Fixed canonicalization bugs

c3lang · Jan 15, 2023 · 4c5c4e8 · 4c5c4e8
1 parent 4f1c61c
commit 4c5c4e8
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Showing 2 changed files with 9 additions and 2 deletions.
diff --git a/src/tb/opt/canonical.c b/src/tb/opt/canonical.c
@@ -330,13 +330,21 @@ static bool inst_combine(TB_Function* f) {
                 TB_Node* a = &f->nodes[n->cmp.a];
                 TB_Node* b = &f->nodes[n->cmp.b];
 
-                // (cmpeq (cmpeq a 0) 0) => a
                 if (n->type == TB_CMP_EQ && tb_node_is_constant_zero(f, n->cmp.b) &&
                     a->type == TB_CMP_EQ && tb_node_is_constant_zero(f, a->cmp.b)) {
+                    // (cmpeq (cmpeq a 0) 0) => (cmpeq a 0)
                     OPTIMIZER_LOG(r, "removed redundant comparisons");
 
                     n->type = TB_PASS;
                     n->pass.value = a->cmp.a;
+                } else if (n->type == TB_CMP_NE && tb_node_is_constant_zero(f, n->cmp.b) &&
+                    a->type == TB_CMP_EQ && tb_node_is_constant_zero(f, a->cmp.b)) {
+                    // (cmpeq (cmpeq a 0) 0) => (cmpne a 0)
+                    OPTIMIZER_LOG(r, "removed redundant comparisons");
+
+                    n->type = TB_PASS;
+                    n->pass.value = a->cmp.a;
+                    a->type = TB_CMP_NE;
                 } else {
                     // Sometimes we promote some types up when we don't need to
                     // (cmp (sxt/zxt A) (int B))

diff --git a/src/tb/opt/fold.h b/src/tb/opt/fold.h
@@ -105,7 +105,6 @@ static bool is_associative(TB_NodeTypeEnum type) {
     switch (type) {
         case TB_ADD: case TB_MUL:
         case TB_AND: case TB_XOR: case TB_OR:
-        case TB_CMP_NE: case TB_CMP_EQ:
         return true;
 
         default: