d: Wrong evaluation order of binary expressions (PR101640)
authorIain Buclaw <ibuclaw@gdcproject.org>
Tue, 27 Jul 2021 11:24:34 +0000 (13:24 +0200)
committerIain Buclaw <ibuclaw@gdcproject.org>
Wed, 28 Jul 2021 11:13:06 +0000 (13:13 +0200)
The use of fold_build2 can in some cases swap the order of its operands
if that is the more optimal thing to do.  However this breaks semantic
guarantee of left-to-right evaluation in D.

PR d/101640

gcc/d/ChangeLog:

* expr.cc (binary_op): Use build2 instead of fold_build2.

gcc/testsuite/ChangeLog:

* gdc.dg/pr96429.d: Update test.
* gdc.dg/pr101640.d: New test.

gcc/d/expr.cc
gcc/testsuite/gdc.dg/pr101640.d [new file with mode: 0644]
gcc/testsuite/gdc.dg/pr96429.d

index e76cae9..b78778e 100644 (file)
@@ -157,7 +157,7 @@ binary_op (tree_code code, tree type, tree arg0, tree arg1)
          eptype = type;
        }
 
-      ret = fold_build2 (code, eptype, arg0, arg1);
+      ret = build2 (code, eptype, arg0, arg1);
     }
 
   return d_convert (type, ret);
diff --git a/gcc/testsuite/gdc.dg/pr101640.d b/gcc/testsuite/gdc.dg/pr101640.d
new file mode 100644 (file)
index 0000000..68de408
--- /dev/null
@@ -0,0 +1,11 @@
+// https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101640
+// { dg-do compile }
+// { dg-options "-fdump-tree-original" }
+
+int fun101640(ref int);
+
+int test101640(int val)
+{
+    // { dg-final { scan-tree-dump "= val \\\+ fun101640 \\\(\\\(int &\\\) &val\\\);" "original" } }
+    return val + fun101640(val);
+}
index af096e2..9940a03 100644 (file)
@@ -3,7 +3,7 @@
 // { dg-options "-fdump-tree-original" }
 ptrdiff_t subbyte(byte* bp1, byte* bp2)
 {
-    // { dg-final { scan-tree-dump "bp1 - bp2;" "original" } }
+    // { dg-final { scan-tree-dump "\\\(bp1 - bp2\\\) /\\\[ex\\\] 1;" "original" } }
     return bp1 - bp2;
 }