diff options
| author | Duncan Sands <baldrick@free.fr> | 2012-05-25 12:03:02 +0000 |
|---|---|---|
| committer | Duncan Sands <baldrick@free.fr> | 2012-05-25 12:03:02 +0000 |
| commit | 0fd120b970fe9a036ae664ad1bfbf04e55b3b8a7 (patch) | |
| tree | da1ffda08fb9cc5555443bc4792c69090f9508b9 /test/Transforms/Reassociate | |
| parent | c7a098fbb23f7f6cfbbbfc097b22c10cf4211ab6 (diff) | |
Make the reassociation pass more powerful so that it can handle expressions
with arbitrary topologies (previously it would give up when hitting a diamond
in the use graph for example). The testcase from PR12764 is now reduced from
a pile of additions to the optimal 1617*%x0+208. In doing this I changed the
previous strategy of dropping all uses for expression leaves to one of dropping
all but one use. This works out more neatly (but required a bunch of tweaks)
and is also safer: some recently fixed bugs during recursive linearization were
because the linearization code thinks it completely owns a node if it has no uses
outside the expression it is linearizing. But if the node was also in another
expression that had been linearized (and thus all uses of the node from that
expression dropped) then the conclusion that it is completely owned by the
expression currently being linearized is wrong. Keeping one use from within each
linearized expression avoids this kind of mistake.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157467 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'test/Transforms/Reassociate')
| -rw-r--r-- | test/Transforms/Reassociate/2012-05-08-UndefLeak.ll | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/test/Transforms/Reassociate/2012-05-08-UndefLeak.ll b/test/Transforms/Reassociate/2012-05-08-UndefLeak.ll index 8019361569..1e522e6160 100644 --- a/test/Transforms/Reassociate/2012-05-08-UndefLeak.ll +++ b/test/Transforms/Reassociate/2012-05-08-UndefLeak.ll @@ -1,8 +1,12 @@ ; RUN: opt < %s -reassociate -S | FileCheck %s ; PR12169 +; PR12764 define i64 @f(i64 %x0) { -; CHECK-NOT: undef +; CHECK: @f +; CHECK-NEXT: mul i64 %x0, 208 +; CHECK-NEXT: add i64 %{{.*}}, 1617 +; CHECK-NEXT: ret i64 %t0 = add i64 %x0, 1 %t1 = add i64 %x0, 2 %t2 = add i64 %x0, 3 |