[llvm-profgen] Always generate line-number based profile under --fill-zero-for-all-funcs

[hoy]

Summary

The swtich --fill-zero-for-all-funcs is used to generate an empty profile that can be used by downstream tools to compute an inline deicison tree out of a binary. Since the probe-based non-cs profile generation is not supported, I'm making it fall back to line-based profile generation.

[wenlei]

Can we just use -use-dwarf-correlation to skip pseudo-probe decoding and go through dwarf path for this purpose? Using -fill-zero-for-all-funcs switch to decide whether we use probe can be confusing.

[hoy]

In D118060#3267004, @wenlei wrote:

Can we just use -use-dwarf-correlation to skip pseudo-probe decoding and go through dwarf path for this purpose? Using -fill-zero-for-all-funcs switch to decide whether we use probe can be confusing.

Oh that works. I forgot about such a switch. Thanks for reminding.

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

 ; RUN: llvm-profgen --format=text --perfscript=%S/Inputs/inline-noprobe.perfscript --binary=%S/Inputs/inline-noprobe.perfbin --output=%t --skip-symbolization
 ; RUN: FileCheck %s --input-file %t --check-prefix=CHECK-RAW-PROFILE
 ; RUN: llvm-profgen --format=text --use-dwarf-correlation --perfscript=%S/Inputs/inline-noprobe.perfscript --binary=%S/Inputs/inline-noprobe.perfbin --output=%t --skip-symbolization
 ; RUN: FileCheck %s --input-file %t --check-prefix=CHECK-RAW-PROFILE
 ; RUN: llvm-profgen --format=text --unsymbolized-profile=%t --binary=%S/Inputs/inline-noprobe.perfbin --output=%t1
 ; RUN: FileCheck %s --input-file %t1 --check-prefix=CHECK
 ; RUN: llvm-profgen --format=text --unsymbolized-profile=%t --binary=%S/Inputs/inline-noprobe.perfbin --output=%t1 --update-total-samples
 ; RUN: FileCheck %s --input-file %t1 --check-prefix=CHECK-UPDATE-TOTAL-SAMPLE
 ; RUN: llvm-profgen --format=text --use-dwarf-correlation --perfscript=%S/Inputs/inline-noprobe.perfscript --binary=%S/Inputs/inline-noprobe.perfbin --output=%t
 ; RUN: FileCheck %s --input-file %t --check-prefix=CHECK
-; RUN: echo -e "0\n0" > %t
-; RUN: llvm-profgen --format=text --unsymbolized-profile=%t --binary=%S/Inputs/inline-noprobe.perfbin --output=%t1 --fill-zero-for-all-funcs
-; RUN: FileCheck %s --input-file %t1 --check-prefix=CHECK-ALL-ZERO
 ; RUN: llvm-profgen --format=text --unsymbolized-profile=%S/Inputs/out-of-bounds.raw.prof --binary=%S/Inputs/inline-noprobe.perfbin --output=%t1
 ; RUN: FileCheck %s --input-file %t1 --check-prefix=CHECK-OB
 
 CHECK: main:2609:0
 CHECK:  0: 0
 CHECK:  2: 0
 CHECK:  1: foo:2609
 CHECK:   2.1: 42

 CHECK-UPDATE-TOTAL-SAMPLE:   4: 0
 CHECK-UPDATE-TOTAL-SAMPLE:   65526: 62
 CHECK-UPDATE-TOTAL-SAMPLE:   3.1: bar:84
 CHECK-UPDATE-TOTAL-SAMPLE:    1: 42
 CHECK-UPDATE-TOTAL-SAMPLE:    65533: 42
 CHECK-UPDATE-TOTAL-SAMPLE:   3.2: bar:21
 CHECK-UPDATE-TOTAL-SAMPLE:    1: 21
 
-CHECK-ALL-ZERO: bar:0:0
-CHECK-ALL-ZERO:  1: 0
-CHECK-ALL-ZERO:  5: 0
-CHECK-ALL-ZERO: foo:0:0
-CHECK-ALL-ZERO:  0: 0
-CHECK-ALL-ZERO:  2.1: 0
-CHECK-ALL-ZERO:  3: 0
-CHECK-ALL-ZERO:  3.2: 0
-CHECK-ALL-ZERO:  4: 0
-CHECK-ALL-ZERO:  3.1: bar:0
-CHECK-ALL-ZERO:   1: 0
-CHECK-ALL-ZERO:  3.2: bar:0
-CHECK-ALL-ZERO:   1: 0
-CHECK-ALL-ZERO:   7: 0
-CHECK-ALL-ZERO: main:0:0
-CHECK-ALL-ZERO:  0: 0
-CHECK-ALL-ZERO:  2: 0
-CHECK-ALL-ZERO:  1: foo:0
-CHECK-ALL-ZERO:   2.1: 0
-CHECK-ALL-ZERO:   3: 0
-CHECK-ALL-ZERO:   3.2: 0
-CHECK-ALL-ZERO:   4: 0
-CHECK-ALL-ZERO:   3.1: bar:0
-CHECK-ALL-ZERO:    1: 0
-CHECK-ALL-ZERO:   3.2: bar:0
-CHECK-ALL-ZERO:    1: 0
-
 CHECK-RAW-PROFILE:      3
 CHECK-RAW-PROFILE-NEXT: 650-691:21
 CHECK-RAW-PROFILE-NEXT: 669-677:20
 CHECK-RAW-PROFILE-NEXT: 669-691:21
 CHECK-RAW-PROFILE-NEXT: 2
 CHECK-RAW-PROFILE-NEXT: 677->650:21
 CHECK-RAW-PROFILE-NEXT: 691->669:43
 

