llvm-project/llvm/test/CodeGen/AArch64/post-ra-machine-sink.mir

401 lines
8.0 KiB
Plaintext
Raw Normal View History

[CodeGen] Add a new pass for PostRA sink Summary: This pass sinks COPY instructions into a successor block, if the COPY is not used in the current block and the COPY is live-in to a single successor (i.e., doesn't require the COPY to be duplicated). This avoids executing the the copy on paths where their results aren't needed. This also exposes additional opportunites for dead copy elimination and shrink wrapping. These copies were either not handled by or are inserted after the MachineSink pass. As an example of the former case, the MachineSink pass cannot sink COPY instructions with allocatable source registers; for AArch64 these type of copy instructions are frequently used to move function parameters (PhyReg) into virtual registers in the entry block.. For the machine IR below, this pass will sink %w19 in the entry into its successor (%bb.1) because %w19 is only live-in in %bb.1. ``` %bb.0: %wzr = SUBSWri %w1, 1 %w19 = COPY %w0 Bcc 11, %bb.2 %bb.1: Live Ins: %w19 BL @fun %w0 = ADDWrr %w0, %w19 RET %w0 %bb.2: %w0 = COPY %wzr RET %w0 ``` As we sink %w19 (CSR in AArch64) into %bb.1, the shrink-wrapping pass will be able to see %bb.0 as a candidate. With this change I observed 12% more shrink-wrapping candidate and 13% more dead copies deleted in spec2000/2006/2017 on AArch64. Reviewers: qcolombet, MatzeB, thegameg, mcrosier, gberry, hfinkel, john.brawn, twoh, RKSimon, sebpop, kparzysz Reviewed By: sebpop Subscribers: evandro, sebpop, sfertile, aemerson, mgorny, javed.absar, kristof.beyls, llvm-commits Differential Revision: https://reviews.llvm.org/D41463 llvm-svn: 328237
2018-03-23 04:06:47 +08:00
# RUN: llc -mtriple=aarch64-none-linux-gnu -run-pass=postra-machine-sink -verify-machineinstrs -o - %s | FileCheck %s
---
# Sink w19 to %bb.1.
# CHECK-LABEL: name: sinkcopy1
# CHECK-LABEL: bb.0:
# CHECK-NOT: $w19 = COPY killed $w0
# CHECK-LABEL: bb.1:
# CHECK: liveins: $w1, $w0
# CHECK: renamable $w19 = COPY killed $w0
name: sinkcopy1
tracksRegLiveness: true
body: |
bb.0:
liveins: $w0, $w1
$w1 = SUBSWri $w1, 1, 0, implicit-def $nzcv
renamable $w19 = COPY killed $w0
Bcc 11, %bb.1, implicit $nzcv
B %bb.2
bb.1:
liveins: $w1, $w19
$w0 = ADDWrr $w1, $w19
RET $x0
bb.2:
$w0 = COPY $wzr
RET $x0
...
---
# Sink w19 to %bb.2.
# CHECK-LABEL: name: sinkcopy2
# CHECK-LABEL: bb.0:
# CHECK-NOT: renamable $w19 = COPY killed $w0
# CHECK-LABEL: bb.2:
# CHECK: liveins: $w1, $w0
# CHECK: renamable $w19 = COPY killed $w0
name: sinkcopy2
tracksRegLiveness: true
body: |
bb.0:
liveins: $w0, $w1
$w1 = SUBSWri $w1, 1, 0, implicit-def $nzcv
renamable $w19 = COPY killed $w0
Bcc 11, %bb.2, implicit $nzcv
B %bb.1
bb.1:
$w0 = COPY $wzr
RET $x0
bb.2:
liveins: $w1, $w19
$w0 = ADDWrr $w1, $w19
RET $x0
...
