4357824c63
Cleanup profile reader classes to prepare for complex refactoring as propsed in D147740 (Use MD5 as key for profile map). Change is too complicated so I am cleaning up the reader implementation first with these goals. - Reduce duplicated/similar logic - Reduce virtual functions, changing them to non-virtual - Reduce unnecessry checks, indirections, and dead writes. This is patch 1/n. This patch refactors NameTable Explaining several decisions here 1. useMD5() means whether names of the profiles (the ProfileMap) are represented as MD5. It is NOT whether the input profile format is MD5. This function is an interface for IPO passes to decide whether to match function names or function MD5. There are two motives here: (a) Eventually we want to use MD5 to represent all function contexts because it is much faster to use it as a key for lookup tables (prototype implementation D147740), so in compilation mode we call setProfileUseMD5() to force use MD5. While in tools mode (llvm-profdata) we want to keep the function name info if it's in the input profile. (b) We also propose to allow multiple name tables and profile sections in ExtBinary format, and it could consist of name tables with or without using MD5, in this case MD5 prevails and other name tables are converted to MD5. 2. MD5 handling logic is pushed up to BinaryReader base class, because this trades a non-devirtualized virtual function call with a predictable branch. ReadStringFromTable() accounts for >5% time when loading a full 1 GB profile, it should not be virtual. Reviewed By: davidxl Differential Revision: https://reviews.llvm.org/D148868
13 lines
914 B
Plaintext
13 lines
914 B
Plaintext
Test several edge cases with unusual name table data in ExtBinary format.
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1- Multiple fixed-length MD5 name tables. Reading a new table should clear the content from old table, and a valid name index for the old name table should become invalid if the new name table has fewer entries.
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RUN: not llvm-profdata show --sample %p/Inputs/sample-multiple-nametables.profdata
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2- Multiple name tables, the first one has an empty string, the second one tricks the reader into expecting fixed-length MD5 values. Reader should not attempt "lazy loading" of the MD5 string in this case.
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RUN: not llvm-profdata show --sample %p/Inputs/sample-nametable-empty-string.profdata
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3- The data of the name table is placed after the data of the profiles. The reader should handle it correctly.
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RUN: llvm-profdata merge --sample --text %p/Inputs/sample-nametable-after-samples.profdata | FileCheck %s
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CHECK: 18446744073709551615:2:9
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