From: Pip Cet <pipcet@gmail.com>
To: Andrea Corallo <akrl@sdf.org>
Cc: 46670@debbugs.gnu.org, Mauricio Collares <mauricio@collares.org>
Subject: bug#46670: 28.0.50; [feature/native-comp] possible miscompilation affecting lsp-mode
Date: Wed, 24 Feb 2021 09:28:39 +0000 [thread overview]
Message-ID: <CAOqdjBfw0XpoDwLBQUyHbvb2m8is_q94OSWohuKeJmkVE9-A=g@mail.gmail.com> (raw)
In-Reply-To: <xjf35xlkfax.fsf@sdf.org>
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On Wed, Feb 24, 2021 at 9:04 AM Andrea Corallo <akrl@sdf.org> wrote:
> Pip Cet <pipcet@gmail.com> writes:
>
> > On Tue, Feb 23, 2021 at 11:36 PM Andrea Corallo <akrl@sdf.org> wrote:
> >> Pip Cet <pipcet@gmail.com> writes:
> >> > Is this one of them, or am I confused?
> >>
> >> What's suspitions with that? At present I'm admittedly quite done but
> >> it looks okay to me.
> >
> > We're emitting
> >
> > (assume ,lhs (and ,lhs ,rhs))
> >
> > even when NEGATED is t.
>
> Nope, when NEGATED is t the complete sequence we are emitting is (see
> line just following your diff hunk):
>
> (assume tmp-mvar (not rhs))
But tmp-mvar is in the same slot as RHS.
> (assume lhs (and lhs tmp-mvar))
So this is equivalent (after the next SSA rename) to
(assume lhs (and lhs rhs))
> That's indeed the reason why it's working in the 39 testcases.
No, the reason it's "working" is that we never assert our assumes.
I've got a patch here that does just that :-)
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[-- Type: text/x-patch, Size: 5583 bytes --]
From 6470b5ef25007ece8fea5754bee204e6b5ba0312 Mon Sep 17 00:00:00 2001
From: Pip Cet <pipcet@gmail.com>
Date: Wed, 24 Feb 2021 09:25:44 +0000
Subject: [PATCH] Assert at runtime that assume's assumptions actually hold.
* src/comp.c (emit_limple_insn): Handle (assert) insns.
(Fcomp__assert): New function.
(syms_of_comp): New defsubr for above.
* lisp/emacs-lisp/comp.el (comp-passes): Add `comp-assert-assumes'
pass.
(comp-emit-assert, comp-assert-assumes-func, comp-assert-assumes):
New functions.
---
lisp/emacs-lisp/comp.el | 40 ++++++++++++++++++++++++
src/comp.c | 69 +++++++++++++++++++++++++++++++++++++++++
2 files changed, 109 insertions(+)
diff --git a/lisp/emacs-lisp/comp.el b/lisp/emacs-lisp/comp.el
index 60c040926e54c..d53b8876aa8ad 100644
--- a/lisp/emacs-lisp/comp.el
+++ b/lisp/emacs-lisp/comp.el
@@ -178,6 +178,7 @@ comp-passes
comp-tco
comp-fwprop
comp-remove-type-hints
+ comp-assert-assumes
comp-final)
"Passes to be executed in order.")
@@ -3385,6 +3386,45 @@ comp-remove-type-hints
(comp-ctxt-funcs-h comp-ctxt)))
\f
+;;; Assert-assumes pass specific code.
+(defun comp-emit-assert (lhs assertion)
+ (let (insns)
+ (pcase assertion
+ ((and (pred comp-mvar-p))
+ (let ((f `(lambda (x y) (equal x y))))
+ (comp-add-const-to-relocs f)
+ (push `(assert ,f ,lhs ,assertion) insns)))
+ ((and (pred comp-cstr-p)))
+ (`(and . ,operands)
+ (dolist (op operands)
+ (setq insns (nconc insns (comp-emit-assert lhs op)))))
+ (`(not ,(and (pred comp-mvar-p) operand))
+ (let ((f `(lambda (x y) (not (equal x y)))))
+ (comp-add-const-to-relocs f)
+ (push `(assert ,f ,lhs ,assertion) insns))))
+ insns))
+
+(defun comp-assert-assumes-func ()
+ (cl-loop
+ for b being each hash-value of (comp-func-blocks comp-func)
+ do (comp-loop-insn-in-block b
+ (pcase insn
+ (`(assume ,(and (pred comp-mvar-p) lhs)
+ ,rhs)
+ (let ((f `(lambda (x y) (not (equal x y)))))
+ (comp-add-const-to-relocs f)
+ (setf (cdr insn-cell)
+ (nconc (comp-emit-assert lhs rhs)
+ (cdr insn-cell)))))))))
+
+(defun comp-assert-assumes (_)
+ "Turn (assume ...) insns into asserts."
+ (maphash (lambda (_ f)
+ (let ((comp-func f))
+ (comp-assert-assumes-func)
+ (comp-log-func comp-func 3)))
+ (comp-ctxt-funcs-h comp-ctxt)))
+\f
;;; Final pass specific code.
