DS_WRITE_B32 killed %0, %5, 0

--- |
  define amdgpu_kernel void @mem_dependency(i32 addrspace(3)* %ptr.0) nounwind {
    %ptr.4 = getelementptr i32, i32 addrspace(3)* %ptr.0, i32 1
    %ptr.64 = getelementptr i32, i32 addrspace(3)* %ptr.0, i32 16
    %1 = load i32, i32 addrspace(3)* %ptr.0
    store i32 %1, i32 addrspace(3)* %ptr.64
    %2 = load i32, i32 addrspace(3)* %ptr.64
    %3 = load i32, i32 addrspace(3)* %ptr.4
    %4 = add i32 %2, %3
    store i32 %4, i32 addrspace(3)* %ptr.0
    ret void
  }

  @lds0 = external dso_local unnamed_addr addrspace(3) global [256 x i32], align 4
  @lds1 = external dso_local unnamed_addr addrspace(3) global [256 x i32], align 4
  @lds2 = external dso_local unnamed_addr addrspace(3) global [256 x i32], align 4
  @lds3 = external dso_local unnamed_addr addrspace(3) global [256 x i32], align 4

  define void @asm_defines_address() #0 {
  bb:
    %tmp1 = load i32, i32 addrspace(3)* getelementptr inbounds ([256 x i32], [256 x i32] addrspace(3)* @lds0, i32 0, i32 0), align 4
    %0 = and i32 %tmp1, 255
    %tmp3 = load i32, i32 addrspace(3)* getelementptr ([256 x i32], [256 x i32] addrspace(3)* @lds1, i32 0, i32 undef), align 4
    %tmp6 = load i32, i32 addrspace(3)* getelementptr ([256 x i32], [256 x i32] addrspace(3)* @lds3, i32 0, i32 undef), align 4
    %tmp7 = tail call i32 asm "v_or_b32 $0, 0, $1", "=v,v"(i32 %tmp6) #1
    %tmp10 = lshr i32 %tmp7, 16
    %tmp11 = and i32 %tmp10, 255
    %tmp12 = getelementptr inbounds [256 x i32], [256 x i32] addrspace(3)* @lds1, i32 0, i32 %tmp11
    %tmp13 = load i32, i32 addrspace(3)* %tmp12, align 4
    %tmp14 = xor i32 %tmp3, %tmp13
    %tmp15 = lshr i32 %tmp14, 8
    %tmp16 = and i32 %tmp15, 16711680
    %tmp19 = lshr i32 %tmp16, 16
    %tmp20 = and i32 %tmp19, 255
    %tmp21 = getelementptr inbounds [256 x i32], [256 x i32] addrspace(3)* @lds1, i32 0, i32 %tmp20
    %tmp22 = load i32, i32 addrspace(3)* %tmp21, align 4
    %tmp24 = load i32, i32 addrspace(3)* getelementptr ([256 x i32], [256 x i32] addrspace(3)* @lds2, i32 0, i32 undef), align 4
    %tmp25 = xor i32 %tmp22, %tmp24
    %tmp26 = and i32 %tmp25, -16777216
    %tmp28 = or i32 %0, %tmp26
    store volatile i32 %tmp28, i32 addrspace(1)* undef
    ret void
  }

  attributes #0 = { convergent nounwind }
  attributes #1 = { convergent nounwind readnone }

...
---
name:            mem_dependency
alignment:       0
exposesReturnsTwice: false
legalized:       false
regBankSelected: false
selected:        false
tracksRegLiveness: true
liveins:
  - { reg: '$vgpr0', virtual-reg: '%1' }
frameInfo:
  isFrameAddressTaken: false
  isReturnAddressTaken: false
  hasStackMap:     false
  hasPatchPoint:   false
  stackSize:       0
  offsetAdjustment: 0
  maxAlignment:    0
  adjustsStack:    false
  hasCalls:        false
  maxCallFrameSize: 0
  hasOpaqueSPAdjustment: false
  hasVAStart:      false
  hasMustTailInVarArgFunc: false
body:             |
  bb.0:
    liveins: $vgpr0

    %1:vgpr_32 = COPY $vgpr0
    $m0 = S_MOV_B32 -1
    %2:vgpr_32 = DS_READ_B32 %1, 0, 0, implicit $m0, implicit $exec :: (load 4 from %ir.ptr.0)
    DS_WRITE_B32 %1, killed %2, 64, 0, implicit $m0, implicit $exec :: (store 4 into %ir.ptr.64)

    ; Make this load unmergeable, to tempt SILoadStoreOptimizer into merging the
    ; other two loads.
    %6:vreg_64 = DS_READ2_B32 %1, 16, 17, 0, implicit $m0, implicit $exec :: (load 8 from %ir.ptr.64, align 4)
    %3:vgpr_32 = COPY %6.sub0
    %4:vgpr_32 = DS_READ_B32 %1, 4, 0, implicit $m0, implicit $exec :: (load 4 from %ir.ptr.4)
    %5:vgpr_32 = V_ADD_I32_e32 killed %3, killed %4, implicit-def $vcc, implicit $exec
    DS_WRITE_B32 killed %1, %5, 0, 0, implicit killed $m0, implicit $exec :: (store 4 into %ir.ptr.0)
    S_ENDPGM

...
---
# Make sure the asm def isn't moved after the point where it's used for
# the address.
# CHECK-LABEL: name: asm_defines_address
# CHECK: DS_READ2ST64_B32
# CHECK: DS_READ2ST64_B32
# CHECK: INLINEASM
# CHECK: DS_READ_B32
# CHECK: DS_READ_B32
name:            asm_defines_address
tracksRegLiveness: true
registers:
  - { id: 0, class: vgpr_32, preferred-register: '' }
body:             |
  bb.0:
    %1:vgpr_32 = V_MOV_B32_e32 0, implicit $exec
    %2:vgpr_32 = DS_READ_B32 %1, 3072, 0, implicit $m0, implicit $exec :: (dereferenceable load 4 from `i32 addrspace(3)* getelementptr inbounds ([256 x i32], [256 x i32] addrspace(3)* @lds0, i32 0, i32 0)`, addrspace 3)
    %3:vgpr_32 = DS_READ_B32 %1, 2048, 0, implicit $m0, implicit $exec :: (load 4 from `i32 addrspace(3)* getelementptr ([256 x i32], [256 x i32] addrspace(3)* @lds1, i32 0, i32 undef)`, addrspace 3)
    %4:vgpr_32 = DS_READ_B32 %1, 1024, 0, implicit $m0, implicit $exec :: (load 4 from `i32 addrspace(3)* getelementptr ([256 x i32], [256 x i32] addrspace(3)* @lds3, i32 0, i32 undef)`, addrspace 3)
    INLINEASM &"v_or_b32 $0, 0, $1", 32, 327690, def %0, 327689, %4
    %5:vgpr_32 = DS_READ_B32 %0, 2048, 0, implicit $m0, implicit $exec :: (load 4 from %ir.tmp12, addrspace 3)
    %6:vgpr_32 = DS_READ_B32 %5, 2048, 0, implicit $m0, implicit $exec :: (load 4 from %ir.tmp21, addrspace 3)
    %7:vgpr_32 = DS_READ_B32 %1, 0, 0, implicit $m0, implicit $exec :: (load 4 from `i32 addrspace(3)* getelementptr ([256 x i32], [256 x i32] addrspace(3)* @lds2, i32 0, i32 undef)`, addrspace 3)
    S_SETPC_B64_return undef $sgpr30_sgpr31, implicit %6, implicit %7

...