Add `simd_rotate_left` simd_rotate_right`

3 files changed, 62 insertions, 0 deletions

diff --git a/src/check_builtin.cpp b/src/check_builtin.cpp
index 682667972..54bede3a8 100644
--- a/src/check_builtin.cpp
+++ b/src/check_builtin.cpp
@@ -933,6 +933,29 @@ bool check_builtin_simd_operation(CheckerContext *c, Operand *operand, Ast *call
 			return true;
 		}
 
+	case BuiltinProc_simd_rotate_left:
+	case BuiltinProc_simd_rotate_right:
+		{
+			Operand x = {};
+			check_expr(c, &x, ce->args[0]); if (x.mode == Addressing_Invalid) { return false; }
+			if (!is_type_simd_vector(x.type)) {
+				error(x.expr, "'%.*s' expected a simd vector type", LIT(builtin_name));
+				return false;
+			}
+			Operand offset = {};
+			check_expr(c, &offset, ce->args[1]); if (offset.mode == Addressing_Invalid) { return false; }
+			convert_to_typed(c, &offset, t_i64);
+			if (!is_type_integer(offset.type) || offset.mode != Addressing_Constant) {
+				error(offset.expr, "'%.*s' expected a constant integer offset");
+				return false;
+			}
+			check_assignment(c, &offset, t_i64, builtin_name);
+
+			operand->type = x.type;
+			operand->mode = Addressing_Value;
+			return true;
+		}
+
 	default:
 		GB_PANIC("Unhandled simd intrinsic: %.*s", LIT(builtin_name));
 	}
diff --git a/src/checker_builtin_procs.hpp b/src/checker_builtin_procs.hpp
index 07c425cfa..13fe2822c 100644
--- a/src/checker_builtin_procs.hpp
+++ b/src/checker_builtin_procs.hpp
@@ -170,6 +170,8 @@ BuiltinProc__simd_begin,
 	BuiltinProc_simd_nearest,
 
 	BuiltinProc_simd_reverse,
+	BuiltinProc_simd_rotate_left,
+	BuiltinProc_simd_rotate_right,
 BuiltinProc__simd_end,
 	
 	// Platform specific intrinsics
@@ -444,6 +446,8 @@ gb_global BuiltinProc builtin_procs[BuiltinProc_COUNT] = {
 	{STR_LIT("simd_nearest"), 1, false, Expr_Expr, BuiltinProcPkg_intrinsics},
 
 	{STR_LIT("simd_reverse"), 1, false, Expr_Expr, BuiltinProcPkg_intrinsics},
+	{STR_LIT("simd_rotate_left"), 2, false, Expr_Expr, BuiltinProcPkg_intrinsics},
+	{STR_LIT("simd_rotate_right"), 2, false, Expr_Expr, BuiltinProcPkg_intrinsics},
 	{STR_LIT(""), 0, false, Expr_Stmt, BuiltinProcPkg_intrinsics},
 
 
diff --git a/src/llvm_backend_proc.cpp b/src/llvm_backend_proc.cpp
index dbdc51078..c433334d1 100644
--- a/src/llvm_backend_proc.cpp
+++ b/src/llvm_backend_proc.cpp
@@ -1353,6 +1353,41 @@ lbValue lb_build_builtin_simd_proc(lbProcedure *p, Ast *expr, TypeAndValue const
 			return res;
 		}
 
+	case BuiltinProc_simd_rotate_left:
+	case BuiltinProc_simd_rotate_right:
+		{
+
+			i64 count = get_array_type_count(arg0.type);
+			GB_ASSERT(is_power_of_two(count));
+			BigInt bi_count = {};
+			big_int_from_i64(&bi_count, count);
+
+			TypeAndValue const &tv = ce->args[1]->tav;
+			ExactValue val = exact_value_to_integer(tv.value);
+			GB_ASSERT(val.kind == ExactValue_Integer);
+			BigInt *bi = &val.value_integer;
+			if (builtin_id == BuiltinProc_simd_rotate_right) {
+				big_int_neg(bi, bi);
+			}
+			big_int_rem(bi, bi, &bi_count);
+			big_int_dealloc(&bi_count);
+
+			i64 left = big_int_to_i64(bi);
+
+			LLVMValueRef *values = gb_alloc_array(temporary_allocator(), LLVMValueRef, count);
+			LLVMTypeRef llvm_u32 = lb_type(m, t_u32);
+			for (i64 i = 0; i < count; i++) {
+				u64 idx = cast(u64)(i+left) & cast(u64)(count-1);
+				values[i] = LLVMConstInt(llvm_u32, idx, false);
+			}
+			LLVMValueRef mask = LLVMConstVector(values, cast(unsigned)count);
+
+			LLVMValueRef v = arg0.value;
+			res.value = LLVMBuildShuffleVector(p->builder, v, v, mask, "");
+			return res;
+		}
+
+
 	case BuiltinProc_simd_add_sat:
 	case BuiltinProc_simd_sub_sat:
 		{