fix 0-x being turned into x

diff --git a/fold.c b/fold.c
index c9f1a0695c07f8fe1b9c35b62f7bbfab4eaaa360..0128dece56cf030039463c7c0619c482a3ac455e 100644 (file)
--- a/fold.c
+++ b/fold.c
@@ -799,8 +799,10 @@ static ast_expression *fold_superfluous(ast_expression *left, ast_expression *ri
             break;
 
 
-        case INSTR_ADD_F:
         case INSTR_SUB_F:
+            if (swapped)
+                return NULL;
+        case INSTR_ADD_F:
             if (fold_immvalue_float(load) == 0.0f) {
                 ++opts_optimizationcount[OPTIM_PEEPHOLE];
                 ast_unref(right);
@@ -816,8 +818,10 @@ static ast_expression *fold_superfluous(ast_expression *left, ast_expression *ri
             }
             break;
 
-        case INSTR_ADD_V:
         case INSTR_SUB_V:
+            if (swapped)
+                return NULL;
+        case INSTR_ADD_V:
             if (vec3_cmp(fold_immvalue_vector(load), vec3_create(0, 0, 0))) {
                 ++opts_optimizationcount[OPTIM_PEEPHOLE];
                 ast_unref(right);