From d238007cf8cbf718c2ddcdd2c057ca767a20c03c Mon Sep 17 00:00:00 2001
From: Matthew Flatt <mflatt@racket-lang.org>
Date: Thu, 28 Feb 2019 09:24:28 -0700
Subject: [PATCH] fix JIT-inlined `unsafe-flrandom`

Relevant to racket/typed-racket#807
---
 .../racket-test-core/tests/racket/unsafe.rktl | 25 +++++++++++++++++++
 racket/src/racket/src/jitinline.c             |  1 +
 2 files changed, 26 insertions(+)

diff --git a/pkgs/racket-test-core/tests/racket/unsafe.rktl b/pkgs/racket-test-core/tests/racket/unsafe.rktl
index a7905d80e8..697badc6c0 100644
--- a/pkgs/racket-test-core/tests/racket/unsafe.rktl
+++ b/pkgs/racket-test-core/tests/racket/unsafe.rktl
@@ -934,6 +934,31 @@
                    (unsafe-fxlshift 1 63)
                    (unsafe-fxlshift 1 31)))
 
+;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; Check that allocation by inlined `unsafe-flrandom` is ok
+
+(test #t
+      symbol?
+      (let ([r (current-pseudo-random-generator)])
+        (for/fold ([v #f]) ([i (in-range 1000000)])
+          ;; The pattern of `if`s here is intended to check the JIT's
+          ;; runstack pointer is syned for allocation
+          (let* ([a (let ([v (unsafe-flrandom r)])
+                      (if (negative? v)
+                          (error "oops")
+                          v))]
+                 [b (let ([v (unsafe-flrandom r)])
+                      (if (negative? v)
+                          (error "oops")
+                          v))]
+                 [c (let ([v (unsafe-flrandom r)])
+                      (if (negative? v)
+                          (error "oops")
+                          v))])
+            (if (and (eqv? a b) (eqv? b c))
+                'same
+                'diff)))))
+
 ;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
 (report-errs)
diff --git a/racket/src/racket/src/jitinline.c b/racket/src/racket/src/jitinline.c
index 3b60f5b6b0..21a79baf44 100644
--- a/racket/src/racket/src/jitinline.c
+++ b/racket/src/racket/src/jitinline.c
@@ -2151,6 +2151,7 @@ int scheme_generate_inlined_unary(mz_jit_state *jitter, Scheme_App2_Rec *app, in
       scheme_mz_unbox_restore(jitter, &ubs);
 
       mz_runstack_unskipped(jitter, 1);
+      mz_rs_sync();
 
       mz_prepare(1);
       jit_pusharg_p(JIT_R0);