On Thu, May 28, 2015 at 10:37:53AM -0700, H.J. Lu wrote:
> This patch extends -fno-plt to normal non-PIC calls on x86. -fno-plt
> works in 64-bit mode with the existing binutils. For 32-bit, we need
> the updated assembler and linker to support "call/jmp *foo@GOT" with
> a new relocation different from R_386_GOT32 to indicate that this
> relocation applies to indirect branches. A configure time check is
> added to verify that 32-bit assembler generates a known relocation
> which is different from R_386_GOT32. A new 32-bit relocaton is needed
> since "call/jmp *foo@GOT" requires a different relocation from R_386_GOT32
> which is used together with a GOT register in "call/jmp *foo@GOT(%reg)".
>
> OK for master?
>
> Thanks.
>
> H.J.
> ---
> * configure.ac (HAVE_AS_INDIRECT_BRANCH_VIA_GOT): New. Defined
> if 32-bit assembler generates a known relocation which is
> different from R_386_GOT32.
> * config.in: Regenerated.
> * configure: Likewise.
> * config/i386/i386.c (ix86_output_call_insn): Extend -fno-plt
> to normal non-PIC branches.
Here is the updated patch to properly handle local functions with
testcases.
H.J.
---
gcc/
* configure.ac (HAVE_AS_INDIRECT_BRANCH_VIA_GOT): New. Defined
if 32-bit assembler generates a known relocation which is
different from R_386_GOT32.
* config.in: Regenerated.
* configure: Likewise.
* config/i386/i386.c (ix86_output_call_insn): Extend -fno-plt
to normal non-PIC branches.
* config/i386/i386.h (TARGET_ELF): New.
gcc/testsuite/
* gcc.target/i386/pr66232-6.c: New tests.
* gcc.target/i386/pr66232-7.c: Likewise.
* gcc.target/i386/pr66232-8.c: Likewise.
* gcc.target/i386/pr66232-9.c: Likewise.
* gcc.target/i386/pr66232-10.c: Likewise.
* gcc.target/i386/pr66232-11.c: Likewise.
* gcc.target/i386/pr66232-12.c: Likewise.
* gcc.target/i386/pr66232-13.c: Likewise.
* lib/target-supports.exp (check_effective_target_branch_via_got):
New.
---
gcc/config.in | 14 +++++---
gcc/config/i386/i386.c | 40 +++++++++++++++++++++--
gcc/config/i386/i386.h | 2 ++
gcc/configure | 47 ++++++++++++++++++++++++++-
gcc/configure.ac | 18 ++++++++++-
gcc/testsuite/gcc.target/i386/pr66232-10.c | 13 ++++++++
gcc/testsuite/gcc.target/i386/pr66232-11.c | 14 ++++++++
gcc/testsuite/gcc.target/i386/pr66232-12.c | 13 ++++++++
gcc/testsuite/gcc.target/i386/pr66232-13.c | 13 ++++++++
gcc/testsuite/gcc.target/i386/pr66232-6.c | 13 ++++++++
gcc/testsuite/gcc.target/i386/pr66232-7.c | 14 ++++++++
gcc/testsuite/gcc.target/i386/pr66232-8.c | 13 ++++++++
gcc/testsuite/gcc.target/i386/pr66232-9.c | 13 ++++++++
gcc/testsuite/lib/target-supports.exp | 52 ++++++++++++++++++++++++++++++
14 files changed, 271 insertions(+), 8 deletions(-)
create mode 100644 gcc/testsuite/gcc.target/i386/pr66232-10.c
create mode 100644 gcc/testsuite/gcc.target/i386/pr66232-11.c
create mode 100644 gcc/testsuite/gcc.target/i386/pr66232-12.c
create mode 100644 gcc/testsuite/gcc.target/i386/pr66232-13.c
create mode 100644 gcc/testsuite/gcc.target/i386/pr66232-6.c
create mode 100644 gcc/testsuite/gcc.target/i386/pr66232-7.c
create mode 100644 gcc/testsuite/gcc.target/i386/pr66232-8.c
create mode 100644 gcc/testsuite/gcc.target/i386/pr66232-9.c
diff --git a/gcc/config.in b/gcc/config.in
index daaf906..0ee5c38 100644
--- a/gcc/config.in
+++ b/gcc/config.in
@@ -363,6 +363,12 @@
#endif
+/* Define true if the assembler supports 'call *foo@GOT'. */
+#ifndef USED_FOR_TARGET
+#undef HAVE_AS_INDIRECT_BRANCH_VIA_GOT
+#endif
+
+
/* Define if your assembler supports the Sun syntax for cmov. */
#ifndef USED_FOR_TARGET
#undef HAVE_AS_IX86_CMOV_SUN_SYNTAX
@@ -686,8 +692,8 @@
#endif
-/* Define to 1 if we found a declaration for 'basename', otherwise define to
- 0. */
+/* Define to 1 if you have the declaration of `basename(const char*)', and to
+ 0 if you don't. */
#ifndef USED_FOR_TARGET
#undef HAVE_DECL_BASENAME
#endif
@@ -963,8 +969,8 @@
#endif
-/* Define to 1 if we found a declaration for 'strstr', otherwise define to 0.
