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| author | Aditya Kumar <hiraditya@msn.com> | 2017-12-13 19:40:07 +0000 |
|---|---|---|
| committer | Aditya Kumar <hiraditya@msn.com> | 2017-12-13 19:40:07 +0000 |
| commit | 2bf4af887ec2aa30a4014c64ac9df026917d9e12 (patch) | |
| tree | 8af82eff0b568541f31eb4a405a62c0bea8ca645 /test/Transforms | |
| parent | 267645038a86f99779cfe82b230c47c494dbe4a3 (diff) | |
[GVNHoist] Fix: PR35222 gvn-hoist incorrectly erases load
w.r.t. the paper
"A Practical Improvement to the Partial Redundancy Elimination in SSA Form"
(https://sites.google.com/site/jongsoopark/home/ssapre.pdf)
Proper dominance check was missing here, so having a loopinfo should not be required.
Committing this diff as this fixes the bug, if there are
further concerns, I'll be happy to work on them.
Differential Revision: https://reviews.llvm.org/D39781
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@320607 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'test/Transforms')
| -rw-r--r-- | test/Transforms/GVNHoist/pr35222-hoist-load.ll | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/test/Transforms/GVNHoist/pr35222-hoist-load.ll b/test/Transforms/GVNHoist/pr35222-hoist-load.ll new file mode 100644 index 00000000000..7e9c6200616 --- /dev/null +++ b/test/Transforms/GVNHoist/pr35222-hoist-load.ll @@ -0,0 +1,25 @@ +; RUN: opt -S -gvn-hoist < %s | FileCheck %s +; CHECK: load +; CHECK: load +; Check that the load is not hoisted because the call can potentially +; modify the global + +target datalayout = "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64" + +@heap = external global i32, align 4 + +define i32 @build_tree() unnamed_addr { +entry: + br label %do.body + +do.body: ; preds = %do.body, %entry + %tmp9 = load i32, i32* @heap, align 4 + %cmp = call i1 @pqdownheap(i32 %tmp9) + br i1 %cmp, label %do.body, label %do.end + +do.end: ; preds = %do.body + %tmp20 = load i32, i32* @heap, align 4 + ret i32 %tmp20 +} + +declare i1 @pqdownheap(i32) |