From d3e7b48a8e5058d129923800cc63bf778bd4e9bd Mon Sep 17 00:00:00 2001
From: Victor Gomes <victorgomes@chromium.org>
Date: Fri, 11 Sep 2020 11:59:30 +0200
Subject: [PATCH] [wasm] Disable safe_to_skip_adaptor optimization

This optimization does not work when the stack arguments are reversed.

Change-Id: Ib543e6ca234cc70708909e0b3cd474b1309ec40e
Bug: chromium:1126769, v8:10201
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2404775
Commit-Queue: Victor Gomes <victorgomes@chromium.org>
Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
Auto-Submit: Victor Gomes <victorgomes@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69842}
---
 src/compiler/wasm-compiler.cc | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/compiler/wasm-compiler.cc b/src/compiler/wasm-compiler.cc
index 3215de5396..7629152fa8 100644
--- a/src/compiler/wasm-compiler.cc
+++ b/src/compiler/wasm-compiler.cc
@@ -7072,10 +7072,14 @@ std::pair<WasmImportCallKind, Handle<JSReceiver>> ResolveWasmImportCall(
       Compiler::Compile(function, Compiler::CLEAR_EXCEPTION,
                         &is_compiled_scope);
     }
+#ifndef V8_REVERSE_JSARGS
+    // This optimization is disabled when the arguments are reversed. It will be
+    // subsumed when the argumens adaptor frame is removed.
     if (shared->is_safe_to_skip_arguments_adaptor()) {
       return std::make_pair(
           WasmImportCallKind::kJSFunctionArityMismatchSkipAdaptor, callable);
     }
+#endif
 
     return std::make_pair(WasmImportCallKind::kJSFunctionArityMismatch,
                           callable);