From 0eca30db2fe14f1c1786752f7c565ddda1c02064 Mon Sep 17 00:00:00 2001
From: vamsi-parasa <srinivas.vamsi.parasa@intel.com>
Date: Thu, 12 Jun 2025 12:33:07 -0700
Subject: [PATCH 1/3] 8359386: Fix incorrect value for max_size of C2CodeStub
 when APX is used

---
 src/hotspot/cpu/x86/c2_MacroAssembler_x86.cpp | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/hotspot/cpu/x86/c2_MacroAssembler_x86.cpp b/src/hotspot/cpu/x86/c2_MacroAssembler_x86.cpp
index 177be6e59f74a..d36430ad0c0f7 100644
--- a/src/hotspot/cpu/x86/c2_MacroAssembler_x86.cpp
+++ b/src/hotspot/cpu/x86/c2_MacroAssembler_x86.cpp
@@ -4687,7 +4687,9 @@ void C2_MacroAssembler::convertF2I(BasicType dst_bt, BasicType src_bt, Register
     }
   }
 
-  auto stub = C2CodeStub::make<Register, XMMRegister, address>(dst, src, slowpath_target, 23, convertF2I_slowpath);
+  // Using the APX extended general purpose registers increases the instruction encoding size by 4 bytes.
+  int max_size = dst->encoding() <= 15 ? 23 : 27;
+  auto stub = C2CodeStub::make<Register, XMMRegister, address>(dst, src, slowpath_target, max_size, convertF2I_slowpath);
   jcc(Assembler::equal, stub->entry());
   bind(stub->continuation());
 }

From 37dede6e7a5b2b253958d3092a6ac9883f77fdc8 Mon Sep 17 00:00:00 2001
From: vamsi-parasa <srinivas.vamsi.parasa@intel.com>
Date: Mon, 16 Jun 2025 12:37:08 -0700
Subject: [PATCH 2/3] update max_size computation to be explicit

---
 src/hotspot/cpu/x86/c2_MacroAssembler_x86.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/hotspot/cpu/x86/c2_MacroAssembler_x86.cpp b/src/hotspot/cpu/x86/c2_MacroAssembler_x86.cpp
index d36430ad0c0f7..4ff288472d4b3 100644
--- a/src/hotspot/cpu/x86/c2_MacroAssembler_x86.cpp
+++ b/src/hotspot/cpu/x86/c2_MacroAssembler_x86.cpp
@@ -4688,7 +4688,7 @@ void C2_MacroAssembler::convertF2I(BasicType dst_bt, BasicType src_bt, Register
   }
 
   // Using the APX extended general purpose registers increases the instruction encoding size by 4 bytes.
-  int max_size = dst->encoding() <= 15 ? 23 : 27;
+  int max_size = 23 + (UseAPX ? 4 : 0);
   auto stub = C2CodeStub::make<Register, XMMRegister, address>(dst, src, slowpath_target, max_size, convertF2I_slowpath);
   jcc(Assembler::equal, stub->entry());
   bind(stub->continuation());

From 4fe56be6bf1845b305d76c78633780381450190f Mon Sep 17 00:00:00 2001
From: vamsi-parasa <srinivas.vamsi.parasa@intel.com>
Date: Mon, 16 Jun 2025 20:59:47 -0700
Subject: [PATCH 3/3] Fix the change in the stub size by 1 byte

---
 src/hotspot/cpu/x86/c2_MacroAssembler_x86.cpp | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/hotspot/cpu/x86/c2_MacroAssembler_x86.cpp b/src/hotspot/cpu/x86/c2_MacroAssembler_x86.cpp
index 4ff288472d4b3..4317bb3d01825 100644
--- a/src/hotspot/cpu/x86/c2_MacroAssembler_x86.cpp
+++ b/src/hotspot/cpu/x86/c2_MacroAssembler_x86.cpp
@@ -4655,6 +4655,7 @@ static void convertF2I_slowpath(C2_MacroAssembler& masm, C2GeneralStub<Register,
   __ subptr(rsp, 8);
   __ movdbl(Address(rsp), src);
   __ call(RuntimeAddress(target));
+  // APX REX2 encoding for pop(dst) increases the stub size by 1 byte.
   __ pop(dst);
   __ jmp(stub.continuation());
 #undef __
@@ -4687,8 +4688,8 @@ void C2_MacroAssembler::convertF2I(BasicType dst_bt, BasicType src_bt, Register
     }
   }
 
-  // Using the APX extended general purpose registers increases the instruction encoding size by 4 bytes.
-  int max_size = 23 + (UseAPX ? 4 : 0);
+  // Using the APX extended general purpose registers increases the instruction encoding size by 1 byte.
+  int max_size = 23 + (UseAPX ? 1 : 0);
   auto stub = C2CodeStub::make<Register, XMMRegister, address>(dst, src, slowpath_target, max_size, convertF2I_slowpath);
   jcc(Assembler::equal, stub->entry());
   bind(stub->continuation());