Recommit "Enable MachineOutliner by default under -Oz for AArch64"

Fixed the ASAN failure from before in r338148, so recommiting.

This patch enables the MachineOutliner by default in AArch64 under -Oz.

The MachineOutliner offers around a 4.5% improvement on the current -Oz code
size improvements.

We have done work into improving the debuggability of outlined code, so that
users of -Oz won't be surprised by the optimization. We have also been executing
the LLVM test suite and common external tests such as the SPEC suites
continuously with no issue. The outliner has a low compile-time overhead of
roughly 1%. At this point, the outliner would be a really good addition to the
-Oz pass pipeline!

llvm-svn: 338160
This commit is contained in:
Jessica Paquette 2018-07-27 20:18:27 +00:00
parent 717ca64899
commit 98b9ddd887
10 changed files with 97 additions and 12 deletions

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@ -5482,3 +5482,8 @@ MachineBasicBlock::iterator AArch64InstrInfo::insertOutlinedCall(
return CallPt;
}
bool AArch64InstrInfo::shouldOutlineFromFunctionByDefault(
MachineFunction &MF) const {
return MF.getFunction().optForMinSize();
}

View File

@ -249,6 +249,7 @@ public:
insertOutlinedCall(Module &M, MachineBasicBlock &MBB,
MachineBasicBlock::iterator &It, MachineFunction &MF,
const outliner::Candidate &C) const override;
bool shouldOutlineFromFunctionByDefault(MachineFunction &MF) const override;
/// Returns true if the instruction sets to an immediate value that can be
/// executed more efficiently.
bool isExynosResetFast(const MachineInstr &MI) const;

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@ -255,6 +255,9 @@ AArch64TargetMachine::AArch64TargetMachine(const Target &T, const Triple &TT,
// AArch64 supports the MachineOutliner.
setMachineOutliner(true);
// AArch64 supports default outlining behaviour.
setSupportsDefaultOutlining(true);
}
AArch64TargetMachine::~AArch64TargetMachine() = default;

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@ -154,6 +154,8 @@
; CHECK-NEXT: Insert fentry calls
; CHECK-NEXT: Insert XRay ops
; CHECK-NEXT: Implement the 'patchable-function' attribute
; CHECK-NEXT: Machine Outliner
; CHECK-NEXT: FunctionPass Manager
; CHECK-NEXT: Lazy Machine Block Frequency Analysis
; CHECK-NEXT: Machine Optimization Remark Emitter
; CHECK-NEXT: AArch64 Assembly Printer

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@ -1,6 +1,6 @@
; RUN: llc %s -mtriple=arm64-apple-darwin -o - | \
; RUN: FileCheck --check-prefixes=CHECK,CHECK-DARWIN %s
; RUN: llc %s -mtriple=arm64-linux-gnu -o - | \
; RUN: llc %s -enable-machine-outliner=never -mtriple=arm64-apple-darwin -o - \
; RUN: | FileCheck --check-prefixes=CHECK,CHECK-DARWIN %s
; RUN: llc %s -enable-machine-outliner=never -mtriple=arm64-linux-gnu -o - | \
; RUN: FileCheck --check-prefixes=CHECK,CHECK-LINUX %s
; <rdar://problem/14199482> ARM64: Calls to bzero() replaced with calls to memset()

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@ -26,8 +26,8 @@
; requested. (This hard-codes the previous pass to the Assembly Printer,
; please adjust accordingly.)
; HOTNESS: Executing Pass 'Implement the 'patchable-function' attribute'
; HOTNESS-NEXT: Freeing Pass 'Implement the 'patchable-function' attribute'
; HOTNESS: Freeing Pass 'Machine Outliner'
; HOTNESS-NEXT: Executing Pass 'Function Pass Manager'
; HOTNESS-NEXT: Executing Pass 'Lazy Machine Block Frequency Analysis'
; HOTNESS-NEXT: Executing Pass 'Machine Optimization Remark Emitter'
; HOTNESS-NEXT: Building MachineBlockFrequencyInfo on the fly
@ -41,8 +41,8 @@
; HOTNESS: arm64-summary-remarks.ll:5:0: 1 instructions in function (hotness: 33)
; NO_HOTNESS: Executing Pass 'Implement the 'patchable-function' attribute'
; NO_HOTNESS-NEXT: Freeing Pass 'Implement the 'patchable-function' attribute'
; NO_HOTNESS: Freeing Pass 'Machine Outliner'
; NO_HOTNESS-NEXT: Executing Pass 'Function Pass Manager'
; NO_HOTNESS-NEXT: Executing Pass 'Lazy Machine Block Frequency Analysis'
; NO_HOTNESS-NEXT: Executing Pass 'Machine Optimization Remark Emitter'
; NO_HOTNESS-NEXT: Executing Pass 'AArch64 Assembly Printer'

