File 2833-Inline-erts_cmp.patch of Package erlang
From 1056d2d1fd49f669a2001f03890e13c9cba76c1e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?John=20H=C3=B6gberg?= <john@erlang.org>
Date: Thu, 25 Oct 2018 08:33:08 +0200
Subject: [PATCH 3/4] Inline erts_cmp
This greatly increases the performance of '--'/2 which does a lot
of term comparisons.
---
erts/emulator/beam/atom.c | 2 +-
erts/emulator/beam/erl_utils.h | 61 ++++++++++++++++++++++++++++++++++++++--
erts/emulator/beam/utils.c | 64 ++++--------------------------------------
3 files changed, 64 insertions(+), 63 deletions(-)
diff --git a/erts/emulator/beam/atom.c b/erts/emulator/beam/atom.c
index 5381611fab..59b51fd15e 100644
--- a/erts/emulator/beam/atom.c
+++ b/erts/emulator/beam/atom.c
@@ -174,7 +174,7 @@ atom_alloc(Atom* tmpl)
/*
* Precompute ordinal value of first 3 bytes + 7 bits.
- * This is used by utils.c:erts_cmp_atoms().
+ * This is used by erl_utils.h:erts_cmp_atoms().
* We cannot use the full 32 bits of the first 4 bytes,
* since we use the sign of the difference between two
* ordinal values to represent their relative order.
diff --git a/erts/emulator/beam/erl_utils.h b/erts/emulator/beam/erl_utils.h
index b3bfa69052..880febba8b 100644
--- a/erts/emulator/beam/erl_utils.h
+++ b/erts/emulator/beam/erl_utils.h
@@ -22,6 +22,7 @@
#define ERL_UTILS_H__
#include "sys.h"
+#include "atom.h"
#include "erl_smp.h"
#include "erl_printf.h"
@@ -112,10 +113,12 @@ int eq(Eterm, Eterm);
#define EQ(x,y) (((x) == (y)) || (is_not_both_immed((x),(y)) && eq((x),(y))))
-int erts_cmp_atoms(Eterm a, Eterm b);
-Sint erts_cmp(Eterm, Eterm, int, int);
-Sint erts_cmp_compound(Eterm, Eterm, int, int);
+ERTS_GLB_INLINE Sint erts_cmp(Eterm, Eterm, int, int);
+ERTS_GLB_INLINE int erts_cmp_atoms(Eterm a, Eterm b);
+
Sint cmp(Eterm a, Eterm b);
+Sint erts_cmp_compound(Eterm, Eterm, int, int);
+
#define CMP(A,B) erts_cmp(A,B,0,0)
#define CMP_TERM(A,B) erts_cmp(A,B,1,0)
#define CMP_EQ_ONLY(A,B) erts_cmp(A,B,0,1)
@@ -150,4 +153,56 @@ Sint cmp(Eterm a, Eterm b);
if (erts_cmp_compound(X,Y,0,EqOnly) Op 0) { Action; }; \
}
+#define erts_float_comp(x,y) (((x)<(y)) ? -1 : (((x)==(y)) ? 0 : 1))
+
+#if ERTS_GLB_INLINE_INCL_FUNC_DEF
+
+ERTS_GLB_INLINE int erts_cmp_atoms(Eterm a, Eterm b) {
+ Atom *aa = atom_tab(atom_val(a));
+ Atom *bb = atom_tab(atom_val(b));
+
+ byte *name_a, *name_b;
+ int len_a, len_b, diff;
+
+ diff = aa->ord0 - bb->ord0;
+
+ if (diff != 0) {
+ return diff;
+ }
+
+ name_a = &aa->name[3];
+ name_b = &bb->name[3];
+ len_a = aa->len-3;
+ len_b = bb->len-3;
+
+ if (len_a > 0 && len_b > 0) {
+ diff = sys_memcmp(name_a, name_b, MIN(len_a, len_b));
+
+ if (diff != 0) {
+ return diff;
+ }
+ }
+
+ return len_a - len_b;
+}
+
+ERTS_GLB_INLINE Sint erts_cmp(Eterm a, Eterm b, int exact, int eq_only) {
+ if (is_atom(a) && is_atom(b)) {
+ return erts_cmp_atoms(a, b);
+ } else if (is_both_small(a, b)) {
+ return (signed_val(a) - signed_val(b));
+ } else if (is_float(a) && is_float(b)) {
+ FloatDef af, bf;
+
+ GET_DOUBLE(a, af);
+ GET_DOUBLE(b, bf);
+
+ return erts_float_comp(af.fd, bf.fd);
+ }
+
+ return erts_cmp_compound(a,b,exact,eq_only);
+}
+
+#endif /* ERTS_GLB_INLINE_INCL_FUNC_DEF */
+
#endif
diff --git a/erts/emulator/beam/utils.c b/erts/emulator/beam/utils.c
index 08f8ca9788..d81bd89a48 100644
--- a/erts/emulator/beam/utils.c
+++ b/erts/emulator/beam/utils.c
@@ -2615,27 +2615,6 @@ not_equal:
}
-/*
- * Lexically compare two strings of bytes (string s1 length l1 and s2 l2).
