From 95f366ee21e47e13d44b534db51af11536acda35 Mon Sep 17 00:00:00 2001
From: Rudolf Polzer <divVerent@gmail.com>
Date: Fri, 3 Jan 2025 18:24:48 -0500
Subject: [PATCH] Add opcodes for uint and bit shifting.

- OP_RSHIFT_I
- OP_LSHIFT_I
- OP_LE_U
- OP_LT_U
- OP_DIV_U
- OP_RSHIFT_U

For all other ops FTEQCC emits the _I operations; this is technically
broken but meh. Compile DP with `-fwrapv` if you care.
---
 prvm_edict.c       |  6 ++++++
 prvm_exec.c        | 22 +++++++++++++++++--
 prvm_execprogram.h | 53 +++++++++++++++++++++++++++++++++++++++++++---
 3 files changed, 76 insertions(+), 5 deletions(-)

diff --git a/prvm_edict.c b/prvm_edict.c
index 0bc9bbbd..c6fadd16 100644
--- a/prvm_edict.c
+++ b/prvm_edict.c
@@ -2443,6 +2443,12 @@ void PRVM_Prog_Load(prvm_prog_t *prog, const char *filename, unsigned char *data
 		case OP_STOREP_FNC:
 		case OP_STOREP_V:
 		case OP_STOREP_I:
+		case OP_RSHIFT_I:
+		case OP_LSHIFT_I:
+		case OP_LE_U:
+		case OP_LT_U:
+		case OP_DIV_U:
+		case OP_RSHIFT_U:
 			if (a >= prog->progs_numglobals || b >= prog->progs_numglobals || c >= prog->progs_numglobals)
 				prog->error_cmd("%s: out of bounds global index (statement %d)", __func__, i);
 			prog->statements[i].op = op;
diff --git a/prvm_exec.c b/prvm_exec.c
index 9bd38270..fc1e6b20 100644
--- a/prvm_exec.c
+++ b/prvm_exec.c
@@ -205,8 +205,8 @@ NULL,
 "DIV_VF",
 
 NULL,
-NULL,
-NULL,
+"RSHIFT_I",
+"LSHIFT_I",
 
 "GLOBALADDRESS",
 "ADD_PIW",
@@ -294,6 +294,24 @@ NULL,
 NULL,
 
 "GLOAD_V",
+
+NULL,
+NULL,
+
+NULL,
+NULL,
+NULL,
+NULL,
+
+
+NULL,
+NULL,
+
+
+"^2LE_U",
+"^2LT_U",
+"DIV_U",
+"RSHIFT_U",
 };
 
 
diff --git a/prvm_execprogram.h b/prvm_execprogram.h
index bf9100fe..173677fa 100644
--- a/prvm_execprogram.h
+++ b/prvm_execprogram.h
@@ -204,8 +204,8 @@ prvm_eval_t *src;
 	&&handle_OP_DIV_VF,
 
 	NULL,
-	NULL,
-	NULL,
+	&&handle_OP_RSHIFT_I,
+	&&handle_OP_LSHIFT_I,
 
 	&&handle_OP_GLOBALADDRESS,
 	&&handle_OP_ADD_PIW,
@@ -287,11 +287,31 @@ prvm_eval_t *src;
 	&&handle_OP_GLOAD_S,
 	&&handle_OP_GLOAD_FNC,
 	&&handle_OP_BOUNDCHECK,
+
+	NULL,
 	NULL,
 	NULL,
+	NULL,
+
+	&&handle_OP_GLOAD_V,
+
+	NULL,
+	NULL,
+
+	NULL,
+	NULL,
+	NULL,
+	NULL,
+
+
 	NULL,
 	NULL,
-	&&handle_OP_GLOAD_V
+
+
+	&&handle_OP_LE_U,
+	&&handle_OP_LT_U,
+	&&handle_OP_DIV_U,
+	&&handle_OP_RSHIFT_U,
 	    };
 #define DISPATCH_OPCODE() \
     goto *dispatchtable[(++st)->op]
@@ -1207,6 +1227,33 @@ prvm_eval_t *src;
 				OPC->ivector[1] = ptr->ivector[1];
 				OPC->ivector[2] = ptr->ivector[2];
 				DISPATCH_OPCODE();
+			HANDLE_OPCODE(OP_RSHIFT_I):
+				OPC->_int = OPA->_int >> OPB->_int;
+				DISPATCH_OPCODE();
+			HANDLE_OPCODE(OP_LSHIFT_I):
+				OPC->_int = OPA->_int << OPB->_int;
+				DISPATCH_OPCODE();
+			HANDLE_OPCODE(OP_LE_U):
+				OPC->_int = (OPA->_uint <= OPB->_uint);
+				DISPATCH_OPCODE();
+			HANDLE_OPCODE(OP_LT_U):
+				OPC->_int = (OPA->_uint < OPB->_uint);
+				DISPATCH_OPCODE();
+			HANDLE_OPCODE(OP_DIV_U):
+				if( OPB->_uint != 0 )
+				{
+					OPC->_uint = OPA->_uint / OPB->_uint;
+				}
+				else
+				{
+					PRE_ERROR();
+					VM_Warning(prog, "Attempted division of %u by zero\n", OPA->_uint);
+					OPC->_uint = 0;
+				}
+				DISPATCH_OPCODE();
+			HANDLE_OPCODE(OP_RSHIFT_U):
+				OPC->_uint = OPA->_uint >> OPB->_uint;
+				DISPATCH_OPCODE();
 
 #if !USE_COMPUTED_GOTOS
 			default:
-- 
2.39.5