Some undocumented instruction updates

docs/x86/ops/SALC/README.md

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+---
+layout: page
+title: "x86 Instructions: SALC"
+permalink: /docs/x86/ops/SALC/
+---
+
+SALC (0xD6)
+---
+
+### Description
+
+From [http://www.rcollins.org/secrets/opcodes/SALC.html](http://www.rcollins.org/secrets/opcodes/SALC.html):
+
+	An undocumented op code that performs an operation common to every Assembly language subroutine to C and many
+	other higher level languages. This instruction is a C programmers 'dream' instruction for interfacing to assembly
+	language.
+	
+	Undocumented:  Available to all Intel x86 processors
+				   Useful in production source code.
+																 SALC
+	Flags:                                       SET Carry flag to AL
+	+-+-+-+-+-+-+-+-+-+                                  +----------+
+	|O|D|I|T|S|Z|A|P|C|                                  | 11010110 |
+	+-+-+-+-+-+-+-+-+-+                                  +----------+
+	| | | | | | | | | |                                  |    D6    |
+	+-+-+-+-+-+-+-+-+-+                                  +----------+
+	
+	The name SALC simply stands for SET the Carry flag in AL. This instruction is categorized as an undocumented
+	single-byte proprietary instruction. Intel claims it can be emulated as a NOP. Hardly a NOP, this instruction
+	sets AL=FF if the Carry Flag is set (CF=1), or resets AL=00 if the Carry Flag is clear (CF=0). It can best be
+	emulated as SBB AL,AL. SALC doesn't change any flags, where SBB AL,AL does. This instruction is most useful to
+	high-level language programmers whose programs call assembly language, and expect AL to indicate success or failure.
+	Since it is convenient for assembly language programs to return status in the CF, this instruction will convert
+	that status to a form compatible with high level languages.
+	
+	Over the years, this instruction has been given many names by various discoverers. I originally gave it the name
+	SETCAL, but the most common name I've seen in print is SETALC. The name given above, SALC is an official Intel name.
+	While perusing the P6 opcode map, I always check for known, undocumented opcodes. After weeding through the map
+	for many minutes, my patience and perseverance paid off. I found the opcode, and its name. Intel's name for this
+	opcode is SALC. This would indicate that Intel plans to officially document this instruction, beginning with the P6.