- */
+/* Define to 1 if you have the declaration of `strstr(const char*,const
+ char*)', and to 0 if you don't. */
#ifndef USED_FOR_TARGET
#undef HAVE_DECL_STRSTR
#endif
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index e77cd04..63ebc7f 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -25611,7 +25611,25 @@ ix86_output_call_insn (rtx_insn *insn, rtx call_op)
if (SIBLING_CALL_P (insn))
{
if (direct_p)
- xasm = "%!jmp\t%P0";
+ {
+ if (!SYMBOL_REF_LOCAL_P (call_op)
+ && !flag_plt
+ && !flag_pic
+ && TARGET_ELF)
+ {
+ /* Avoid PLT. */
+ if (TARGET_64BIT)
+ xasm = "%!jmp\t*%p0@GOTPCREL(%%rip)";
+ else
+#ifdef HAVE_AS_INDIRECT_BRANCH_VIA_GOT
+ xasm = "%!jmp\t*%p0@GOT";
+#else
+ xasm = "%!jmp\t%P0";
+#endif
+ }
+ else
+ xasm = "%!jmp\t%P0";
+ }
/* SEH epilogue detection requires the indirect branch case
to include REX.W. */
else if (TARGET_SEH)
@@ -25654,7 +25672,25 @@ ix86_output_call_insn (rtx_insn *insn, rtx call_op)
}
if (direct_p)
- xasm = "%!call\t%P0";
+ {
+ if (!SYMBOL_REF_LOCAL_P (call_op)
+ && !flag_plt
+ && !flag_pic
+ && TARGET_ELF)
+ {
+ /* Avoid PLT. */
+ if (TARGET_64BIT)
+ xasm = "%!call\t*%p0@GOTPCREL(%%rip)";
+ else
+#ifdef HAVE_AS_INDIRECT_BRANCH_VIA_GOT
+ xasm = "%!call\t*%p0@GOT";
+#else
+ xasm = "%!call\t%P0";
+#endif
+ }
+ else
+ xasm = "%!call\t%P0";
+ }
else
xasm = "%!call\t%A0";
diff --git a/gcc/config/i386/i386.h b/gcc/config/i386/i386.h
index 34ef343..9b7f10f 100644
--- a/gcc/config/i386/i386.h
+++ b/gcc/config/i386/i386.h
@@ -584,6 +584,8 @@ extern tree x86_mfence;
/* This is re-defined by cygming.h. */
#define TARGET_PECOFF 0
+#define TARGET_ELF (!TARGET_MACHO && !TARGET_SEH && !TARGET_PECOFF)
+
/* The default abi used by target. */
#define DEFAULT_ABI SYSV_ABI
diff --git a/gcc/configure b/gcc/configure
index a9a76d6..4419035 100755
--- a/gcc/configure
+++ b/gcc/configure
@@ -25361,7 +25361,7 @@ $as_echo "#define HAVE_AS_IX86_DIFF_SECT_DELTA 1"
