[PPCGCodeGeneration] Fix runtime check adjustments since they make assumptions about BB layout.

- There is a conditional branch that is used to switch between the old
   and new versions of the code.

- If we detect that the build was unsuccessful, `PPCGCodeGeneration` will
  change the runtime check to be always set to false.

- To actually *reach* this runtime check instruction, `PPCGCodeGeneration`
  was using assumptions about the layout of the BBs.

- However, invariant load hoisting violates this assumption by inserting
  an extra basic block in the middle.

- Fix the assumption on the layout by having `createScopConditionally`
   return the conditional branch instruction.

- Use this reference to set to always-false.

llvm-svn: 308010

1 files changed, 1 insertions, 1 deletions

diff --git a/polly/lib/CodeGen/CodeGeneration.cpp b/polly/lib/CodeGen/CodeGeneration.cpp
index 8617e1c0b3d..5e845f1ae33 100644
--- a/polly/lib/CodeGen/CodeGeneration.cpp
+++ b/polly/lib/CodeGen/CodeGeneration.cpp
@@ -176,7 +176,7 @@ static bool CodeGen(Scop &S, IslAstInfo &AI, LoopInfo &LI, DominatorTree &DT,
   // which may introduce scalar dependences that prevent us from correctly
   // code generating this scop.
   BBPair StartExitBlocks =
-      executeScopConditionally(S, Builder.getTrue(), DT, RI, LI);
+      std::get<0>(executeScopConditionally(S, Builder.getTrue(), DT, RI, LI));
   BasicBlock *StartBlock = std::get<0>(StartExitBlocks);
   BasicBlock *ExitBlock = std::get<1>(StartExitBlocks);