From 0481d29d49cc26a944d0d502360f044cb493a4b5 Mon Sep 17 00:00:00 2001 From: Bill Wendling Date: Tue, 27 Sep 2011 22:14:12 +0000 Subject: This is the start of the new SjLj EH preparation pass, which will replace the current IR-level pass. The old SjLj EH pass has some problems, especially with the new EH model. Most significantly, it violates some of the new restrictions the new model has. For instance, the 'dispatch' table wants to jump to the landing pad, but we cannot allow that because only an invoke's unwind edge can jump to a landing pad. This requires us to mangle the code something awful. In addition, we need to keep the now dead landingpad instructions around instead of CSE'ing them because the DWARF emitter uses that information (they are dead because no control flow edge will execute them - the control flow edge from an invoke's unwind is superceded by the edge coming from the dispatch). Basically, this pass belongs not at the IR level where SSA is king, but at the code-gen level, where we have more flexibility. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@140646 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/LLVMTargetMachine.cpp | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'lib/CodeGen/LLVMTargetMachine.cpp') diff --git a/lib/CodeGen/LLVMTargetMachine.cpp b/lib/CodeGen/LLVMTargetMachine.cpp index 8f463e2d3f..9196816b35 100644 --- a/lib/CodeGen/LLVMTargetMachine.cpp +++ b/lib/CodeGen/LLVMTargetMachine.cpp @@ -45,6 +45,9 @@ namespace llvm { bool EnableFastISel; } +static cl::opt DisableOldSjLjEH("disable-old-sjlj-eh", cl::Hidden, + cl::desc("Disable the old SjLj EH preparation pass")); + static cl::opt DisablePostRA("disable-post-ra", cl::Hidden, cl::desc("Disable Post Regalloc")); static cl::opt DisableBranchFold("disable-branch-fold", cl::Hidden, @@ -322,7 +325,8 @@ bool LLVMTargetMachine::addCommonCodeGenPasses(PassManagerBase &PM, // removed from the parent invoke(s). This could happen when a landing // pad is shared by multiple invokes and is also a target of a normal // edge from elsewhere. - PM.add(createSjLjEHPass(getTargetLowering())); + if (!DisableOldSjLjEH) + PM.add(createSjLjEHPass(getTargetLowering())); // FALLTHROUGH case ExceptionHandling::DwarfCFI: case ExceptionHandling::ARM: -- cgit v1.2.3