From 4d37e7e3fd851428dede4d05d3e69d03795a744a Mon Sep 17 00:00:00 2001 From: Zachary Amsden Date: Sat, 3 Sep 2005 15:56:38 -0700 Subject: [PATCH] i386: inline assembler: cleanup and encapsulate descriptor and task register management i386 inline assembler cleanup. This change encapsulates descriptor and task register management. Also, it is possible to improve assembler generation in two cases; savesegment may store the value in a register instead of a memory location, which allows GCC to optimize stack variables into registers, and MOV MEM, SEG is always a 16-bit write to memory, making the casting in math-emu unnecessary. Signed-off-by: Zachary Amsden Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/i386/math-emu/get_address.c | 13 +++---------- 1 file changed, 3 insertions(+), 10 deletions(-) (limited to 'arch/i386/math-emu') diff --git a/arch/i386/math-emu/get_address.c b/arch/i386/math-emu/get_address.c index 91175738e94..9819b705efa 100644 --- a/arch/i386/math-emu/get_address.c +++ b/arch/i386/math-emu/get_address.c @@ -155,7 +155,6 @@ static long pm_address(u_char FPU_modrm, u_char segment, { struct desc_struct descriptor; unsigned long base_address, limit, address, seg_top; - unsigned short selector; segment--; @@ -173,17 +172,11 @@ static long pm_address(u_char FPU_modrm, u_char segment, /* fs and gs aren't used by the kernel, so they still have their user-space values. */ case PREFIX_FS_-1: - /* The cast is needed here to get gcc 2.8.0 to use a 16 bit register - in the assembler statement. */ - - __asm__("mov %%fs,%0":"=r" (selector)); - addr->selector = selector; + /* N.B. - movl %seg, mem is a 2 byte write regardless of prefix */ + savesegment(fs, addr->selector); break; case PREFIX_GS_-1: - /* The cast is needed here to get gcc 2.8.0 to use a 16 bit register - in the assembler statement. */ - __asm__("mov %%gs,%0":"=r" (selector)); - addr->selector = selector; + savesegment(gs, addr->selector); break; default: addr->selector = PM_REG_(segment); -- cgit v1.2.3