[llvm-profgen] Turn on CS nested profile generation by default for CSSPGO.

[hoy]

Summary

CS nested profile has a benefit over the CS flat profile that is to speed up the build while achieve an on-par performance. I'm turning it on by default for CSSPGO.

[wenlei]

lgtm, thanks.

llvm/test/tools/llvm-profgen/cs-extbinary.test

 ; test for dwarf-based cs profile
-; RUN: llvm-profgen --format=extbinary --perfscript=%S/Inputs/recursion-compression-noprobe.perfscript --binary=%S/Inputs/recursion-compression-noprobe.perfbin --output=%t1 --profile-summary-hot-count=0 --csspgo-preinliner=0
+; RUN: llvm-profgen --format=extbinary --perfscript=%S/Inputs/recursion-compression-noprobe.perfscript --binary=%S/Inputs/recursion-compression-noprobe.perfbin --output=%t1 --profile-summary-hot-count=0 --csspgo-preinliner=0 --gen-cs-nested-profile=0
 ; RUN: llvm-profdata merge --sample --text --output=%t2 %t1
 ; RUN: FileCheck %S/recursion-compression-noprobe.test --input-file %t2
 ; RUN: llvm-profdata merge --sample --extbinary --output=%t3 %t2 && llvm-profdata merge --sample --text --output=%t4 %t3
 ; RUN: diff -b %t2 %t4
 
 
 ; test for probe-based cs profile
-; RUN: llvm-profgen --format=extbinary --perfscript=%S/Inputs/recursion-compression-pseudoprobe.perfscript --binary=%S/Inputs/recursion-compression-pseudoprobe.perfbin --output=%t5 --profile-summary-hot-count=0 --csspgo-preinliner=0
+; RUN: llvm-profgen --format=extbinary --perfscript=%S/Inputs/recursion-compression-pseudoprobe.perfscript --binary=%S/Inputs/recursion-compression-pseudoprobe.perfbin --output=%t5 --profile-summary-hot-count=0 --csspgo-preinliner=0 --gen-cs-nested-profile=0
 ; RUN: llvm-profdata merge --sample --text --output=%t6 %t5
 ; RUN: FileCheck %S/recursion-compression-pseudoprobe.test --input-file %t6
 ; RUN: llvm-profdata merge --sample --extbinary --output=%t7 %t6 && llvm-profdata merge --sample --text --output=%t8 %t7
 ; RUN: diff -b %t6 %t8

llvm/test/tools/llvm-profgen/cs-interrupt.test

 ;; The test fails on Windows. Fix it before removing the following requirement.
 ; REQUIRES: x86_64-linux
-; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/cs-interrupt.perfscript --binary=%S/Inputs/noinline-cs-noprobe.perfbin --output=%t --skip-symbolization --profile-summary-cold-count=0 --csspgo-preinliner=0
+; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/cs-interrupt.perfscript --binary=%S/Inputs/noinline-cs-noprobe.perfbin --output=%t --skip-symbolization --profile-summary-cold-count=0 --csspgo-preinliner=0 --gen-cs-nested-profile=0
 ; RUN: FileCheck %s --input-file %t --check-prefix=CHECK-UNWINDER
-; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/cs-interrupt.perfscript --binary=%S/Inputs/noinline-cs-noprobe.perfbin --output=%t --profile-summary-cold-count=0 --csspgo-preinliner=0
+; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/cs-interrupt.perfscript --binary=%S/Inputs/noinline-cs-noprobe.perfbin --output=%t --profile-summary-cold-count=0 --csspgo-preinliner=0 --gen-cs-nested-profile=0
 ; RUN: FileCheck %s --input-file %t
 
 ; CHECK:[main:1 @ foo]:88:0
 ; CHECK: 2: 5
 ; CHECK: 3: 5 bar:5
 ; CHECK:[main:1 @ foo:3 @ bar]:74:5
 ; CHECK: 0: 5
 ; CHECK: 1: 5

llvm/test/tools/llvm-profgen/cs-preinline.test

 ; Test default llvm-profgen with preinline off
-; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/inline-cs-noprobe.perfscript --binary=%S/Inputs/inline-cs-noprobe.perfbin --csspgo-preinliner=0 --output=%t
+; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/inline-cs-noprobe.perfscript --binary=%S/Inputs/inline-cs-noprobe.perfbin --csspgo-preinliner=0 --gen-cs-nested-profile=0 --output=%t
 ; RUN: FileCheck %s --input-file %t --check-prefix=CHECK-DEFAULT
 
