8df75969ae
The original MFS work D85368 shows good performance improvement with Instrumented FDO. However, AutoFDO or Flow-Sensitive AutoFDO (FSAFDO) does not show performance gain. This is mainly caused by a less accurate profile compared to the iFDO profile. For the past few months, we have been working to improve FSAFDO quality, like in D145171. Taking advantage of this improvement, MFS now shows performance improvements over FSAFDO profiles. That being said, 2 minor changes need to be made, 1) An FS-AutoFDO profile generation pass needs to be added right before MFS pass and an FSAFDO profile load pass is needed when FS-AutoFDO is enabled and the MFS flag is present. 2) MFS only applies to hot functions, because we believe (and experiment also shows) FS-AutoFDO is more accurate about functions that have plenty of samples than those with no or very few samples. With this improvement, we see a 1.2% performance improvement in clang benchmark, 0.9% QPS improvement in our internal search benchmark, and 3%-5% improvement in internal storage benchmark. This is #1 of the two patches that enables the improvement. Reviewed By: wenlei, snehasish, xur Differential Revision: https://reviews.llvm.org/D152399
475 lines
13 KiB
LLVM
475 lines
13 KiB
LLVM
; RUN: llc < %s -mtriple=x86_64-unknown-linux-gnu -split-machine-functions | FileCheck %s -check-prefix=MFS-DEFAULTS
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; RUN: llc < %s -mtriple=x86_64-unknown-linux-gnu -split-machine-functions -mfs-psi-cutoff=0 -mfs-count-threshold=2000 | FileCheck %s --dump-input=always -check-prefix=MFS-OPTS1
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; RUN: llc < %s -mtriple=x86_64-unknown-linux-gnu -split-machine-functions -mfs-psi-cutoff=950000 | FileCheck %s -check-prefix=MFS-OPTS2
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; RUN: llc < %s -mtriple=x86_64-unknown-linux-gnu -split-machine-functions -mfs-split-ehcode | FileCheck %s -check-prefix=MFS-EH-SPLIT
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; RUN: sed 's/InstrProf/SampleProfile/g' %s > %t.ll
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; RUN: llc < %t.ll -mtriple=x86_64-unknown-linux-gnu -split-machine-functions | FileCheck %s --check-prefix=FSAFDO-MFS
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; RUN: llc < %t.ll -mtriple=x86_64-unknown-linux-gnu -split-machine-functions | FileCheck %s --check-prefix=FSAFDO-MFS2
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define void @foo1(i1 zeroext %0) nounwind !prof !14 !section_prefix !15 {
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;; Check that cold block is moved to .text.split.
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; MFS-DEFAULTS-LABEL: foo1
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; MFS-DEFAULTS: .section .text.split.foo1
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; MFS-DEFAULTS-NEXT: foo1.cold:
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; MFS-DEFAULTS-NOT: callq bar
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; MFS-DEFAULTS-NEXT: callq baz
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br i1 %0, label %2, label %4, !prof !17
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2: ; preds = %1
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%3 = call i32 @bar()
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br label %6
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4: ; preds = %1
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%5 = call i32 @baz()
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br label %6
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6: ; preds = %4, %2
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%7 = tail call i32 @qux()
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ret void
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}
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define void @foo2(i1 zeroext %0) nounwind !prof !23 !section_prefix !16 {
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;; Check that function marked unlikely is not split.
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; MFS-DEFAULTS-LABEL: foo2
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; MFS-DEFAULTS-NOT: foo2.cold:
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br i1 %0, label %2, label %4, !prof !17
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2: ; preds = %1
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%3 = call i32 @bar()
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br label %6
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4: ; preds = %1
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%5 = call i32 @baz()
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br label %6
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6: ; preds = %4, %2
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%7 = tail call i32 @qux()
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ret void
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}
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define void @foo3(i1 zeroext %0) nounwind !section_prefix !15 {
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;; Check that function without profile data is not split.
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; MFS-DEFAULTS-LABEL: foo3
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; MFS-DEFAULTS-NOT: foo3.cold:
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br i1 %0, label %2, label %4
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2: ; preds = %1
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%3 = call i32 @bar()
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br label %6
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4: ; preds = %1
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%5 = call i32 @baz()
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br label %6
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6: ; preds = %4, %2
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%7 = tail call i32 @qux()
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ret void
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}
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define void @foo4(i1 zeroext %0, i1 zeroext %1) nounwind !prof !20 {
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;; Check that count threshold works.
