intel/elk_asm: Add BranchCtrl support

We emit it for gfx8, so the assembler should support it too.

Signed-off-by: Sviatoslav Peleshko <sviatoslav.peleshko@globallogic.com>
Reviewed-by: Caio Oliveira <caio.oliveira@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/31747>

src/intel/compiler/elk/elk_asm.h

@@ -72,6 +72,7 @@ struct options {
    unsigned access_mode:1;
    unsigned compression_control:2;
    unsigned thread_control:2;
+   unsigned branch_control:1;
    unsigned no_dd_check:1; // Dependency control
    unsigned no_dd_clear:1; // Dependency control
    unsigned mask_control:1;

src/intel/compiler/elk/elk_disasm.c

@@ -64,8 +64,8 @@ elk_has_uip(const struct intel_device_info *devinfo, enum elk_opcode opcode)
           opcode == ELK_OPCODE_HALT;
 }
 
-static bool
-has_branch_ctrl(const struct intel_device_info *devinfo, enum elk_opcode opcode)
+bool
+elk_has_branch_ctrl(const struct intel_device_info *devinfo, enum elk_opcode opcode)
 {
    if (devinfo->ver < 8)
       return false;
@@ -2000,7 +2000,7 @@ elk_disassemble_inst(FILE *file, const struct elk_isa_info *isa,
       err |= control(file, "thread control", thread_ctrl,
                      elk_inst_thread_control(devinfo, inst),
                      &space);
-      if (has_branch_ctrl(devinfo, opcode)) {
+      if (elk_has_branch_ctrl(devinfo, opcode)) {
          err |= control(file, "branch ctrl", branch_ctrl,
                         elk_inst_branch_control(devinfo, inst), &space);
       } else if (devinfo->ver >= 6) {

src/intel/compiler/elk/elk_eu.h

@@ -175,6 +175,7 @@ void elk_init_codegen(const struct elk_isa_info *isa,
                       struct elk_codegen *p, void *mem_ctx);
 bool elk_has_jip(const struct intel_device_info *devinfo, enum elk_opcode opcode);
 bool elk_has_uip(const struct intel_device_info *devinfo, enum elk_opcode opcode);
+bool elk_has_branch_ctrl(const struct intel_device_info *devinfo, enum elk_opcode opcode);
 const struct elk_shader_reloc *elk_get_shader_relocs(struct elk_codegen *p,
                                                      unsigned *num_relocs);
 const unsigned *elk_get_program( struct elk_codegen *p, unsigned *sz );

src/intel/compiler/elk/elk_gram.y

@@ -294,9 +294,18 @@ i965_asm_set_instruction_options(struct elk_codegen *p,
                                  options.no_dd_clear);
 	elk_inst_set_debug_control(p->devinfo, elk_last_inst,
 			           options.debug_control);
-	if (p->devinfo->ver >= 6)
+	if (elk_has_branch_ctrl(p->devinfo, elk_inst_opcode(p->isa, elk_last_inst))) {
+		if (options.acc_wr_control)
+			error(NULL, "Instruction does not support AccWrEnable\n");
+
+		elk_inst_set_branch_control(p->devinfo, elk_last_inst,
+		                            options.branch_control);
+	} else if (options.branch_control) {
+		error(NULL, "Instruction does not support BranchCtrl\n");
+	} else if (p->devinfo->ver >= 6) {
 		elk_inst_set_acc_wr_control(p->devinfo, elk_last_inst,
 					    options.acc_wr_control);
+	}
 	elk_inst_set_cmpt_control(p->devinfo, elk_last_inst,
 				  options.compaction);
 }
@@ -455,6 +464,9 @@ add_label(struct elk_codegen *p, const char* label_name, enum instr_label_type t
 /* thread control */
 %token ATOMIC SWITCH
 
+/* branch control */
+%token BRANCH_CTRL
+
 /* quater control */
 %token QTR_2Q QTR_3Q QTR_4Q QTR_2H QTR_2N QTR_3N QTR_4N QTR_5N
 %token QTR_6N QTR_7N QTR_8N
@@ -566,6 +578,9 @@ add_instruction_option(struct options *options, struct instoption opt)
 	case ATOMIC:
 		options->thread_control |= ELK_THREAD_ATOMIC;
 		break;
+	case BRANCH_CTRL:
+		options->branch_control = true;
+		break;
 	case NODDCHK:
 		options->no_dd_check = true;
 		break;
@@ -2284,7 +2299,12 @@ instoption_list:
 instoption:
 	ALIGN1 	        { $$.uint_value = ALIGN1;}
 	| ALIGN16 	{ $$.uint_value = ALIGN16; }
-	| ACCWREN 	{ $$.uint_value = ACCWREN; }
+	| ACCWREN
+	{
+		if (p->devinfo->ver < 6)
+			error(&@1, "AccWrEnable not supported before Gfx6\n");
+		$$.uint_value = ACCWREN;
+	}
 	| SECHALF 	{ $$.uint_value = SECHALF; }
 	| COMPR 	{ $$.uint_value = COMPR; }
 	| COMPR4 	{ $$.uint_value = COMPR4; }
@@ -2295,6 +2315,12 @@ instoption:
 	| EOT 	        { $$.uint_value = EOT; }
 	| SWITCH 	{ $$.uint_value = SWITCH; }
 	| ATOMIC 	{ $$.uint_value = ATOMIC; }
+	| BRANCH_CTRL
+	{
+		if (p->devinfo->ver < 8)
+			error(&@1, "BranchCtrl not supported before Gfx8\n");
+		$$.uint_value = BRANCH_CTRL;
+	}
 	| CMPTCTRL 	{ $$.uint_value = CMPTCTRL; }
 	| WECTRL 	{ $$.uint_value = WECTRL; }
 	| QTR_2Q 	{ $$.uint_value = QTR_2Q; }

src/intel/compiler/elk/elk_lex.l

@@ -277,6 +277,9 @@ nomask      	{ return MASK_DISABLE; }
 atomic       	{ return ATOMIC; }
 switch       	{ return SWITCH; }
 
+ /* Branch control */
+BranchCtrl	{ return BRANCH_CTRL; }
+
  /* compression control */
 compr 		{ return COMPR; }
 compr4    	{ return COMPR4; }