Index: lib/Target/WebAssembly/MCTargetDesc/WebAssemblyMCCodeEmitter.cpp
===================================================================
--- lib/Target/WebAssembly/MCTargetDesc/WebAssemblyMCCodeEmitter.cpp
+++ lib/Target/WebAssembly/MCTargetDesc/WebAssemblyMCCodeEmitter.cpp
@@ -23,9 +23,11 @@
 #include "llvm/MC/MCRegisterInfo.h"
 #include "llvm/MC/MCSubtargetInfo.h"
 #include "llvm/MC/MCSymbol.h"
+#include "llvm/Support/Debug.h"
 #include "llvm/Support/EndianStream.h"
 #include "llvm/Support/LEB128.h"
 #include "llvm/Support/raw_ostream.h"
+
 using namespace llvm;
 
 #define DEBUG_TYPE "mccodeemitter"
@@ -60,6 +62,7 @@
     const MCSubtargetInfo &STI) const {
   uint64_t Start = OS.tell();
 
+  DEBUG(dbgs() << "encodeInstruction: " << MI << "\n");
   uint64_t Binary = getBinaryCodeForInstr(MI, Fixups, STI);
   if (Binary <= UINT8_MAX) {
     OS << uint8_t(Binary);
@@ -86,8 +89,11 @@
         assert(Desc.TSFlags == 0 &&
                "WebAssembly non-variable_ops don't use TSFlags");
         const MCOperandInfo &Info = Desc.OpInfo[i];
+        DEBUG(dbgs() << "Encoding immediate: type=" << int(Info.OperandType) << "\n");
         if (Info.OperandType == WebAssembly::OPERAND_I32IMM) {
           encodeSLEB128(int32_t(MO.getImm()), OS);
+        } else if (Info.OperandType == WebAssembly::OPERAND_OFFSET32) {
+          encodeULEB128(uint32_t(MO.getImm()), OS);
         } else if (Info.OperandType == WebAssembly::OPERAND_I64IMM) {
           encodeSLEB128(int64_t(MO.getImm()), OS);
         } else if (Info.OperandType == WebAssembly::OPERAND_GLOBAL) {
Index: test/MC/WebAssembly/offset.ll
===================================================================
--- /dev/null
+++ test/MC/WebAssembly/offset.ll
@@ -0,0 +1,15 @@
+; RUN: llc -filetype=obj %s -o - | obj2yaml | FileCheck %s
+
+target triple = "wasm32-unknown-unknown-wasm"
+
+define i32 @load_i32_from_negative_address() {
+  %s = inttoptr i32 -1 to i32*
+  %t = load i32, i32* %s
+  ret i32 %t
+}
+
+; CHECK:        - Type:            CODE
+; CHECK-NEXT:     Functions:
+; CHECK-NEXT:       - Index:           0
+; CHECK-NEXT:         Locals:
+; CHECK-NEXT:         Body:            41002802FFFFFFFF0F0B