[gamecode] Implement the conversion instructions

Not all possibilities are supported because converting between int and
uint, and long and ulong is essentially a no-op. However, thanks to
Deek's suggestion, not only are all reasonable conversions available,
conversions for all widths are available, so vector conversions are
supported.

The code for the conversions is generated.

libs/gamecode/Makemodule.am

@@ -31,7 +31,10 @@ pr_opcode_src = \
 	${pr_opcode_hinc}
 libs/gamecode/pr_opcode.lo: libs/gamecode/pr_opcode.c ${pr_opcode_src}
 
-BUILT_SOURCES += $(pr_opcode_cinc) $(pr_opcode_hinc)
+convert_py = $(srcdir)/libs/gamecode/convert.py
+pr_convert_cinc = $(top_builddir)/libs/gamecode/pr_convert.cinc
+
+BUILT_SOURCES += $(pr_opcode_cinc) $(pr_opcode_hinc) $(pr_convert_cinc)
 
 $(pr_opcode_cinc): $(opcodes_py)
 	$(V_PY)$(PYTHON) $(opcodes_py) table > $(pr_opcode_cinc).t && \
@@ -41,3 +44,7 @@ $(pr_opcode_hinc): $(opcodes_py)
 	$(V_PY) mkdir -p `dirname $(pr_opcode_hinc)` &&\
 	$(PYTHON) $(opcodes_py) enum > $(pr_opcode_hinc).t && \
 	$(am__mv) $(pr_opcode_hinc).t $(pr_opcode_hinc)
+
+$(pr_convert_cinc): $(convert_py)
+	$(V_PY)$(PYTHON) $(convert_py) table > $(pr_convert_cinc).t && \
+	$(am__mv) $(pr_convert_cinc).t $(pr_convert_cinc)

libs/gamecode/convert.py

@@ -0,0 +1,66 @@
+print("""// types are encoded as ubf where:
+//  u = 0: signed, u = 1: unsigned
+//  b = 0: 32-bit, b = 1: 64-bit
+//  f = 0: int,    f = 1: float/double
+// width is ww where:
+//  ww = 00: 1 component
+//  ww = 01: 2 components
+//  ww = 10: 3 components
+//  ww = 11: 4 components
+// full conversion code is wwsssddd where:
+//  ww = width
+//  sss = src type
+//  ddd = dst type
+// case values are in octal
+""")
+types = [
+    "int",
+    "float",
+    "long",
+    "double",
+    "uint",
+    None,       # no such thing as unsigned float
+    "ulong",
+    None,       # no such thing as unsigned double
+]
+#does not include size (2 or 4, 3 is special)
+vec_types = [
+    "ivec",
+    "vec",
+    "lvec",
+    "dvec",
+    "uivec",
+    None,       # no such thing as unsigned float
+    "ulvec",
+    None,       # no such thing as unsigned double
+]
+skip_matrix = [
+    #i  f  l  d   ui X  ul X
+    [1, 0, 0, 0,  1, 1, 0, 1],  # i
+    [0, 1, 0, 0,  0, 1, 0, 1],  # f
+    [0, 0, 1, 0,  0, 1, 1, 1],  # l
+    [0, 0, 0, 1,  0, 1, 0, 1],  # d
+
+    [1, 0, 0, 0,  1, 1, 0, 1],  # ui
+    [1, 1, 1, 1,  1, 1, 1, 1],  # X
+    [0, 0, 1, 0,  0, 1, 1, 1],  # ul
+    [1, 1, 1, 1,  1, 1, 1, 1],  # X
+]
+for width in range(4):
+    for src_type in range(8):
+        for dst_type in range(8):
+            if skip_matrix[src_type][dst_type]:
+                continue
+            case = (width << 6) | (src_type << 3) | (dst_type)
+            if width == 0:
+                print(f"case {case:04o}: OPC({types[dst_type]}) = (pr_{types[dst_type]}_t) OPA({types[src_type]}); break;")
+            elif width == 2:
+                print(f"case {case:04o}: VectorCompUop(&OPC({types[dst_type]}), (pr_{types[dst_type]}_t), &OPA({types[src_type]})); break;")
+            else:
+                if (src_type & 2) == (dst_type & 2):
+                    print(f"case {case:04o}: OPC({vec_types[dst_type]}{width+1}) = (pr_{vec_types[dst_type]}{width+1}_t) OPA({vec_types[src_type]}{width+1}); break;")
+                else:
+                    print(f"case {case:04o}:")
+                    for i in range(width + 1):
+                        print(f"\t(&OPC({types[dst_type]}))[{i}] = (pr_{types[dst_type]}_t) (&OPA({types[src_type]}))[{i}];")
+                    print(f"\tbreak;")

