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| author | Owen Anderson <resistor@mac.com> | 2010-12-15 22:32:38 +0000 |
|---|---|---|
| committer | Owen Anderson <resistor@mac.com> | 2010-12-15 22:32:38 +0000 |
| commit | 12984de3140534da4f312190118726963a2b521e (patch) | |
| tree | 3de799bb13ddb25aae0f2ba6cc629109aeef63d6 /test | |
| parent | e194b26ffd23aa464324429323647af4fcb7df7b (diff) | |
| download | llvm-12984de3140534da4f312190118726963a2b521e.tar.gz llvm-12984de3140534da4f312190118726963a2b521e.tar.bz2 llvm-12984de3140534da4f312190118726963a2b521e.tar.xz | |
Add an InstCombine transform to recognize instances of manual overflow-safe addition
(performing the addition in a wider type and explicitly checking for overflow), and
fold them down to intrinsics. This currently only supports signed-addition, but could
be generalized if someone works out the magic constant formulas for other operations.
Fixes <rdar://problem/8558713>.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121905 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'test')
| -rw-r--r-- | test/Transforms/InstCombine/overflow.ll | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/test/Transforms/InstCombine/overflow.ll b/test/Transforms/InstCombine/overflow.ll new file mode 100644 index 0000000000..f3f8ca3d61 --- /dev/null +++ b/test/Transforms/InstCombine/overflow.ll @@ -0,0 +1,27 @@ +; RUN: opt -S -instcombine < %s | FileCheck %s +; <rdar://problem/8558713> + +; CHECK: @test1 +define i32 @test1(i32 %a, i32 %b) nounwind ssp { +entry: +; CHECK-NOT: sext + %conv = sext i32 %a to i64 + %conv2 = sext i32 %b to i64 + %add = add nsw i64 %conv2, %conv + %add.off = add i64 %add, 2147483648 +; CHECK: llvm.sadd.with.overflow + %0 = icmp ugt i64 %add.off, 4294967295 + br i1 %0, label %if.then, label %if.end + +if.then: + %call = tail call i32 (...)* @throwAnExceptionOrWhatever() nounwind + br label %if.end + +if.end: +; CHECK-NOT: trunc + %conv9 = trunc i64 %add to i32 +; CHECK: ret i32 + ret i32 %conv9 +} + +declare i32 @throwAnExceptionOrWhatever(...) |