---
# Sink w19 and w20 to %bb.1.
# CHECK-LABEL: name: sinkcopy3
# CHECK-LABEL: bb.0:
# CHECK-NOT: renamable $w19 = COPY killed $w0
# CHECK-LABEL: bb.1:
# CHECK: liveins: $w1, $w0
# CHECK: renamable $w19 = COPY killed $w0
# CHECK: renamable $w20 = COPY killed $w1
name: sinkcopy3
tracksRegLiveness: true
body: |
bb.0:
liveins: $w0, $w1
$w1 = SUBSWri $w1, 1, 0, implicit-def $nzcv
renamable $w19 = COPY killed $w0
renamable $w20 = COPY killed $w1
bb.1:
liveins: $w19, $w20
$w0 = COPY $w19
$w1 = COPY $w20
RET $x0
...
# Sink w19 to %bb.1 and w20 to %bb.2.
# CHECK-LABEL: name: sinkcopy4
# CHECK-LABEL: bb.0:
# CHECK-NOT: renamable $w19 = COPY killed $w0
# CHECK-NOT: renamable $w20 = COPY killed $w1
# CHECK-LABEL: bb.1:
# CHECK: liveins: $w1, $w0
# CHECK: renamable $w19 = COPY killed $w0
# CHECK-LABEL: bb.2:
# CHECK: liveins: $w0, $w1
# CHECK: renamable $w20 = COPY killed $w1
name: sinkcopy4
tracksRegLiveness: true
body: |
bb.0:
liveins: $w0, $w1
$w1 = SUBSWri $w1, 1, 0, implicit-def $nzcv
renamable $w19 = COPY killed $w0
renamable $w20 = COPY killed $w1
Bcc 11, %bb.2, implicit $nzcv
B %bb.1
bb.1:
liveins: $w1, $w19
$w0 = ADDWrr $w1, $w19
RET $x0
bb.2:
liveins: $w0, $w20
$w0 = ADDWrr $w0, $w20
RET $x0
...
# Sink w19 to %bb.3 through %bb.2.
# CHECK-LABEL: name: sinkcopy5
# CHECK-LABEL: bb.0:
# CHECK-NOT: renamable $w19 = COPY $w0
# CHECK-LABEL: bb.2:
# CHECK: $w1 = ADDWrr $w1, $w0
# CHECK-LABEL: bb.3:
# CHECK: liveins: $w1, $w0
# CHECK: renamable $w19 = COPY killed $w0
name: sinkcopy5
tracksRegLiveness: true
body: |
bb.0:
liveins: $w0, $w1
$w1 = SUBSWri $w1, 1, 0, implicit-def $nzcv
renamable $w19 = COPY $w0
Bcc 11, %bb.2, implicit $nzcv
bb.1:
liveins: $x0
$w19 = COPY $wzr
RET $x0
bb.2:
liveins: $w0, $w1, $w19
$w1 = ADDWrr $w1, killed $w0
bb.3:
liveins: $w1, $w19
$w0 = ADDWrr $w1, $w19
RET $x0
...
# Sink w19 to %bb.3, but through %bb.2.
# CHECK-LABEL: name: sinkcopy6
# CHECK-LABEL: bb.0:
# CHECK-NOT: renamable $w19 = COPY $w0
# CHECK-NOT: renamable $w20 = COPY $w0
# CHECK-LABEL: bb.2:
# CHECK: liveins: $w1, $w0
# CHECK: renamable $w19 = COPY $w0
# CHECK: renamable $w20 = COPY $w19
name: sinkcopy6
tracksRegLiveness: true
body: |
bb.0:
liveins: $w0, $w1
$w1 = SUBSWri $w1, 1, 0, implicit-def $nzcv
renamable $w19 = COPY $w0
renamable $w20 = COPY $w19
Bcc 11, %bb.2, implicit $nzcv
bb.1:
$w0 = COPY $wzr
RET $x0
bb.2:
liveins: $w1, $w20
$w0 = ADDWrr killed $w1, $w20
RET $x0
...
