From 9bd07e5c83ccb50c1d2a3499079c04663a8ff3d0 Mon Sep 17 00:00:00 2001
From: "alexey.lysiuk" <alexey.lysiuk@gmail.com>
Date: Sun, 31 Jan 2021 14:47:33 +0200
Subject: [PATCH] - improved JIT simple frame error message

https://forum.zdoom.org/viewtopic.php?t=71340
---
 src/common/scripting/jit/jit.cpp | 25 +++++++++++++++++++++++--
 1 file changed, 23 insertions(+), 2 deletions(-)

diff --git a/src/common/scripting/jit/jit.cpp b/src/common/scripting/jit/jit.cpp
index 6d141e652..9823a6029 100644
--- a/src/common/scripting/jit/jit.cpp
+++ b/src/common/scripting/jit/jit.cpp
@@ -333,8 +333,29 @@ void JitCompiler::SetupSimpleFrame()
 		}
 	}
 
-	if (sfunc->NumArgs != argsPos || regd > sfunc->NumRegD || regf > sfunc->NumRegF || rega > sfunc->NumRegA)
-		I_FatalError("JIT: sfunc->NumArgs != argsPos || regd > sfunc->NumRegD || regf > sfunc->NumRegF || rega > sfunc->NumRegA");
+	const char *errorDetails = nullptr;
+
+	if (sfunc->NumArgs != argsPos)
+	{
+		errorDetails = "arguments";
+	}
+	else if (regd > sfunc->NumRegD)
+	{
+		errorDetails = "integer registers";
+	}
+	else if (regf > sfunc->NumRegF)
+	{
+		errorDetails = "floating point registers";
+	}
+	else if (rega > sfunc->NumRegA)
+	{
+		errorDetails = "address registers";
+	}
+
+	if (errorDetails)
+	{
+		I_FatalError("JIT: inconsistent number of %s for function %s", errorDetails, sfunc->PrintableName.GetChars());
+	}
 
 	for (int i = regd; i < sfunc->NumRegD; i++)
 		cc.xor_(regD[i], regD[i]);