 ; Test llvm-profgen with preinliner on will merge not inlinable profile into base profile.
-; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/inline-cs-noprobe.perfscript --binary=%S/Inputs/inline-cs-noprobe.perfbin --csspgo-preinliner=1 --sample-profile-hot-inline-threshold=3000 --sample-profile-cold-inline-threshold=45 --output=%t
+; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/inline-cs-noprobe.perfscript --binary=%S/Inputs/inline-cs-noprobe.perfbin --csspgo-preinliner=1 --gen-cs-nested-profile=0 --sample-profile-hot-inline-threshold=3000 --sample-profile-cold-inline-threshold=45 --output=%t
 ; RUN: FileCheck %s --input-file %t --check-prefix=CHECK-PREINL
 
 ; Test preinliner threshold that prevents all possible inlining and merges everything into base profile.
-; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/inline-cs-noprobe.perfscript --binary=%S/Inputs/inline-cs-noprobe.perfbin --csspgo-preinliner=1 --sample-profile-hot-inline-threshold=3000 --sample-profile-cold-inline-threshold=0 --output=%t
+; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/inline-cs-noprobe.perfscript --binary=%S/Inputs/inline-cs-noprobe.perfbin --csspgo-preinliner=1 --gen-cs-nested-profile=0 --sample-profile-hot-inline-threshold=3000 --sample-profile-cold-inline-threshold=0 --output=%t
 ; RUN: FileCheck %s --input-file %t --check-prefix=CHECK-NO-PREINL
 
 ; Test cold profile trimming. Only base profiles should be dropped.
-; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/inline-cs-noprobe.perfscript --binary=%S/Inputs/inline-cs-noprobe.perfbin --csspgo-preinliner=1 --sample-profile-hot-inline-threshold=3000 --sample-profile-cold-inline-threshold=45 --output=%t --trim-cold-profile=1 --profile-summary-hot-count=400
+; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/inline-cs-noprobe.perfscript --binary=%S/Inputs/inline-cs-noprobe.perfbin --csspgo-preinliner=1 --gen-cs-nested-profile=0 --sample-profile-hot-inline-threshold=3000 --sample-profile-cold-inline-threshold=45 --output=%t --trim-cold-profile=1 --profile-summary-hot-count=400
 
 ; RUN: FileCheck %s --input-file %t --check-prefix=CHECK-TRIM
 
 ; Test llvm-profgen with preinliner on will merge not inlinable profile into base profile.
 ; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/inline-cs-noprobe.perfscript --binary=%S/Inputs/inline-cs-noprobe.perfbin  --csspgo-preinliner=1 --sample-profile-hot-inline-threshold=3000 --sample-profile-cold-inline-threshold=45 --output=%t --gen-cs-nested-profile=1
 ; RUN: FileCheck %s --input-file %t --check-prefix=CHECK-PREINL-NEST
 
 ; CHECK-DEFAULT:     [main:1 @ foo]:309:0

llvm/test/tools/llvm-profgen/fname-canonicalization.test

 ; Test unique linkage name decoding and canonicalization from dwarf debug info
-; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/unique-linkage-name-dwarf.perfscript --binary=%S/Inputs/unique-linkage-name-dwarf.perfbin --output=%t --profile-summary-cold-count=0 --csspgo-preinliner=0
+; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/unique-linkage-name-dwarf.perfscript --binary=%S/Inputs/unique-linkage-name-dwarf.perfbin --output=%t --profile-summary-cold-count=0 --csspgo-preinliner=0 --gen-cs-nested-profile=0
 ; RUN: FileCheck %s --input-file %t --check-prefix=CHECK-DWARF-FNAME
 
 ; CHECK-DWARF-FNAME:[main:1 @ foo]:309:0
 ; CHECK-DWARF-FNAME: 2: 14
 ; CHECK-DWARF-FNAME: 3: 29 bar.__uniq.26267048767521081047744692097241227776:14
 ; CHECK-DWARF-FNAME:[main:1 @ foo:3 @ bar.__uniq.26267048767521081047744692097241227776]:84:0
 ; CHECK-DWARF-FNAME: 1: 14
 
