1 files changed, 28 insertions, 16 deletions
diff --git a/contrib/llvm/lib/Target/WebAssembly/WebAssemblyPeephole.cpp b/contrib/llvm/lib/Target/WebAssembly/WebAssemblyPeephole.cpp
index 32dde88..d2fbc5a 100644
--- a/contrib/llvm/lib/Target/WebAssembly/WebAssemblyPeephole.cpp
+++ b/contrib/llvm/lib/Target/WebAssembly/WebAssemblyPeephole.cpp
@@ -80,19 +80,31 @@ static bool MaybeRewriteToFallthrough(MachineInstr &MI, MachineBasicBlock &MBB,
     return false;
   if (&MBB != &MF.back())
     return false;
-  if (&MI != &MBB.back())
-    return false;
+  if (MF.getSubtarget<WebAssemblySubtarget>()
+        .getTargetTriple().isOSBinFormatELF()) {
+    if (&MI != &MBB.back())
+      return false;
+  } else {
+    MachineBasicBlock::iterator End = MBB.end();
+    --End;
+    assert(End->getOpcode() == WebAssembly::END_FUNCTION);
+    --End;
+    if (&MI != &*End)
+      return false;
+  }
 
-  // If the operand isn't stackified, insert a COPY to read the operand and
-  // stackify it.
-  MachineOperand &MO = MI.getOperand(0);
-  unsigned Reg = MO.getReg();
-  if (!MFI.isVRegStackified(Reg)) {
-    unsigned NewReg = MRI.createVirtualRegister(MRI.getRegClass(Reg));
-    BuildMI(MBB, MI, MI.getDebugLoc(), TII.get(CopyLocalOpc), NewReg)
-        .addReg(Reg);
-    MO.setReg(NewReg);
-    MFI.stackifyVReg(NewReg);
+  if (FallthroughOpc != WebAssembly::FALLTHROUGH_RETURN_VOID) {
+    // If the operand isn't stackified, insert a COPY to read the operand and
+    // stackify it.
+    MachineOperand &MO = MI.getOperand(0);
+    unsigned Reg = MO.getReg();
+    if (!MFI.isVRegStackified(Reg)) {
+      unsigned NewReg = MRI.createVirtualRegister(MRI.getRegClass(Reg));
+      BuildMI(MBB, MI, MI.getDebugLoc(), TII.get(CopyLocalOpc), NewReg)
+          .addReg(Reg);
+      MO.setReg(NewReg);
+      MFI.stackifyVReg(NewReg);
+    }
   }
 
   // Rewrite the return.
@@ -127,7 +139,7 @@ bool WebAssemblyPeephole::runOnMachineFunction(MachineFunction &MF) {
           if (Name == TLI.getLibcallName(RTLIB::MEMCPY) ||
               Name == TLI.getLibcallName(RTLIB::MEMMOVE) ||
               Name == TLI.getLibcallName(RTLIB::MEMSET)) {
-            LibFunc::Func Func;
+            LibFunc Func;
             if (LibInfo.getLibFunc(Name, Func)) {
               const auto &Op2 = MI.getOperand(2);
               if (!Op2.isReg())
@@ -188,9 +200,9 @@ bool WebAssemblyPeephole::runOnMachineFunction(MachineFunction &MF) {
             WebAssembly::COPY_V128);
         break;
       case WebAssembly::RETURN_VOID:
-        if (!DisableWebAssemblyFallthroughReturnOpt &&
-            &MBB == &MF.back() && &MI == &MBB.back())
-          MI.setDesc(TII.get(WebAssembly::FALLTHROUGH_RETURN_VOID));
+        Changed |= MaybeRewriteToFallthrough(
+            MI, MBB, MF, MFI, MRI, TII, WebAssembly::FALLTHROUGH_RETURN_VOID,
+            WebAssembly::INSTRUCTION_LIST_END);
         break;
       }