- *
- * s1 < s2 return -1
- * s1 = s2 return 0
- * s1 > s2 return +1
- */
-static int cmpbytes(byte *s1, int l1, byte *s2, int l2)
-{
- int i;
- i = 0;
- while((i < l1) && (i < l2)) {
- if (s1[i] < s2[i]) return(-1);
- if (s1[i] > s2[i]) return(1);
- i++;
- }
- if (l1 < l2) return(-1);
- if (l1 > l2) return(1);
- return(0);
-}
-
/*
* Compare objects.
@@ -2649,20 +2628,6 @@ static int cmpbytes(byte *s1, int l1, byte *s2, int l2)
*
*/
-
-#define float_comp(x,y) (((x)<(y)) ? -1 : (((x)==(y)) ? 0 : 1))
-
-int erts_cmp_atoms(Eterm a, Eterm b)
-{
- Atom *aa = atom_tab(atom_val(a));
- Atom *bb = atom_tab(atom_val(b));
- int diff = aa->ord0 - bb->ord0;
- if (diff)
- return diff;
- return cmpbytes(aa->name+3, aa->len-3,
- bb->name+3, bb->len-3);
-}
-
/* cmp(Eterm a, Eterm b)
* For compatibility with HiPE - arith-based compare.
*/
@@ -2673,22 +2638,6 @@ Sint cmp(Eterm a, Eterm b)
Sint erts_cmp_compound(Eterm a, Eterm b, int exact, int eq_only);
-Sint erts_cmp(Eterm a, Eterm b, int exact, int eq_only)
-{
- if (is_atom(a) && is_atom(b)) {
- return erts_cmp_atoms(a, b);
- } else if (is_both_small(a, b)) {
- return (signed_val(a) - signed_val(b));
- } else if (is_float(a) && is_float(b)) {
- FloatDef af, bf;
- GET_DOUBLE(a, af);
- GET_DOUBLE(b, bf);
- return float_comp(af.fd, bf.fd);
- }
- return erts_cmp_compound(a,b,exact,eq_only);
-}
-
-
/* erts_cmp(Eterm a, Eterm b, int exact)
* exact = 1 -> term-based compare
* exact = 0 -> arith-based compare
@@ -2985,7 +2934,7 @@ tailrecur_ne:
GET_DOUBLE(a, af);
GET_DOUBLE(b, bf);
- ON_CMP_GOTO(float_comp(af.fd, bf.fd));
+ ON_CMP_GOTO(erts_float_comp(af.fd, bf.fd));
}
case (_TAG_HEADER_POS_BIG >> _TAG_PRIMARY_SIZE):
case (_TAG_HEADER_NEG_BIG >> _TAG_PRIMARY_SIZE):
@@ -3022,10 +2971,7 @@ tailrecur_ne:
ErlFunThing* f2 = (ErlFunThing *) fun_val(b);
Sint diff;
- diff = cmpbytes(atom_tab(atom_val(f1->fe->module))->name,
- atom_tab(atom_val(f1->fe->module))->len,
- atom_tab(atom_val(f2->fe->module))->name,
- atom_tab(atom_val(f2->fe->module))->len);
+ diff = erts_cmp_atoms((f1->fe)->module, (f2->fe)->module);
if (diff != 0) {
RETURN_NEQ(diff);
}
@@ -3219,7 +3165,7 @@ tailrecur_ne:
if (f2.fd < MAX_LOSSLESS_FLOAT && f2.fd > MIN_LOSSLESS_FLOAT) {
/* Float is within the no loss limit */
f1.fd = signed_val(aw);
- j = float_comp(f1.fd, f2.fd);
+ j = erts_float_comp(f1.fd, f2.fd);
}
#if ERTS_SIZEOF_ETERM == 8
else if (f2.fd > (double) (MAX_SMALL + 1)) {
@@ -3266,7 +3212,7 @@ tailrecur_ne:
if (big_to_double(aw, &f1.fd) < 0) {
j = big_sign(aw) ? -1 : 1;
} else {
- j = float_comp(f1.fd, f2.fd);
+ j = erts_float_comp(f1.fd, f2.fd);
}
} else {
big = double_to_big(f2.fd, big_buf, sizeof(big_buf)/sizeof(Eterm));
@@ -3282,7 +3228,7 @@ tailrecur_ne:
if (f1.fd < MAX_LOSSLESS_FLOAT && f1.fd > MIN_LOSSLESS_FLOAT) {
/* Float is within the no loss limit */
f2.fd = signed_val(bw);
- j = float_comp(f1.fd, f2.fd);
+ j = erts_float_comp(f1.fd, f2.fd);
}
#if ERTS_SIZEOF_ETERM == 8
else if (f1.fd > (double) (MAX_SMALL + 1)) {
--
2.16.4