---
# Sink w19 regardless of the def of wzr in bb.0.
# CHECK-LABEL: name: sinkcopy7
# CHECK-LABEL: bb.0:
# CHECK-NOT: renamable $w19 = COPY $w0
# CHECK-LABEL: bb.2:
# CHECK: renamable $w19 = COPY $wzr
name: sinkcopy7
tracksRegLiveness: true
body: |
bb.0:
liveins: $w0, $w1
renamable $w19 = COPY $wzr
$wzr = SUBSWri $w1, 1, 0, implicit-def $nzcv
Bcc 11, %bb.2, implicit $nzcv
B %bb.1
bb.1:
$x0 = COPY $xzr
RET $x0
bb.2:
liveins: $w0, $w19
$w0 = ADDWrr $w0, $w19
RET $x0
...
[CodeGen] Add a new pass for PostRA sink Summary: This pass sinks COPY instructions into a successor block, if the COPY is not used in the current block and the COPY is live-in to a single successor (i.e., doesn't require the COPY to be duplicated). This avoids executing the the copy on paths where their results aren't needed. This also exposes additional opportunites for dead copy elimination and shrink wrapping. These copies were either not handled by or are inserted after the MachineSink pass. As an example of the former case, the MachineSink pass cannot sink COPY instructions with allocatable source registers; for AArch64 these type of copy instructions are frequently used to move function parameters (PhyReg) into virtual registers in the entry block.. For the machine IR below, this pass will sink %w19 in the entry into its successor (%bb.1) because %w19 is only live-in in %bb.1. ``` %bb.0: %wzr = SUBSWri %w1, 1 %w19 = COPY %w0 Bcc 11, %bb.2 %bb.1: Live Ins: %w19 BL @fun %w0 = ADDWrr %w0, %w19 RET %w0 %bb.2: %w0 = COPY %wzr RET %w0 ``` As we sink %w19 (CSR in AArch64) into %bb.1, the shrink-wrapping pass will be able to see %bb.0 as a candidate. With this change I observed 12% more shrink-wrapping candidate and 13% more dead copies deleted in spec2000/2006/2017 on AArch64. Reviewers: qcolombet, MatzeB, thegameg, mcrosier, gberry, hfinkel, john.brawn, twoh, RKSimon, sebpop, kparzysz Reviewed By: sebpop Subscribers: evandro, sebpop, sfertile, aemerson, mgorny, javed.absar, kristof.beyls, llvm-commits Differential Revision: https://reviews.llvm.org/D41463 llvm-svn: 328237
2018-03-23 04:06:47 +08:00
---
# Sink w19 to %bb.3 through %bb.2.
# CHECK-LABEL: name: sinkcopy8
# CHECK-LABEL: bb.0:
# CHECK-NOT: renamable $w19 = COPY $w0, implicit-def $x19
# CHECK-LABEL: bb.2:
# CHECK: $w1 = ADDWrr $w1, $w0, implicit $x0
# CHECK-LABEL: bb.3:
# CHECK: liveins: $x1, $w0
# CHECK: renamable $w19 = COPY killed $w0, implicit-def $x19
name: sinkcopy8
tracksRegLiveness: true
body: |
bb.0:
liveins: $w0, $x1
$w1 = SUBSWri $w1, 1, 0, implicit-def $nzcv
renamable $w19 = COPY $w0, implicit-def $x19
Bcc 11, %bb.2, implicit $nzcv
[CodeGen] Add a new pass for PostRA sink Summary: This pass sinks COPY instructions into a successor block, if the COPY is not used in the current block and the COPY is live-in to a single successor (i.e., doesn't require the COPY to be duplicated). This avoids executing the the copy on paths where their results aren't needed. This also exposes additional opportunites for dead copy elimination and shrink wrapping. These copies were either not handled by or are inserted after the MachineSink pass. As an example of the former case, the MachineSink pass cannot sink COPY instructions with allocatable source registers; for AArch64 these type