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| author | Richard Biener <rguenther@suse.de> | 2014-12-04 14:44:57 +0000 |
|---|---|---|
| committer | Richard Biener <rguenth@gcc.gnu.org> | 2014-12-04 14:44:57 +0000 |
| commit | 881083d629878da043d3f0d7ab5584e77253626c (patch) | |
| tree | 6da8594866f29cf2ae6e684675423173b67aca42 | |
| parent | 04be694e4d9132523f01de8d9873c6b07164afb2 (diff) | |
| download | gcc-881083d629878da043d3f0d7ab5584e77253626c.zip gcc-881083d629878da043d3f0d7ab5584e77253626c.tar.gz gcc-881083d629878da043d3f0d7ab5584e77253626c.tar.bz2 | |
match-and-simplify.texi: Update for recent changes.
2014-12-04 Richard Biener <rguenther@suse.de>
* doc/match-and-simplify.texi: Update for recent changes.
From-SVN: r218372
| -rw-r--r-- | gcc/ChangeLog | 4 | ||||
| -rw-r--r-- | gcc/doc/match-and-simplify.texi | 40 |
2 files changed, 44 insertions, 0 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 7902ac0..f937c44 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,7 @@ +2014-12-04 Richard Biener <rguenther@suse.de> + + * doc/match-and-simplify.texi: Update for recent changes. + 2014-12-04 Martin Jambor <mjambor@suse.cz> * ipa-prop.h (ipa_alignment): New type. diff --git a/gcc/doc/match-and-simplify.texi b/gcc/doc/match-and-simplify.texi index d63d8b8..2d8faf8 100644 --- a/gcc/doc/match-and-simplify.texi +++ b/gcc/doc/match-and-simplify.texi @@ -224,6 +224,46 @@ In this example the pattern will be repeated four times with @code{plus, minus, minus}, @code{minus, plus, plus}, @code{minus, plus, minus}. +To avoid repeating operator lists in @code{for} you can name +them via + +@smallexample +(define_operator_list pmm plus minus mult) +@end smallexample + +and use them in @code{for} operator lists where they get expanded. + +@smallexample +(for opa (pmm trunc_div) + (simplify... +@end smallexample + +So this example iterates over @code{plus}, @code{minus}, @code{mult} +and @code{trunc_div}. + +Using operator lists can also remove the need to explicitely write +a @code{for}. All operator list uses that appear in a @code{simplify} +or @code{match} pattern in operator positions will implicitely +be added to a new @code{for}. For example + +@smallexample +(define_operator_list SQRT BUILT_IN_SQRTF BUILT_IN_SQRT BUILT_IN_SQRTL) +(define_operator_list POW BUILT_IN_POWF BUILT_IN_POW BUILT_IN_POWL) +(simplify + (SQRT (POW @@0 @@1)) + (POW (abs @@0) (mult @@1 @{ built_real (TREE_TYPE (@@1), dconsthalf); @}))) +@end smallexample + +is the same as + +@smallexample +(for SQRT (BUILT_IN_SQRTF BUILT_IN_SQRT BUILT_IN_SQRTL) + POW (BUILT_IN_POWF BUILT_IN_POW BUILT_IN_POWL) + (simplify + (SQRT (POW @@0 @@1)) + (POW (abs @@0) (mult @@1 @{ built_real (TREE_TYPE (@@1), dconsthalf); @})))) +@end smallexample + Another building block are @code{with} expressions in the result expression which nest the generated code in a new C block followed by its argument: |