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; MFS-OPTS1-LABEL: foo4
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; MFS-OPTS1: .section .text.split.foo4
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; MFS-OPTS1-NEXT: foo4.cold:
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; MFS-OPTS1-NOT: callq bar
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; MFS-OPTS1-NOT: callq baz
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; MFS-OPTS1-NEXT: callq bam
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br i1 %0, label %3, label %7, !prof !18
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3:
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%4 = call i32 @bar()
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br label %7
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5:
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%6 = call i32 @baz()
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br label %7
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7:
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br i1 %1, label %8, label %10, !prof !19
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8:
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%9 = call i32 @bam()
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br label %12
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10:
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%11 = call i32 @baz()
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br label %12
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12:
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%13 = tail call i32 @qux()
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ret void
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}
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define void @foo5(i1 zeroext %0, i1 zeroext %1) nounwind !prof !20 {
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;; Check that profile summary info cutoff works.
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; MFS-OPTS2-LABEL: foo5
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; MFS-OPTS2: .section .text.split.foo5
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; MFS-OPTS2-NEXT: foo5.cold:
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; MFS-OPTS2-NOT: callq bar
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; MFS-OPTS2-NOT: callq baz
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; MFS-OPTS2-NEXT: callq bam
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br i1 %0, label %3, label %7, !prof !21
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3:
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%4 = call i32 @bar()
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br label %7
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5:
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%6 = call i32 @baz()
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br label %7
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7:
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br i1 %1, label %8, label %10, !prof !22
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8:
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%9 = call i32 @bam()
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br label %12
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10:
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%11 = call i32 @baz()
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br label %12
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12:
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%13 = call i32 @qux()
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ret void
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}
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define void @foo6(i1 zeroext %0) nounwind section "nosplit" !prof !14 {
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;; Check that function with section attribute is not split.
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; MFS-DEFAULTS-LABEL: foo6
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; MFS-DEFAULTS-NOT: foo6.cold:
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br i1 %0, label %2, label %4, !prof !17
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2: ; preds = %1
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%3 = call i32 @bar()
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br label %6
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4: ; preds = %1
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%5 = call i32 @baz()
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br label %6
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6: ; preds = %4, %2
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%7 = tail call i32 @qux()
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ret void
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}
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define i32 @foo7(i1 zeroext %0) personality ptr @__gxx_personality_v0 !prof !14 {
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;; Check that a single cold ehpad is split out.
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; MFS-DEFAULTS-LABEL: foo7
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; MFS-DEFAULTS: .section .text.split.foo7,"ax",@progbits
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; MFS-DEFAULTS-NEXT: foo7.cold:
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; MFS-DEFAULTS: callq baz
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; MFS-DEFAULTS: callq _Unwind_Resume@PLT
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entry:
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invoke void @_Z1fv()
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to label %try.cont unwind label %lpad
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lpad:
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%1 = landingpad { ptr, i32 }
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cleanup
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catch ptr @_ZTIi
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resume { ptr, i32 } %1
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try.cont:
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br i1 %0, label %2, label %4, !prof !17
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2: ; preds = try.cont
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%3 = call i32 @bar()
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br label %6
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4: ; preds = %1
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%5 = call i32 @baz()
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br label %6
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6: ; preds = %4, %2
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%7 = tail call i32 @qux()
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ret i32 %7
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}
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define i32 @foo8(i1 zeroext %0) personality ptr @__gxx_personality_v0 !prof !14 {
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;; Check that all ehpads are treated as hot if one of them is hot.
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; MFS-DEFAULTS-LABEL: foo8
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; MFS-DEFAULTS: callq _Unwind_Resume@PLT
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; MFS-DEFAULTS: callq _Unwind_Resume@PLT
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; MFS-DEFAULTS: .section .text.split.foo8,"ax",@progbits
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; MFS-DEFAULTS-NEXT: foo8.cold:
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; MFS-DEFAULTS: callq baz
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;; Check that all ehpads are by default treated as cold with -mfs-split-ehcode.
