[PATCH] D13354: Assign correct edge weights to unwind destinations when lowering invoke statement.

[Cong Hou via llvm-commits]

congh added inline comments.

================
Comment at: lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp:1203
@@ +1202,3 @@
+  BranchProbabilityInfo *BPI = FuncInfo.BPI;
+  // A lambda that updates the weight of the edge to the new EHPadBB.
+  auto GetUnwindDest = [BPI, &Weight](const BasicBlock *EHPadBB,
----------------
rnk wrote:
> This is just code that runs on every iteration of the while loop. We don't need a lambda, just put it before the end of the loop. You'll have to create a `NewEHPadBB` local variable and assign it to EHPadBB, but that seems OK to me.
I have removed the lambda by putting it to the end of the loop (the else case should escape from this part).

================
Comment at: test/CodeGen/X86/catchpad-weight.ll:1
@@ +1,2 @@
+; RUN: llc -march=x86-64 -print-machineinstrs=expand-isel-pseudos %s -o /dev/null 2>&1 | FileCheck %s
+
----------------
rnk wrote:
> I think the IR for this C++ code would make a better test case:
>   struct A {};
>   struct B {};
>   struct C {};
>   struct HasDtor {
>     ~HasDtor();
>   };
>   void may_throw();
>   int main() {
>     HasDtor o;
>     try {
>       may_throw();
>     } catch (A) {
>     } catch (B) {
>     } catch (C) {
>     }
>   }
> Then the invoke for `may_throw` has five total successors: the normal edge, the three catchpads, and the cleanup.
> 
> You can get the catchpad IR like this:
>   $ clang -c --target=x86_64-windows-msvc t.cpp -S -emit-llvm -o - -fexceptions -O2
Yes, this test case is more complete. I have replaced the old test case with this one. Thanks!


http://reviews.llvm.org/D13354