[Guile-commits] 404/437: Correct wrong live information for some code patterns

[Andy Wingo]

wingo pushed a commit to branch lightning
in repository guile.

commit aa939b8ef87c1469c675294330648db8e802321c
Author: pcpa <address@hidden>
Date:   Thu May 5 17:55:29 2016 -0300

    Correct wrong live information for some code patterns
    
        * lib/lightning.c: Correct wrong movr simplification,
        remove no longer needed code to set return registers live
        and update live register set when reaching a label boundary,
        but do not descend if the block has been already visited.
        The later need some tuning for complex code generation, where
        it will still have issues.
---
 ChangeLog       |  7 ++++++-
 lib/lightning.c | 53 +++--------------------------------------------------
 2 files changed, 9 insertions(+), 51 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 8c4b46e..baf1069 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,6 +1,11 @@
 2016-05-05 Paulo Andrade <address@hidden>
 
-       * lib/lightning.c: Correct wrong movr simplification.
+       * lib/lightning.c: Correct wrong movr simplification,
+       remove no longer needed code to set return registers live
+       and update live register set when reaching a label boundary,
+       but do not descend if the block has been already visited.
+       The later need some tuning for complex code generation, where
+       it will still have issues.
 
 2015-11-30 Paulo Andrade <address@hidden>
 
diff --git a/lib/lightning.c b/lib/lightning.c
index e8db723..0dfec48 100644
--- a/lib/lightning.c
+++ b/lib/lightning.c
@@ -1701,20 +1701,6 @@ _jit_reglive(jit_state_t *_jit, jit_node_t *node)
                else if (!(spec & jit_class_sav))
                    jit_regset_clrbit(&_jitc->reglive, value);
            }
-#if defined(JIT_RET)
-           /* Explicitly set return registers as live, because retval
-            * should be free to not create a note, and/or user not
-            * call jit_retval (but not a good idea to expect JIT_R0
-            * to match JIT_RET) */
-           jit_regset_setbit(&_jitc->reglive, JIT_RET);
-#  if __arm__
-           /* FIXME need a better logic (and r2-r3 may contain results) */
-           jit_regset_setbit(&_jitc->reglive, _R1);
-#  endif
-#endif
-#if defined(JIT_FRET)
-           jit_regset_setbit(&_jitc->reglive, JIT_FRET);
-#endif
            break;
        default:
            value = jit_classify(node->code);
@@ -2209,36 +2195,21 @@ _jit_update(jit_state_t *_jit, jit_node_t *node,
        switch (node->code) {
            case jit_code_label:
                block = _jitc->blocks.ptr + node->v.w;
-               if (bmp_tst(node->v.w))
-                   return;
-               bmp_set(node->v.w);
                jit_regset_and(&ztmp, mask, &block->reglive);
                if (jit_regset_set_p(&ztmp)) {
                    jit_regset_ior(live, live, &ztmp);
                    jit_regset_com(&ztmp, &ztmp);
                    jit_regset_and(mask, mask, &ztmp);
                }
+               if (bmp_tst(node->v.w))
+                   return;
+               bmp_set(node->v.w);
                break;
            case jit_code_prolog:
                jit_regset_set_ui(mask, 0);
                return;
            case jit_code_epilog:
                jit_regset_set_ui(mask, 0);
-#if defined(JIT_RET)
-               /* On some backends it may be required to allocate one
-                * or more registers to jump from a jit_ret* to the
-                * epilog label.
-                * Because currently there is no type information,
-                * assume JIT_RET and JIT_FRET are live in the epilog.
-                * Only JIT_RET really should be marked as live, to
-                * prevent it being allocated, usually in the jump to
-                * the epilog, but also mark JIT_FRET as live for the
-                * sake of correctness. */
-               jit_regset_setbit(live, JIT_RET);
-#endif
-#if defined(JIT_FRET)
-               jit_regset_setbit(live, JIT_FRET);
-#endif
                return;
            case jit_code_callr:
                value = jit_regno(node->u.w);
@@ -2249,24 +2220,6 @@ _jit_update(jit_state_t *_jit, jit_node_t *node,
                    }
                }
            case jit_code_calli:
-#if defined(JIT_RET)
-               if (jit_regset_tstbit(mask, JIT_RET)) {
-                   jit_regset_setbit(live, JIT_RET);
-                   jit_regset_clrbit(mask, JIT_RET);
-               }
-#  if __arm__
-               if (jit_regset_tstbit(mask, _R1)) {
-                   jit_regset_setbit(live, _R1);
-                   jit_regset_clrbit(mask, _R1);
-               }
-#  endif
-#endif
-#if defined(JIT_FRET)
-               if (jit_regset_tstbit(mask, JIT_FRET)) {
-                   jit_regset_setbit(live, JIT_FRET);
-                   jit_regset_clrbit(mask, JIT_FRET);
-               }
-#endif
                for (value = 0; value < _jitc->reglen; ++value) {
                    value = jit_regset_scan1(mask, value);
                    if (value >= _jitc->reglen)