r600/sb: replace memset by using member initialization/assignment

Closes #2860

Signed-off-by: Gert Wollny <gert.wollny@collabora.com>
Reviewed-by: Michel Dänzer <mdaenzer@redhat.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4939>

src/gallium/drivers/r600/r600_isa.h

@@ -36,6 +36,7 @@ extern "C" {
 /* ALU flags */
 enum alu_op_flags
 {
+	AF_NONE = 0,
 	AF_V		= (1<<0),    /* allowed in vector slots */
 
 	/* allowed in scalar(trans) slot (slots xyz on cayman, may be replicated

src/gallium/drivers/r600/sb/sb_bc.h

@@ -495,6 +495,15 @@ struct bc_alu_src {
 	unsigned abs:1;
 	unsigned rel:1;
 	literal value;
+
+	void clear() {
+		sel = 0;
+		chan = 0;
+		neg = 0;
+		abs = 0;
+		rel = 0;
+		value = 0;
+	}
 };
 
 struct bc_alu {
@@ -529,6 +538,31 @@ struct bc_alu {
 		this->op = op;
 		op_ptr = r600_isa_alu(op);
 	}
+	void clear() {
+		op_ptr = nullptr;
+		op = 0;
+		for (int i = 0; i < 3; ++i)
+			src[i].clear();
+		dst_gpr = 0;
+		dst_chan = 0;
+		dst_rel = 0;
+		clamp = 0;
+		omod = 0;
+		bank_swizzle = 0;
+		index_mode = 0;
+		last = 0;
+		pred_sel = 0;
+		fog_merge = 0;
+		write_mask = 0;
+		update_exec_mask = 0;
+		update_pred = 0;
+		slot = 0;
+		lds_idx_offset = 0;
+		slot_flags = AF_NONE;
+	}
+	bc_alu() {
+		clear();
+	}
 };
 
 struct bc_fetch {

src/gallium/drivers/r600/sb/sb_expr.cpp

@@ -719,7 +719,7 @@ bool expr_handler::fold_assoc(alu_node *n) {
 			n->src[0] = n->src[2];
 			n->bc.src[0] = n->bc.src[2];
 			n->src[1] = sh.get_const_value(cr);
-			memset(&n->bc.src[1], 0, sizeof(bc_alu_src));
+			n->bc.src[1].clear();
 
 			n->src.resize(2);
 			n->bc.set_op(ALU_OP2_ADD);
@@ -729,7 +729,7 @@ bool expr_handler::fold_assoc(alu_node *n) {
 		n->bc.src[0] = a->bc.src[last_arg];
 		n->bc.src[0].neg ^= cur_neg;
 		n->src[1] = sh.get_const_value(cr);
-		memset(&n->bc.src[1], 0, sizeof(bc_alu_src));
+		n->bc.src[1].clear();
 	}
 
 	return false;
@@ -770,7 +770,7 @@ bool expr_handler::fold_alu_op2(alu_node& n) {
 			case ALU_OP2_ADD:  // (ADD x, x) => (MUL x, 2)
 				if (!sh.safe_math) {
 					n.src[1] = sh.get_const_value(2.0f);
-					memset(&n.bc.src[1], 0, sizeof(bc_alu_src));
+					n.bc.src[1].clear();
 					n.bc.set_op(ALU_OP2_MUL);
 					return fold_alu_op2(n);
 				}
@@ -1070,7 +1070,7 @@ bool expr_handler::fold_alu_op3(alu_node& n) {
 				}
 
 				n.src[1] = t;
-				memset(&n.bc.src[1], 0, sizeof(bc_alu_src));
+				n.bc.src[1].clear();
 
 				n.src.resize(2);
 
@@ -1101,7 +1101,7 @@ bool expr_handler::fold_alu_op3(alu_node& n) {
 				dv = cv0.f * cv1.f;
 				n.bc.set_op(ALU_OP2_ADD);
 				n.src[0] = sh.get_const_value(dv);
-				memset(&n.bc.src[0], 0, sizeof(bc_alu_src));
+				n.bc.src[0].clear();
 				n.src[1] = n.src[2];
 				n.bc.src[1] = n.bc.src[2];
 				n.src.resize(2);

src/gallium/drivers/r600/sb/sb_if_conversion.cpp

@@ -99,8 +99,8 @@ void if_conversion::convert_kill_instructions(region_node *r,
 			a->src[0] = cnd;
 			a->src[1] = sh.get_const_value(0);
 			// clear modifiers
-			memset(&a->bc.src[0], 0, sizeof(bc_alu_src));
-			memset(&a->bc.src[1], 0, sizeof(bc_alu_src));
+			a->bc.src[0].clear();
+			a->bc.src[1].clear();
 		} else {
 			// kill with constant 'false' condition, this shouldn't happen
 			// but remove it anyway

src/gallium/drivers/r600/sb/sb_ir.h

@@ -1012,7 +1012,7 @@ public:
 
 class alu_node : public node {
 protected:
-	alu_node() : node(NT_OP, NST_ALU_INST) { memset(&bc, 0, sizeof(bc_alu)); }
+	alu_node() : node(NT_OP, NST_ALU_INST) {  }
 public:
 	bc_alu bc;
 

src/gallium/drivers/r600/sb/sb_peephole.cpp

@@ -131,8 +131,8 @@ void peephole::optimize_cc_op2(alu_node* a) {
 		std::swap(a->src[0],a->src[1]);
 		swapped = true;
 		// clear modifiers
-		memset(&a->bc.src[0], 0, sizeof(bc_alu_src));
-		memset(&a->bc.src[1], 0, sizeof(bc_alu_src));
+		a->bc.src[0].clear();
+		a->bc.src[1].clear();
 	}
 
 	if (swapped || (a->src[1]->is_const() &&