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-rw-r--r--ld/ChangeLog10
-rw-r--r--ld/emultempl/armelf.em12
-rw-r--r--ld/ld.texinfo11
3 files changed, 31 insertions, 2 deletions
diff --git a/ld/ChangeLog b/ld/ChangeLog
index 36fba51..3af8c71 100644
--- a/ld/ChangeLog
+++ b/ld/ChangeLog
@@ -1,3 +1,13 @@
+2005-04-15 Julian Brown <julian@codesourcery.com>
+
+ * ld.texinfo: Document --use-blx.
+ * emultempl/armelf.em (use_blx): New variable.
+ (arm_elf_create_output_section_statements): Communicate value of
+ use_blx to bfd.
+ (PARSE_AND_LIST_PROLOGUE): Add OPTION_USE_BLX.
+ (PARSE_AND_LIST_OPTIONS): Add --use-blx option.
+ (PARSE_AND_LIST_ARGS_CASES): Add OPTION_USE_BLX case.
+
2005-04-14 Alan Modra <amodra@bigpond.net.au>
* Makefile.am (NO_WERROR): Define. Use instead of -Wno-error.
diff --git a/ld/emultempl/armelf.em b/ld/emultempl/armelf.em
index 886cf8b..d380400 100644
--- a/ld/emultempl/armelf.em
+++ b/ld/emultempl/armelf.em
@@ -32,6 +32,7 @@ static int byteswap_code = 0;
static int target1_is_rel = 0${TARGET1_IS_REL};
static char *target2_type = "${TARGET2_TYPE}";
static int fix_v4bx = 0;
+static int use_blx = 0;
static void
gld${EMULATION_NAME}_before_parse (void)
@@ -192,7 +193,7 @@ static void
arm_elf_create_output_section_statements (void)
{
bfd_elf32_arm_set_target_relocs (&link_info, target1_is_rel, target2_type,
- fix_v4bx);
+ fix_v4bx, use_blx);
}
EOF
@@ -206,7 +207,8 @@ PARSE_AND_LIST_PROLOGUE='
#define OPTION_TARGET1_REL 303
#define OPTION_TARGET1_ABS 304
#define OPTION_TARGET2 305
-#define OPTION_FIX_V4BX 306
+#define OPTION_FIX_V4BX 306
+#define OPTION_USE_BLX 307
'
PARSE_AND_LIST_SHORTOPTS=p
@@ -219,6 +221,7 @@ PARSE_AND_LIST_LONGOPTS='
{ "target1-abs", no_argument, NULL, OPTION_TARGET1_ABS},
{ "target2", required_argument, NULL, OPTION_TARGET2},
{ "fix-v4bx", no_argument, NULL, OPTION_FIX_V4BX},
+ { "use-blx", no_argument, NULL, OPTION_USE_BLX},
'
PARSE_AND_LIST_OPTIONS='
@@ -228,6 +231,7 @@ PARSE_AND_LIST_OPTIONS='
fprintf (file, _(" --target1=abs Interpret R_ARM_TARGET1 as R_ARM_ABS32\n"));
fprintf (file, _(" --target2=<type> Specify definition of R_ARM_TARGET2\n"));
fprintf (file, _(" --fix-v4bx Rewrite BX rn as MOV pc, rn for ARMv4\n"));
+ fprintf (file, _(" --use-blx Enable use of BLX instructions\n"));
'
PARSE_AND_LIST_ARGS_CASES='
@@ -258,6 +262,10 @@ PARSE_AND_LIST_ARGS_CASES='
case OPTION_FIX_V4BX:
fix_v4bx = 1;
break;
+
+ case OPTION_USE_BLX:
+ use_blx = 1;
+ break;
'
# We have our own after_open and before_allocation functions, but they call
diff --git a/ld/ld.texinfo b/ld/ld.texinfo
index 99afaf2..7860e25 100644
--- a/ld/ld.texinfo
+++ b/ld/ld.texinfo
@@ -5262,6 +5262,17 @@ linker, which causes v4t @code{BX rM} instructions to be rewritten as
In the former case, the switch should not be used, and @samp{R_ARM_V4BX}
relocations are ignored.
+@cindex USE_BLX
+@kindex --use-blx
+The @samp{--use-blx} switch enables the linker to use ARM/Thumb
+BLX instructions (available on ARMv5t and above) in various
+situations. Currently it is used to perform calls via the PLT from Thumb
+code using BLX rather than using BX and a mode-switching stub before
+each PLT entry. This should lead to such calls executing slightly faster.
+
+This option is enabled implicitly for SymbianOS, so there is no need to
+specify it if you are using that target.
+
@ifclear GENERIC
@lowersections
@end ifclear