>>confdefs.h
fi
- # These two are used unconditionally by i386.[ch]; it is to be defined
+ # These three are used unconditionally by i386.[ch]; it is to be defined
# to 1 if the feature is present, 0 otherwise.
as_ix86_gotoff_in_data_opt=
if test x$gas = xyes; then
@@ -25407,6 +25407,51 @@ cat >>confdefs.h <<_ACEOF
_ACEOF
+ as_ix86_indirect_branch_via_got_opt=
+ if test x$gas = xyes; then
+ as_ix86_indirect_branch_via_got_opt="--32"
+ fi
+ { $as_echo "$as_me:${as_lineno-$LINENO}: checking assembler for call
*foo@GOT" >&5
+$as_echo_n "checking assembler for call *foo@GOT... " >&6; }
+if test "${gcc_cv_as_ix86_indirect_branch_via_got+set}" = set; then :
+ $as_echo_n "(cached) " >&6
+else
+ gcc_cv_as_ix86_indirect_branch_via_got=no
+ if test $in_tree_gas = yes; then
+ if test $gcc_cv_gas_vers -ge `expr \( \( 2 \* 1000 \) + 26 \) \* 1000 + 0`
+ then gcc_cv_as_ix86_indirect_branch_via_got=yes
+fi
+ elif test x$gcc_cv_as != x; then
+ $as_echo ' .text
+ call *foo@GOT' > conftest.s
+ if { ac_try='$gcc_cv_as $gcc_cv_as_flags
$as_ix86_indirect_branch_via_got_opt -o conftest.o conftest.s >&5'
+ { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
+ (eval $ac_try) 2>&5
+ ac_status=$?
+ $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+ test $ac_status = 0; }; }
+ then
+ if test x$gcc_cv_readelf != x \
+ && $gcc_cv_readelf -r conftest.o | grep R_386_ | grep -v R_386_GOT32 >
/dev/null 2>&1; then
+ gcc_cv_as_ix86_indirect_branch_via_got=yes
+ fi
+ else
+ echo "configure: failed program was" >&5
+ cat conftest.s >&5
+ fi
+ rm -f conftest.o conftest.s
+ fi
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result:
$gcc_cv_as_ix86_indirect_branch_via_got" >&5
+$as_echo "$gcc_cv_as_ix86_indirect_branch_via_got" >&6; }
+if test $gcc_cv_as_ix86_indirect_branch_via_got = yes; then
+
+cat >>confdefs.h <<_ACEOF
+#define HAVE_AS_INDIRECT_BRANCH_VIA_GOT 1
+_ACEOF
+
+fi
+
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking assembler for rep and
lock prefix" >&5
$as_echo_n "checking assembler for rep and lock prefix... " >&6; }
if test "${gcc_cv_as_ix86_rep_lock_prefix+set}" = set; then :
diff --git a/gcc/configure.ac b/gcc/configure.ac
index 83f9c09..543e650 100644
--- a/gcc/configure.ac
+++ b/gcc/configure.ac
@@ -3953,7 +3953,7 @@ foo: nop
[AC_DEFINE(HAVE_AS_IX86_DIFF_SECT_DELTA, 1,
[Define if your assembler supports the subtraction of symbols in
different sections.])])
- # These two are used unconditionally by i386.[ch]; it is to be defined
+ # These three are used unconditionally by i386.[ch]; it is to be defined
# to 1 if the feature is present, 0 otherwise.
as_ix86_gotoff_in_data_opt=
if test x$gas = xyes; then
@@ -3971,6 +3971,22 @@ foo: nop
[`if test $gcc_cv_as_ix86_gotoff_in_data = yes; then echo 1; else echo
0; fi`],
[Define true if the assembler supports '.long foo@GOTOFF'.])
+ as_ix86_indirect_branch_via_got_opt=
+ if test x$gas = xyes; then
+ as_ix86_indirect_branch_via_got_opt="--32"
+ fi
+ gcc_GAS_CHECK_FEATURE([call *foo@GOT],
+ gcc_cv_as_ix86_indirect_branch_via_got, [2,26,0],
+ [$as_ix86_indirect_branch_via_got_opt],
+[ .text
+ call *foo@GOT],
+ [if test x$gcc_cv_readelf != x \
+ && $gcc_cv_readelf -r conftest.o | grep R_386_ | grep -v R_386_GOT32 >
/dev/null 2>&1; then
+ gcc_cv_as_ix86_indirect_branch_via_got=yes
+ fi],
+ [AC_DEFINE_UNQUOTED(HAVE_AS_INDIRECT_BRANCH_VIA_GOT, 1,
+ [Define true if the assembler supports 'call *foo@GOT'.])])
