[M3commit] CVS Update: cm3

[Jay Krell]

CVSROOT:	/usr/cvs
Changes by:	jkrell at birch.	10/02/12 11:45:54

Modified files:
	cm3/m3-sys/m3back/src/: Codex86.m3 M3x86.m3 

Log message:
	fix compare_exchange by hand-building the modrm part of the instruction
	Still, it would be better if compare_exchange took a Var parameter
	in the function call instead of on the stack.
	Witness the code:
	0000018E: 8D3538000000        LEA ESI gv.2[_MM_Main]+56
	00000194: 8D3D98000000        LEA EDI gv.2[_MM_Main]+152
	0000019A: 8BC7                MOV EAX EDI
	0000019C: 8B1D9C000000        MOV EBX gv.2[_MM_Main]+156
	000001A2: F00FB133            LOCK CMPXCHG  ESI EBX
	
	should really be more like:
	
	00000194: 8D3D98000000        MOV EAX gv.2[_MM_Main]+152
	0000019C: 8B1D9C000000        MOV EBX gv.2[_MM_Main]+156
	000001A2: F00FB133            LOCK CMPXCHG  gv.2[_MM_Main]+56 EBX
	
	which should be easy to achieve if compare_exchange took
	its parameters in the function call instead of on the stack.
	3 instructions instead of 5!