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[PATCH 5/5] Generate R_386_GOT32x relocation for -fno-plt -fno-pic
- From: "H.J. Lu" <hjl dot tools at gmail dot com>
- To: gcc-patches at gcc dot gnu dot org
- Date: Thu, 22 Oct 2015 10:09:05 -0700
- Subject: [PATCH 5/5] Generate R_386_GOT32x relocation for -fno-plt -fno-pic
- Authentication-results: sourceware.org; auth=none
- References: <1445533745-19016-1-git-send-email-hjl dot tools at gmail dot com>
This patch extends -fno-plt to non-PIC 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", which accesses the
GOT slot without a base register, with a new R_386_GOT32x relocation.
gcc/
* config/i386/i386.c (ix86_nopic_noplt_attribute_p): Check
HAVE_LD_R_386_GOT32X == 0 before returning false.
(ix86_output_call_insn): Generate "%!jmp/call\t*%p0@GOT" for
32-bit.
gcc/testsuite/
* gcc.target/i386/pr66232-10.c: New file.
* 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_r_386_got32x):
New.
(check_effective_target_r_x86_64_gotpcrelx): Likewise.
---
gcc/config/i386/i386.c | 19 +++++-
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/lib/target-supports.exp | 104 +++++++++++++++++++++++++++++
6 files changed, 173 insertions(+), 3 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
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index f5b1717..b4c57ba 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -26904,7 +26904,8 @@ static bool
ix86_nopic_noplt_attribute_p (rtx call_op)
{
if (flag_pic || ix86_cmodel == CM_LARGE
- || !TARGET_64BIT || TARGET_MACHO || TARGET_SEH || TARGET_PECOFF
+ || (!TARGET_64BIT && HAVE_LD_R_386_GOT32X == 0)
+ || TARGET_MACHO || TARGET_SEH || TARGET_PECOFF
|| SYMBOL_REF_LOCAL_P (call_op))
return false;
@@ -26929,8 +26930,14 @@ ix86_output_call_insn (rtx_insn *insn, rtx call_op)
if (SIBLING_CALL_P (insn))
{
+ /* ix86_nopic_noplt_attribute_p returns false for PIC. */
if (direct_p && ix86_nopic_noplt_attribute_p (call_op))
- xasm = "%!jmp\t*%p0@GOTPCREL(%%rip)";
+ {
+ if (TARGET_64BIT)
+ xasm = "%!jmp\t*%p0@GOTPCREL(%%rip)";
+ else
+ xasm = "%!jmp\t*%p0@GOT";
+ }
else if (direct_p)
xasm = "%!jmp\t%P0";
/* SEH epilogue detection requires the indirect branch case
@@ -26974,8 +26981,14 @@ ix86_output_call_insn (rtx_insn *insn, rtx call_op)
seh_nop_p = true;
}
+ /* ix86_nopic_noplt_attribute_p returns false for PIC. */
if (direct_p && ix86_nopic_noplt_attribute_p (call_op))
- xasm = "%!call\t*%p0@GOTPCREL(%%rip)";
+ {
+ if (TARGET_64BIT)
+ xasm = "%!call\t*%p0@GOTPCREL(%%rip)";
+ else
+ xasm = "%!call\t*%p0@GOT";
+ }
else if (direct_p)
xasm = "%!call\t%P0";
else
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..2e902d6
--- /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);
+
+void
+foo (void)
+{
+ bar ();
+}
+
+/* { dg-final { scan-assembler "jmp\[ \t\]*.bar@GOTPCREL" { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler "jmp\[ \t\]*.bar@GOT" { target { ia32 && r_386_got32x } } } } */
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..9254759
--- /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);
+
+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 && r_386_got32x } } } } */
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..97c3a3c
--- /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);
+
+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 && r_386_got32x } } } } */
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..14ad039
--- /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);
+
+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 && r_386_got32x } } } } */
diff --git a/gcc/testsuite/lib/target-supports.exp b/gcc/testsuite/lib/target-supports.exp
index 2de8fac..e6d4601 100644
--- a/gcc/testsuite/lib/target-supports.exp
+++ b/gcc/testsuite/lib/target-supports.exp
@@ -6472,6 +6472,110 @@ proc check_effective_target_pie_copyreloc { } {
return $pie_copyreloc_available_saved
}
+# Return 1 if the x86 target generates R_386_GOT32X for "call *foo@GOT",
+# 0 otherwise. Cache the result.
+
+proc check_effective_target_r_386_got32x { } {
+ global r_386_got32x_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 r_386_got32x_available_saved] {
+ verbose "check_effective_target_r_386_got32x returning saved $r_386_got32x_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 "#if HAVE_LD_R_386_GOT32X == 0"
+ puts $f "# error Assembler does not support R_386_GOT32X."
+ puts $f "#endif"
+ close $f
+
+ verbose "check_effective_target_r_386_got32x 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_r_386_got32x testfile compilation passed" 2
+ set r_386_got32x_available_saved 1
+ } else {
+ verbose "check_effective_target_r_386_got32x testfile compilation failed" 2
+ set r_386_got32x_available_saved 0
+ }
+ }
+
+ return $r_386_got32x_available_saved
+}
+
+# Return 1 if the x86 target generates R_386_GOT32X for
+# "call *foo@GOTPCREL(%rip)", 0 otherwise. Cache the result.
+
+proc check_effective_target_r_x86_64_gotpcrelx { } {
+ global r_x86_64_gotpcrelx_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 r_x86_64_gotpcrelx_available_saved] {
+ verbose "check_effective_target_r_x86_64_gotpcrelx returning saved $r_x86_64_gotpcrelx_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 "#if HAVE_LD_R_X86_64_GOTPCRELX == 0"
+ puts $f "# error Assembler does not support R_X86_64_GOTPCRELX."
+ puts $f "#endif"
+ close $f
+
+ verbose "check_effective_target_r_x86_64_gotpcrelx 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_r_x86_64_gotpcrelx testfile compilation passed" 2
+ set r_x86_64_gotpcrelx_available_saved 1
+ } else {
+ verbose "check_effective_target_r_x86_64_gotpcrelx testfile compilation failed" 2
+ set r_x86_64_gotpcrelx_available_saved 0
+ }
+ }
+
+ return $r_x86_64_gotpcrelx_available_saved
+}
+
# Return 1 if the target uses comdat groups.
proc check_effective_target_comdat_group {} {
--
2.4.3