of copy instructions are frequently used to move function parameters (PhyReg) into virtual registers in the entry block.. For the machine IR below, this pass will sink %w19 in the entry into its successor (%bb.1) because %w19 is only live-in in %bb.1. ``` %bb.0: %wzr = SUBSWri %w1, 1 %w19 = COPY %w0 Bcc 11, %bb.2 %bb.1: Live Ins: %w19 BL @fun %w0 = ADDWrr %w0, %w19 RET %w0 %bb.2: %w0 = COPY %wzr RET %w0 ``` As we sink %w19 (CSR in AArch64) into %bb.1, the shrink-wrapping pass will be able to see %bb.0 as a candidate. With this change I observed 12% more shrink-wrapping candidate and 13% more dead copies deleted in spec2000/2006/2017 on AArch64. Reviewers: qcolombet, MatzeB, thegameg, mcrosier, gberry, hfinkel, john.brawn, twoh, RKSimon, sebpop, kparzysz Reviewed By: sebpop Subscribers: evandro, sebpop, sfertile, aemerson, mgorny, javed.absar, kristof.beyls, llvm-commits Differential Revision: https://reviews.llvm.org/D41463 llvm-svn: 328237
2018-03-23 04:06:47 +08:00
bb.1:
liveins: $x0
$w19 = COPY $wzr
RET $x0
bb.2:
liveins: $w0, $x1, $x19
$w1 = ADDWrr $w1, $w0, implicit killed $x0
bb.3:
liveins: $x1, $x19
$x0 = ADDXrr $x1, $x19
RET $x0
...
---
[CodeGen] Add a new pass for PostRA sink Summary: This pass sinks COPY instructions into a successor block, if the COPY is not used in the current block and the COPY is live-in to a single successor (i.e., doesn't require the COPY to be duplicated). This avoids executing the the copy on paths where their results aren't needed. This also exposes additional opportunites for dead copy elimination and shrink wrapping. These copies were either not handled by or are inserted after the MachineSink pass. As an example of the former case, the MachineSink pass cannot sink COPY instructions with allocatable source registers; for AArch64 these type of copy instructions are frequently used to move function parameters (PhyReg) into virtual registers in the entry block.. For the machine IR below, this pass will sink %w19 in the entry into its successor (%bb.1) because %w19 is only live-in in %bb.1. ``` %bb.0: %wzr = SUBSWri %w1, 1 %w19 = COPY %w0 Bcc 11, %bb.2 %bb.1: Live Ins: %w19 BL @fun %w0 = ADDWrr %w0, %w19 RET %w0 %bb.2: %w0 = COPY %wzr RET %w0 ``` As we sink %w19 (CSR in AArch64) into %bb.1, the shrink-wrapping pass will be able to see %bb.0 as a candidate. With this change I observed 12% more shrink-wrapping candidate and 13% more dead copies deleted in spec2000/2006/2017 on AArch64. Reviewers: qcolombet, MatzeB, thegameg, mcrosier, gberry, hfinkel, john.brawn, twoh, RKSimon, sebpop, kparzysz Reviewed By: sebpop Subscribers: evandro, sebpop, sfertile, aemerson, mgorny, javed.absar, kristof.beyls, llvm-commits Differential Revision: https://reviews.llvm.org/D41463 llvm-svn: 328237
2018-03-23 04:06:47 +08:00
# Don't sink w19 as w0 is defined in bb.0.
# CHECK-LABEL: name: donotsinkcopy1
# CHECK-LABEL: bb.0:
# CHECK: renamable $w19 = COPY $w0
# CHECK: $w0 = LDRWui $sp, 0
name: donotsinkcopy1
tracksRegLiveness: true
body: |
bb.0:
liveins: $w0, $w1
$w1 = SUBSWri $w1, 1, 0, implicit-def $nzcv
renamable $w19 = COPY $w0
$w0 = LDRWui $sp, 0 :: (load 4)
Bcc 11, %bb.2, implicit $nzcv
B %bb.1
bb.1:
$x0 = COPY $xzr
RET $x0
bb.2:
liveins: $w0, $w19
$w0 = ADDWrr $w0, $w19
RET $x0
...
