[PATCH] i386: Remove build support for GCC older than GCC 6
H.J. Lu
hjl.tools@gmail.com
Mon Apr 6 14:49:14 GMT 2020
Since GCC 6.2 or later is required to build glibc, remove build support
for GCC older than GCC 6.
Testd with GCC 6.4 and GCC 9.3.
---
sysdeps/i386/sysdep.h | 2 -
sysdeps/i386/tls-macros.h | 37 +----
sysdeps/unix/sysv/linux/i386/sysdep.h | 206 ++++----------------------
3 files changed, 28 insertions(+), 217 deletions(-)
diff --git a/sysdeps/i386/sysdep.h b/sysdeps/i386/sysdep.h
index 6094af8fec..2f786a251b 100644
--- a/sysdeps/i386/sysdep.h
+++ b/sysdeps/i386/sysdep.h
@@ -18,8 +18,6 @@
#include <sysdeps/x86/sysdep.h>
-#include <features.h> /* For __GNUC_PREREQ. */
-
/* It is desirable that the names of PIC thunks match those used by
GCC so that multiple copies are eliminated by the linker. Because
GCC 4.6 and earlier use __i686 in the names, it is necessary to
diff --git a/sysdeps/i386/tls-macros.h b/sysdeps/i386/tls-macros.h
index 053cba05d1..9c1303dc45 100644
--- a/sysdeps/i386/tls-macros.h
+++ b/sysdeps/i386/tls-macros.h
@@ -1,5 +1,3 @@
-#include <features.h> /* For __GNUC_PREREQ. */
-
#define TLS_LE(x) \
({ int *__l; \
asm ("movl %%gs:0,%0\n\t" \
@@ -7,15 +5,7 @@
: "=r" (__l)); \
__l; })
-#if defined PIC && !__GNUC_PREREQ (5,0)
-# define TLS_IE(x) \
- ({ int *__l; \
- asm ("movl %%gs:0,%0\n\t" \
- "subl " #x "@gottpoff(%%ebx),%0" \
- : "=r" (__l)); \
- __l; })
-#else
-# define TLS_IE(x) \
+#define TLS_IE(x) \
({ int *__l, __b; \
asm ("call 1f\n\t" \
".subsection 1\n" \
@@ -27,18 +17,8 @@
"subl " #x "@gottpoff(%%ebx),%0" \
: "=r" (__l), "=&b" (__b)); \
__l; })
-#endif
-#if defined PIC && !__GNUC_PREREQ (5,0)
-# define TLS_LD(x) \
- ({ int *__l, __c, __d; \
- asm ("leal " #x "@tlsldm(%%ebx),%%eax\n\t" \
- "call ___tls_get_addr@plt\n\t" \
- "leal " #x "@dtpoff(%%eax), %%eax" \
- : "=a" (__l), "=&c" (__c), "=&d" (__d)); \
- __l; })
-#else
-# define TLS_LD(x) \
+#define TLS_LD(x) \
({ int *__l, __b, __c, __d; \
asm ("call 1f\n\t" \
".subsection 1\n" \
@@ -51,18 +31,8 @@
"leal " #x "@dtpoff(%%eax), %%eax" \
: "=a" (__l), "=&b" (__b), "=&c" (__c), "=&d" (__d)); \
__l; })
-#endif
-#if defined PIC && !__GNUC_PREREQ (5,0)
-# define TLS_GD(x) \
- ({ int *__l, __c, __d; \
- asm ("leal " #x "@tlsgd(%%ebx),%%eax\n\t" \
- "call ___tls_get_addr@plt\n\t" \
- "nop" \
- : "=a" (__l), "=&c" (__c), "=&d" (__d)); \
- __l; })
-#else
-# define TLS_GD(x) \
+#define TLS_GD(x) \
({ int *__l, __b, __c, __d; \
asm ("call 1f\n\t" \
".subsection 1\n" \
@@ -75,4 +45,3 @@
"nop" \
: "=a" (__l), "=&b" (__b), "=&c" (__c), "=&d" (__d)); \
__l; })
-#endif
diff --git a/sysdeps/unix/sysv/linux/i386/sysdep.h b/sysdeps/unix/sysv/linux/i386/sysdep.h
index 6671afe65e..cfa562ecb0 100644
--- a/sysdeps/unix/sysv/linux/i386/sysdep.h
+++ b/sysdeps/unix/sysv/linux/i386/sysdep.h
@@ -43,15 +43,6 @@
# endif
#endif
-/* Since GCC 5 and above can properly spill %ebx with PIC when needed,
- we can inline syscalls with 6 arguments if GCC 5 or above is used
