Add `intrinsics.cpu_relax`

src/check_expr.cpp

@@ -5280,6 +5280,10 @@ bool check_builtin_procedure(CheckerContext *c, Operand *operand, Ast *call, i32
 		break;
 	}
 
+	case BuiltinProc_cpu_relax:
+		operand->mode = Addressing_NoValue;
+		break;
+
 	case BuiltinProc_atomic_fence:
 	case BuiltinProc_atomic_fence_acq:
 	case BuiltinProc_atomic_fence_rel:

src/checker_builtin_procs.hpp

@@ -36,6 +36,8 @@ enum BuiltinProcId {
 	BuiltinProc_simd_vector,
 	BuiltinProc_soa_struct,
 
+	BuiltinProc_cpu_relax,
+
 	BuiltinProc_atomic_fence,
 	BuiltinProc_atomic_fence_acq,
 	BuiltinProc_atomic_fence_rel,
@@ -214,6 +216,8 @@ gb_global BuiltinProc builtin_procs[BuiltinProc_COUNT] = {
 	{STR_LIT("simd_vector"), 2, false, Expr_Expr, BuiltinProcPkg_intrinsics}, // Type
 	{STR_LIT("soa_struct"),  2, false, Expr_Expr, BuiltinProcPkg_intrinsics}, // Type
 
+	{STR_LIT("cpu_relax"),  0, false, Expr_Stmt, BuiltinProcPkg_intrinsics},
+
 	{STR_LIT("atomic_fence"),        0, false, Expr_Stmt, BuiltinProcPkg_intrinsics},
 	{STR_LIT("atomic_fence_acq"),    0, false, Expr_Stmt, BuiltinProcPkg_intrinsics},
 	{STR_LIT("atomic_fence_rel"),    0, false, Expr_Stmt, BuiltinProcPkg_intrinsics},

src/ir.cpp

@@ -197,6 +197,7 @@ gbAllocator ir_allocator(void) {
 	IR_INSTR_KIND(ZeroInit, struct { irValue *address; })             \
 	IR_INSTR_KIND(Store,    struct { irValue *address, *value; bool is_volatile; }) \
 	IR_INSTR_KIND(Load,     struct { Type *type; irValue *address; i64 custom_align; }) \
+	IR_INSTR_KIND(InlineCode, struct { BuiltinProcId id; Array<irValue *> operands; }) \
 	IR_INSTR_KIND(AtomicFence, struct { BuiltinProcId id; })          \
 	IR_INSTR_KIND(AtomicStore, struct {                               \
 		irValue *address, *value;                                     \
@@ -1063,6 +1064,14 @@ irValue *ir_instr_load(irProcedure *p, irValue *address) {
 	return v;
 }
 
+irValue *ir_instr_inline_code(irProcedure *p, BuiltinProcId id, Array<irValue *> operands) {
+	irValue *v = ir_alloc_instr(p, irInstr_InlineCode);
+	irInstr *i = &v->Instr;
+	i->InlineCode.id = id;
+	i->InlineCode.operands = operands;
+	return v;
+}
+
 irValue *ir_instr_atomic_fence(irProcedure *p, BuiltinProcId id) {
 	irValue *v = ir_alloc_instr(p, irInstr_AtomicFence);
 	irInstr *i = &v->Instr;
@@ -6914,6 +6923,9 @@ irValue *ir_build_builtin_proc(irProcedure *proc, Ast *expr, TypeAndValue tv, Bu
 
 
 	// "Intrinsics"
+	case BuiltinProc_cpu_relax:
+		return ir_emit(proc, ir_instr_inline_code(proc, id, {}));
+
 	case BuiltinProc_atomic_fence:
 	case BuiltinProc_atomic_fence_acq:
 	case BuiltinProc_atomic_fence_rel:

src/ir_print.cpp

@@ -1483,6 +1483,18 @@ void ir_print_instr(irFileBuffer *f, irModule *m, irValue *value) {
 		break;
 	}
 
+	case irInstr_InlineCode:
+		{
+			switch (instr->InlineCode.id) {
+			case BuiltinProc_cpu_relax:
+				ir_write_str_lit(f, "call void asm sideeffect \"pause\", \"\"()");
+				break;
+			default: GB_PANIC("Unknown inline code %d", instr->InlineCode.id); break;
+			}
+		}
+		break;
+
+
 	case irInstr_AtomicFence:
 		ir_write_str_lit(f, "fence ");
 		switch (instr->AtomicFence.id) {