third_party/llvm-7.0/llvm/test/CodeGen/AArch64/machine-dead-copy.mir

# RUN: llc -mtriple=aarch64-none-linux-gnu -run-pass machine-cp  -verify-machineinstrs  -o - %s | FileCheck %s

--- |
  define i32 @copyprop1(i32 %a, i32 %b) { ret i32 %a }
  define i32 @copyprop2(i32 %a, i32 %b) { ret i32 %a }
  define i32 @copyprop3(i32 %a, i32 %b) { ret i32 %a }
  define i32 @copyprop4(i32 %a, i32 %b) { ret i32 %a }
  define i32 @copyprop5(i32 %a, i32 %b) { ret i32 %a }
  define i32 @copyprop6(i32 %a, i32 %b) { ret i32 %a }
  declare i32 @foo(i32)
...
---
# The first copy is dead copy which is not used.
# CHECK-LABEL: name: copyprop1
# CHECK: bb.0:
# CHECK-NOT: $w20 = COPY
name: copyprop1
body: |
  bb.0:
    liveins: $w0,  $w1
    $w20 = COPY $w1
    BL @foo, csr_aarch64_aapcs, implicit $w0, implicit-def $w0
    RET_ReallyLR implicit $w0
...
---
# The first copy is not a dead copy which is used in the second copy after the
# call.
# CHECK-LABEL: name: copyprop2
# CHECK: bb.0:
# CHECK: $w20 = COPY
name: copyprop2
body: |
  bb.0:
    liveins: $w0,  $w1
    $w20 = COPY $w1
    BL @foo, csr_aarch64_aapcs, implicit $w0, implicit-def $w0
    $w0 = COPY $w20
    RET_ReallyLR implicit $w0
...
---
# Both the first and second copy are dead copies which are not used.
# CHECK-LABEL: name: copyprop3
# CHECK: bb.0:
# CHECK-NOT: COPY
name: copyprop3
body: |
  bb.0:
    liveins: $w0,  $w1
    $w20 = COPY $w1
    BL @foo, csr_aarch64_aapcs, implicit $w0, implicit-def $w0
    $w20 = COPY $w0
    RET_ReallyLR implicit $w0
...
# The second copy is removed as a NOP copy, after then the first copy become
# dead which should be removed as well.
# CHECK-LABEL: name: copyprop4
# CHECK: bb.0:
# CHECK-NOT: COPY
name: copyprop4
body: |
  bb.0:
    liveins: $w0,  $w1
    $w20 = COPY $w0
    $w0 = COPY $w20
    BL @foo, csr_aarch64_aapcs, implicit $w0, implicit-def $w0
    RET_ReallyLR implicit $w0
...

# Don't try to erase any COPY which overlaps itself.
# CHECK-LABEL: name: copyprop5
# CHECK: bb.0:
# CHECK: COPY killed $q26_q27_q28_q29
# CHECK: COPY killed $q28_q29_q30_q31
name: copyprop5
body: |
  bb.0:
    liveins: $q26_q27_q28_q29
    $q28_q29_q30_q31 = COPY killed $q26_q27_q28_q29
    $q26_q27_q28_q29 = COPY killed $q28_q29_q30_q31
    BL @foo, csr_aarch64_aapcs, implicit killed $q26_q27_q28_q29
    RET_ReallyLR
...

# Don't try to analyze any COPY which overlaps itself.
# CHECK-LABEL: name: copyprop6
# CHECK: bb.0:
# CHECK: COPY killed $q26_q27_q28_q29
# CHECK: $q30 = COPY $q28
name: copyprop6
body: |
  bb.0:
    liveins: $q26_q27_q28_q29
    $q28_q29_q30_q31 = COPY killed $q26_q27_q28_q29
    $q30 = COPY $q28
    BL @foo, csr_aarch64_aapcs, implicit killed $q28_q29_q30_q31
    RET_ReallyLR
...