libs/gamecode/pr_exec.c

@@ -2915,6 +2915,7 @@ pr_exec_ruamoko (progs_t *pr, int exitdepth)
 				pr->pr_xstatement = pr_jump_mode (pr, st);
 				st = pr->pr_statements + pr->pr_xstatement;
 				break;
+			// 0 0101
 			case OP_IFNZ_A:
 			case OP_IFNZ_B:
 			case OP_IFNZ_C:
@@ -2972,9 +2973,17 @@ pr_exec_ruamoko (progs_t *pr, int exitdepth)
 				PR_CallFunction (pr, function);
 				st = pr->pr_statements + pr->pr_xstatement;
 				break;
-			// 0 0101
-			//        nnn spare
-			//OP_CONV
+			// 0 0110
+			//        0nnn spare
+			//        10nn spare
+			case OP_CONV:
+				switch (st->b) {
+#include "libs/gamecode/pr_convert.cinc"
+					default:
+						PR_RunError (pr, "invalid conversion code: %04o",
+									 st->b);
+				}
+				break;
 			case OP_WITH:
 				pr->pr_bases[st->c & 3] = pr_with (pr, st);
 				break;
@@ -3002,7 +3011,6 @@ pr_exec_ruamoko (progs_t *pr, int exitdepth)
 					pr->pr_edict_area[think].func_var = op_b->func_var;
 				}
 				break;
-			// 0 0110
 			// 0 0111
 			case OP_CROSS_F:
 				{
@@ -3121,14 +3129,16 @@ pr_exec_ruamoko (progs_t *pr, int exitdepth)
 			// 0 1010
 			OP_cmp(GT, >);
 			// 0 1011
+			// spare
 			// 0 1100
 			OP_cmp(NE, !=);
 			// 0 1101
 			OP_cmp(GE, >=);
 			// 0 1110
 			OP_cmp(LE, <=);
-			// 0 1011
-			//FIXME conversion 2
+
+			// 0 1111
+			// spare
 
 #define OP_op_1(OP, T, t, op) \
 			case OP_##OP##_##T##_1: \
@@ -3311,9 +3321,9 @@ pr_exec_ruamoko (progs_t *pr, int exitdepth)
 			//FIXME scale ops
 			// 1 1010
 			OP_cmp_T (GT, u, int, ivec2, ivec4, >, uint, uivec2, uivec4);
-			//FIXME conversion ops
+			// spare
 			OP_cmp_T (GT, U, long, lvec2, lvec4, >, ulong, ulvec2, ulvec4);
-			//FIXME conversion ops
+			// spare
 			// 1 1011
 			case OP_LEA_A:
 			case OP_LEA_B:
@@ -3447,14 +3457,14 @@ pr_exec_ruamoko (progs_t *pr, int exitdepth)
 			case OP_V4QMUL_F:
 				OPC(vec4) = vqmulf (OPA(vec4), OPB(vec4));
 				break;
-
+			// spare
 			OP_cmp_T (LE, U, long, lvec2, lvec4, <=, ulong, ulvec2, ulvec4);
 			case OP_V4QMUL_D:
 				OPC(dvec4) = vqmuld (OPA(dvec4), OPB(dvec4));
 				break;
-
+			// spare
 			// 1 1111
-
+			// spare
 			default:
 				PR_RunError (pr, "Bad opcode o%03o", st->op & OP_MASK);
 		}