[Guile-commits] 02/03: Maybe enter JIT when returning from interpreted functions

[Andy Wingo]

wingo pushed a commit to branch lightning
in repository guile.

commit 24d09b16b60c6c8f0dee8e3cd69de0e677601ee7
Author: Andy Wingo <address@hidden>
Date:   Wed Aug 29 17:54:19 2018 +0200

    Maybe enter JIT when returning from interpreted functions
    
    * libguile/jit.c (scm_jit_compute_mcode): Minor optimization.
    * libguile/vm-engine.c (return-values): Maybe return to JIT code.
---
 libguile/jit.c       | 13 +++++--------
 libguile/vm-engine.c | 21 ++++++++++++++-------
 2 files changed, 19 insertions(+), 15 deletions(-)

diff --git a/libguile/jit.c b/libguile/jit.c
index c9328d2..867ee7f 100644
--- a/libguile/jit.c
+++ b/libguile/jit.c
@@ -4425,14 +4425,11 @@ scm_sys_jit_compile (SCM fn)
 const uint8_t *
 scm_jit_compute_mcode (scm_thread *thread, struct scm_jit_function_data *data)
 {
-  const uint32_t *start = (const uint32_t *) (((char *)data) + data->start);
-
-  /* Until the JIT is tested, don't automatically JIT-compile code.
-     Just return whatever code is already there.  If we decide to buy
-     later, replace with something that wires up a call to
-     "compute_mcode".  */
-  if (start == thread->vm.ip)
-    return data->mcode;
+  uint8_t *mcode_start = data->mcode;
+  const uint32_t *vcode_start = (const uint32_t *) (((char *)data) + 
data->start);
+
+  if (mcode_start && vcode_start == thread->vm.ip)
+    return mcode_start;
 
   return NULL;
 }
diff --git a/libguile/vm-engine.c b/libguile/vm-engine.c
index c8db813..58ff53c 100644
--- a/libguile/vm-engine.c
+++ b/libguile/vm-engine.c
@@ -565,18 +565,25 @@ VM_NAME (scm_thread *thread)
     {
       union scm_vm_stack_element *old_fp;
       size_t frame_size = 3;
+      uint8_t *mcode;
 
       RETURN_HOOK ();
 
       old_fp = VP->fp;
-      ip = SCM_FRAME_VIRTUAL_RETURN_ADDRESS (VP->fp);
-      VP->fp = SCM_FRAME_DYNAMIC_LINK (VP->fp);
-
-      /* Clear stack frame.  */
-      while (frame_size--)
-        old_fp[frame_size].as_scm = SCM_BOOL_F;
+      VP->fp = SCM_FRAME_DYNAMIC_LINK (old_fp);
 
-      NEXT (0);
+      mcode = SCM_FRAME_MACHINE_RETURN_ADDRESS (old_fp);
+      if (mcode)
+        {
+          scm_jit_enter_mcode (thread, mcode);
+          CACHE_REGISTER ();
+          NEXT (0);
+        }
+      else
+        {
+          ip = SCM_FRAME_VIRTUAL_RETURN_ADDRESS (old_fp);
+          NEXT (0);
+        }
     }