---
# Don't sink w19 as w19 is used in bb.0.
# CHECK-LABEL: name: donotsinkcopy2
# CHECK-LABEL: bb.0:
# CHECK: renamable $w19 = COPY $w0
# CHECK: STRWui $w1, $x19, 0
name: donotsinkcopy2
tracksRegLiveness: true
body: |
bb.0:
liveins: $w0, $w1
$w1 = SUBSWri $w1, 1, 0, implicit-def $nzcv
renamable $w19 = COPY $w0
STRWui $w1, $x19, 0 :: (store 4)
Bcc 11, %bb.2, implicit $nzcv
B %bb.1
bb.1:
$x0 = COPY $xzr
RET $x0
bb.2:
liveins: $w0, $w19
$w0 = ADDWrr $w0, $w19
RET $x0
...
---
# Don't sink w19 as w19 is used in both %bb.1 and %bb.2.
# CHECK-LABEL: name: donotsinkcopy3
# CHECK-LABEL: bb.0:
# CHECK: renamable $w19 = COPY $w0
name: donotsinkcopy3
tracksRegLiveness: true
body: |
bb.0:
liveins: $w0, $w1
$w1 = SUBSWri $w1, 1, 0, implicit-def $nzcv
renamable $w19 = COPY $w0
Bcc 11, %bb.2, implicit $nzcv
B %bb.1
bb.1:
liveins: $w19
$w0 = COPY $w19
RET $x0
bb.2:
liveins: $w0, $w19
$w0 = ADDWrr $w0, $w19
RET $x0
...
---
# Don't sink w19 as %bb.2 has multiple predecessors.
# CHECK-LABEL: name: donotsinkcopy4
# CHECK-LABEL: bb.0:
# CHECK: renamable $w19 = COPY $w0
name: donotsinkcopy4
tracksRegLiveness: true
body: |
bb.0:
liveins: $w0, $w1
$w1 = SUBSWri $w1, 1, 0, implicit-def $nzcv
renamable $w19 = COPY $w0
Bcc 11, %bb.2, implicit $nzcv
B %bb.1
bb.1:
liveins: $w0
$w19 = COPY $w0
B %bb.2
bb.2:
liveins: $w0, $w19
$w0 = ADDWrr $w0, $w19
RET $x0
...
# Don't sink w19 after sinking w20.
# CHECK-LABEL: name: donotsinkcopy5
# CHECK-LABEL: bb.0:
# CHECK: renamable $w19 = COPY $w0
# CHECK-LABEL: bb.2:
# CHECK: liveins: $w0, $w19
# CHECK: renamable $w20 = COPY $w19
name: donotsinkcopy5
tracksRegLiveness: true
body: |
bb.0:
liveins: $w0, $w1
$w1 = SUBSWri $w1, 1, 0, implicit-def $nzcv
renamable $w19 = COPY $w0
renamable $w20 = COPY $w19
Bcc 11, %bb.2, implicit $nzcv
bb.1:
liveins: $w19
$w0 = COPY $w19
RET $x0
bb.2:
liveins: $w0, $w20
$w0 = ADDWrr killed $w0, $w20
RET $x0
...
---
# Don't sink w19 as x19 is live-in in %bb.2.
# CHECK-LABEL: name: donotsinkcopy6
# CHECK-LABEL: bb.0:
name: donotsinkcopy6
tracksRegLiveness: true
body: |
bb.0:
liveins: $x0, $w1
$w1 = SUBSWri $w1, 1, 0, implicit-def $nzcv
renamable $x19 = COPY $x0
Bcc 11, %bb.2, implicit $nzcv
B %bb.1
bb.1:
liveins: $w19
$w0 = COPY $w19
RET $x0
bb.2:
liveins: $x0, $x19
$x0 = ADDXrr $x0, $x19
RET $x0
...