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Add optimized tagged integer addition/subtractions for x86_64.

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This results in a 17% improvement in the execution time of the "+" and
"-" benchmarks for fixnums.

* libguile/vm-i-scheme.c (ASM_ADD, ASM_SUB)[defined __x86_64__ &&
  SCM_GNUC_PREREQ (4, 5)]: New macros.
  (add)[defined ASM_ADD]: Use `ASM_ADD' for the fast path.
  (sub)[defined ASM_SUB]: Use `ASM_SUB' for the fast path.

* test-suite/tests/numbers.test ("+")["fixnum + fixnum = bignum
  (32-bit)", "fixnum + fixnum = bignum (64-bit)", "bignum + fixnum =
  fixnum", "wrong type"]: New tests.
  ("-")["fixnum - fixnum = bignum (32-bit)", "fixnum - fixnum = bignum
  (64-bit)", "bignum - fixnum = fixnum", "wrong type"]: New tests.

* test-suite/tests/00-initial-env.test ("goopsless")["+ wrong type
  argument"]: Use `with-test-prefix/c&e' instead of `with-test-prefix'.
  ["- wrong type argument"]: New test prefix.
This commit is contained in:
Ludovic Courtès 2010-11-17 23:06:26 +01:00
parent f13f1e9f6f
commit 0c57673a11
3 changed files with 111 additions and 6 deletions
Download patch file Download diff file Expand all files Collapse all files

71
libguile/vm-i-scheme.c
View file

@ -210,6 +210,8 @@ VM_DEFINE_FUNCTION (149, ge, "ge?", 2)
*/
/* The maximum/minimum tagged integers. */
#undef INUM_MAX
#undef INUM_MIN
#define INUM_MAX (INTPTR_MAX - 1)
#define INUM_MIN (INTPTR_MIN + scm_tc2_int)
@ -227,9 +229,68 @@ VM_DEFINE_FUNCTION (149, ge, "ge?", 2)
RETURN (SFUNC (x, y)); \
}
/* Assembly tagged integer arithmetic routines. This code uses the
`asm goto' feature introduced in GCC 4.5. */
#if defined __x86_64__ && SCM_GNUC_PREREQ (4, 5)
/* The macros below check the CPU's overflow flag to improve fixnum
arithmetic. The %rcx register is explicitly clobbered because `asm
goto' can't have outputs, in which case the `r' constraint could be
used to let the register allocator choose a register.
TODO: Use `cold' label attribute in GCC 4.6.
http://gcc.gnu.org/ml/gcc-patches/2010-10/msg01777.html */
# define ASM_ADD(x, y) \
{ \
asm volatile goto ("mov %1, %%rcx; " \
"test %[tag], %%cl; je %l[slow_add]; " \
"test %[tag], %0; je %l[slow_add]; " \
"add %0, %%rcx; jo %l[slow_add]; " \
"sub %[tag], %%rcx; " \
"mov %%rcx, (%[vsp])\n" \
: /* no outputs */ \
: "r" (x), "r" (y), \
[vsp] "r" (sp), [tag] "i" (scm_tc2_int) \
: "rcx", "memory" \
: slow_add); \
NEXT; \
} \
slow_add: \
do { } while (0)
# define ASM_SUB(x, y) \
{ \
asm volatile goto ("mov %0, %%rcx; " \
"test %[tag], %%cl; je %l[slow_sub]; " \
"test %[tag], %1; je %l[slow_sub]; " \
"sub %1, %%rcx; jo %l[slow_sub]; " \
"add %[tag], %%rcx; " \
"mov %%rcx, (%[vsp])\n" \
: /* no outputs */ \
: "r" (x), "r" (y), \
[vsp] "r" (sp), [tag] "i" (scm_tc2_int) \
: "rcx", "memory" \
: slow_sub); \
NEXT; \
} \
slow_sub: \
do { } while (0)
#endif
VM_DEFINE_FUNCTION (150, add, "add", 2)
{
#ifndef ASM_ADD
FUNC2 (+, scm_sum);
#else
ARGS2 (x, y);
ASM_ADD (x, y);
SYNC_REGISTER ();
RETURN (scm_sum (x, y));
#endif
}
VM_DEFINE_FUNCTION (151, add1, "add1", 1)
@ -256,7 +317,14 @@ VM_DEFINE_FUNCTION (151, add1, "add1", 1)
VM_DEFINE_FUNCTION (152, sub, "sub", 2)
{
#ifndef ASM_SUB
FUNC2 (-, scm_difference);
#else
ARGS2 (x, y);
ASM_SUB (x, y);
SYNC_REGISTER ();
RETURN (scm_difference (x, y));
#endif
}
VM_DEFINE_FUNCTION (153, sub1, "sub1", 1)
@ -281,6 +349,9 @@ VM_DEFINE_FUNCTION (153, sub1, "sub1", 1)
RETURN (scm_difference (x, SCM_I_MAKINUM (1)));
}
# undef ASM_ADD
# undef ASM_SUB
VM_DEFINE_FUNCTION (154, mul, "mul", 2)
{
ARGS2 (x, y);

