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author | H.J. Lu <hjl.tools@gmail.com> | 2015-10-15 04:33:15 -0700 |
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committer | H.J. Lu <hjl.tools@gmail.com> | 2015-10-15 05:03:24 -0700 |
commit | 83c01ab32b9aa7b27e4e88ed2969d14549e33c5c (patch) | |
tree | 02a2124b188dab51710cb83850eda69bfe517c01 /ChangeLog.11 | |
parent | a014cecd82b71b70a6a843e250e06b541ad524f7 (diff) | |
download | glibc-83c01ab32b9aa7b27e4e88ed2969d14549e33c5c.tar.gz glibc-83c01ab32b9aa7b27e4e88ed2969d14549e33c5c.tar.xz glibc-83c01ab32b9aa7b27e4e88ed2969d14549e33c5c.zip |
i386: Remove syscall assembly codes with 6 arguments
This patch removes i386 assembly implementation for mmap, mmap64, semtimeop now that i386 have 6 argument syscall support from C code and GCC 5 can inline syscalls with 6 arguments. We also compile mmap.c, mmap64.c and semtimedop.c with -fomit-frame-pointer since %ebp may be used to pass the 6th argument to syscall. Fo sysdeps/unix/sysv/linux/i386/mmap.c, with -O2 -march=i686 -mtune=generic, GCC 5.2 now generates: <__mmap>: 0: sub $0x10,%esp 3: mov 0x28(%esp),%eax 7: mov %ebx,(%esp) a: mov 0x18(%esp),%ecx e: mov %esi,0x4(%esp) 12: mov 0x14(%esp),%ebx 16: mov %edi,0x8(%esp) 1a: mov 0x1c(%esp),%edx 1e: test $0xfff,%eax 23: mov 0x20(%esp),%esi 27: mov %ebp,0xc(%esp) 2b: mov 0x24(%esp),%edi 2f: jne 60 <__mmap+0x60> 31: shr $0xc,%eax 34: mov %eax,%ebp 36: mov $0xc0,%eax 3b: call *%gs:0x10 42: cmp $0xfffff000,%eax 47: ja 65 <__mmap+0x65> 49: mov (%esp),%ebx 4c: mov 0x4(%esp),%esi 50: mov 0x8(%esp),%edi 54: mov 0xc(%esp),%ebp 58: add $0x10,%esp 5b: ret 5c: lea 0x0(%esi,%eiz,1),%esi 60: mov $0xffffffea,%eax 65: mov (%esp),%ebx 68: mov 0x4(%esp),%esi 6c: mov 0x8(%esp),%edi 70: mov 0xc(%esp),%ebp 74: add $0x10,%esp 77: jmp 78 <__mmap+0x78> vs sysdeps/unix/sysv/linux/i386/mmap.S: <__mmap>: 0: push %ebp 1: push %ebx 2: push %esi 3: push %edi 4: mov 0x14(%esp),%ebx 8: mov 0x18(%esp),%ecx c: mov 0x1c(%esp),%edx 10: mov 0x20(%esp),%esi 14: mov 0x24(%esp),%edi 18: mov 0x28(%esp),%ebp 1c: test $0xfff,%ebp 22: mov $0xffffffea,%eax 27: jne 38 <__mmap+0x38> 29: shr $0xc,%ebp 2c: mov $0xc0,%eax 31: call *%gs:0x10 38: pop %edi 39: pop %esi 3a: pop %ebx 3b: pop %ebp 3c: cmp $0xfffff000,%eax 41: ja 44 <__mmap+0x44> 43: ret 44: call 45 <__mmap+0x45> 45: R_386_PC32 __x86.get_pc_thunk.cx 49: add $0x2,%ecx 4b: R_386_GOTPC _GLOBAL_OFFSET_TABLE_ 4f: mov 0x0(%ecx),%ecx 51: R_386_TLS_GOTIE __libc_errno 55: neg %eax 57: mov %eax,%gs:(%ecx) 5a: or $0xffffffff,%eax 5d: ret The C version has: 3: mov 0x28(%esp),%eax ... 1e: test $0xfff,%eax ... 31: sar $0xc,%eax 34: mov %eax,%ebp is due to missing $ebx register constraint for inline asm. We have to use "r" constraint with register unsigned int _a6 asm ("ebp") = (unsigned int) (arg6); and compiler chose %eax for offset (arg6) in if (offset & (MMAP_PAGE_UNIT - 1)) * sysdeps/unix/sysv/linux/i386/Makefile (CFLAGS-epoll_pwait.c): Add -fomit-frame-pointer. (CFLAGS-mmap.c): Likewise. (CFLAGS-mmap64.c): Likewise. (CFLAGS-semtimedop.c): Likewise. * sysdeps/unix/sysv/linux/i386/mmap.c: New file. * sysdeps/unix/sysv/linux/i386/mmap.S: Remove file. * sysdeps/unix/sysv/linux/i386/mmap64.S: Likewise. * sysdeps/unix/sysv/linux/i386/semtimedop.S: Likewise.
Diffstat (limited to 'ChangeLog.11')
0 files changed, 0 insertions, 0 deletions