[WebAssembly] Restore stack pointer right after catch instruction

Summary:
After the staack is unwound due to a thrown exxception,
`__stack_pointer` global can point to an invalid address. So
a `global.set` to restore `__stack_pointer` should be inserted right
after `catch` instruction.

But after r352598 the `global.set` instruction is inserted not right
after `catch` but after `block` - `br-on-exn` - `end_block` -
`extract_exception` sequence. This CL fixes it.

While doing that, we can actually move ReplacePhysRegs pass after
LateEHPrepare and merge EHRestoreStackPointer pass into LateEHPrepare,
and now placing `global.set` to `__stack_pointer` right after `catch` is
much easier. Otherwise it is hard to guarantee that `global.set` is
still right after `catch` and not touched with other transformations, in
which case we have to do something to hoist it.

Reviewers: dschuff

Subscribers: mgorny, sbc100, jgravelle-google, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D57421

llvm-svn: 352681

1 files changed, 0 insertions, 2 deletions

diff --git a/llvm/lib/Target/WebAssembly/WebAssembly.h b/llvm/lib/Target/WebAssembly/WebAssembly.h
index 27bc156eae8..2a7efe1176f 100644
--- a/llvm/lib/Target/WebAssembly/WebAssembly.h
+++ b/llvm/lib/Target/WebAssembly/WebAssembly.h
@@ -38,7 +38,6 @@ FunctionPass *createWebAssemblyArgumentMove();
 FunctionPass *createWebAssemblySetP2AlignOperands();
 
 // Late passes.
-FunctionPass *createWebAssemblyEHRestoreStackPointer();
 FunctionPass *createWebAssemblyReplacePhysRegs();
 FunctionPass *createWebAssemblyPrepareForLiveIntervals();
 FunctionPass *createWebAssemblyOptimizeLiveIntervals();
@@ -63,7 +62,6 @@ void initializeFixFunctionBitcastsPass(PassRegistry &);
 void initializeOptimizeReturnedPass(PassRegistry &);
 void initializeWebAssemblyArgumentMovePass(PassRegistry &);
 void initializeWebAssemblySetP2AlignOperandsPass(PassRegistry &);
-void initializeWebAssemblyEHRestoreStackPointerPass(PassRegistry &);
 void initializeWebAssemblyReplacePhysRegsPass(PassRegistry &);
 void initializeWebAssemblyPrepareForLiveIntervalsPass(PassRegistry &);
 void initializeWebAssemblyOptimizeLiveIntervalsPass(PassRegistry &);