diff options
Diffstat (limited to 'llvm/test/Transforms/InstCombine/overflow.ll')
| -rw-r--r-- | llvm/test/Transforms/InstCombine/overflow.ll | 30 |
1 files changed, 29 insertions, 1 deletions
diff --git a/llvm/test/Transforms/InstCombine/overflow.ll b/llvm/test/Transforms/InstCombine/overflow.ll index f3f8ca3d61d..e54d315cd04 100644 --- a/llvm/test/Transforms/InstCombine/overflow.ll +++ b/llvm/test/Transforms/InstCombine/overflow.ll @@ -1,6 +1,8 @@ ; RUN: opt -S -instcombine < %s | FileCheck %s ; <rdar://problem/8558713> +declare i32 @throwAnExceptionOrWhatever(...) + ; CHECK: @test1 define i32 @test1(i32 %a, i32 %b) nounwind ssp { entry: @@ -24,4 +26,30 @@ if.end: ret i32 %conv9 } -declare i32 @throwAnExceptionOrWhatever(...) +; CHECK: @test2 +; This form should not be promoted for two reasons: 1) it is unprofitable to +; promote it since the add.off instruction has another use, and 2) it is unsafe +; because the add-with-off makes the high bits of the original add live. +define i32 @test2(i32 %a, i32 %b, i64* %P) nounwind ssp { +entry: + %conv = sext i32 %a to i64 + %conv2 = sext i32 %b to i64 + %add = add nsw i64 %conv2, %conv + %add.off = add i64 %add, 2147483648 + + store i64 %add.off, i64* %P + +; CHECK-NOT: 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: + %conv9 = trunc i64 %add to i32 +; CHECK: ret i32 + ret i32 %conv9 +} + |