+
gcc_GAS_CHECK_FEATURE([rep and lock prefix],
gcc_cv_as_ix86_rep_lock_prefix,,,
[rep movsl
diff --git a/gcc/testsuite/gcc.target/i386/pr66232-10.c
b/gcc/testsuite/gcc.target/i386/pr66232-10.c
new file mode 100644
index 0000000..e95c789
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr66232-10.c
@@ -0,0 +1,13 @@
+/* { dg-do compile { target *-*-linux* } } */
+/* { dg-options "-O2 -fno-pic -fno-plt" } */
+
+extern void bar (void) __attribute__((visibility("hidden")));
+
+void
+foo (void)
+{
+ bar ();
+}
+
+/* { dg-final { scan-assembler-not "jmp\[ \t\]*.bar@GOTPCREL" { target { !
ia32 } } } } */
+/* { dg-final { scan-assembler-not "jmp\[ \t\]*.bar@GOT" { target ia32 } } } */
diff --git a/gcc/testsuite/gcc.target/i386/pr66232-11.c
b/gcc/testsuite/gcc.target/i386/pr66232-11.c
new file mode 100644
index 0000000..63a1809
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr66232-11.c
@@ -0,0 +1,14 @@
+/* { dg-do compile { target *-*-linux* } } */
+/* { dg-options "-O2 -fno-pic -fno-plt" } */
+
+extern void bar (void) __attribute__((visibility("hidden")));
+
+int
+foo (void)
+{
+ bar ();
+ return 0;
+}
+
+/* { dg-final { scan-assembler-not "call\[ \t\]*.bar@GOTPCREL" { target { !
ia32 } } } } */
+/* { dg-final { scan-assembler-not "call\[ \t\]*.bar@GOT" { target ia32 } } }
*/
diff --git a/gcc/testsuite/gcc.target/i386/pr66232-12.c
b/gcc/testsuite/gcc.target/i386/pr66232-12.c
new file mode 100644
index 0000000..89bb605
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr66232-12.c
@@ -0,0 +1,13 @@
+/* { dg-do compile { target *-*-linux* } } */
+/* { dg-options "-O2 -fno-pic -fno-plt" } */
+
+extern int bar (void) __attribute__((visibility("hidden")));
+
+int
+foo (void)
+{
+ return bar ();
+}
+
+/* { dg-final { scan-assembler-not "jmp\[ \t\]*.bar@GOTPCREL" { target { !
ia32 } } } } */
+/* { dg-final { scan-assembler-not "jmp\[ \t\]*.bar@GOT" { target ia32 } } } */
diff --git a/gcc/testsuite/gcc.target/i386/pr66232-13.c
b/gcc/testsuite/gcc.target/i386/pr66232-13.c
new file mode 100644
index 0000000..4aec477
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr66232-13.c
@@ -0,0 +1,13 @@
+/* { dg-do compile { target *-*-linux* } } */
+/* { dg-options "-O2 -fno-pic -fno-plt" } */
+
+extern int bar (void) __attribute__((visibility("hidden")));
+
+int
+foo (void)
+{
+ return bar () + 1;
+}
+
+/* { dg-final { scan-assembler-not "call\[ \t\]*.bar@GOTPCREL" { target { !
