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[Guile-commits] 02/03: Fix JIT compilation of [positional-]arguments<=?
From: |
Andy Wingo |
Subject: |
[Guile-commits] 02/03: Fix JIT compilation of [positional-]arguments<=? |
Date: |
Wed, 5 Sep 2018 16:10:22 -0400 (EDT) |
wingo pushed a commit to branch lightning
in repository guile.
commit 218fe1b962c6f98173184ab19d5ff92e57a771d8
Author: Andy Wingo <address@hidden>
Date: Wed Sep 5 21:53:56 2018 +0200
Fix JIT compilation of [positional-]arguments<=?
* libguile/jit.c (compile_check_arguments)
(compile_check_positional_arguments): Fix these functions. The
compiler uses "jge" as a "compare result not NONE", but the VM
instructions set NONE on greater-than, not greater-than-or-equal.
Sad!
---
libguile/jit.c | 25 ++++++++++++++++---------
1 file changed, 16 insertions(+), 9 deletions(-)
diff --git a/libguile/jit.c b/libguile/jit.c
index 67242bd..347abbb 100644
--- a/libguile/jit.c
+++ b/libguile/jit.c
@@ -3170,10 +3170,12 @@ compile_check_arguments (scm_jit_state *j, uint32_t
expected)
k = emit_branch_if_frame_locals_count_less_than (j, t, expected);
break;
case scm_op_jge:
- if (expected == 0)
- k = jit_jmpi (); /* Shouldn't happen. */
- else
- k = emit_branch_if_frame_locals_count_greater_than (j, t, expected -
1);
+ /* The arguments<=? instruction sets NONE to indicate
+ greater-than, whereas for <, NONE usually indicates
+ greater-than-or-equal, hence the name jge. So we need to fuse
+ to greater-than, not greater-than-or-equal. Perhaps we just
+ need to rename jge to br-if-none. */
+ k = emit_branch_if_frame_locals_count_greater_than (j, t, expected);
break;
default:
UNREACHABLE ();
@@ -3185,7 +3187,7 @@ static void
compile_check_positional_arguments (scm_jit_state *j, uint32_t nreq, uint32_t
expected)
{
uint32_t *target;
- jit_node_t *lt, *ge, *head;
+ jit_node_t *lt, *gt, *head;
jit_gpr_t walk = T0, min = T1, obj = T2;
ASSERT_HAS_REGISTER_STATE (FP_IN_REGISTER | SP_IN_REGISTER);
@@ -3193,7 +3195,12 @@ compile_check_positional_arguments (scm_jit_state *j,
uint32_t nreq, uint32_t ex
switch (fuse_conditional_branch (j, &target))
{
case scm_op_jge:
- /* Break to target if npos >= expected. */
+ /* Like arguments<=?, this instruction sets NONE to indicate
+ greater-than, whereas for <, NONE usually indicates
+ greater-than-or-equal, hence the name jge. So we need to fuse
+ to greater-than, not greater-than-or-equal. Perhaps we just
+ need to rename jge to br-if-none. */
+ /* Break to target if npos > expected. */
break;
default:
UNREACHABLE ();
@@ -3205,14 +3212,14 @@ compile_check_positional_arguments (scm_jit_state *j,
uint32_t nreq, uint32_t ex
head = jit_label ();
emit_subtract_stack_slots (j, walk, walk, 1);
lt = jit_bltr (walk, SP);
- /* npos >= expected if walk <= min. */
- ge = jit_bler (walk, min);
+ /* npos > expected if walk < min. */
+ gt = jit_bltr (walk, min);
emit_ldr (j, obj, walk);
jit_patch_at (emit_branch_if_immediate (j, obj), head);
jit_patch_at (emit_branch_if_heap_object_not_tc7 (j, obj, obj,
scm_tc7_keyword),
head);
jit_patch (lt);
- add_inter_instruction_patch (j, ge, target);
+ add_inter_instruction_patch (j, gt, target);
}
static void