 
 ; Test unique linkage name decoding and canonicalization from pseudo probe info
-; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/unique-linkage-name-probe.perfscript --binary=%S/Inputs/unique-linkage-name-probe.perfbin --output=%t --profile-summary-cold-count=0 --csspgo-preinliner=0
+; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/unique-linkage-name-probe.perfscript --binary=%S/Inputs/unique-linkage-name-probe.perfbin --output=%t --profile-summary-cold-count=0 --csspgo-preinliner=0 --gen-cs-nested-profile=0
 ; RUN: FileCheck %s --input-file %t --check-prefix=CHECK-PROBE-FNAME
 
 ; CHECK-PROBE-FNAME:[main:2 @ foo]:75:0
 ; CHECK-PROBE-FNAME: 2: 15
 ; CHECK-PROBE-FNAME: 3: 15
 ; CHECK-PROBE-FNAME: 4: 15
 ; CHECK-PROBE-FNAME: 6: 15
 ; CHECK-PROBE-FNAME: 8: 15 _ZL3barii.__uniq.276699478366846449772231447066107882794:15

llvm/test/tools/llvm-profgen/func-split.test

-; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/func-split.perfscript --binary=%S/Inputs/func-split.perfbin --output=%t
+; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/func-split.perfscript --binary=%S/Inputs/func-split.perfbin --output=%t --gen-cs-nested-profile=0
 ; RUN: FileCheck %s --input-file %t --check-prefix=CHECK
-; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/func-split.perfscript --binary=%S/Inputs/func-split.perfbin --output=%t --ignore-stack-samples
+; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/func-split.perfscript --binary=%S/Inputs/func-split.perfbin --output=%t --ignore-stack-samples --gen-cs-nested-profile=0
 ; RUN: FileCheck %s --input-file %t --check-prefix=CHECK-STRIP-CTX
 
 ;CHECK: [foo]:409:0
 ;CHECK:  2.1: 27
 ;CHECK:  3: 27
 ;CHECK:  3.1: 2 bar:2
 ;CHECK:  3.2: 26
 ;CHECK: [foo:3.1 @ bar]:8:0

llvm/test/tools/llvm-profgen/inline-cs-noprobe.test

 ; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/inline-cs-noprobe.perfscript --binary=%S/Inputs/inline-cs-noprobe.perfbin --output=%t --skip-symbolization --profile-summary-cold-count=0
 ; RUN: FileCheck %s --input-file %t --check-prefix=CHECK-UNWINDER
-; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/inline-cs-noprobe.perfscript --binary=%S/Inputs/inline-cs-noprobe.perfbin --output=%t --profile-summary-cold-count=0 --csspgo-preinliner=0
+; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/inline-cs-noprobe.perfscript --binary=%S/Inputs/inline-cs-noprobe.perfbin --output=%t --profile-summary-cold-count=0 --csspgo-preinliner=0 --gen-cs-nested-profile=0
 ; RUN: FileCheck %s --input-file %t
-; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/inline-cs-noprobe.perfscript --binary=%S/Inputs/inline-cs-noprobe.perfbin --output=%t --profile-summary-cold-count=0 --ignore-stack-samples --csspgo-preinliner=0
+; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/inline-cs-noprobe.perfscript --binary=%S/Inputs/inline-cs-noprobe.perfbin --output=%t --profile-summary-cold-count=0 --ignore-stack-samples --csspgo-preinliner=0 --gen-cs-nested-profile=0
 ; RUN: FileCheck %s --input-file %t --check-prefix=CHECK-STRIP-CTX
 
-; RUN: llvm-profgen --format=extbinary --perfscript=%S/Inputs/inline-cs-noprobe.perfscript --binary=%S/Inputs/inline-cs-noprobe.perfbin --output=%t --profile-summary-cold-count=0 --populate-profile-symbol-list=1 --csspgo-preinliner=0
+; RUN: llvm-profgen --format=extbinary --perfscript=%S/Inputs/inline-cs-noprobe.perfscript --binary=%S/Inputs/inline-cs-noprobe.perfbin --output=%t --profile-summary-cold-count=0 --populate-profile-symbol-list=1 --csspgo-preinliner=0 --gen-cs-nested-profile=0
 ; RUN: llvm-profdata show -show-prof-sym-list -sample %t | FileCheck %s --check-prefix=CHECK-SYM-LIST
 
