diff --git a/libs/vkd3d-shader/hlsl.y b/libs/vkd3d-shader/hlsl.y
index 54227041..edb24911 100644
--- a/libs/vkd3d-shader/hlsl.y
+++ b/libs/vkd3d-shader/hlsl.y
@@ -1214,19 +1214,20 @@ static bool add_effect_group(struct hlsl_ctx *ctx, const char *name, struct hlsl
     return true;
 }
 
-static bool parse_reservation_index(const char *string, char *type, uint32_t *index, unsigned int bracket_offset)
+static bool parse_reservation_index(const char *string, unsigned int bracket_offset,
+        struct hlsl_reg_reservation *reservation)
 {
     char *endptr;
 
-    *type = ascii_tolower(string[0]);
+    reservation->reg_type = ascii_tolower(string[0]);
 
     if (string[1] == '\0')
     {
-        *index = bracket_offset;
+        reservation->reg_index = bracket_offset;
         return true;
     }
 
-    *index = strtoul(string + 1, &endptr, 10) + bracket_offset;
+    reservation->reg_index = strtoul(string + 1, &endptr, 10) + bracket_offset;
 
     if (endptr == string + 1)
         return false;
@@ -6556,7 +6557,7 @@ register_reservation:
       ':' KW_REGISTER '(' any_identifier ')'
         {
             memset(&$$, 0, sizeof($$));
-            if (!parse_reservation_index($4, &$$.reg_type, &$$.reg_index, 0))
+            if (!parse_reservation_index($4, 0, &$$))
                 hlsl_error(ctx, &@4, VKD3D_SHADER_ERROR_HLSL_INVALID_RESERVATION,
                         "Invalid register reservation '%s'.", $4);
 
@@ -6565,8 +6566,7 @@ register_reservation:
     | ':' KW_REGISTER '(' any_identifier '[' expr ']' ')'
         {
             memset(&$$, 0, sizeof($$));
-            if (!parse_reservation_index($4, &$$.reg_type, &$$.reg_index,
-                    evaluate_static_expression_as_uint(ctx, $6, &@6)))
+            if (!parse_reservation_index($4, evaluate_static_expression_as_uint(ctx, $6, &@6), &$$))
             {
                 hlsl_error(ctx, &@4, VKD3D_SHADER_ERROR_HLSL_INVALID_RESERVATION,
                         "Invalid register reservation '%s'.", $4);
@@ -6578,13 +6578,13 @@ register_reservation:
     | ':' KW_REGISTER '(' any_identifier ',' any_identifier ')'
         {
             memset(&$$, 0, sizeof($$));
-            if (parse_reservation_index($6, &$$.reg_type, &$$.reg_index, 0))
+            if (parse_reservation_index($6, 0, &$$))
             {
                 hlsl_fixme(ctx, &@4, "Reservation shader target %s.", $4);
             }
             else if (parse_reservation_space($6, &$$.reg_space))
             {
-                if (!parse_reservation_index($4, &$$.reg_type, &$$.reg_index, 0))
+                if (!parse_reservation_index($4, 0, &$$))
                     hlsl_error(ctx, &@4, VKD3D_SHADER_ERROR_HLSL_INVALID_RESERVATION,
                             "Invalid register reservation '%s'.", $4);
             }
@@ -6605,8 +6605,7 @@ register_reservation:
                 hlsl_error(ctx, &@9, VKD3D_SHADER_ERROR_HLSL_INVALID_RESERVATION,
                         "Invalid register space reservation '%s'.", $9);
 
-            if (!parse_reservation_index($4, &$$.reg_type, &$$.reg_index,
-                    evaluate_static_expression_as_uint(ctx, $6, &@6)))
+            if (!parse_reservation_index($4, evaluate_static_expression_as_uint(ctx, $6, &@6), &$$))
             {
                 hlsl_error(ctx, &@4, VKD3D_SHADER_ERROR_HLSL_INVALID_RESERVATION,
                         "Invalid register reservation '%s'.", $4);
@@ -6621,8 +6620,7 @@ register_reservation:
             hlsl_fixme(ctx, &@4, "Reservation shader target %s.", $4);
 
             memset(&$$, 0, sizeof($$));
-            if (!parse_reservation_index($6, &$$.reg_type, &$$.reg_index,
-                    evaluate_static_expression_as_uint(ctx, $8, &@8)))
+            if (!parse_reservation_index($6, evaluate_static_expression_as_uint(ctx, $8, &@8), &$$))
             {
                 hlsl_error(ctx, &@6, VKD3D_SHADER_ERROR_HLSL_INVALID_RESERVATION,
                         "Invalid register reservation '%s'.", $6);
@@ -6637,7 +6635,7 @@ register_reservation:
             hlsl_fixme(ctx, &@4, "Reservation shader target %s.", $4);
 
             memset(&$$, 0, sizeof($$));
-            if (!parse_reservation_index($6, &$$.reg_type, &$$.reg_index, 0))
+            if (!parse_reservation_index($6, 0, &$$))
                 hlsl_error(ctx, &@6, VKD3D_SHADER_ERROR_HLSL_INVALID_RESERVATION,
                         "Invalid register reservation '%s'.", $6);
 
@@ -6654,8 +6652,7 @@ register_reservation:
             hlsl_fixme(ctx, &@4, "Reservation shader target %s.", $4);
 
             memset(&$$, 0, sizeof($$));
-            if (!parse_reservation_index($6, &$$.reg_type, &$$.reg_index,
-                    evaluate_static_expression_as_uint(ctx, $8, &@8)))
+            if (!parse_reservation_index($6, evaluate_static_expression_as_uint(ctx, $8, &@8), &$$))
             {
                 hlsl_error(ctx, &@6, VKD3D_SHADER_ERROR_HLSL_INVALID_RESERVATION,
                         "Invalid register reservation '%s'.", $6);