ldst-opt.mir 4.52 KB
# RUN: llc -mtriple=aarch64--linux-gnu -run-pass=aarch64-ldst-opt %s -verify-machineinstrs -o - | FileCheck %s
---
name: promote-load-from-store
tracksRegLiveness: true
body: |
  bb.0:
    liveins: $w1, $x0, $lr

    STRWui killed $w1, $x0, 0 :: (store 4)
    CFI_INSTRUCTION 0
    CFI_INSTRUCTION 0
    CFI_INSTRUCTION 0
    CFI_INSTRUCTION 0
    CFI_INSTRUCTION 0
    CFI_INSTRUCTION 0
    CFI_INSTRUCTION 0
    CFI_INSTRUCTION 0
    CFI_INSTRUCTION 0
    CFI_INSTRUCTION 0
    CFI_INSTRUCTION 0
    CFI_INSTRUCTION 0
    CFI_INSTRUCTION 0
    CFI_INSTRUCTION 0
    CFI_INSTRUCTION 0
    CFI_INSTRUCTION 0
    CFI_INSTRUCTION 0
    CFI_INSTRUCTION 0
    CFI_INSTRUCTION 0
    CFI_INSTRUCTION 0
    $w0 = LDRHHui killed $x0, 1 :: (load 2)
    RET $lr, implicit $w0

...
# Don't count transient instructions towards search limits.
# CHECK-LABEL: name: promote-load-from-store
# CHECK: STRWui $w1
# CHECK: UBFMWri killed $w1
---
name: store-pair
tracksRegLiveness: true
body: |
  bb.0:
    liveins: $w1, $x0, $lr

    STRWui $w1, $x0, 0 :: (store 4)
    CFI_INSTRUCTION 0
    CFI_INSTRUCTION 0
    CFI_INSTRUCTION 0
    CFI_INSTRUCTION 0
    CFI_INSTRUCTION 0
    CFI_INSTRUCTION 0
    CFI_INSTRUCTION 0
    CFI_INSTRUCTION 0
    CFI_INSTRUCTION 0
    CFI_INSTRUCTION 0
    CFI_INSTRUCTION 0
    CFI_INSTRUCTION 0
    CFI_INSTRUCTION 0
    CFI_INSTRUCTION 0
    CFI_INSTRUCTION 0
    CFI_INSTRUCTION 0
    CFI_INSTRUCTION 0
    CFI_INSTRUCTION 0
    CFI_INSTRUCTION 0
    CFI_INSTRUCTION 0
    STRWui killed $w1, killed $x0, 1 :: (store 4)
    RET $lr

...
# CHECK-LABEL: name: store-pair
# CHECK: STPWi
---
name: store-pair-clearkill0
tracksRegLiveness: true
body: |
  bb.0:
    liveins: $w1, $x0, $lr

    STRWui $w1, $x0, 0 :: (store 4)
    $w2 = COPY $w1
    $x3 = COPY $x0
    STRWui killed $w1, killed $x0, 1 :: (store 4)
    RET $lr
...
# When merging a lower store with an upper one, we must clear kill flags on
# the lower store.
# CHECK-LABEL: store-pair-clearkill0
# CHECK-NOT: STPWi $w1, killed $w1, $x0, 0 :: (store 4)
# CHECK: STPWi $w1, $w1, $x0, 0 :: (store 4)
# CHECK: $w2 = COPY $w1
# CHECK: RET $lr
---
name: store-pair-clearkill1
tracksRegLiveness: true
body: |
  bb.0:
    liveins: $x0, $lr

    $w1 = MOVi32imm 13
    $w2 = MOVi32imm 7
    STRWui $w1, $x0, 1 :: (store 4)
    $w2 = COPY killed $w1
    STRWui killed $w2, $x0, 0 :: (store 4)

    $w1 = MOVi32imm 42
    $w2 = MOVi32imm 7
    STRWui $w1, $x0, 0 :: (store 4)
    $w2 = COPY killed $w1
    STRWui killed $w2, killed $x0, 1 :: (store 4)

    RET $lr
...
# When merging an upper store with a lower one, kill flags along the way need
# to be removed; In this case the kill flag on $w1.
# CHECK-LABEL: store-pair-clearkill1
# CHECK: $w1 = MOVi32imm
# CHECK: $w2 = MOVi32imm
# CHECK-NOT: $w2 = COPY killed $w1
# CHECK: $w2 = COPY $w1
# CHECK: STPWi killed $w2, $w1, $x0, 0

# CHECK: $w1 = MOVi32imm
# CHECK: $w2 = MOVi32imm
# CHECK-NOT: $w2 = COPY killed $w1
# CHECK: $w2 = COPY $w1
# CHECK: STPWi $w1, killed $w2, killed $x0, 0
---
name: store-load-clearkill
tracksRegLiveness: true
body: |
  bb.0:
    liveins: $w1

    STRWui $w1, $sp, 0 :: (store 4)
    $wzr = COPY killed $w1 ; killing use of $w1
    $w11 = LDRWui $sp, 0 :: (load 4)
    HINT 0, implicit $w11 ; some use of $w11
...
# When replaceing the load of a store-load pair with a copy the kill flags
# along the way need to be cleared.
# CHECK-LABEL: name: store-load-clearkill
# CHECK: STRWui $w1, $sp, 0 :: (store 4)
# CHECK-NOT: COPY killed $w1
# CHECK: $wzr = COPY $w1
# CHECK: $w11 = ORRWrs $wzr, $w1, 0
# CHECK: HINT 0, implicit $w11
---
name: promote-load-from-store-undef
tracksRegLiveness: true
body: |
  bb.0:
    liveins: $x0, $x2, $lr

    STRWui undef $w1, $x0, 0 :: (store 4)
    $w0 = LDRBBui $x0, 1 :: (load 2)
    STRHHui undef $w3, $x2, 0 :: (store 4)
    $w1 = LDRBBui $x2, 0 :: (load 4)
    RET $lr, implicit $w0
...
# CHECK-LABEL: name: promote-load-from-store-undef
# CHECK: STRWui undef $w1
# CHECK: UBFMWri undef $w1
# CHECK: STRHHui undef $w3
# CHECK: ANDWri undef $w3
---
name: promote-load-from-store-trivial-kills
tracksRegLiveness: true
body: |
  bb.0:
    liveins: $x0, $lr

    STRXui $x0, $sp, 0 :: (store 8)
    STRXui killed $x0, $sp, 2 :: (store 8)
    $x0 = LDRXui $sp, 0 :: (load 8)
    BL &bar, csr_aarch64_aapcs, implicit-def $lr, implicit $sp, implicit $x0, implicit-def $sp
    RET $lr
...
# CHECK-LABEL: name: promote-load-from-store-trivial-kills
# CHECK: STRXui $x0, $sp, 0
# CHECK: STRXui $x0, $sp, 2
# CHECK-NOT: LDRXui
# CHECK-NOT: ORR
# CHECK: BL &bar, csr_aarch64_aapcs, implicit-def $lr, implicit $sp, implicit $x0, implicit-def $sp