1 files changed, 53 insertions, 0 deletions
diff --git a/deps/v8/src/heap/cppgc/asm/ia32/push_registers_asm.cc b/deps/v8/src/heap/cppgc/asm/ia32/push_registers_asm.cc
new file mode 100644
index 00000000000..ed9c14a50e9
--- /dev/null
+++ b/deps/v8/src/heap/cppgc/asm/ia32/push_registers_asm.cc
@@ -0,0 +1,53 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Push all callee-saved registers to get them on the stack for conservative
+// stack scanning.
+//
+// See asm/x64/push_registers_clang.cc for why the function is not generated
+// using clang.
+//
+// Do not depend on V8_TARGET_OS_* defines as some embedders may override the
+// GN toolchain (e.g. ChromeOS) and not provide them.
+
+// We maintain 16-byte alignment at calls. There is an 4-byte return address
+// on the stack and we push 28 bytes which maintains 16-byte stack alignment
+// at the call.
+//
+// The following assumes cdecl calling convention.
+// Source: https://en.wikipedia.org/wiki/X86_calling_conventions#cdecl
+asm(
+#ifdef _WIN32
+    ".globl _PushAllRegistersAndIterateStack            \n"
+    "_PushAllRegistersAndIterateStack:                  \n"
+#else   // !_WIN32
+    ".globl PushAllRegistersAndIterateStack             \n"
+    ".type PushAllRegistersAndIterateStack, %function   \n"
+    ".hidden PushAllRegistersAndIterateStack            \n"
+    "PushAllRegistersAndIterateStack:                   \n"
+#endif  // !_WIN32
+    // [ IterateStackCallback ]
+    // [ StackVisitor*        ]
+    // [ Stack*               ]
+    // [ ret                  ]
+    // ebp is callee-saved. Maintain proper frame pointer for debugging.
+    "  push %ebp                                        \n"
+    "  movl %esp, %ebp                                  \n"
+    "  push %ebx                                        \n"
+    "  push %esi                                        \n"
+    "  push %edi                                        \n"
+    // Save 3rd parameter (IterateStackCallback).
+    "  movl 28(%esp), %ecx                              \n"
+    // Pass 3rd parameter as esp (stack pointer).
+    "  push %esp                                        \n"
+    // Pass 2nd parameter (StackVisitor*).
+    "  push 28(%esp)                                    \n"
+    // Pass 1st parameter (Stack*).
+    "  push 28(%esp)                                    \n"
+    "  call *%ecx                                       \n"
+    // Pop the callee-saved registers.
+    "  addl $24, %esp                                   \n"
+    // Restore rbp as it was used as frame pointer.
+    "  pop %ebp                                         \n"
+    "  ret                                              \n");