r300/compiler: disable register allocation for indexable temporaries in VS

If there is relative addressing of temporaries, we cannot change register
indices, so skip register allocation entirely. To utilize register allocation
at least partially, we need separate indexable and non-indexable register
files in both TGSI and Mesa IR.

src/mesa/drivers/dri/r300/compiler/r3xx_vertprog.c

@@ -624,10 +624,9 @@ static void allocate_temporary_registers(struct r300_vertex_program_compiler * c
 	struct temporary_allocation * ta;
 	unsigned int i, j;
 
-	compiler->code->num_temporaries = 0;
 	memset(hwtemps, 0, sizeof(hwtemps));
 
-	/* Pass 1: Count original temporaries and allocate structures */
+	/* Pass 1: Count original temporaries. */
 	for(inst = compiler->Base.Program.Instructions.Next; inst != &compiler->Base.Program.Instructions; inst = inst->Next) {
 		const struct rc_opcode_info * opcode = rc_get_opcode_info(inst->U.I.Opcode);
 
@@ -645,12 +644,30 @@ static void allocate_temporary_registers(struct r300_vertex_program_compiler * c
 			}
 		}
 	}
+	compiler->code->num_temporaries = num_orig_temps;
+
+	/* Pass 2: If there is relative addressing of temporaries, we cannot change register indices. Give up. */
+	for (inst = compiler->Base.Program.Instructions.Next; inst != &compiler->Base.Program.Instructions; inst = inst->Next) {
+		const struct rc_opcode_info *opcode = rc_get_opcode_info(inst->U.I.Opcode);
+
+		if (opcode->HasDstReg)
+			if (inst->U.I.DstReg.RelAddr)
+				return;
 
+		for (i = 0; i < opcode->NumSrcRegs; ++i) {
+			if (inst->U.I.SrcReg[i].File == RC_FILE_TEMPORARY &&
+			    inst->U.I.SrcReg[i].RelAddr) {
+				return;
+			}
+		}
+	}
+
+	compiler->code->num_temporaries = 0;
 	ta = (struct temporary_allocation*)memory_pool_malloc(&compiler->Base.Pool,
 			sizeof(struct temporary_allocation) * num_orig_temps);
 	memset(ta, 0, sizeof(struct temporary_allocation) * num_orig_temps);
 
-	/* Pass 2: Determine original temporary lifetimes */
+	/* Pass 3: Determine original temporary lifetimes */
 	for(inst = compiler->Base.Program.Instructions.Next; inst != &compiler->Base.Program.Instructions; inst = inst->Next) {
 		const struct rc_opcode_info * opcode = rc_get_opcode_info(inst->U.I.Opcode);
 		/* Instructions inside of loops need to use the ENDLOOP
@@ -685,7 +702,7 @@ static void allocate_temporary_registers(struct r300_vertex_program_compiler * c
 		}
 	}
 
-	/* Pass 3: Register allocation */
+	/* Pass 4: Register allocation */
 	for(inst = compiler->Base.Program.Instructions.Next; inst != &compiler->Base.Program.Instructions; inst = inst->Next) {
 		const struct rc_opcode_info * opcode = rc_get_opcode_info(inst->U.I.Opcode);
 
@@ -937,9 +954,12 @@ void r3xx_compile_vertex_program(struct r300_vertex_program_compiler* compiler)
 
 	rc_dataflow_swizzles(&compiler->Base);
 
+	debug_program_log(compiler, "after dataflow");
+
 	allocate_temporary_registers(compiler);
 
-	debug_program_log(compiler, "after dataflow");
+	debug_program_log(compiler, "after register allocation");
+
 
 	translate_vertex_program(compiler);