deps: V8: cherry-pick cf1bce40a5ef

richardlau · aduh95 · commit 180c15012251 · 2026-03-31T10:46:05.000+02:00
Original commit message: [wasm] Fix S128Const on big endian Since http://crrev.com/c/2944437 globals are no longer little endian enforced. S128Const handling in the initializer needs to take this into account and byte reverse values which are hard coded in little endian order. This is currently causing failures on Node.js upstream: #59034 (comment) Change-Id: Ifcc9ade93ee51565ab19b16e9dadf0ff5752f7a6 Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/7704213 Commit-Queue: Milad Farazmand <mfarazma@ibm.com> Reviewed-by: Manos Koukoutos <manoskouk@chromium.org> Cr-Commit-Position: refs/heads/main@{#106082} Refs: v8/v8@cf1bce4 PR-URL: #62449 Refs: v8/v8@cf1bce4 Reviewed-By: Guy Bedford <guybedford@gmail.com> Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
diff --git a/deps/v8/src/wasm/constant-expression-interface.cc b/deps/v8/src/wasm/constant-expression-interface.cc
@@ -40,7 +40,17 @@ void ConstantExpressionInterface::S128Const(FullDecoder* decoder,
                                             const Simd128Immediate& imm,
                                             Value* result) {
   if (!generate_value()) return;
+#if V8_TARGET_BIG_ENDIAN
+  // Globals are not little endian enforced, they use native byte order and we
+  // need to reverse the bytes on big endian platforms.
+  uint8_t value[kSimd128Size];
+  for (int i = 0; i < kSimd128Size; i++) {
+    value[i] = imm.value[kSimd128Size - 1 - i];
+  }
+  result->runtime_value = WasmValue(value, kWasmS128);
+#else
   result->runtime_value = WasmValue(imm.value, kWasmS128);
+#endif
 }
 
 void ConstantExpressionInterface::UnOp(FullDecoder* decoder, WasmOpcode opcode,