 ; CHECK-SYM-LIST: Dump profile symbol list
 ; CHECK-SYM-LIST: bar
 ; CHECK-SYM-LIST: foo
 ; CHECK-SYM-LIST: main
 
 ; CHECK:[main:1 @ foo]:309:0

llvm/test/tools/llvm-profgen/inline-cs-pseudoprobe.test

 ; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/inline-cs-pseudoprobe.perfscript --binary=%S/Inputs/inline-cs-pseudoprobe.perfbin --output=%t --skip-symbolization --profile-summary-cold-count=0 --use-offset=0
 ; RUN: FileCheck %s --input-file %t --check-prefix=CHECK-UNWINDER
 ; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/inline-cs-pseudoprobe.perfscript --binary=%S/Inputs/inline-cs-pseudoprobe.perfbin --output=%t --skip-symbolization --profile-summary-cold-count=0 --use-offset=1
 ; RUN: FileCheck %s --input-file %t --check-prefix=CHECK-UNWINDER-OFFSET
 ; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/inline-cs-pseudoprobe.perfscript --binary=%S/Inputs/inline-cs-pseudoprobe.perfbin --output=%t --skip-symbolization --profile-summary-cold-count=0 --use-offset=1 --use-first-loadable-segment-as-base=1
 ; RUN: FileCheck %s --input-file %t --check-prefix=CHECK-UNWINDER-OFFSET2
-; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/inline-cs-pseudoprobe.perfscript --binary=%S/Inputs/inline-cs-pseudoprobe.perfbin --output=%t --profile-summary-cold-count=0 --csspgo-preinliner=0
+; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/inline-cs-pseudoprobe.perfscript --binary=%S/Inputs/inline-cs-pseudoprobe.perfbin --output=%t --profile-summary-cold-count=0 --csspgo-preinliner=0 --gen-cs-nested-profile=0
 ; RUN: FileCheck %s --input-file %t
 
 ; CHECK:     [main:2 @ foo]:74:0
 ; CHECK-NEXT: 1: 0
 ; CHECK-NEXT: 2: 15
 ; CHECK-NEXT: 3: 15
 ; CHECK-NEXT: 4: 14
 ; CHECK-NEXT: 5: 1

llvm/test/tools/llvm-profgen/merge-cold-profile.test

 ; Used the data from recursion-compression.test, refer it for the unmerged output
-; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/recursion-compression-pseudoprobe.perfscript --binary=%S/Inputs/recursion-compression-pseudoprobe.perfbin --output=%t1 --compress-recursion=-1 --profile-summary-hot-count=8 --csspgo-preinliner=0
+; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/recursion-compression-pseudoprobe.perfscript --binary=%S/Inputs/recursion-compression-pseudoprobe.perfbin --output=%t1 --compress-recursion=-1 --profile-summary-hot-count=8 --csspgo-preinliner=0 --gen-cs-nested-profile=0
 ; RUN: FileCheck %s --input-file %t1
 
 ; Test --trim-cold-profile=0
-; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/recursion-compression-pseudoprobe.perfscript --binary=%S/Inputs/recursion-compression-pseudoprobe.perfbin --output=%t2 --compress-recursion=-1 --profile-summary-hot-count=100 --trim-cold-profile=0 --csspgo-preinliner=0
+; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/recursion-compression-pseudoprobe.perfscript --binary=%S/Inputs/recursion-compression-pseudoprobe.perfbin --output=%t2 --compress-recursion=-1 --profile-summary-hot-count=100 --trim-cold-profile=0 --csspgo-preinliner=0 --gen-cs-nested-profile=0
 ; RUN: FileCheck %s --input-file %t2 --check-prefix=CHECK-KEEP-COLD
 
 ; Test --csprof-merge-cold-context=0
-; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/recursion-compression-pseudoprobe.perfscript --binary=%S/Inputs/recursion-compression-pseudoprobe.perfbin --output=%t3 --compress-recursion=-1 --profile-summary-hot-count=10 --csprof-merge-cold-context=0 --csspgo-preinliner=0
+; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/recursion-compression-pseudoprobe.perfscript --binary=%S/Inputs/recursion-compression-pseudoprobe.perfbin --output=%t3 --compress-recursion=-1 --profile-summary-hot-count=10 --csprof-merge-cold-context=0 --csspgo-preinliner=0 --gen-cs-nested-profile=0
 ; RUN: FileCheck %s --input-file %t3 --check-prefix=CHECK-UNMERGED
 