- to compile glibc. Disable GCC 5 optimization when compiling for
- profiling or when -fno-omit-frame-pointer is used since asm ("ebp")
- can't be used to put the 6th argument in %ebp for syscall. */
-#if __GNUC_PREREQ (5,0) && !defined PROF && CAN_USE_REGISTER_ASM_EBP
-# define OPTIMIZE_FOR_GCC_5
-#endif
-
#ifdef __ASSEMBLER__
/* Linux uses a negative return value to indicate syscall errors,
@@ -239,48 +230,6 @@
extern int __syscall_error (int)
attribute_hidden __attribute__ ((__regparm__ (1)));
-#ifndef OPTIMIZE_FOR_GCC_5
-/* We need some help from the assembler to generate optimal code. We
- define some macros here which later will be used. */
-asm (".L__X'%ebx = 1\n\t"
- ".L__X'%ecx = 2\n\t"
- ".L__X'%edx = 2\n\t"
- ".L__X'%eax = 3\n\t"
- ".L__X'%esi = 3\n\t"
- ".L__X'%edi = 3\n\t"
- ".L__X'%ebp = 3\n\t"
- ".L__X'%esp = 3\n\t"
- ".macro bpushl name reg\n\t"
- ".if 1 - \\name\n\t"
- ".if 2 - \\name\n\t"
- "error\n\t"
- ".else\n\t"
- "xchgl \\reg, %ebx\n\t"
- ".endif\n\t"
- ".endif\n\t"
- ".endm\n\t"
- ".macro bpopl name reg\n\t"
- ".if 1 - \\name\n\t"
- ".if 2 - \\name\n\t"
- "error\n\t"
- ".else\n\t"
- "xchgl \\reg, %ebx\n\t"
- ".endif\n\t"
- ".endif\n\t"
- ".endm\n\t");
-
-/* Six-argument syscalls use an out-of-line helper, because an inline
- asm using all registers apart from %esp cannot work reliably and
- the assembler does not support describing an asm that saves and
- restores %ebp itself as a separate stack frame. This structure
- stores the arguments not passed in registers; %edi is passed with a
- pointer to this structure. */
-struct libc_do_syscall_args
-{
- int ebx, edi, ebp;
-};
-#endif
-
# define VDSO_NAME "LINUX_2.6"
# define VDSO_HASH 61765110
@@ -313,41 +262,23 @@ struct libc_do_syscall_args
INTERNAL_SYSCALL_MAIN_INLINE(name, 5, args)
/* Each object using 6-argument inline syscalls must include a
definition of __libc_do_syscall. */
-#ifdef OPTIMIZE_FOR_GCC_5
-# define INTERNAL_SYSCALL_MAIN_6(name, args...) \
- INTERNAL_SYSCALL_MAIN_INLINE(name, 6, args)
-#else /* GCC 5 */
-# define INTERNAL_SYSCALL_MAIN_6(name, arg1, arg2, arg3, \
- arg4, arg5, arg6) \
- struct libc_do_syscall_args _xv = \
- { \
- (int) (arg1), \
- (int) (arg5), \
- (int) (arg6) \
- }; \
- asm volatile ( \
- "movl %1, %%eax\n\t" \
- "call __libc_do_syscall" \
- : "=a" (resultvar) \
- : "i" (__NR_##name), "c" (arg2), "d" (arg3), "S" (arg4), "D" (&_xv) \
- : "memory", "cc")
-#endif /* GCC 5 */
+#define INTERNAL_SYSCALL_MAIN_6(name, args...) \
+ INTERNAL_SYSCALL_MAIN_INLINE(name, 6, args)
#define INTERNAL_SYSCALL(name, nr, args...) \
({ \
register unsigned int resultvar; \
INTERNAL_SYSCALL_MAIN_##nr (name, args); \
(int) resultvar; })
#if I386_USE_SYSENTER
-# ifdef OPTIMIZE_FOR_GCC_5
-# ifdef PIC
-# define INTERNAL_SYSCALL_MAIN_INLINE(name, nr, args...) \
+# ifdef PIC
+# define INTERNAL_SYSCALL_MAIN_INLINE(name, nr, args...) \
LOADREGS_##nr(args) \
asm volatile ( \
"call *%%gs:%P2" \
: "=a" (resultvar) \
