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[PATCH] Use __BYTE_ORDER__ predefined macro instead of runtime check
- From: Janne Blomqvist <blomqvist dot janne at gmail dot com>
- To: fortran at gcc dot gnu dot org, gcc-patches at gcc dot gnu dot org
- Cc: Janne Blomqvist <blomqvist dot janne at gmail dot com>
- Date: Wed, 22 Nov 2017 14:34:07 +0200
- Subject: [PATCH] Use __BYTE_ORDER__ predefined macro instead of runtime check
- Authentication-results: sourceware.org; auth=none
By using the __BYTE_ORDER__ predefined macro we don't need the
determine_endianness function anymore.
Regtested on x86_64-pc-linux-gnu, Ok for trunk?
libgfortran/ChangeLog:
2017-11-22 Janne Blomqvist <jb@gcc.gnu.org>
* io/inquire.c (inquire_via_unit): Use __BYTE_ORDER__ predefined
macro.
* io/open.c (st_open): Likewise.
* io/transfer.c (data_transfer_init): Likewise.
* io/write.c (btoa_big): Likewise.
(otoa_big): Likewise.
(ztoa_big): Likewise.
* libgfortran.h (big_endian): Remove variable.
(GFOR_POINTER_TO_L1): Use __BYTE_ORDER__ macro.
* runtime/main.c (determine_endianness): Remove function.
(init): Remove call to determine_endianness.
* runtime/minimal.c: Remove setting big_endian variable.
---
libgfortran/io/inquire.c | 5 ++---
libgfortran/io/open.c | 6 ++----
libgfortran/io/transfer.c | 6 ++----
libgfortran/io/write.c | 6 +++---
libgfortran/libgfortran.h | 6 +-----
libgfortran/runtime/main.c | 28 ----------------------------
libgfortran/runtime/minimal.c | 7 -------
7 files changed, 10 insertions(+), 54 deletions(-)
diff --git a/libgfortran/io/inquire.c b/libgfortran/io/inquire.c
index 4cf87d3..fe353c5 100644
--- a/libgfortran/io/inquire.c
+++ b/libgfortran/io/inquire.c
@@ -612,13 +612,12 @@ inquire_via_unit (st_parameter_inquire *iqp, gfc_unit *u)
else
switch (u->flags.convert)
{
- /* big_endian is 0 for little-endian, 1 for big-endian. */
case GFC_CONVERT_NATIVE:
- p = big_endian ? "BIG_ENDIAN" : "LITTLE_ENDIAN";
+ p = __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ ? "BIG_ENDIAN" : "LITTLE_ENDIAN";
break;
case GFC_CONVERT_SWAP:
- p = big_endian ? "LITTLE_ENDIAN" : "BIG_ENDIAN";
+ p = __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ ? "LITTLE_ENDIAN" : "BIG_ENDIAN";
break;
default:
diff --git a/libgfortran/io/open.c b/libgfortran/io/open.c
index 9d3988a..fab2065 100644
--- a/libgfortran/io/open.c
+++ b/libgfortran/io/open.c
@@ -805,8 +805,6 @@ st_open (st_parameter_open *opp)
conv = compile_options.convert;
}
- /* We use big_endian, which is 0 on little-endian machines
- and 1 on big-endian machines. */
switch (conv)
{
case GFC_CONVERT_NATIVE:
@@ -814,11 +812,11 @@ st_open (st_parameter_open *opp)
break;
case GFC_CONVERT_BIG:
- conv = big_endian ? GFC_CONVERT_NATIVE : GFC_CONVERT_SWAP;
+ conv = __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ ? GFC_CONVERT_NATIVE : GFC_CONVERT_SWAP;
break;
case GFC_CONVERT_LITTLE:
- conv = big_endian ? GFC_CONVERT_SWAP : GFC_CONVERT_NATIVE;
+ conv = __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ ? GFC_CONVERT_SWAP : GFC_CONVERT_NATIVE;
break;
default:
diff --git a/libgfortran/io/transfer.c b/libgfortran/io/transfer.c
index 1eb23fb..acaa88a 100644
--- a/libgfortran/io/transfer.c
+++ b/libgfortran/io/transfer.c
@@ -2723,8 +2723,6 @@ data_transfer_init (st_parameter_dt *dtp, int read_flag)
if (conv == GFC_CONVERT_NONE)
conv = compile_options.convert;
- /* We use big_endian, which is 0 on little-endian machines
- and 1 on big-endian machines. */
switch (conv)
{
case GFC_CONVERT_NATIVE:
