[llvm] r370965 - [WebAssembly] Initialize memory in start function

[Thomas Lively via llvm-commits]

Author: tlively
Date: Wed Sep  4 12:50:39 2019
New Revision: 370965

URL: http://llvm.org/viewvc/llvm-project?rev=370965&view=rev
Log:
[WebAssembly] Initialize memory in start function

Summary:
 - `__wasm_init_memory` is now the WebAssembly start function instead
   of being called from `__wasm_call_ctors` or called directly by the
   runtime.
 - Adds a new synthetic data symbol `__wasm_init_memory_flag` that is
   atomically incremented from zero to one by the thread responsible
   for initializing memory.
 - All threads now unconditionally perform data.drop on all passive
   segments.
 - Removes --passive-segments and --active-segments flags and controls
   segment type based on --shared-memory instead. The deleted flags
   were only present to ameliorate the upgrade path in Emscripten.

Reviewers: sbc100, aheejin

Subscribers: dschuff, jgravelle-google, sunfish, jfb, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D65783

Modified:
    llvm/trunk/include/llvm/BinaryFormat/Wasm.h

Modified: llvm/trunk/include/llvm/BinaryFormat/Wasm.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/BinaryFormat/Wasm.h?rev=370965&r1=370964&r2=370965&view=diff
==============================================================================
--- llvm/trunk/include/llvm/BinaryFormat/Wasm.h (original)
+++ llvm/trunk/include/llvm/BinaryFormat/Wasm.h Wed Sep  4 12:50:39 2019
@@ -251,9 +251,21 @@ enum : unsigned {
   WASM_OPCODE_F32_CONST = 0x43,
   WASM_OPCODE_F64_CONST = 0x44,
   WASM_OPCODE_I32_ADD = 0x6a,
+};
+
+// Opcodes used in synthetic functions.
+enum : unsigned {
+  WASM_OPCODE_IF = 0x04,
+  WASM_OPCODE_ELSE = 0x05,
+  WASM_OPCODE_DROP = 0x1a,
   WASM_OPCODE_MISC_PREFIX = 0xfc,
   WASM_OPCODE_MEMORY_INIT = 0x08,
   WASM_OPCODE_DATA_DROP = 0x09,
+  WASM_OPCODE_ATOMICS_PREFIX = 0xfe,
+  WASM_OPCODE_ATOMIC_NOTIFY = 0x00,
+  WASM_OPCODE_I32_ATOMIC_WAIT = 0x01,
+  WASM_OPCODE_I32_ATOMIC_STORE = 0x17,
+  WASM_OPCODE_I32_RMW_CMPXCHG = 0x48,
 };
 
 enum : unsigned {