en Copyright 2015 Java http://172.16.0.5:8080/history/llvm-project-15.0.7/llvm/test/tools/llvm-profgen/Inputs/inline-cs-pseudoprobe.perfbin#bd524955 [CSSPGO] Undoing the concept of dangling pseudo probeAs a follow-up to https://reviews.llvm.org/D104129, I'm cleaning up the danling probe related code in both the compiler and llvm-profgen.I'm seeing a 5% size win for the pseudo_probe section for SPEC2017 and 10% for Ciner. Certain benchmark such as 602.gcc has a 20% size win. No obvious difference seen on build time for SPEC2017 and Cinder.Reviewed By: wenleiDifferential Revision: https://reviews.llvm.org/D104477 List of files: /llvm-project-15.0.7/llvm/test/tools/llvm-profgen/Inputs/inline-cs-pseudoprobe.perfbin Thu, 17 Jun 2021 18:09:13 +0000 Hongtao Yu <hoy@fb.com> http://172.16.0.5:8080/history/llvm-project-15.0.7/llvm/test/tools/llvm-profgen/Inputs/inline-cs-pseudoprobe.perfbin#b3154d11 [CSSPGO][llvm-profgen] Pseudo probe decoding and disassemblingThis change implements pseudo probe decoding and disassembling for llvm-profgen/CSSPGO. Please see https://groups.google.com/g/llvm-dev/c/1p1rdYbL93s and https://reviews.llvm.org/D89707 for more context about CSSPGO and llvm-profgen.**ELF section format**Please see the encoding patch(https://reviews.llvm.org/D91878) for more details of the format, just copy the example here:Two section(`.pseudo_probe_desc` and  `.pseudoprobe` ) is emitted in ELF to support pseudo probe.The format of `.pseudo_probe_desc` section looks like:```.section .pseudo_probe_desc,"",@progbits.quad 6309742469962978389 // Func GUID.quad 4294967295 // Func Hash.byte 9 // Length of func name.ascii "_Z5funcAi" // Func name.quad 7102633082150537521.quad 138828622701.byte 12.ascii "_Z8funcLeafi".quad 446061515086924981.quad 4294967295.byte 9.ascii "_Z5funcBi".quad -2016976694713209516.quad 72617220756.byte 7.ascii "_Z3fibi"```For each `.pseudoprobe` section, the encoded binary data consists of a single function record corresponding to an outlined function (i.e, a function with a code entry in the `.text` section). A function record has the following format :```FUNCTION BODY (one for each outlined function present in the text section) GUID (uint64) GUID of the function NPROBES (ULEB128) Number of probes originating from this function. NUM_INLINED_FUNCTIONS (ULEB128) Number of callees inlined into this function, aka number of first-level inlinees PROBE RECORDS A list of NPROBES entries. Each entry contains: INDEX (ULEB128) TYPE (uint4) 0 - block probe, 1 - indirect call, 2 - direct call ATTRIBUTE (uint3) reserved ADDRESS_TYPE (uint1) 0 - code address, 1 - address delta CODE_ADDRESS (uint64 or ULEB128) code address or address delta, depending on ADDRESS_TYPE INLINED FUNCTION RECORDS A list of NUM_INLINED_FUNCTIONS entries describing each of the inlined callees. Each record contains: INLINE SITE GUID of the inlinee (uint64) ID of the callsite probe (ULEB128) FUNCTION BODY A FUNCTION BODY entry describing the inlined function.```**Disassembling**A switch `--show-pseudo-probe` is added to use along with `--show-disassembly` to print disassembly code with pseudo probe directives.For example:```00000000002011a0 <foo2>: 2011a0: 50 push rax 2011a1: 85 ff test edi,edi [Probe]: FUNC: foo2 Index: 1 Type: Block 2011a3: 74 02 je 2011a7 <foo2+0x7> [Probe]: FUNC: foo2 Index: 3 Type: Block [Probe]: FUNC: foo2 Index: 4 Type: Block [Probe]: FUNC: foo Index: 1 Type: Block Inlined: @ foo2:6 2011a5: 58 pop rax 2011a6: c3 ret [Probe]: FUNC: foo2 Index: 2 Type: Block 2011a7: bf 01 00 00 00 mov edi,0x1 [Probe]: FUNC: foo2 Index: 5 Type: IndirectCall 2011ac: ff d6 call rsi [Probe]: FUNC: foo2 Index: 4 Type: Block 2011ae: 58 pop rax 2011af: c3 ret```**Implementation**- `PseudoProbeDecoder` is added in ProfiledBinary as an infra for the decoding. It decoded the two section and generate two map: `GUIDProbeFunctionMap` stores all the `PseudoProbeFunction` which is the abstraction of a general function. `AddressProbesMap` stores all the pseudo probe info indexed by its address.- All the inline info is encoded into binary as a trie(`PseudoProbeInlineTree`) and will be constructed from the decoding. Each pseudo probe can get its inline context(`getInlineContext`) by traversing its inline tree node backwards.Test Plan:ninja & ninja check-llvmDifferential Revision: https://reviews.llvm.org/D92334 List of files: /llvm-project-15.0.7/llvm/test/tools/llvm-profgen/Inputs/inline-cs-pseudoprobe.perfbin Tue, 24 Nov 2020 04:33:23 +0000 wlei <wlei@fb.com>