(defun comp-args-to-lambda-list (args)
diff --git a/src/comp.c b/src/comp.c
index a8b8ef95fa14d..2a5eebee104ed 100644
--- a/src/comp.c
+++ b/src/comp.c
@@ -2037,6 +2037,58 @@ emit_limple_insn (Lisp_Object insn)
n);
emit_cond_jump (test, target1, target2);
}
+ else if (EQ (op, Qassert))
+ {
+ Lisp_Object callee = Qcomp__assert;
+ emit_comment (SSDATA (Fprin1_to_string (arg[0], Qnil)));
+ imm_reloc_t reloc = obj_to_reloc (arg[0]);
+ gcc_jit_rvalue *assert_args[i];
+ assert_args[0] = gcc_jit_lvalue_as_rvalue (
+ gcc_jit_context_new_array_access (comp.ctxt,
+ NULL,
+ reloc.array.r_val,
+ reloc.idx));
+ for (ptrdiff_t j = 1; j < i; j++)
+ assert_args[j] = emit_mvar_rval (arg[j]);
+
+ gcc_jit_lvalue *tmp_arr =
+ gcc_jit_function_new_local (
+ comp.func,
+ NULL,
+ gcc_jit_context_new_array_type
+ (comp.ctxt,
+ NULL,
+ comp.lisp_obj_type,
+ i),
+ "local_%d");
+
+ for (ptrdiff_t j = 0; j < i; j++)
+ {
+ gcc_jit_block_add_assignment (
+ comp.block,
+ NULL,
+ gcc_jit_context_new_array_access (
+ comp.ctxt,
+ NULL,
+ gcc_jit_lvalue_as_rvalue (tmp_arr),
+ gcc_jit_context_new_rvalue_from_int (comp.ctxt,
+ comp.int_type,
+ j)),
+ assert_args[j]);
+ }
+
+ gcc_jit_rvalue *call = emit_call_ref (callee,
+ i,
+ gcc_jit_context_new_array_access (comp.ctxt,
+ NULL,
+ gcc_jit_lvalue_as_rvalue (tmp_arr),
+ comp.zero),
+ false);
+
+ gcc_jit_block_add_eval (comp.block,
+ NULL,
+ call);
+ }
else if (EQ (op, Qphi) || EQ (op, Qassume))
{
/* Nothing to do for phis or assumes in the backend. */
@@ -4980,6 +5032,20 @@ DEFUN ("comp--late-register-subr", Fcomp__late_register_subr,
return Qnil;
}
+DEFUN ("comp--assert", Fcomp__assert, Scomp__assert, 1, MANY, 0,
+ doc: /* */)
+ (ptrdiff_t nargs, Lisp_Object *args)
+{
+ if (NILP (Ffuncall (nargs, args)))
+ {
+ xsignal1 (Qnative_compiler_error,
+ Fcons (build_string ("assertion failed"),
+ Flist (nargs, args)));
+ }
+
+ return Qnil;
+}
+
static bool
file_in_eln_sys_dir (Lisp_Object filename)
{
@@ -5076,6 +5142,8 @@ syms_of_comp (void)
DEFSYM (Qdirect_call, "direct-call");
DEFSYM (Qdirect_callref, "direct-callref");
DEFSYM (Qassume, "assume");
+ DEFSYM (Qassert, "assert");
+ DEFSYM (Qcomp__assert, "comp--assert");
DEFSYM (Qsetimm, "setimm");
DEFSYM (Qreturn, "return");
DEFSYM (Qunreachable, "unreachable");
@@ -5179,6 +5247,7 @@ syms_of_comp (void)
defsubr (&Scomp__register_lambda);
defsubr (&Scomp__register_subr);
defsubr (&Scomp__late_register_subr);
+ defsubr (&Scomp__assert);
defsubr (&Snative_elisp_load);
staticpro (&comp.exported_funcs_h);
--
2.30.0
next prev parent reply other threads:[~2021-02-24 9:28 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-21 0:12 bug#46670: 28.0.50; [feature/native-comp] possible miscompilation affecting lsp-mode Mauricio Collares
2021-02-21 11:51 ` Pip Cet
2021-02-21 11:56 ` Pip Cet
2021-02-21 21:03 ` Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-02-21 22:46 ` Pip Cet
2021-02-22 9:37 ` Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-02-22 10:04 ` Pip Cet
2021-02-22 10:25 ` Pip Cet
2021-02-22 11:23 ` Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-02-22 12:11 ` Pip Cet
2021-02-22 13:12 ` Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-02-23 7:59 ` Pip Cet
2021-02-23 9:04 ` Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-02-23 23:26 ` Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-02-24 2:10 ` Mauricio Collares
2021-02-24 8:22 ` Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-02-23 19:09 ` Pip Cet
2021-02-23 23:36 ` Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-02-24 4:31 ` Pip Cet
2021-02-24 9:04 ` Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-02-24 9:28 ` Pip Cet [this message]
2021-02-24 9:42 ` Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-02-24 9:46 ` Pip Cet
2021-02-24 10:06 ` Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-02-25 12:41 ` Pip Cet
2021-02-25 14:58 ` Eli Zaretskii
2021-02-25 15:14 ` Pip Cet
2021-02-25 15:31 ` Eli Zaretskii
2021-02-25 16:56 ` Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-02-25 20:59 ` Pip Cet
2021-02-26 19:33 ` Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-02-26 20:30 ` Pip Cet
2021-02-26 20:44 ` Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-02-26 20:11 ` Eli Zaretskii
2021-02-26 20:32 ` Pip Cet
2021-02-27 5:06 ` Pip Cet
2021-02-27 7:49 ` Eli Zaretskii
2021-02-27 9:39 ` Pip Cet
2021-02-27 10:24 ` Eli Zaretskii
2021-02-27 12:39 ` Pip Cet
2021-02-27 13:30 ` Eli Zaretskii
2021-02-27 17:15 ` Pip Cet
2021-02-27 18:40 ` Eli Zaretskii
2021-02-28 8:14 ` Pip Cet
2021-03-01 5:24 ` Richard Stallman
2021-03-01 6:40 ` Pip Cet
2021-02-22 11:16 ` Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-02-23 9:07 ` Pip Cet
2021-02-23 22:55 ` Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-02-24 7:00 ` Pip Cet
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