Revert "[Backport] Security bug 1395604"

It is not applicable on this branch.

This reverts commit 83f89843310c5e690b6fa01faf67bca409669cbd.

Change-Id: I8a8bd6084a8d7168416ee80d53a1aeea8e1813cf
Reviewed-on: https://codereview.qt-project.org/c/qt/qtwebengine-chromium/+/455569
Reviewed-by: Michal Klocek <michal.klocek@qt.io>

1 files changed, 1 insertions, 16 deletions

diff --git a/chromium/v8/src/compiler/backend/x64/code-generator-x64.cc b/chromium/v8/src/compiler/backend/x64/code-generator-x64.cc
index 3e6819bf506..e0cf602b11e 100644
--- a/chromium/v8/src/compiler/backend/x64/code-generator-x64.cc
+++ b/chromium/v8/src/compiler/backend/x64/code-generator-x64.cc
@@ -4819,22 +4819,7 @@ void CodeGenerator::AssembleMove(InstructionOperand* source,
     case MoveType::kStackToRegister: {
       Operand src = g.ToOperand(source);
       if (source->IsStackSlot()) {
-        MachineRepresentation mr =
-            LocationOperand::cast(source)->representation();
-        const bool is_32_bit = mr == MachineRepresentation::kWord32 ||
-                               mr == MachineRepresentation::kCompressed ||
-                               mr == MachineRepresentation::kCompressedPointer;
-        // TODO(13581): Fix this for other code kinds (see
-        // https://crbug.com/1356461).
-        if (code_kind() == CodeKind::WASM_FUNCTION && is_32_bit) {
-          // When we need only 32 bits, move only 32 bits. Benefits:
-          // - Save a byte here and there (depending on the destination
-          //   register; "movl eax, ..." is smaller than "movq rax, ...").
-          // - Safeguard against accidental decompression of compressed slots.
-          __ movl(g.ToRegister(destination), src);
-        } else {
-          __ movq(g.ToRegister(destination), src);
-        }
+        __ movq(g.ToRegister(destination), src);
       } else {
         DCHECK(source->IsFPStackSlot());
         XMMRegister dst = g.ToDoubleRegister(destination);