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| author | Benjamin Kramer <benny.kra@googlemail.com> | 2013-06-21 19:30:05 +0000 |
|---|---|---|
| committer | Benjamin Kramer <benny.kra@googlemail.com> | 2013-06-21 19:30:05 +0000 |
| commit | 93702a3b0754052d926c75082abf7ca156b80c45 (patch) | |
| tree | 10b032704125296644321d26cc84d3053da88dc7 /test | |
| parent | 65af4b5333f539b9e572ebb9c4d4e97a897e5130 (diff) | |
| download | llvm-93702a3b0754052d926c75082abf7ca156b80c45.tar.gz llvm-93702a3b0754052d926c75082abf7ca156b80c45.tar.bz2 llvm-93702a3b0754052d926c75082abf7ca156b80c45.tar.xz | |
BlockFrequency: Saturate at 1 instead of 0 when multiplying a frequency with a branch probability.
Zero is used by BlockFrequencyInfo as a special "don't know" value. It also
causes a sink for frequencies as you can't ever get off a zero frequency with
more multiplies.
This recovers a 10% regression on MultiSource/Benchmarks/7zip. A zero frequency
was propagated into an inner loop causing excessive spilling.
PR16402.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184584 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'test')
| -rw-r--r-- | test/Analysis/BlockFrequencyInfo/singularity.ll | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/test/Analysis/BlockFrequencyInfo/singularity.ll b/test/Analysis/BlockFrequencyInfo/singularity.ll new file mode 100644 index 0000000000..9077cc0656 --- /dev/null +++ b/test/Analysis/BlockFrequencyInfo/singularity.ll @@ -0,0 +1,65 @@ +; RUN: opt < %s -analyze -block-freq | FileCheck %s +; PR16402 + +define void @test1(i32 %n) nounwind { +entry: + %call = tail call i32* @cond() nounwind + %tobool = icmp eq i32* %call, null + br i1 %tobool, label %land.lhs.true, label %if.end + +land.lhs.true: ; preds = %entry + %call1 = tail call i32* @cond() nounwind + %tobool2 = icmp eq i32* %call1, null + br i1 %tobool2, label %land.lhs.true3, label %if.end + +land.lhs.true3: ; preds = %land.lhs.true + %call4 = tail call i32* @cond() nounwind + %tobool5 = icmp eq i32* %call4, null + br i1 %tobool5, label %land.lhs.true6, label %if.end + +land.lhs.true6: ; preds = %land.lhs.true3 + %call7 = tail call i32* @cond() nounwind + %tobool8 = icmp eq i32* %call7, null + br i1 %tobool8, label %land.lhs.true9, label %if.end + +land.lhs.true9: ; preds = %land.lhs.true6 + %call10 = tail call i32* @cond() nounwind + %tobool11 = icmp eq i32* %call10, null + br i1 %tobool11, label %land.lhs.true12, label %if.end + +land.lhs.true12: ; preds = %land.lhs.true9 + %call13 = tail call i32* @cond() nounwind + %tobool14 = icmp eq i32* %call13, null + br i1 %tobool14, label %land.lhs.true15, label %if.end + +land.lhs.true15: ; preds = %land.lhs.true12 + %call16 = tail call i32* @cond() nounwind + %tobool17 = icmp eq i32* %call16, null + br i1 %tobool17, label %for.cond.preheader, label %if.end + +for.cond.preheader: ; preds = %land.lhs.true15 + %cmp21 = icmp eq i32 %n, 0 + br i1 %cmp21, label %for.end, label %for.body + +for.body: ; preds = %for.cond.preheader, %for.body + %i.022 = phi i32 [ %inc, %for.body ], [ 0, %for.cond.preheader ] + %call18 = tail call i32 @call() nounwind + %inc = add nsw i32 %i.022, 1 + %cmp = icmp eq i32 %inc, %n + br i1 %cmp, label %for.end, label %for.body + +for.end: ; preds = %for.body, %for.cond.preheader + %call19 = tail call i32* @cond() nounwind + br label %if.end + +if.end: ; preds = %land.lhs.true15, %land.lhs.true12, %land.lhs.true9, %land.lhs.true6, %land.lhs.true3, %land.lhs.true, %entry, %for.end + ret void + +; CHECK: entry = 1024 +; CHECK-NOT: for.body = 0 +; CHECK-NOT: for.end = 0 +} + +declare i32* @cond() nounwind + +declare i32 @call() nounwind |