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| author | Chris Lattner <sabre@nondot.org> | 2011-02-21 02:13:39 +0000 |
|---|---|---|
| committer | Chris Lattner <sabre@nondot.org> | 2011-02-21 02:13:39 +0000 |
| commit | 19310fc199418d5f71bb4824f75de21a8324c93e (patch) | |
| tree | d3e4d4709c44c29efe5fb70426e80efe0856e0c1 /lib/Target/README.txt | |
| parent | 408b534e431cc317f1116cd78df96da2af7cafd9 (diff) | |
| download | llvm-19310fc199418d5f71bb4824f75de21a8324c93e.tar.gz llvm-19310fc199418d5f71bb4824f75de21a8324c93e.tar.bz2 llvm-19310fc199418d5f71bb4824f75de21a8324c93e.tar.xz | |
add a missed loop deletion case.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126103 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Target/README.txt')
| -rw-r--r-- | lib/Target/README.txt | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/lib/Target/README.txt b/lib/Target/README.txt index bda764deff..f85914b61d 100644 --- a/lib/Target/README.txt +++ b/lib/Target/README.txt @@ -254,6 +254,20 @@ unsigned long reverse(unsigned v) { //===---------------------------------------------------------------------===// +[LOOP DELETION] + +We don't delete this output free loop, because trip count analysis doesn't +realize that it is finite (if it were infinite, it would be undefined). Not +having this blocks Loop Idiom from matching strlen and friends. + +void foo(char *C) { + int x = 0; + while (*C) + ++x,++C; +} + +//===---------------------------------------------------------------------===// + [LOOP RECOGNITION] These idioms should be recognized as popcount (see PR1488): |