16
test-suite/tests/00-initial-env.test
View file

@ -29,7 +29,7 @@
(with-test-prefix "goopsless"
(with-test-prefix "+ wrong type argument"
(with-test-prefix/c&e "+ wrong type argument"
;; The following tests assume that `+' hasn't been turned into a generic
;; and extended. Since the ECMAScript run-time library does exactly
@ -45,4 +45,16 @@
(pass-if-exception "implicit forcing is not supported"
exception:wrong-type-arg
(+ (delay (* 3 7)) 13))))
(+ (delay (* 3 7)) 13)))
(with-test-prefix/c&e "- wrong type argument"
;; Same for `-'.
(pass-if-exception "1st argument string"
exception:wrong-type-arg
(+ "1" 2))
(pass-if-exception "2nd argument symbol"
exception:wrong-type-arg
(+ 1 'bar))))

30
test-suite/tests/numbers.test
View file

@ -2459,16 +2459,27 @@
;;; +
;;;
(with-test-prefix "+"
(with-test-prefix/c&e "+"
(pass-if "documented?"
(documented? +)))
(documented? +))
;; The maximum fixnum on a 32-bit architecture: 2^29 - 1.
(pass-if "fixnum + fixnum = bignum (32-bit)"
(eqv? 536870912 (+ 536870910 2)))
;; The maximum fixnum on a 64-bit architecture: 2^61 - 1.
(pass-if "fixnum + fixnum = bignum (64-bit)"
(eqv? 2305843009213693952 (+ 2305843009213693950 2)))
(pass-if "bignum + fixnum = fixnum"
(eqv? 0 (+ (1+ most-positive-fixnum) most-negative-fixnum))))
;;;
;;; -
;;;
(with-test-prefix "-"
(with-test-prefix/c&e "-"
(pass-if "-inum - +bignum"
(= #x-100000000000000000000000000000001
@ -2480,7 +2491,18 @@
(pass-if "big - -inum"
(= #x100000000000000000000000000000001
(- #x100000000000000000000000000000000 -1))))
(- #x100000000000000000000000000000000 -1)))
;; The mininum fixnum on a 32-bit architecture: -2^29.
(pass-if "fixnum - fixnum = bignum (32-bit)"
(eqv? -536870912 (- -536870910 2)))
;; The minimum fixnum on a 64-bit architecture: -2^61.
(pass-if "fixnum - fixnum = bignum (64-bit)"
(eqv? -2305843009213693952 (- -2305843009213693950 2)))
(pass-if "bignum - fixnum = fixnum"
(eqv? most-positive-fixnum (- (1+ most-positive-fixnum) 1))))
;;;
;;; *