Re: Excessive use of `eassert`

[Paul Eggert <eggert@cs.ucla.edu>]

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On 2024-01-21 07:54, Stefan Monnier wrote:
> I still get:
> 
>      (gdb) x/12i init_window
> ...
>         0xbbad5 <init_window+25>:    call   0xa2d57 <make_lisp_symbol>

Thanks, I reproduced that on Ubuntu 23.10 on x86-64 by configuring with 
--enable-checking and compiling with gcc -O0.

I installed the attached patch to try to speed things up for that setup.

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From df7c6211cb960b88bc0aaef85babf7e9384d5f2e Mon Sep 17 00:00:00 2001
From: Paul Eggert <eggert@cs.ucla.edu>
Date: Sun, 21 Jan 2024 17:18:23 -0800
Subject: [PATCH] Speed up builtin_lisp_symbol when not optimizing
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Content-Transfer-Encoding: 8bit

This should help when building with --enable-checking and
compiling with gcc -O0.  Problem reorted by Stefan Monnier in:
https://lists.gnu.org/r/emacs-devel/2024-01/msg00770.html
* src/lisp.h (lisp_h_builtin_lisp_symbol): New macro,
with a body equivalent in effect to the old ‘builtin_lisp_symbol’
but faster when not optimizing.
(builtin_lisp_symbol): Use it.
If DEFINE_KEY_OPS_AS_MACROS, also define as macro.
---
 src/lisp.h | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/lisp.h b/src/lisp.h
index ae78947805e..29d2a08785a 100644
--- a/src/lisp.h
+++ b/src/lisp.h
@@ -409,6 +409,10 @@ #define lisp_h_FIXNUMP(x) \
        & ((1 << INTTYPEBITS) - 1)))
 #define lisp_h_FLOATP(x) TAGGEDP (x, Lisp_Float)
 #define lisp_h_NILP(x)  BASE_EQ (x, Qnil)
+/* Equivalent to "make_lisp_symbol (&lispsym[INDEX])",
+   and typically faster when compiling without optimization.  */
+#define lisp_h_builtin_lisp_symbol(index) \
+  TAG_PTR (Lisp_Symbol, (index) * sizeof *lispsym)
 #define lisp_h_SET_SYMBOL_VAL(sym, v) \
    (eassert ((sym)->u.s.redirect == SYMBOL_PLAINVAL), \
     (sym)->u.s.val.value = (v))
@@ -475,6 +479,7 @@ #define lisp_h_XHASH(a) XUFIXNUM_RAW (a)
 # define FLOATP(x) lisp_h_FLOATP (x)
 # define FIXNUMP(x) lisp_h_FIXNUMP (x)
 # define NILP(x) lisp_h_NILP (x)
+# define builtin_lisp_symbol(index) lisp_h_builtin_lisp_symbol (index)
 # define SET_SYMBOL_VAL(sym, v) lisp_h_SET_SYMBOL_VAL (sym, v)
 # define SYMBOL_CONSTANT_P(sym) lisp_h_SYMBOL_CONSTANT_P (sym)
 # define SYMBOL_TRAPPED_WRITE_P(sym) lisp_h_SYMBOL_TRAPPED_WRITE_P (sym)
@@ -1171,9 +1176,9 @@ make_lisp_symbol (struct Lisp_Symbol *sym)
 }
 
 INLINE Lisp_Object
-builtin_lisp_symbol (int index)
+(builtin_lisp_symbol) (int index)
 {
-  return make_lisp_symbol (&lispsym[index]);
+  return lisp_h_builtin_lisp_symbol (index);
 }
 
 INLINE bool
-- 
2.40.1