请教：GAS中Sparc指令的描述～～

在文件sparc-opc.c中有关于sparc指令的描述，但是有些细节偶不太懂，请大侠指点，谢谢～～！！
比如对‘ld’指令的描述，有如下代码(各种宏在最后有说明)：

1. 拿第二行做例子
"ld", F3(3, 0x00, 0), F3(~3, ~0x00, ~0)|RS2_G0, "[1],d", 0, v6 }, /* ld [rs1+%g0],d */

这条语句表示什么意思呢？能详细的说一下么？

2. 为什么每条指令都有很多条语句来描述呢？

#define COMMUTEOP(opcode, op3, arch_mask)
{ opcode, F3(2, op3, 0), F3(~2, ~op3, ~0)|ASI(~0), "1,2,d", 0, arch_mask },
{ opcode, F3(2, op3, 1), F3(~2, ~op3, ~1), "1,i,d", 0, arch_mask },
{ opcode, F3(2, op3, 1), F3(~2, ~op3, ~1), "i,1,d", 0, arch_mask }

const struct sparc_opcode sparc_opcodes[] = {

{ "ld", F3(3, 0x00, 0), F3(~3, ~0x00, ~0), "[1+2],d", 0, v6 },
{ "ld", F3(3, 0x00, 0), F3(~3, ~0x00, ~0)|RS2_G0, "[1],d", 0, v6 }, /* ld [rs1+%g0],d */
{ "ld", F3(3, 0x00, 1), F3(~3, ~0x00, ~1), "[1+i],d", 0, v6 },
{ "ld", F3(3, 0x00, 1), F3(~3, ~0x00, ~1), "[i+1],d", 0, v6 },
{ "ld", F3(3, 0x00, 1), F3(~3, ~0x00, ~1)|RS1_G0, "[i],d", 0, v6 },
{ "ld", F3(3, 0x00, 1), F3(~3, ~0x00, ~1)|SIMM13(~0), "[1],d", 0, v6 }, /* ld [rs1+0],d */
{ "ld", F3(3, 0x20, 0), F3(~3, ~0x20, ~0), "[1+2],g", 0, v6 },
{ "ld", F3(3, 0x20, 0), F3(~3, ~0x20, ~0)|RS2_G0, "[1],g", 0, v6 }, /* ld [rs1+%g0],d */
{ "ld", F3(3, 0x20, 1), F3(~3, ~0x20, ~1), "[1+i],g", 0, v6 },
{ "ld", F3(3, 0x20, 1), F3(~3, ~0x20, ~1), "[i+1],g", 0, v6 },
{ "ld", F3(3, 0x20, 1), F3(~3, ~0x20, ~1)|RS1_G0, "[i],g", 0, v6 },
{ "ld", F3(3, 0x20, 1), F3(~3, ~0x20, ~1)|SIMM13(~0), "[1],g", 0, v6 }, /* ld [rs1+0],d */

{ "ld", F3(3, 0x21, 0), F3(~3, ~0x21, ~0)|RD(~0), "[1+2],F", 0, v6 },
{ "ld", F3(3, 0x21, 0), F3(~3, ~0x21, ~0)|RS2_G0|RD(~0),"[1],F", 0, v6 }, /* ld [rs1+%g0],d */
{ "ld", F3(3, 0x21, 1), F3(~3, ~0x21, ~1)|RD(~0), "[1+i],F", 0, v6 },
{ "ld", F3(3, 0x21, 1), F3(~3, ~0x21, ~1)|RD(~0), "[i+1],F", 0, v6 },
{ "ld", F3(3, 0x21, 1), F3(~3, ~0x21, ~1)|RS1_G0|RD(~0),"[i],F", 0, v6 },
{ "ld", F3(3, 0x21, 1), F3(~3, ~0x21, ~1)|SIMM13(~0)|RD(~0),"[1],F", 0, v6 }, /* ld [rs1+0],d */