: "a" (__NR_##name), "i" (offsetof (tcbhead_t, sysinfo)) \
ASMARGS_##nr(args) : "memory", "cc")
-# define INTERNAL_SYSCALL_NCS(name, nr, args...) \
+# define INTERNAL_SYSCALL_NCS(name, nr, args...) \
({ \
register unsigned int resultvar; \
LOADREGS_##nr(args) \
@@ -357,14 +288,14 @@ struct libc_do_syscall_args
: "a" (name), "i" (offsetof (tcbhead_t, sysinfo)) \
ASMARGS_##nr(args) : "memory", "cc"); \
(int) resultvar; })
-# else
-# define INTERNAL_SYSCALL_MAIN_INLINE(name, nr, args...) \
+# else
+# define INTERNAL_SYSCALL_MAIN_INLINE(name, nr, args...) \
LOADREGS_##nr(args) \
asm volatile ( \
"call *_dl_sysinfo" \
: "=a" (resultvar) \
: "a" (__NR_##name) ASMARGS_##nr(args) : "memory", "cc")
-# define INTERNAL_SYSCALL_NCS(name, nr, args...) \
+# define INTERNAL_SYSCALL_NCS(name, nr, args...) \
({ \
register unsigned int resultvar; \
LOADREGS_##nr(args) \
@@ -373,63 +304,15 @@ struct libc_do_syscall_args
: "=a" (resultvar) \
: "a" (name) ASMARGS_##nr(args) : "memory", "cc"); \
(int) resultvar; })
-# endif
-# else /* GCC 5 */
-# ifdef PIC
-# define INTERNAL_SYSCALL_MAIN_INLINE(name, nr, args...) \
- EXTRAVAR_##nr \
- asm volatile ( \
- LOADARGS_##nr \
- "movl %1, %%eax\n\t" \
- "call *%%gs:%P2\n\t" \
- RESTOREARGS_##nr \
- : "=a" (resultvar) \
- : "i" (__NR_##name), "i" (offsetof (tcbhead_t, sysinfo)) \
- ASMFMT_##nr(args) : "memory", "cc")
-# define INTERNAL_SYSCALL_NCS(name, nr, args...) \
- ({ \
- register unsigned int resultvar; \
- EXTRAVAR_##nr \
- asm volatile ( \
- LOADARGS_##nr \
- "call *%%gs:%P2\n\t" \
- RESTOREARGS_##nr \
- : "=a" (resultvar) \
- : "0" (name), "i" (offsetof (tcbhead_t, sysinfo)) \
- ASMFMT_##nr(args) : "memory", "cc"); \
- (int) resultvar; })
-# else
-# define INTERNAL_SYSCALL_MAIN_INLINE(name, nr, args...) \
- EXTRAVAR_##nr \
- asm volatile ( \
- LOADARGS_##nr \
- "movl %1, %%eax\n\t" \
- "call *_dl_sysinfo\n\t" \
- RESTOREARGS_##nr \
- : "=a" (resultvar) \
- : "i" (__NR_##name) ASMFMT_##nr(args) : "memory", "cc")
-# define INTERNAL_SYSCALL_NCS(name, nr, args...) \
- ({ \
- register unsigned int resultvar; \
- EXTRAVAR_##nr \
- asm volatile ( \
- LOADARGS_##nr \
- "call *_dl_sysinfo\n\t" \
- RESTOREARGS_##nr \
- : "=a" (resultvar) \
- : "0" (name) ASMFMT_##nr(args) : "memory", "cc"); \
- (int) resultvar; })
-# endif
-# endif /* GCC 5 */
+# endif
#else
-# ifdef OPTIMIZE_FOR_GCC_5
-# define INTERNAL_SYSCALL_MAIN_INLINE(name, nr, args...) \
+# define INTERNAL_SYSCALL_MAIN_INLINE(name, nr, args...) \
LOADREGS_##nr(args) \
asm volatile ( \
"int $0x80" \
: "=a" (resultvar) \
: "a" (__NR_##name) ASMARGS_##nr(args) : "memory", "cc")
-# define INTERNAL_SYSCALL_NCS(name, nr, args...) \
+# define INTERNAL_SYSCALL_NCS(name, nr, args...) \
({ \
register unsigned int resultvar; \
LOADREGS_##nr(args) \
@@ -438,28 +321,6 @@ struct libc_do_syscall_args
: "=a" (resultvar) \
: "a" (name) ASMARGS_##nr(args) : "memory", "cc"); \
(int) resultvar; })
-# else /* GCC 5 */
-# define INTERNAL_SYSCALL_MAIN_INLINE(name, nr, args...) \
