Add `intrinsics.count_zeros`

4 files changed, 14 insertions, 0 deletions

diff --git a/src/check_builtin.cpp b/src/check_builtin.cpp
index d3dbb3120..00963487f 100644
--- a/src/check_builtin.cpp
+++ b/src/check_builtin.cpp
@@ -1923,6 +1923,7 @@ bool check_builtin_procedure(CheckerContext *c, Operand *operand, Ast *call, i32
 		break;
 
 	case BuiltinProc_count_ones:
+	case BuiltinProc_count_zeros:
 	case BuiltinProc_count_trailing_zeros:
 	case BuiltinProc_count_leading_zeros:
 	case BuiltinProc_reverse_bits:
diff --git a/src/checker_builtin_procs.hpp b/src/checker_builtin_procs.hpp
index 7282e9895..98ef5180b 100644
--- a/src/checker_builtin_procs.hpp
+++ b/src/checker_builtin_procs.hpp
@@ -46,6 +46,7 @@ enum BuiltinProcId {
 	BuiltinProc_read_cycle_counter,
 
 	BuiltinProc_count_ones,
+	BuiltinProc_count_zeros,
 	BuiltinProc_count_trailing_zeros,
 	BuiltinProc_count_leading_zeros,
 	BuiltinProc_reverse_bits,
@@ -265,6 +266,7 @@ gb_global BuiltinProc builtin_procs[BuiltinProc_COUNT] = {
 	{STR_LIT("read_cycle_counter"), 0, false, Expr_Expr, BuiltinProcPkg_intrinsics},
 
 	{STR_LIT("count_ones"),           1, false, Expr_Expr, BuiltinProcPkg_intrinsics},
+	{STR_LIT("count_zeros"),          1, false, Expr_Expr, BuiltinProcPkg_intrinsics},
 	{STR_LIT("count_trailing_zeros"), 1, false, Expr_Expr, BuiltinProcPkg_intrinsics},
 	{STR_LIT("count_leading_zeros"),  1, false, Expr_Expr, BuiltinProcPkg_intrinsics},
 	{STR_LIT("reverse_bits"),         1, false, Expr_Expr, BuiltinProcPkg_intrinsics},
diff --git a/src/llvm_backend.cpp b/src/llvm_backend.cpp
index c6f1c3693..c52c9269e 100644
--- a/src/llvm_backend.cpp
+++ b/src/llvm_backend.cpp
@@ -9113,6 +9113,8 @@ lbValue lb_build_builtin_proc(lbProcedure *p, Ast *expr, TypeAndValue const &tv,
 
 	case BuiltinProc_count_ones:
 		return lb_emit_count_ones(p, lb_build_expr(p, ce->args[0]), tv.type);
+	case BuiltinProc_count_zeros:
+		return lb_emit_count_zeros(p, lb_build_expr(p, ce->args[0]), tv.type);
 
 	case BuiltinProc_reverse_bits:
 		return lb_emit_reverse_bits(p, lb_build_expr(p, ce->args[0]), tv.type);
@@ -9971,6 +9973,14 @@ lbValue lb_emit_count_ones(lbProcedure *p, lbValue x, Type *type) {
 	return res;
 }
 
+lbValue lb_emit_count_zeros(lbProcedure *p, lbValue x, Type *type) {
+	i64 sz = 8*type_size_of(type);
+	lbValue size = lb_const_int(p->module, type, cast(u64)sz);
+	lbValue count = lb_emit_count_ones(p, x, type);
+	return lb_emit_arith(p, Token_Sub, size, count, type);
+}
+
+
 
 lbValue lb_emit_count_trailing_zeros(lbProcedure *p, lbValue x, Type *type) {
 	x = lb_emit_conv(p, x, type);
diff --git a/src/llvm_backend.hpp b/src/llvm_backend.hpp
index b25d94abb..e8811a91e 100644
--- a/src/llvm_backend.hpp
+++ b/src/llvm_backend.hpp
@@ -395,6 +395,7 @@ lbValue lb_emit_conv(lbProcedure *p, lbValue value, Type *t);
 LLVMMetadataRef lb_debug_type(lbModule *m, Type *type);
 
 lbValue lb_emit_count_ones(lbProcedure *p, lbValue x, Type *type);
+lbValue lb_emit_count_zeros(lbProcedure *p, lbValue x, Type *type);
 lbValue lb_emit_count_trailing_zeros(lbProcedure *p, lbValue x, Type *type);
 lbValue lb_emit_count_leading_zeros(lbProcedure *p, lbValue x, Type *type);
 lbValue lb_emit_reverse_bits(lbProcedure *p, lbValue x, Type *type);