1.0.44.34: gtn: KLUDGE the lambda-var assignment to not break tail-calls.

[sbcl.git] / src / compiler / gtn.lisp

diff --git a/src/compiler/gtn.lisp b/src/compiler/gtn.lisp
index ca2c23f..b665ddf 100644 (file)
--- a/src/compiler/gtn.lisp
+++ b/src/compiler/gtn.lisp
@@ -56,6 +56,16 @@
           ;; live over the dynamic contour of the physenv.
           (setf (tn-sc res) (svref *backend-sc-numbers*
                                    sb!vm:control-stack-sc-number))
+          ;; KLUDGE: In the case of a tail-local-call, the entire
+          ;; stack frame is overwritten by the physenv of the called
+          ;; function.  Unfortunately, the tail-call appears to end
+          ;; the dynamic contour of the physenv, meaning that the
+          ;; stack slot occupied by the LAMBDA-VAR may be reassigned.
+          ;; Ideally, we might make the TN physenv-live across the
+          ;; physenvs of the tail-set of the lambda, but as a stopgap
+          ;; we can make it component-live instead.
+          (component-live-tn res)
+          #+(or)
           (physenv-live-tn res (lambda-physenv fun)))
 
          (debug-variable-p