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| author | Matthijs Kooijman <matthijs@stdin.nl> | 2008-06-05 07:55:49 +0000 |
|---|---|---|
| committer | Matthijs Kooijman <matthijs@stdin.nl> | 2008-06-05 07:55:49 +0000 |
| commit | 845f524c25de18917f72e8847d7e138d65e4ef08 (patch) | |
| tree | ecaa9ac4209ddead0213f491182c122ef7ece196 /docs | |
| parent | 67944fc42755a32a864c105d604e8829e5ccc4b2 (diff) | |
| download | llvm-845f524c25de18917f72e8847d7e138d65e4ef08.tar.gz llvm-845f524c25de18917f72e8847d7e138d65e4ef08.tar.bz2 llvm-845f524c25de18917f72e8847d7e138d65e4ef08.tar.xz | |
Update comments and documentation to reflect that GCSE and ValueNumbering are
deprecated by the GVN and GVNPRE passes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51983 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'docs')
| -rw-r--r-- | docs/Passes.html | 22 |
1 files changed, 20 insertions, 2 deletions
diff --git a/docs/Passes.html b/docs/Passes.html index 21b03f5399..bb1a64bd97 100644 --- a/docs/Passes.html +++ b/docs/Passes.html @@ -298,7 +298,7 @@ perl -e '$/ = undef; for (split(/\n/, <>)) { s:^ *///? ?::; print " <p>\n" if ! <!-------------------------------------------------------------------------- --> <div class="doc_subsection"> - <a name="basicvn">Basic Value Numbering (default GVN impl)</a> + <a name="basicvn">Basic Value Numbering (default Value Numbering impl)</a> </div> <div class="doc_text"> <p> @@ -307,6 +307,12 @@ perl -e '$/ = undef; for (split(/\n/, <>)) { s:^ *///? ?::; print " <p>\n" if ! lexically identical expressions. This does not require any ahead of time analysis, so it is a very fast default implementation. </p> + <p> + The ValueNumbering analysis passes are mostly deprecated. They are only used + by the <a href="#gcse">Global Common Subexpression Elimination pass</a>, which + is deprecated by the <a href="#gvn">Global Value Numbering pass</a> (which + does its value numbering on its own). + </p> </div> <!-------------------------------------------------------------------------- --> @@ -859,9 +865,13 @@ perl -e '$/ = undef; for (split(/\n/, <>)) { s:^ *///? ?::; print " <p>\n" if ! <p> This pass is designed to be a very quick global transformation that eliminates global common subexpressions from a function. It does this by - using an existing value numbering implementation to identify the common + using an existing value numbering analysis pass to identify the common subexpressions, eliminating them when possible. </p> + <p> + This pass is deprecated by the <a href="#gvn">Global Value Numbering pass</a> + (which does a better job with its own value numbering). + </p> </div> <!-------------------------------------------------------------------------- --> @@ -899,6 +909,10 @@ perl -e '$/ = undef; for (split(/\n/, <>)) { s:^ *///? ?::; print " <p>\n" if ! This pass performs global value numbering to eliminate fully redundant instructions. It also performs simple dead load elimination. </p> + <p> + Note that this pass does the value numbering itself, it does not use the + ValueNumbering analysis passes. + </p> </div> <!-------------------------------------------------------------------------- --> @@ -916,6 +930,10 @@ perl -e '$/ = undef; for (split(/\n/, <>)) { s:^ *///? ?::; print " <p>\n" if ! live ranges, and should be used with caution on platforms that are very sensitive to register pressure. </p> + <p> + Note that this pass does the value numbering itself, it does not use the + ValueNumbering analysis passes. + </p> </div> <!-------------------------------------------------------------------------- --> |