- EXTRAVAR_##nr \
- asm volatile ( \
- LOADARGS_##nr \
- "movl %1, %%eax\n\t" \
- "int $0x80\n\t" \
- RESTOREARGS_##nr \
- : "=a" (resultvar) \
- : "i" (__NR_##name) ASMFMT_##nr(args) : "memory", "cc")
-# define INTERNAL_SYSCALL_NCS(name, nr, args...) \
- ({ \
- register unsigned int resultvar; \
- EXTRAVAR_##nr \
- asm volatile ( \
- LOADARGS_##nr \
- "int $0x80\n\t" \
- RESTOREARGS_##nr \
- : "=a" (resultvar) \
- : "0" (name) ASMFMT_##nr(args) : "memory", "cc"); \
- (int) resultvar; })
-# endif /* GCC 5 */
#endif
#define LOADARGS_0
@@ -514,35 +375,33 @@ struct libc_do_syscall_args
# define RESTOREARGS_5
#endif
-#ifdef OPTIMIZE_FOR_GCC_5
-# define LOADREGS_0()
-# define ASMARGS_0()
-# define LOADREGS_1(arg1) \
+#define LOADREGS_0()
+#define ASMARGS_0()
+#define LOADREGS_1(arg1) \
LOADREGS_0 ()
-# define ASMARGS_1(arg1) \
+#define ASMARGS_1(arg1) \
ASMARGS_0 (), "b" ((unsigned int) (arg1))
-# define LOADREGS_2(arg1, arg2) \
+#define LOADREGS_2(arg1, arg2) \
LOADREGS_1 (arg1)
-# define ASMARGS_2(arg1, arg2) \
+#define ASMARGS_2(arg1, arg2) \
ASMARGS_1 (arg1), "c" ((unsigned int) (arg2))
-# define LOADREGS_3(arg1, arg2, arg3) \
+#define LOADREGS_3(arg1, arg2, arg3) \
LOADREGS_2 (arg1, arg2)
-# define ASMARGS_3(arg1, arg2, arg3) \
+#define ASMARGS_3(arg1, arg2, arg3) \
ASMARGS_2 (arg1, arg2), "d" ((unsigned int) (arg3))
-# define LOADREGS_4(arg1, arg2, arg3, arg4) \
+#define LOADREGS_4(arg1, arg2, arg3, arg4) \
LOADREGS_3 (arg1, arg2, arg3)
-# define ASMARGS_4(arg1, arg2, arg3, arg4) \
+#define ASMARGS_4(arg1, arg2, arg3, arg4) \
ASMARGS_3 (arg1, arg2, arg3), "S" ((unsigned int) (arg4))
-# define LOADREGS_5(arg1, arg2, arg3, arg4, arg5) \
+#define LOADREGS_5(arg1, arg2, arg3, arg4, arg5) \
LOADREGS_4 (arg1, arg2, arg3, arg4)
-# define ASMARGS_5(arg1, arg2, arg3, arg4, arg5) \
+#define ASMARGS_5(arg1, arg2, arg3, arg4, arg5) \
ASMARGS_4 (arg1, arg2, arg3, arg4), "D" ((unsigned int) (arg5))
-# define LOADREGS_6(arg1, arg2, arg3, arg4, arg5, arg6) \
+#define LOADREGS_6(arg1, arg2, arg3, arg4, arg5, arg6) \
register unsigned int _a6 asm ("ebp") = (unsigned int) (arg6); \
LOADREGS_5 (arg1, arg2, arg3, arg4, arg5)
-# define ASMARGS_6(arg1, arg2, arg3, arg4, arg5, arg6) \
+#define ASMARGS_6(arg1, arg2, arg3, arg4, arg5, arg6) \
ASMARGS_5 (arg1, arg2, arg3, arg4, arg5), "r" (_a6)
-#endif /* GCC 5 */
#define ASMFMT_0()
#ifdef __PIC__
@@ -580,21 +439,6 @@ struct libc_do_syscall_args
# define EXTRAVAR_5
#endif
-/* Consistency check for position-independent code. Disabled for GCC 5
- and above since there is no fixed PIC register in GCC 5 and above. */
-#if defined __PIC__ && !__GNUC_PREREQ (5,0)
-# define check_consistency() \
- ({ int __res; \
- __asm__ __volatile__ \
- (LOAD_PIC_REG_STR (cx) ";" \
- "subl %%ebx, %%ecx;" \
- "je 1f;" \
- "ud2;" \
- "1:\n" \
- : "=c" (__res)); \
- __res; })
-#endif
-
#endif /* __ASSEMBLER__ */
--
2.25.1
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