Bug 1204028: Evaluate LHS reference before RHS in destructuring

Issue #73
[Depends on] Bug 1147371: Implement IteratorClose

1 files changed, 13 insertions, 0 deletions

diff --git a/js/src/jit/MIRGraph.cpp b/js/src/jit/MIRGraph.cpp
index 3a363a5bfa..d6e0fa8ffc 100644
--- a/js/src/jit/MIRGraph.cpp
+++ b/js/src/jit/MIRGraph.cpp
@@ -790,6 +790,19 @@ MBasicBlock::pick(int32_t depth)
 }
 
 void
+MBasicBlock::unpick(int32_t depth)
+{
+    // unpick take the top of the stack element and move it under the depth-th
+    // element;
+    // unpick(-2):
+    //   A B C D E
+    //   A B C E D [ swapAt(-1) ]
+    //   A B E C D [ swapAt(-2) ]
+    for (int32_t n = -1; n >= depth; n--)
+        swapAt(n);
+}
+
+void
 MBasicBlock::swapAt(int32_t depth)
 {
     uint32_t lhsDepth = stackPosition_ + depth - 1;