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; MFS-EH-SPLIT-LABEL: foo8
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; MFS-EH-SPLIT: callq baz
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; MFS-EH-SPLIT: .section .text.split.foo8,"ax",@progbits
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; MFS-EH-SPLIT-NEXT: foo8.cold:
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; MFS-EH-SPLIT: callq _Unwind_Resume@PLT
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; MFS-EH-SPLIT: callq _Unwind_Resume@PLT
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entry:
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invoke void @_Z1fv()
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to label %try.cont unwind label %lpad1
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lpad1:
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%1 = landingpad { ptr, i32 }
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cleanup
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catch ptr @_ZTIi
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resume { ptr, i32 } %1
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try.cont:
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br i1 %0, label %hot, label %cold, !prof !17
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hot:
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%2 = call i32 @bar()
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invoke void @_Z1fv()
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to label %exit unwind label %lpad2, !prof !21
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lpad2:
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%3 = landingpad { ptr, i32 }
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cleanup
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catch ptr @_ZTIi
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resume { ptr, i32 } %3
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cold:
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%4 = call i32 @baz()
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br label %exit
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exit:
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%5 = tail call i32 @qux()
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ret i32 %5
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}
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define void @foo9(i1 zeroext %0) nounwind #0 !prof !14 {
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;; Check that function with section attribute is not split.
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; MFS-DEFAULTS-LABEL: foo9
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; MFS-DEFAULTS-NOT: foo9.cold:
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br i1 %0, label %2, label %4, !prof !17
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2: ; preds = %1
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%3 = call i32 @bar()
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br label %6
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4: ; preds = %1
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%5 = call i32 @baz()
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br label %6
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6: ; preds = %4, %2
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%7 = tail call i32 @qux()
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ret void
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}
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define i32 @foo10(i1 zeroext %0) personality ptr @__gxx_personality_v0 !prof !14 {
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;; Check that nop is inserted just before the EH pad if it's beginning a section.
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; MFS-DEFAULTS-LABEL: foo10
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; MFS-DEFAULTS-LABEL: callq baz
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; MFS-DEFAULTS: .section .text.split.foo10,"ax",@progbits
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; MFS-DEFAULTS-NEXT: foo10.cold:
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; MFS-DEFAULTS: nop
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; MFS-DEFAULTS: callq _Unwind_Resume@PLT
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entry:
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invoke void @_Z1fv()
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to label %try.cont unwind label %lpad, !prof !17
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lpad:
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%1 = landingpad { ptr, i32 }
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cleanup
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catch ptr @_ZTIi
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resume { ptr, i32 } %1
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try.cont:
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%2 = call i32 @baz()
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ret i32 %2
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}
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define void @foo11(i1 zeroext %0) personality ptr @__gxx_personality_v0 {
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;; Check that function having landing pads are split with mfs-split-ehcode
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;; even in the absence of profile data
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; MFS-EH-SPLIT-LABEL: foo11
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; MFS-EH-SPLIT: .section .text.split.foo11,"ax",@progbits
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; MFS-EH-SPLIT-NEXT: foo11.cold:
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; MFS-EH-SPLIT: nop
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; MFS-EH-SPLIT: callq _Unwind_Resume@PLT
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entry:
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invoke void @_Z1fv()
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to label %2 unwind label %lpad
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lpad:
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%1 = landingpad { ptr, i32 }
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cleanup
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catch ptr @_ZTIi
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resume { ptr, i32 } %1
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2: ; preds = entry
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%3 = tail call i32 @qux()
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ret void
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}
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define i32 @foo12(i1 zeroext %0) personality ptr @__gxx_personality_v0 !prof !14 {
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;; Check that all code reachable from ehpad is split out with cycles.
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; MFS-EH-SPLIT-LABEL: foo12
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; MFS-EH-SPLIT: .section .text.split.foo12,"ax",@progbits
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; MFS-EH-SPLIT-NEXT: foo12.cold:
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; MFS-EH-SPLIT: callq bar
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; MFS-EH-SPLIT: callq baz
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; MFS-EH-SPLIT: callq qux
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entry:
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invoke void @_Z1fv()
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to label %8 unwind label %lpad
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lpad:
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%1 = landingpad { ptr, i32 }
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cleanup
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catch ptr @_ZTIi
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br label %2
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2: ; preds = lpad
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%3 = call i32 @bar()
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br i1 %0, label %4, label %6
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4: ; preds = lpad
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%5 = call i32 @baz()
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br label %6
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6: ; preds = %4, %2
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%7 = tail call i32 @qux()
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br i1 %0, label %2, label %8
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8: ; preds = %6
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ret i32 0
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}
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define i32 @foo13(i1 zeroext %0) personality ptr @__gxx_personality_v0 !prof !14{
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;; Check that all code reachable from EH
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;; that is also reachable from outside EH pad
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;; is not touched.
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; MFS-EH-SPLIT-LABEL: foo13
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; MFS-EH-SPLIT: callq bam
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; MFS-EH-SPLIT: .section .text.split.foo13,"ax",@progbits
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; MFS-EH-SPLIT-NEXT: foo13.cold:
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; MFS-EH-SPLIT: callq baz
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; MFS-EH-SPLIT: callq bar
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; MFS-EH-SPLIT: callq qux
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entry:
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invoke void @_Z1fv()
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to label %try.cont unwind label %lpad, !prof !17
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lpad:
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%1 = landingpad { ptr, i32 }
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cleanup
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catch ptr @_ZTIi
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br i1 %0, label %2, label %4, !prof !17
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2: ; preds = lpad
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%3 = call i32 @bar()
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br label %6
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4: ; preds = lpad
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%5 = call i32 @baz()
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br label %6
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6: ; preds = %4, %2
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%7 = tail call i32 @qux()
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br i1 %0, label %2, label %try.cont, !prof !17
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try.cont: ; preds = %entry
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%8 = call i32 @bam()
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ret i32 %8
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}
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define void @foo14(i1 zeroext %0, i1 zeroext %1) nounwind !prof !24 {
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; FSAFDO-MFS: .section .text.split.foo14,"ax"
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; FSAFDO-MFS: foo14.cold:
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br i1 %0, label %3, label %7, !prof !25
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3:
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%4 = call i32 @bar()
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br label %7
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5:
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%6 = call i32 @baz()
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br label %7
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7:
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br i1 %1, label %8, label %10, !prof !26
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8:
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%9 = call i32 @bam()
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br label %12
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10:
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%11 = call i32 @baz()
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br label %12
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12:
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%13 = tail call i32 @qux()
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ret void
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}
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define void @foo15(i1 zeroext %0, i1 zeroext %1) nounwind !prof !27 {
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;; HasAccurateProfile is false, foo15 is hot, but no profile data for
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;; blocks, no split should happen.
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; FSAFDO-MFS2-NOT: .section .text.split.foo15,"ax"
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; FSAFDO-MFS2-NOT: foo15.cold:
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br i1 %0, label %3, label %7
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3:
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%4 = call i32 @bar()
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br label %7
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5:
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%6 = call i32 @baz()
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br label %7
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7:
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br i1 %1, label %8, label %10
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8:
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%9 = call i32 @bam()
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br label %12
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10:
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%11 = call i32 @baz()
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br label %12
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12:
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%13 = tail call i32 @qux()
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ret void
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}
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declare i32 @bar()
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declare i32 @baz()
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declare i32 @bam()
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declare i32 @qux()
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declare void @_Z1fv()
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declare i32 @__gxx_personality_v0(...)
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@_ZTIi = external constant ptr
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attributes #0 = { "implicit-section-name"="nosplit" }
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!llvm.module.flags = !{!0}
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!0 = !{i32 1, !"ProfileSummary", !1}
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!1 = !{!2, !3, !4, !5, !6, !7, !8, !9}
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!2 = !{!"ProfileFormat", !"InstrProf"}
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!3 = !{!"TotalCount", i64 10000}
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!4 = !{!"MaxCount", i64 10}
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!5 = !{!"MaxInternalCount", i64 1}
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!6 = !{!"MaxFunctionCount", i64 1000}
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!7 = !{!"NumCounts", i64 3}
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!8 = !{!"NumFunctions", i64 5}
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!9 = !{!"DetailedSummary", !10}
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!10 = !{!11, !12, !13}
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!11 = !{i32 10000, i64 100, i32 1}
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!12 = !{i32 999900, i64 100, i32 1}
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!13 = !{i32 999999, i64 1, i32 2}
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!14 = !{!"function_entry_count", i64 7000}
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!15 = !{!"function_section_prefix", !"hot"}
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!16 = !{!"function_section_prefix", !"unlikely"}
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!17 = !{!"branch_weights", i32 7000, i32 0}
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!18 = !{!"branch_weights", i32 3000, i32 4000}
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!19 = !{!"branch_weights", i32 1000, i32 6000}
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!20 = !{!"function_entry_count", i64 10000}
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!21 = !{!"branch_weights", i32 6000, i32 4000}
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!22 = !{!"branch_weights", i32 80, i32 9920}
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!23 = !{!"function_entry_count", i64 7}
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!24 = !{!"function_entry_count", i64 10000}
|
|
!25 = !{!"branch_weights", i32 0, i32 7000}
|
|
!26 = !{!"branch_weights", i32 1000, i32 6000}
|
|
!27 = !{!"function_entry_count", i64 10000}
|