1 files changed, 44 insertions, 0 deletions
diff --git a/library/fibers/switchstack_msvc_32.cpp b/library/fibers/switchstack_msvc_32.cpp
new file mode 100644
index 0000000..eae68ee
--- /dev/null
+++ b/library/fibers/switchstack_msvc_32.cpp
@@ -0,0 +1,44 @@
+extern "C" {
+void __declspec(naked) _switchStackInternal(void* to, void** from)
+{
+    __asm {
+    // save callee-saved registers
+    PUSH EBP
+    MOV EBP, ESP
+    PUSH EBX
+    PUSH ESI
+    PUSH EDI
+
+    // store SIMD floating point control word
+    SUB ESP, 4
+    STMXCSR [ESP]
+
+    // store floating point control bytes
+    SUB ESP, 4
+    FSTCW [ESP]
+
+    // save the old stack pointer
+    MOV EDX, dword ptr 12[EBP]
+    MOV [EDX], ESP
+    // set the new stack pointer
+    MOV ESP, dword ptr 8[EBP]
+
+    // restore floating point control bytes
+    FNCLEX
+    FLDCW [ESP]
+    ADD ESP, 4
+
+    // restore SIMD floating point control word
+    LDMXCSR [ESP]
+    ADD ESP, 4
+
+    // pop callee-saved registers
+    POP EDI
+    POP ESI
+    POP EBX
+    POP EBP        
+    
+    RET
+    }
+}
+}