@@ -2732,11 +2730,11 @@ data_transfer_init (st_parameter_dt *dtp, int read_flag)
break;
case GFC_CONVERT_BIG:
- conv = big_endian ? GFC_CONVERT_NATIVE : GFC_CONVERT_SWAP;
+ conv = __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ ? GFC_CONVERT_NATIVE : GFC_CONVERT_SWAP;
break;
case GFC_CONVERT_LITTLE:
- conv = big_endian ? GFC_CONVERT_SWAP : GFC_CONVERT_NATIVE;
+ conv = __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ ? GFC_CONVERT_SWAP : GFC_CONVERT_NATIVE;
break;
default:
diff --git a/libgfortran/io/write.c b/libgfortran/io/write.c
index c9aad15..f417202 100644
--- a/libgfortran/io/write.c
+++ b/libgfortran/io/write.c
@@ -986,7 +986,7 @@ btoa_big (const char *s, char *buffer, int len, GFC_UINTEGER_LARGEST *n)
int i, j;
q = buffer;
- if (big_endian)
+ if (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)
{
const char *p = s;
for (i = 0; i < len; i++)
@@ -1051,7 +1051,7 @@ otoa_big (const char *s, char *buffer, int len, GFC_UINTEGER_LARGEST *n)
*q = '\0';
i = k = octet = 0;
- if (big_endian)
+ if (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)
{
const char *p = s + len - 1;
char c = *p;
@@ -1126,7 +1126,7 @@ ztoa_big (const char *s, char *buffer, int len, GFC_UINTEGER_LARGEST *n)
q = buffer;
- if (big_endian)
+ if (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)
{
const char *p = s;
for (i = 0; i < len; i++)
diff --git a/libgfortran/libgfortran.h b/libgfortran/libgfortran.h
index cdbdd951..10c7507 100644
--- a/libgfortran/libgfortran.h
+++ b/libgfortran/libgfortran.h
@@ -266,12 +266,8 @@ typedef GFC_UINTEGER_4 gfc_char4_t;
simply equal to the kind parameter itself. */
#define GFC_SIZE_OF_CHAR_KIND(kind) (kind)
-/* This will be 0 on little-endian machines and one on big-endian machines. */
-extern int big_endian;
-internal_proto(big_endian);
-
#define GFOR_POINTER_TO_L1(p, kind) \
- (big_endian * (kind - 1) + (GFC_LOGICAL_1 *)(p))
+ ((__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ ? 1: 0) * (kind - 1) + (GFC_LOGICAL_1 *)(p))
#define GFC_INTEGER_1_HUGE \
(GFC_INTEGER_1)((((GFC_UINTEGER_1)1) << 7) - 1)
diff --git a/libgfortran/runtime/main.c b/libgfortran/runtime/main.c
index 8d466d1..2096271 100644
--- a/libgfortran/runtime/main.c
+++ b/libgfortran/runtime/main.c
@@ -33,31 +33,6 @@ stupid_function_name_for_static_linking (void)
return;
}
-/* This will be 0 for little-endian
- machines and 1 for big-endian machines. */
-int big_endian = 0;
-
-
-/* Figure out endianness for this machine. */
-
-static void
-determine_endianness (void)
-{
- union
- {
- GFC_LOGICAL_8 l8;
- GFC_LOGICAL_4 l4[2];
- } u;
-
- u.l8 = 1;
- if (u.l4[0])
- big_endian = 0;
- else if (u.l4[1])
- big_endian = 1;
- else
- runtime_error ("Unable to determine machine endianness");
-}
-
static int argc_save;
static char **argv_save;
@@ -89,9 +64,6 @@ get_args (int *argc, char ***argv)
static void __attribute__((constructor))
init (void)
{
- /* Figure out the machine endianness. */
- determine_endianness ();
-
/* Must be first */
init_variables ();
diff --git a/libgfortran/runtime/minimal.c b/libgfortran/runtime/minimal.c
index 2ef4f15..3c7eca1 100644
--- a/libgfortran/runtime/minimal.c
+++ b/libgfortran/runtime/minimal.c
@@ -40,13 +40,6 @@ stupid_function_name_for_static_linking (void)
options_t options;
-/* This will be 0 for little-endian
- machines and 1 for big-endian machines.
-
- Currently minimal libgfortran only runs on little-endian devices
- which don't support constructors so this is just a constant. */
-int big_endian = 0;
-
static int argc_save;
static char **argv_save;
--
2.7.4