llvm/test/tools/llvm-profgen/zero-all-functions.test

+
+; RUN: echo -e "0\n0" > %t
+; RUN: llvm-profgen --format=text --unsymbolized-profile=%t --binary=%S/Inputs/inline-noprobe.perfbin --output=%t1 --fill-zero-for-all-funcs
+; RUN: FileCheck %s --input-file %t1 --check-prefix=CHECK-LINE
+; RUN: llvm-profgen --format=text --unsymbolized-profile=%t --binary=%S/Inputs/inline-cs-pseudoprobe.perfbin --output=%t2 --fill-zero-for-all-funcs
+; RUN: FileCheck %s --input-file %t2 --check-prefix=CHECK-PROBE
+
+CHECK-LINE:      bar:0:0
+CHECK-LINE-NEXT:  1: 0
+CHECK-LINE-NEXT:  5: 0
+CHECK-LINE-NEXT: foo:0:0
+CHECK-LINE-NEXT:  0: 0
+CHECK-LINE-NEXT:  2.1: 0
+CHECK-LINE-NEXT:  3: 0
+CHECK-LINE-NEXT:  3.2: 0
+CHECK-LINE-NEXT:  4: 0
+CHECK-LINE-NEXT:  3.1: bar:0
+CHECK-LINE-NEXT:   1: 0
+CHECK-LINE-NEXT:   65533: 0
+CHECK-LINE-NEXT:  3.2: bar:0
+CHECK-LINE-NEXT:   1: 0
+CHECK-LINE-NEXT:   7: 0
+CHECK-LINE-NEXT: main:0:0
+CHECK-LINE-NEXT:  0: 0
+CHECK-LINE-NEXT:  2: 0
+CHECK-LINE-NEXT:  1: foo:0
+CHECK-LINE-NEXT:   2.1: 0
+CHECK-LINE-NEXT:   3: 0
+CHECK-LINE-NEXT:   3.2: 0
+CHECK-LINE-NEXT:   4: 0
+CHECK-LINE-NEXT:    65526: 0
+CHECK-LINE-NEXT:   3.1: bar:0
+CHECK-LINE-NEXT:    1: 0
+CHECK-LINE-NEXT:    65533: 0
+CHECK-LINE-NEXT:   3.2: bar:0
+CHECK-LINE-NEXT:    1: 0
+
+CHECK-PROBE:     bar:0:0
+CHECK-PROBE-NEXT: 0: 0
+CHECK-PROBE-NEXT: 1: 0
+CHECK-PROBE-NEXT: 5: 0
+CHECK-PROBE-NEXT:foo:0:0
+CHECK-PROBE-NEXT: 0: 0
+CHECK-PROBE-NEXT: 2: 0
+CHECK-PROBE-NEXT: 3: 0
+CHECK-PROBE-NEXT: 4: 0
+CHECK-PROBE-NEXT: 5: 0
+CHECK-PROBE-NEXT: 65526: 0
+CHECK-PROBE-NEXT: 3: bar:0
+CHECK-PROBE-NEXT:  1: 0
+CHECK-PROBE-NEXT:  65533: 0
+CHECK-PROBE-NEXT:main:0:0
+CHECK-PROBE-NEXT: 0: 0
+CHECK-PROBE-NEXT: 2: 0
+CHECK-PROBE-NEXT: 1: foo:0
+CHECK-PROBE-NEXT:  2: 0
+CHECK-PROBE-NEXT:  3: 0
+CHECK-PROBE-NEXT:  4: 0
+CHECK-PROBE-NEXT:  65526: 0
+CHECK-PROBE-NEXT:  3: bar:0
+CHECK-PROBE-NEXT:   1: 0
+CHECK-PROBE-NEXT:   65533: 0

llvm/tools/llvm-profgen/ProfileGenerator.cpp

ProfileGenerator::getTopLevelFunctionProfile(StringRef FuncName) {
   if (Ret.second) {
     FunctionSamples &FProfile = Ret.first->second;
     FProfile.setContext(Context);
   }
   return Ret.first->second;
 }
 
 void ProfileGenerator::generateProfile() {
-  if (Binary->usePseudoProbes()) {
+  if (Binary->usePseudoProbes() && !FillZeroForAllFuncs) {
     // TODO: Support probe based profile generation
     exitWithError("Probe based profile generation not supported for AutoFDO, "
       "consider dropping `--ignore-stack-samples` or adding `--use-dwarf-correlation`.");
   } else {
     generateLineNumBasedProfile();
   }
   postProcessProfiles();
 }