From 777daf844924e6103a8d8d5650ec23d484696c78 Mon Sep 17 00:00:00 2001
From: Chris Eibl <138194463+chris-eibl@users.noreply.github.com>
Date: Fri, 20 Feb 2026 19:15:28 +0100
Subject: [PATCH 1/2] add Windows64PGOTailcallBuild and
 Windows64PGONoGilTailcallBuild

---
 master/custom/builders.py  |  4 ++++
 master/custom/factories.py | 14 +++++++++++++-
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/master/custom/builders.py b/master/custom/builders.py
index a6baafca..164616f6 100644
--- a/master/custom/builders.py
+++ b/master/custom/builders.py
@@ -36,7 +36,9 @@
     Windows64BigmemBuild,
     Windows64NoGilBuild,
     Windows64PGOBuild,
+    Windows64PGOTailcallBuild,
     Windows64PGONoGilBuild,
+    Windows64PGONoGilTailcallBuild,
     Windows64RefleakBuild,
     Windows64ReleaseBuild,
     MacOSArmWithBrewBuild,
@@ -91,7 +93,9 @@
     ("AMD64 Windows11 Non-Debug", "ware-win11", Windows64ReleaseBuild),
     ("AMD64 Windows11 Refleaks", "ware-win11", Windows64RefleakBuild),
     ("AMD64 Windows Server 2022 NoGIL", "itamaro-win64-srv-22-aws", Windows64NoGilBuild),
+    ("AMD64 Windows PGO Tailcall", "itamaro-win64-srv-22-aws", Windows64PGOTailcallBuild),
     ("AMD64 Windows PGO NoGIL", "itamaro-win64-srv-22-aws", Windows64PGONoGilBuild),
+    ("AMD64 Windows PGO NoGIL Tailcall", "itamaro-win64-srv-22-aws", Windows64PGONoGilTailcallBuild),
 ]
 
 
diff --git a/master/custom/factories.py b/master/custom/factories.py
index 1754d1ae..3f0efea3 100644
--- a/master/custom/factories.py
+++ b/master/custom/factories.py
@@ -686,13 +686,19 @@ class Windows64ReleaseBuild(Windows64Build):
     factory_tags = ["win64", "nondebug"]
 
 
-class Windows64PGOBuild(Windows64ReleaseBuild):
+class Windows64PGOBuild(Windows64Build):
     buildersuffix = ".pgo"
     buildFlags = Windows64Build.buildFlags + ["--pgo"]
     testFlags = [*Windows64Build.testFlags, "+d"]
     factory_tags = ["win64", "nondebug", "pgo"]
 
 
+class Windows64PGOTailcallBuild(Windows64PGOBuild):
+    buildersuffix = ".tailcall.pgo"
+    buildFlags = Windows64PGOBuild.buildFlags + ["--tail-call-interp"]
+    factory_tags = Windows64PGOBuild.factory_tags  + ["tailcall"]
+
+
 class Windows64NoGilBuild(Windows64Build):
     buildersuffix = '.x64.nogil'
     buildFlags = Windows64Build.buildFlags + ["--disable-gil"]
@@ -707,6 +713,12 @@ class Windows64PGONoGilBuild(Windows64PGOBuild):
     factory_tags = ["win64", "nogil", "nondebug", "pgo"]
 
 
+class Windows64PGONoGilTailcallBuild(Windows64PGONoGilBuild):
+    buildersuffix = '.nogil.tailcall.pgo'
+    buildFlags = Windows64PGONoGilBuild.buildFlags + ["--tail-call-interp"]
+    factory_tags = Windows64PGONoGilBuild.factory_tags + ["tailcall"]
+
+
 class WindowsARM64Build(BaseWindowsBuild):
     buildFlags = ["-p", "ARM64"]
     testFlags = ["-p", "ARM64", "-j2"]

From b9f12ab80ef57cb53757c3307a04da49cd27a5c9 Mon Sep 17 00:00:00 2001
From: Chris Eibl <138194463+chris-eibl@users.noreply.github.com>
Date: Sat, 21 Feb 2026 21:03:57 +0100
Subject: [PATCH 2/2] move msvc tc builders to UNSTABLE_BUILDERS_TIER_1

---
 master/custom/builders.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/master/custom/builders.py b/master/custom/builders.py
index 164616f6..eca7cd2f 100644
--- a/master/custom/builders.py
+++ b/master/custom/builders.py
@@ -93,9 +93,7 @@
     ("AMD64 Windows11 Non-Debug", "ware-win11", Windows64ReleaseBuild),
     ("AMD64 Windows11 Refleaks", "ware-win11", Windows64RefleakBuild),
     ("AMD64 Windows Server 2022 NoGIL", "itamaro-win64-srv-22-aws", Windows64NoGilBuild),
-    ("AMD64 Windows PGO Tailcall", "itamaro-win64-srv-22-aws", Windows64PGOTailcallBuild),
     ("AMD64 Windows PGO NoGIL", "itamaro-win64-srv-22-aws", Windows64PGONoGilBuild),
-    ("AMD64 Windows PGO NoGIL Tailcall", "itamaro-win64-srv-22-aws", Windows64PGONoGilTailcallBuild),
 ]
 
 
@@ -238,6 +236,9 @@
 
     # Windows MSVC
     ("AMD64 Windows PGO", "bolen-windows10", Windows64PGOBuild),
+    ("AMD64 Windows PGO Tailcall", "itamaro-win64-srv-22-aws", Windows64PGOTailcallBuild),
+    ("AMD64 Windows PGO NoGIL Tailcall", "itamaro-win64-srv-22-aws", Windows64PGONoGilTailcallBuild),
+
 ]