[WebAssembly] Fix a bug when mixing TRY/LOOP markers
Summary:
When TRY and LOOP markers are in the same BB and END_TRY and END_LOOP
markers are in the same BB, END_TRY should be _before_ END_LOOP, because
LOOP is always before TRY if they are in the same BB. (TRY is placed in
the latest possible position, whereas LOOP is in the earliest possible
position.)
Reviewers: dschuff
Subscribers: sunfish, sbc100, jgravelle-google, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D59751
llvm-svn: 357008
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyCFGStackify.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyCFGStackify.cpp
index b1a4795..7a7838a 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyCFGStackify.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyCFGStackify.cpp
@@ -579,7 +579,9 @@
// the END_TRY marker should go after that. Otherwise, the whole try-catch
// is contained within this loop, so the END_TRY should go before that.
if (MI.getOpcode() == WebAssembly::END_LOOP) {
- if (EndToBegin[&MI]->getParent()->getNumber() >= Header->getNumber())
+ // For a LOOP to be after TRY, LOOP's BB should be after TRY's BB; if they
+ // are in the same BB, LOOP is always before TRY.
+ if (EndToBegin[&MI]->getParent()->getNumber() > Header->getNumber())
BeforeSet.insert(&MI);
#ifndef NDEBUG
else