 ; Test --csprof-frame-depth-for-cold-context
-; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/recursion-compression-pseudoprobe.perfscript --binary=%S/Inputs/recursion-compression-pseudoprobe.perfbin --output=%t2 --compress-recursion=-1 --profile-summary-hot-count=100 --trim-cold-profile=0 --csprof-max-cold-context-depth=2 --csspgo-preinliner=0
+; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/recursion-compression-pseudoprobe.perfscript --binary=%S/Inputs/recursion-compression-pseudoprobe.perfbin --output=%t2 --compress-recursion=-1 --profile-summary-hot-count=100 --trim-cold-profile=0 --csprof-max-cold-context-depth=2 --csspgo-preinliner=0 --gen-cs-nested-profile=0
 ; RUN: FileCheck %s --input-file %t2 --check-prefix=CHECK-COLD-CONTEXT-LENGTH
 
 ; CHECK:     [fa]:14:4
 ; CHECK-NEXT: 1: 4
 ; CHECK-NEXT: 3: 4
 ; CHECK-NEXT: 4: 2
 ; CHECK-NEXT: 5: 1
 ; CHECK-NEXT: 6: 0

llvm/test/tools/llvm-profgen/multi-load-segs.test

-; RUN: llvm-profgen --perfscript=%S/Inputs/multi-load-segs.perfscript --binary=%S/Inputs/multi-load-segs.perfbin --output=%t --format=text --csspgo-preinliner=0
+; RUN: llvm-profgen --perfscript=%S/Inputs/multi-load-segs.perfscript --binary=%S/Inputs/multi-load-segs.perfbin --output=%t --format=text --csspgo-preinliner=0 --gen-cs-nested-profile=0
 ; RUN: FileCheck %s --input-file %t
 
 ;;  %S/Inputs/multi-load-segs.perfbin is an ELF image with two executable load segments.
 ; running llvm-readelf -l %S/Inputs/multi-load-segs.perfbin gives:
 ;;  LOAD           0x000000 0x0000000000200000 0x0000000000200000 0x00075c 0x00075c R   0x1000
 ;;  LOAD           0x000760 0x0000000000201760 0x0000000000201760 0x0004c0 0x0004c0 R E 0x1000
 ;;  LOAD           0x000c20 0x0000000000202c20 0x0000000000202c20 0x0001f0 0x0001f0 RW  0x1000
 ;;  LOAD           0x000e10 0x0000000000203e10 0x0000000000203e10 0x000040 0x000058 RW  0x1000

llvm/test/tools/llvm-profgen/noinline-cs-noprobe.test

 ;; The test fails on Windows. Fix it before removing the following requirement.
 ; REQUIRES: x86_64-linux
 ; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/noinline-cs-noprobe.perfscript --binary=%S/Inputs/noinline-cs-noprobe.perfbin --output=%t --skip-symbolization --profile-summary-cold-count=0
 ; RUN: FileCheck %s --input-file %t --check-prefix=CHECK-UNWINDER
-; RUN: llvm-profgen --format=text --unsymbolized-profile=%t --binary=%S/Inputs/noinline-cs-noprobe.perfbin --output=%t1 --profile-summary-cold-count=0 --csspgo-preinliner=0
+; RUN: llvm-profgen --format=text --unsymbolized-profile=%t --binary=%S/Inputs/noinline-cs-noprobe.perfbin --output=%t1 --profile-summary-cold-count=0 --csspgo-preinliner=0 --gen-cs-nested-profile=0
 ; RUN: FileCheck %s --input-file %t1
-; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/noinline-cs-noprobe.perfscript --binary=%S/Inputs/noinline-cs-noprobe.perfbin --output=%t --profile-summary-cold-count=0 --ignore-stack-samples --csspgo-preinliner=0
+; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/noinline-cs-noprobe.perfscript --binary=%S/Inputs/noinline-cs-noprobe.perfbin --output=%t --profile-summary-cold-count=0 --ignore-stack-samples --csspgo-preinliner=0 --gen-cs-nested-profile=0
 ; RUN: FileCheck %s --input-file %t --check-prefix=CHECK-STRIP-CTX
 ; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/noinline-cs-noprobe.aggperfscript --binary=%S/Inputs/noinline-cs-noprobe.perfbin --output=%t --skip-symbolization --profile-summary-cold-count=0
 ; RUN: FileCheck %s --input-file %t --check-prefix=CHECK-AGG-UNWINDER
-; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/noinline-cs-noprobe.aggperfscript --binary=%S/Inputs/noinline-cs-noprobe.perfbin --output=%t --profile-summary-cold-count=0 --csspgo-preinliner=0
+; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/noinline-cs-noprobe.aggperfscript --binary=%S/Inputs/noinline-cs-noprobe.perfbin --output=%t --profile-summary-cold-count=0 --csspgo-preinliner=0 --gen-cs-nested-profile=0
 ; RUN: FileCheck %s --input-file %t --check-prefix=CHECK-AGG
 
 ; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/noinline-cs-noprobe.perfscript --binary=%S/Inputs/noinline-cs-noprobe.perfbin --output=%t1 --profile-summary-cold-count=0
 ; RUN: llvm-profgen --format=extbinary --perfscript=%S/Inputs/noinline-cs-noprobe.perfscript --binary=%S/Inputs/noinline-cs-noprobe.perfbin --output=%t2 --profile-summary-cold-count=0 -use-md5
 ; RUN: llvm-profdata show --sample -show-sec-info-only %t2 | FileCheck %s --check-prefix=CHECK-MD5
 ; RUN: llvm-profdata show --sample -detailed-summary --function=dummy %t1 > %t.summary
 ; RUN: llvm-profdata show --sample -detailed-summary --function=dummy %t2 > %t2.summary
 ; RUN: diff -b %t.summary %t2.summary

llvm/test/tools/llvm-profgen/noinline-cs-pseudoprobe.test

 ; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/noinline-cs-pseudoprobe.perfscript --binary=%S/Inputs/noinline-cs-pseudoprobe.perfbin --output=%t --skip-symbolization --profile-summary-cold-count=0
 ; RUN: FileCheck %s --input-file %t --check-prefix=CHECK-UNWINDER
-; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/noinline-cs-pseudoprobe.perfscript --binary=%S/Inputs/noinline-cs-pseudoprobe.perfbin --output=%t --profile-summary-cold-count=0 --csspgo-preinliner=0
+; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/noinline-cs-pseudoprobe.perfscript --binary=%S/Inputs/noinline-cs-pseudoprobe.perfbin --output=%t --profile-summary-cold-count=0 --csspgo-preinliner=0 --gen-cs-nested-profile=0
 ; RUN: FileCheck %s --input-file %t
 ; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/noinline-cs-pseudoprobe.aggperfscript --binary=%S/Inputs/noinline-cs-pseudoprobe.perfbin --output=%t --skip-symbolization --profile-summary-cold-count=0
 ; RUN: FileCheck %s --input-file %t --check-prefix=CHECK-UNWINDER
-; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/noinline-cs-pseudoprobe.aggperfscript --binary=%S/Inputs/noinline-cs-pseudoprobe.perfbin --output=%t --profile-summary-cold-count=0 --csspgo-preinliner=0
+; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/noinline-cs-pseudoprobe.aggperfscript --binary=%S/Inputs/noinline-cs-pseudoprobe.perfbin --output=%t --profile-summary-cold-count=0 --csspgo-preinliner=0 --gen-cs-nested-profile=0
 ; RUN: FileCheck %s --input-file %t
 
