From 3b1f1f7b6ac890190538d98ec7901d95258d14c3 Mon Sep 17 00:00:00 2001
From: Marek Roszko <mark.roszko@gmail.com>
Date: Mon, 24 Aug 2020 21:07:26 -0400
Subject: [PATCH] Use CreateFiberEx instead of CreateFiber,
 ConvertThreadToFiberEx instead of ConvertThreadToFiber

- Allows specifying FIBER_FLAG_FLOAT_SWITCH to save FP registers (it doesnt by default on win32 but does on win64)
- Specify a commit stack size one byte less than the reserve stack size or else Windows rounds up to the nearest allocation size above the desired size
---
 thirdparty/libcontext/libcontext.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/thirdparty/libcontext/libcontext.cpp b/thirdparty/libcontext/libcontext.cpp
index 661e966497..7de0e20e3e 100644
--- a/thirdparty/libcontext/libcontext.cpp
+++ b/thirdparty/libcontext/libcontext.cpp
@@ -1284,11 +1284,11 @@ fcontext_t LIBCONTEXT_CALL_CONVENTION make_fcontext(void* sp, size_t size, void(
 {
 	if (!threadHasFibers)
 	{
-		ConvertThreadToFiber(nullptr);
+		ConvertThreadToFiberEx(nullptr, FIBER_FLAG_FLOAT_SWITCH);
 		threadHasFibers = 1;
 	}
 
-	fcontext_t ctx = CreateFiber(size, (LPFIBER_START_ROUTINE) fiberEntry, nullptr );
+	fcontext_t ctx = CreateFiberEx(size - 1, size, FIBER_FLAG_FLOAT_SWITCH, (LPFIBER_START_ROUTINE) fiberEntry, nullptr );
 	fiberParams[ctx].entry = fn;
 
 	return ctx;