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@ -1,5 +1,5 @@
; RUN: llc -verify-machineinstrs < %s -mtriple=aarch64-none-linux-gnu -mcpu=cyclone | FileCheck %s
; RUN: llc -verify-machineinstrs < %s -mtriple=aarch64-none-linux-gnu -mattr=-fp-armv8 | FileCheck --check-prefix=CHECK-NOFP %s
; RUN: llc -enable-machine-outliner=never -verify-machineinstrs < %s -mtriple=aarch64-none-linux-gnu -mcpu=cyclone | FileCheck %s
; RUN: llc -enable-machine-outliner=never -verify-machineinstrs < %s -mtriple=aarch64-none-linux-gnu -mattr=-fp-armv8 | FileCheck --check-prefix=CHECK-NOFP %s
@var32 = global i32 0
@var64 = global i64 0

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@ -0,0 +1,71 @@
# RUN: llc -mtriple=aarch64--- -run-pass=machine-outliner \
# RUN: -verify-machineinstrs %s -o - | FileCheck %s
--- |
define void @outline_1() #0 { ret void }
define void @outline_2() #0 { ret void }
define void @outline_3() #0 { ret void }
define void @dont_outline() #1 { ret void }
attributes #0 = { noredzone minsize optsize }
attributes #1 = { noredzone }
...
---
name: outline_1
tracksRegLiveness: true
body: |
bb.0:
; CHECK-LABEL: bb.0:
; CHECK: OUTLINED
liveins: $w8, $wzr
$w8 = ORRWri $wzr, 1
$w8 = ORRWri $wzr, 2
$w8 = ORRWri $wzr, 3
$w8 = ORRWri $wzr, 4
RET undef $lr
...
---
name: outline_2
tracksRegLiveness: true
body: |
bb.0:
; CHECK-LABEL: bb.0:
; CHECK: OUTLINED
liveins: $w8, $wzr
$w8 = ORRWri $wzr, 1
$w8 = ORRWri $wzr, 2
$w8 = ORRWri $wzr, 3
$w8 = ORRWri $wzr, 4
RET undef $lr
...
---
name: outline_3
tracksRegLiveness: true
body: |
bb.0:
; CHECK-LABEL: bb.0:
; CHECK: OUTLINED
liveins: $w8, $wzr
$w8 = ORRWri $wzr, 1
$w8 = ORRWri $wzr, 2
$w8 = ORRWri $wzr, 3
$w8 = ORRWri $wzr, 4
RET undef $lr
...
---
name: dont_outline
tracksRegLiveness: true
body: |
bb.0:
; CHECK-LABEL: bb.0:
; CHECK-NOT: BL
liveins: $w8, $wzr
$w8 = ORRWri $wzr, 1
$w8 = ORRWri $wzr, 2
$w8 = ORRWri $wzr, 3
$w8 = ORRWri $wzr, 4
RET undef $lr

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@ -14,7 +14,7 @@
; RUN: | FileCheck %s -check-prefix=NEVER
; RUN: llc %s -debug-pass=Structure -verify-machineinstrs \
; RUN: -mtriple arm64---- -o /dev/null 2>&1 \
; RUN: --debug-only=machine-outliner -mtriple arm64---- -o /dev/null 2>&1 \
; RUN: | FileCheck %s -check-prefix=NOT-ADDED
; RUN: llc %s -O=0 -debug-pass=Structure -verify-machineinstrs \
@ -27,10 +27,11 @@
; Cases where it should be added:
; * -enable-machine-outliner
; * -enable-machine-outliner=always
; * -enable-machine-outliner is not passed (AArch64 supports
; target-default outlining)
;
; Cases where it should not be added:
; * -O0 or equivalent
; * -enable-machine-outliner is not passed
; * -enable-machine-outliner=never is passed
; ALWAYS: Machine Outliner
@ -38,7 +39,8 @@
; ENABLE: Machine Outliner
; ENABLE: Machine Outliner: Running on all functions
; NEVER-NOT: Machine Outliner
; NOT-ADDED-NOT: Machine Outliner
; NOT-ADDED: Machine Outliner
; NOT-ADDED: Machine Outliner: Running on target-default functions
; OPTNONE-NOT: Machine Outliner
define void @foo() {

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@ -89,6 +89,7 @@ entry:
; CHECKM1-NOT: %jump-table.1
; CHECKM3-NEXT: %jump-table.0: %bb.1 %bb.2 %bb.3 %bb.4 %bb.7 %bb.7 %bb.7 %bb.7 %bb.7 %bb.7 %bb.7 %bb.7 %bb.7 %bb.5 %bb.6{{$}}
; CHECKM3-NOT: %jump-table.1
; CHECK-DAG: End machine code for function jt2.
bb1: tail call void @ext(i32 1) br label %return
bb2: tail call void @ext(i32 2) br label %return