 
 ; CHECK:     [main:2 @ foo]:75:0
 ; CHECK-NEXT: 1: 0
 ; CHECK-NEXT: 2: 15
 ; CHECK-NEXT: 3: 15
 ; CHECK-NEXT: 4: 15

llvm/test/tools/llvm-profgen/recursion-compression-noprobe.test

 ; Firstly test uncompression(--compress-recursion=0)
-; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/recursion-compression-noprobe.perfscript --binary=%S/Inputs/recursion-compression-noprobe.perfbin --output=%t --compress-recursion=0 --profile-summary-hot-count=0 --csspgo-preinliner=0
+; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/recursion-compression-noprobe.perfscript --binary=%S/Inputs/recursion-compression-noprobe.perfbin --output=%t --compress-recursion=0 --profile-summary-hot-count=0 --csspgo-preinliner=0 --gen-cs-nested-profile=0
 ; RUN: FileCheck %s --input-file %t -check-prefix=CHECK-UNCOMPRESS
-; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/recursion-compression-noprobe.perfscript --binary=%S/Inputs/recursion-compression-noprobe.perfbin --output=%t --profile-summary-hot-count=0 --csspgo-preinliner=0
+; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/recursion-compression-noprobe.perfscript --binary=%S/Inputs/recursion-compression-noprobe.perfbin --output=%t --profile-summary-hot-count=0 --csspgo-preinliner=0 --gen-cs-nested-profile=0
 ; RUN: FileCheck %s --input-file %t
-; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/recursion-compression-noprobe.perfscript --binary=%S/Inputs/recursion-compression-noprobe.perfbin --output=%t --compress-recursion=0 --profile-summary-hot-count=0 --csprof-max-context-depth=2 --csspgo-preinliner=0
+; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/recursion-compression-noprobe.perfscript --binary=%S/Inputs/recursion-compression-noprobe.perfbin --output=%t --compress-recursion=0 --profile-summary-hot-count=0 --csprof-max-context-depth=2 --csspgo-preinliner=0 --gen-cs-nested-profile=0
 ; RUN: FileCheck %s --input-file %t -check-prefix=CHECK-MAX-CTX-DEPTH
 
 ; CHECK-UNCOMPRESS:[main:1 @ foo:3 @ fa:2 @ fb]:48:0
 ; CHECK-UNCOMPRESS: 1: 11
 ; CHECK-UNCOMPRESS: 2: 1 fa:1
 ; CHECK-UNCOMPRESS: 65532: 11
 ; CHECK-UNCOMPRESS:[main:1 @ foo:3 @ fa]:24:0
 ; CHECK-UNCOMPRESS: 1: 1

llvm/test/tools/llvm-profgen/recursion-compression-pseudoprobe.test

 ; Firstly test uncompression(--compress-recursion=0)
-; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/recursion-compression-pseudoprobe.perfscript --binary=%S/Inputs/recursion-compression-pseudoprobe.perfbin --output=%t --compress-recursion=0 --profile-summary-hot-count=0 --csspgo-preinliner=0
+; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/recursion-compression-pseudoprobe.perfscript --binary=%S/Inputs/recursion-compression-pseudoprobe.perfbin --output=%t --compress-recursion=0 --profile-summary-hot-count=0 --csspgo-preinliner=0 --gen-cs-nested-profile=0
 ; RUN: FileCheck %s --input-file %t -check-prefix=CHECK-UNCOMPRESS
 ; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/recursion-compression-pseudoprobe.perfscript --binary=%S/Inputs/recursion-compression-pseudoprobe.perfbin --output=%t --skip-symbolization --profile-summary-hot-count=0
 ; RUN: FileCheck %s --input-file %t --check-prefix=CHECK-UNWINDER
-; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/recursion-compression-pseudoprobe.perfscript --binary=%S/Inputs/recursion-compression-pseudoprobe.perfbin --output=%t --profile-summary-hot-count=0 --csspgo-preinliner=0
+; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/recursion-compression-pseudoprobe.perfscript --binary=%S/Inputs/recursion-compression-pseudoprobe.perfbin --output=%t --profile-summary-hot-count=0 --csspgo-preinliner=0 --gen-cs-nested-profile=0
 ; RUN: FileCheck %s --input-file %t
 ; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/recursion-compression-pseudoprobe-nommap.perfscript --binary=%S/Inputs/recursion-compression-pseudoprobe.perfbin --output=%t --skip-symbolization --profile-summary-hot-count=0
 ; RUN: FileCheck %s --input-file %t --check-prefix=CHECK-UNWINDER
-; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/recursion-compression-pseudoprobe-nommap.perfscript --binary=%S/Inputs/recursion-compression-pseudoprobe.perfbin --output=%t --profile-summary-hot-count=0 --csspgo-preinliner=0
+; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/recursion-compression-pseudoprobe-nommap.perfscript --binary=%S/Inputs/recursion-compression-pseudoprobe.perfbin --output=%t --profile-summary-hot-count=0 --csspgo-preinliner=0 --gen-cs-nested-profile=0
 ; RUN: FileCheck %s --input-file %t
-; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/recursion-compression-pseudoprobe.perfscript --binary=%S/Inputs/recursion-compression-pseudoprobe.perfbin --output=%t --compress-recursion=0 --profile-summary-hot-count=0 --csprof-max-context-depth=0 --csspgo-preinliner=0
+; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/recursion-compression-pseudoprobe.perfscript --binary=%S/Inputs/recursion-compression-pseudoprobe.perfbin --output=%t --compress-recursion=0 --profile-summary-hot-count=0 --csprof-max-context-depth=0 --csspgo-preinliner=0 --gen-cs-nested-profile=0
 ; RUN: FileCheck %s --input-file %t -check-prefix=CHECK-MAX-CTX-DEPTH
 
