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5 C90/C99/C++ Comparisons:
6 http://david.tribble.com/text/cdiffs.htm
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10 To time GCC preprocessing speed without output, use:
12 This is similar to -Eonly.
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16 Creating and using a PTH file for performance measurement (use a release-asserts
19 $ clang -x objective-c-header INPUTS/Cocoa_h.m -o /tmp/tokencache
20 $ clang -token-cache /tmp/tokencache INPUTS/Cocoa_h.m
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24 C++ Template Instantiation benchmark:
25 http://users.rcn.com/abrahams/instantiation_speed/index.html
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29 TODO: File Manager Speedup:
31 We currently do a lot of stat'ing for files that don't exist, particularly
32 when lots of -I paths exist (e.g. see the <iostream> example, check for
33 failures in stat in FileManager::getFile). It would be far better to make
34 the following changes:
35 1. FileEntry contains a sys::Path instead of a std::string for Name.
36 2. sys::Path contains timestamp and size, lazily computed. Eliminate from
38 3. File UIDs are created on request, not when files are opened.
39 These changes make it possible to efficiently have FileEntry objects for
40 files that exist on the file system, but have not been used yet.
43 1. DirectoryEntry gets a boolean value "has read entries". When false, not
44 all entries in the directory are in the file mgr, when true, they are.
45 2. Instead of stat'ing the file in FileManager::getFile, check to see if
46 the dir has been read. If so, fail immediately, if not, read the dir,
48 3. Reading the dir uses the getdirentries syscall, creating an FileEntry
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52 // Specifying targets: -triple and -arch
53 ===---------------------------------------------------------------------===//
55 The clang supports "-triple" and "-arch" options. At most one -triple and one
56 -arch option may be specified. Both are optional.
58 The "selection of target" behavior is defined as follows:
60 (1) If the user does not specify -triple, we default to the host triple.
61 (2) If the user specifies a -arch, that overrides the arch in the host or
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67 verifyInputConstraint and verifyOutputConstraint should not return bool.
69 Instead we should return something like:
71 enum VerifyConstraintResult {
75 OutputOperandConstraintLacksEqualsCharacter,
76 MatchingConstraintNotValidInOutputOperand,
79 InputOperandConstraintContainsEqualsCharacter,
80 MatchingConstraintReferencesInvalidOperandNumber,
83 PercentConstraintUsedWithLastOperand
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