ia32 } } } } */
+/* { dg-final { scan-assembler-not "call\[ \t\]*.bar@GOT" { target ia32 } } }
*/
diff --git a/gcc/testsuite/gcc.target/i386/pr66232-6.c
b/gcc/testsuite/gcc.target/i386/pr66232-6.c
new file mode 100644
index 0000000..b465e59
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr66232-6.c
@@ -0,0 +1,13 @@
+/* { dg-do compile { target *-*-linux* } } */
+/* { dg-options "-O2 -fno-pic -fno-plt" } */
+
+extern void bar (void);
+
+void
+foo (void)
+{
+ bar ();
+}
+
+/* { dg-final { scan-assembler "jmp\[ \t\]*.bar@GOTPCREL" { target { ! ia32 }
} } } */
+/* { dg-final { scan-assembler "jmp\[ \t\]*.bar@GOT" { target { ia32 &&
branch_via_got } } } } */
diff --git a/gcc/testsuite/gcc.target/i386/pr66232-7.c
b/gcc/testsuite/gcc.target/i386/pr66232-7.c
new file mode 100644
index 0000000..2908541
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr66232-7.c
@@ -0,0 +1,14 @@
+/* { dg-do compile { target *-*-linux* } } */
+/* { dg-options "-O2 -fno-pic -fno-plt" } */
+
+extern void bar (void);
+
+int
+foo (void)
+{
+ bar ();
+ return 0;
+}
+
+/* { dg-final { scan-assembler "call\[ \t\]*.bar@GOTPCREL" { target { ! ia32 }
} } } */
+/* { dg-final { scan-assembler "call\[ \t\]*.bar@GOT" { target { ia32 &&
branch_via_got } } } } */
diff --git a/gcc/testsuite/gcc.target/i386/pr66232-8.c
b/gcc/testsuite/gcc.target/i386/pr66232-8.c
new file mode 100644
index 0000000..c23d6bb
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr66232-8.c
@@ -0,0 +1,13 @@
+/* { dg-do compile { target *-*-linux* } } */
+/* { dg-options "-O2 -fno-pic -fno-plt" } */
+
+extern int bar (void);
+
+int
+foo (void)
+{
+ return bar ();
+}
+
+/* { dg-final { scan-assembler "jmp\[ \t\]*.bar@GOTPCREL" { target { ! ia32 }
} } } */
+/* { dg-final { scan-assembler "jmp\[ \t\]*.bar@GOT" { target { ia32 &&
branch_via_got } } } } */
diff --git a/gcc/testsuite/gcc.target/i386/pr66232-9.c
b/gcc/testsuite/gcc.target/i386/pr66232-9.c
new file mode 100644
index 0000000..b0cd40b
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr66232-9.c
@@ -0,0 +1,13 @@
+/* { dg-do compile { target *-*-linux* } } */
+/* { dg-options "-O2 -fno-pic -fno-plt" } */
+
+extern int bar (void);
+
+int
+foo (void)
+{
+ return bar () + 1;
+}
+
+/* { dg-final { scan-assembler "call\[ \t\]*.bar@GOTPCREL" { target { ! ia32 }
} } } */
+/* { dg-final { scan-assembler "call\[ \t\]*.bar@GOT" { target { ia32 &&
branch_via_got } } } } */
diff --git a/gcc/testsuite/lib/target-supports.exp
b/gcc/testsuite/lib/target-supports.exp
index f0c209f..f80fd60 100644
--- a/gcc/testsuite/lib/target-supports.exp
+++ b/gcc/testsuite/lib/target-supports.exp
@@ -6320,6 +6320,58 @@ proc check_effective_target_pie_copyreloc { } {
return $pie_copyreloc_available_saved
}
+# Return 1 if the x86 target supports "call *foo@GOT", 0 otherwise.
+# Cache the result.
+
+proc check_effective_target_branch_via_got { } {
+ global branch_via_got_available_saved
+ global tool
+ global GCC_UNDER_TEST
+
+ if { !([istarget x86_64-*-*] || [istarget i?86-*-*]) } {
+ return 0
+ }
+
+ # Need auto-host.h to check linker support.
+ if { ![file exists ../../auto-host.h ] } {
+ return 0
+ }
+
+ if [info exists branch_via_got_available_saved] {
+ verbose "check_effective_target_branch_via_got returning saved
$branch_via_got_available_saved" 2
+ } else {
+ # Set up and compile to see if linker supports PIE with copy
+ # reloc. Include the current process ID in the file names to
+ # prevent conflicts with invocations for multiple testsuites.
+
+ set src pie[pid].c
+ set obj pie[pid].o
+
+ set f [open $src "w"]
+ puts $f "#include \"../../auto-host.h\""
+ puts $f "#ifndef HAVE_AS_INDIRECT_BRANCH_VIA_GOT"
+ puts $f "# error Assembler does not support call *foo@GOT."
+ puts $f "#endif"
+ close $f
+
+ verbose "check_effective_target_branch_via_got compiling testfile $src"
2
+ set lines [${tool}_target_compile $src $obj object ""]
+
+ file delete $src
+ file delete $obj
+
+ if [string match "" $lines] then {
+ verbose "check_effective_target_branch_via_got testfile compilation
passed" 2
+ set branch_via_got_available_saved 1
+ } else {
+ verbose "check_effective_target_branch_via_got testfile compilation
failed" 2
+ set branch_via_got_available_saved 0
+ }
+ }
+
+ return $branch_via_got_available_saved
+}
+
# Return 1 if the target uses comdat groups.
proc check_effective_target_comdat_group {} {
--
1.9.3