{ "ld", F3(3, 0x30, 0), F3(~3, ~0x30, ~0), "[1+2],D", 0, v6notv9 },
{ "ld", F3(3, 0x30, 0), F3(~3, ~0x30, ~0)|RS2_G0, "[1],D", 0, v6notv9 }, /* ld [rs1+%g0],d */
{ "ld", F3(3, 0x30, 1), F3(~3, ~0x30, ~1), "[1+i],D", 0, v6notv9 },
{ "ld", F3(3, 0x30, 1), F3(~3, ~0x30, ~1), "[i+1],D", 0, v6notv9 },
{ "ld", F3(3, 0x30, 1), F3(~3, ~0x30, ~1)|RS1_G0, "[i],D", 0, v6notv9 },
{ "ld", F3(3, 0x30, 1), F3(~3, ~0x30, ~1)|SIMM13(~0), "[1],D", 0, v6notv9 }, /* ld [rs1+0],d */
{ "ld", F3(3, 0x31, 0), F3(~3, ~0x31, ~0), "[1+2],C", 0, v6notv9 },
{ "ld", F3(3, 0x31, 0), F3(~3, ~0x31, ~0)|RS2_G0, "[1],C", 0, v6notv9 }, /* ld [rs1+%g0],d */
{ "ld", F3(3, 0x31, 1), F3(~3, ~0x31, ~1), "[1+i],C", 0, v6notv9 },
{ "ld", F3(3, 0x31, 1), F3(~3, ~0x31, ~1), "[i+1],C", 0, v6notv9 },
{ "ld", F3(3, 0x31, 1), F3(~3, ~0x31, ~1)|RS1_G0, "[i],C", 0, v6notv9 },
{ "ld", F3(3, 0x31, 1), F3(~3, ~0x31, ~1)|SIMM13(~0), "[1],C", 0, v6notv9 }, /* ld [rs1+0],d */

/* The v9 LDUW is the same as the old 'ld' opcode, it is not the same as the
'ld' pseudo-op in v9. */

各个宏的说明：
#define OP2(x) (((x)&0x7) << 22) /* op2 field of format2 insns */
#define OP3(x) (((x)&0x3f) << 19) /* op3 field of format3 insns */
#define OP(x) ((unsigned)((x)&0x3) << 30) /* op field of all insns */
#define OPF(x) (((x)&0x1ff) << 5) /* opf field of float insns */
#define OPF_LOW5(x) OPF((x)&0x1f) /* v9 */
#define F3F(x, y, z) (OP(x) | OP3(y) | OPF(z)) /* format3 float insns */
#define F3I(x) (((x)&0x1) << 13) /* immediate field of format 3 insns */
#define F2(x, y) (OP(x) | OP2(y)) /* format 2 insns */
#define F3(x, y, z) (OP(x) | OP3(y) | F3I(z)) /* format3 insns */
#define F1(x) (OP(x))
#define DISP30(x) ((x)&0x3fffffff)
#define ASI(x) (((x)&0xff) << 5) /* asi field of format3 insns */
#define RS2(x) ((x)&0x1f) /* rs2 field */
#define SIMM13(x) ((x)&0x1fff) /* simm13 field */
#define RD(x) (((x)&0x1f) << 25) /* destination register field */
#define RS1(x) (((x)&0x1f) << 14) /* rs1 field */
#define ASI_RS2(x) (SIMM13(x))
#define MEMBAR(x) ((x)&0x7f)
#define SLCPOP(x) (((x)&0x7f) << 6) /* sparclet cpop */

#define ANNUL (1<<29)
#define BPRED (1<<19) /* v9 */
#define IMMED F3I(1)
#define RD_G0 RD(~0)
#define RS1_G0 RS1(~0)
#define RS2_G0 RS2(~0)

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Subject: Re: 请教：GAS中Sparc指令的描述～～ Author: EricFisher Posted: 2006-02-21 16:03 Length: 560 byte(s)
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1）参见sparc.h: /* Structure of an opcode table entry. / struct sparc_opcode { const char name; unsigned long match; /* Bits that must be set. / unsigned long lose; / Bits that must not be set. / const char args; /* This was called "delayed" in versions before the flags. / char flags; short architecture; / Bitmask of sparc_opcode_arch_val's. */ }; 2）同一条指令，可能有不同的参数格式。
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Subject: Re: 请教：GAS中Sparc指令的描述～～ Author: kingyoeh Posted: 2006-02-21 21:14 Length: 355 byte(s)
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谢谢这位大哥指点～～偶还有几个问题，请帮帮忙~~~ 1. unsigned long match; /* Bits that must be set. / unsigned long lose; / Bits that must not be set. */ 有‘match’为什么还要‘lose’呢？ lose 的作用是什么呢？ 2. ’flags‘的作用是什么呢？谢谢～～
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Subject: Re: 请教：GAS中Sparc指令的描述～～ Author: EricFisher Posted: 2006-02-22 09:42 Length: 575 byte(s)
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参见sparc.h flag用于标识以下指令 #define F_DELAYED 1 /* Delayed branch / #define F_ALIAS 2 / Alias for a "real" instruction / #define F_UNBR 4 / Unconditional branch / #define F_CONDBR 8 / Conditional branch / #define F_JSR 16 / Subroutine call / #define F_FLOAT 32 / Floating point instruction (not a branch) / #define F_FBR 64 / Floating point branch */ 至于match和lose，是用来根据字节码来标识，确定一条指令。具体的，可以查看sparc的ABI及指令集。
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