[M3commit] CVS Update: cm3

[Jay Krell]

CVSROOT:	/usr/cvs
Changes by:	jkrell at birch.	10/03/08 17:03:48

Modified files:
	cm3/m3-sys/m3back/src/: M3x86.m3 Stackx86.i3 Stackx86.m3 

Log message:
	"rewrite" insert to not use tables and to inline 64bit operations
	
	It is modeled after:
	
	T insert(T to, T from, uint32 offset, uint32 count)
	{
	T mask = ((~((~(T)0) << count)) << offset);
	return (to & ~mask) | ((from << offset) & mask);
	}
	
	I spent some time trying to remove the unnecessary instructions.
	No luck yet. The problem is the codegen wants to preserve offset/count
	after we are done with them.
	
	The usage of the constant "-1" will be optimized later.
	
	Constant offset and count should generate much better code.
	Just constant offset or count, not much different (shift immediate instead of shift by ecx).
	er, actually the shifts might be significantly optimized.
	Calculation of the mask ought to be better just for constant count, to be looked at later.
	
	It may be profitable to come up with other formulas.
	These at least are "branch free" (except for the branches within the shifts).
	
	The basic general patterns are, which you can see follow the C code closely:
	
	insert            Word.32
	00000226: 8B4DD0              MOV ECX tv.103[_n]
	00000229: BEFFFFFFFF          MOV ESI $4294967295
	0000022E: D3E6                SHL ESI
	00000230: F7D6                NOT ESI
	00000232: 8BF9                MOV EDI ECX            This isn't needed!
	00000234: 8B4DD8              MOV ECX tv.101[_m]
	00000237: D3E6                SHL ESI
	00000239: D3E2                SHL EDX
	0000023B: 23D6                AND EDX ESI
	0000023D: F7D6                NOT ESI
	0000023F: 23DE                AND EBX ESI
	00000241: 0BDA                OR EBX EDX
	
	insert            Word.64
	000004EB: 8B4DB0              MOV ECX tv.117[_n]
	000004EE: BBFFFFFFFF          MOV EBX $4294967295
	000004F3: BEFFFFFFFF          MOV ESI $4294967295
	000004F8: 0FA5DE              SHLD ESI EBX ECX
	000004FB: D3E3                SHL EBX
	000004FD: F6C120              TEST ECX $32
	00000500: 7400                JE rel8 L.75
	00000502: 8BF3                MOV ESI EBX
	00000504: 33DB                XOR EBX EBX
	set_label L.75
	00000506: F7D3                NOT EBX
	00000508: F7D6                NOT ESI
	0000050A: 8BF9                MOV EDI ECX
	0000050C: 8B4DB8              MOV ECX tv.115[_m]
	0000050F: 0FA5DE              SHLD ESI EBX ECX
	00000512: D3E3                SHL EBX
	00000514: F6C120              TEST ECX $32
	00000517: 7400                JE rel8 L.76
	00000519: 8BF3                MOV ESI EBX
	0000051B: 33DB                XOR EBX EBX
	set_label L.76
	0000051D: 0FA5C2              SHLD EDX EAX ECX
	00000520: D3E0                SHL EAX
	00000522: F6C120              TEST ECX $32
	00000525: 7400                JE rel8 L.77
	00000527: 8BD0                MOV EDX EAX
	00000529: 33C0                XOR EAX EAX
	set_label L.77
	0000052B: 23C3                AND EAX EBX
	0000052D: 23D6                AND EDX ESI
	0000052F: F7D3                NOT EBX
	00000531: F7D6                NOT ESI
	declare_temp      4 4 Int.32 F tv.119[T$119] -88
	00000533: 897DA8              MOV tv.119[T$119] EDI        This isn't needed!
	00000536: 8B7DE8              MOV EDI tv.108[_a64]
	declare_temp      4 4 Int.32 F tv.120[T$120] -92
	00000539: 894DA4              MOV tv.120[T$120] ECX        This isn't needed!
	0000053C: 8B4DEC              MOV ECX tv.108[_a64]+4
	0000053F: 23FB                AND EDI EBX
	00000541: 23CE                AND ECX ESI
	00000543: 0BF8                OR EDI EAX
	00000545: 0BCA                OR ECX EDX
	free_temp         tv.120[T$120]
	free_temp         tv.119[T$119]