From 12984de3140534da4f312190118726963a2b521e Mon Sep 17 00:00:00 2001 From: Owen Anderson Date: Wed, 15 Dec 2010 22:32:38 +0000 Subject: 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 . git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121905 91177308-0d34-0410-b5e6-96231b3b80d8 --- test/Transforms/InstCombine/overflow.ll | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) create mode 100644 test/Transforms/InstCombine/overflow.ll (limited to 'test') 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 +; + +; 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(...) -- cgit v1.2.3