 
 ; CHECK-UNCOMPRESS: [main:2 @ foo:5 @ fa:8 @ fa:7 @ fb:5 @ fb:5 @ fb:5 @ fb:5 @ fb:5 @ fb:5 @ fb:5 @ fb:5 @ fb:6 @ fa]:4:1
 ; CHECK-UNCOMPRESS:  1: 1
 ; CHECK-UNCOMPRESS:  3: 1
 ; CHECK-UNCOMPRESS:  5: 1
 ; CHECK-UNCOMPRESS:  8: 1 fa:1

llvm/test/tools/llvm-profgen/separate-debuginfo-binary.test

 ; RUN: llvm-objcopy --strip-debug %S/Inputs/inline-noprobe.perfbin %t1
 ; RUN: llvm-objcopy --only-keep-debug %S/Inputs/inline-noprobe.perfbin %t2
 ; RUN: echo -e "0\n0" > %t
 ; RUN: llvm-profgen --format=text --unsymbolized-profile=%t --binary=%t1 --debug-binary=%t2 --output=%t3 --fill-zero-for-all-funcs
 ; RUN: FileCheck %s --input-file %t3 --check-prefix=CHECK
 
 ; RUN: llvm-objcopy --strip-debug %S/Inputs/inline-cs-pseudoprobe.perfbin %t4
 ; RUN: llvm-objcopy --only-keep-debug %S/Inputs/inline-cs-pseudoprobe.perfbin %t5
-; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/inline-cs-pseudoprobe.perfscript --binary=%t4 --debug-binary=%t5 --output=%t6 --profile-summary-hot-count=0 --csspgo-preinliner=0
+; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/inline-cs-pseudoprobe.perfscript --binary=%t4 --debug-binary=%t5 --output=%t6 --profile-summary-hot-count=0 --csspgo-preinliner=0 --gen-cs-nested-profile=0
 ; RUN: FileCheck %s --input-file %t6 --check-prefix=CHECK-CS-PROBE
 
 ; CHECK: bar:0:0
 ; CHECK:  1: 0
 ; CHECK:  5: 0
 ; CHECK: foo:0:0
 ; CHECK:  0: 0
 ; CHECK:  2.1: 0

llvm/test/tools/llvm-profgen/truncated-pseudoprobe.test

-; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/truncated-pseudoprobe.perfscript --binary=%S/Inputs/truncated-pseudoprobe.perfbin --csspgo-preinliner=0 --output=%t
+; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/truncated-pseudoprobe.perfscript --binary=%S/Inputs/truncated-pseudoprobe.perfbin --csspgo-preinliner=0 --gen-cs-nested-profile=0 --output=%t
 ; RUN: FileCheck %s --input-file %t
 
 ; CHECK:     [foo]:75:0
 ; CHECK-NEXT:  1: 0
 ; CHECK-NEXT:  2: 15
 ; CHECK-NEXT:  3: 15
 ; CHECK-NEXT:  4: 15
 ; CHECK-NEXT:  5: 0

llvm/tools/llvm-profgen/ProfileGenerator.cpp

static cl::opt<bool> UpdateTotalSamples(
     "update-total-samples", llvm::cl::init(false),
     llvm::cl::desc(
         "Update total samples by accumulating all its body samples."),
     llvm::cl::Optional);
 
 extern cl::opt<int> ProfileSummaryCutoffHot;
 
 static cl::opt<bool> GenCSNestedProfile(
-    "gen-cs-nested-profile", cl::Hidden, cl::init(false),
+    "gen-cs-nested-profile", cl::Hidden, cl::init(true),
     cl::desc("Generate nested function profiles for CSSPGO"));
 
 using namespace llvm;
 using namespace sampleprof;
 
 namespace llvm {
 namespace sampleprof {