my copy of this seems to be slightly more up-to-date
as regards compiler letters, $x in #pragma lib and #pragma packed not hjdicks.

Notes:
Wed Sep 21 14:21:54 EDT 2011 geoff
    merging it with our version.


Reference: /n/sources/patch/applied/doc-compilers
Date: Thu Sep 15 18:47:22 CES 2011
Signed-off-by: forsyth@terzarima.net
Reviewed-by: geoff

--- /sys/doc/compiler.ms	Thu Sep 15 18:46:02 2011
+++ /sys/doc/compiler.ms	Thu Sep 15 18:45:59 2011
@@ -22,10 +22,10 @@
 Introduction
 .LP
 There are many compilers in the series.
-Six of the compilers (MIPS 3000, SPARC, Intel 386, Power PC, DEC Alpha, and Motorola 68020)
+Eight of the compilers (MIPS 3000, SPARC, Intel 386, AMD64, Power PC, ARM, DEC Alpha, and Motorola 68020)
 are considered active and are used to compile
 current versions of Plan 9.
-Several others (Motorola 68000, Intel 960, ARM 7500, AMD 29000) have had only limited use, such as
+Others such as the Motorola 68000 have had only limited use, such as
 to program peripherals or experimental devices.
 .NH
 Structure
@@ -54,12 +54,12 @@
 \\$1	\f(CW\\$2\fP  \f(CW\\$3\fP  \f(CW\\$4\fP
 ..
 .Ta SPARC kc kl ka
-.Ta Power\ PC qc ql qa
+.Ta PowerPC qc ql qa
 .Ta MIPS vc vl va
 .Ta Motorola\ 68000 1c 1l 1a
 .Ta Motorola\ 68020 2c 2l 2a
-.Ta ARM\ 7500 5c 5l 5a
-.Ta Intel\ 960 6c 6l 6a
+.Ta ARM 5c 5l 5a
+.Ta AMD64 6c 6l 6a
 .Ta DEC\ Alpha 7c 7l 7a
 .Ta Intel\ 386 8c 8l 8a
 .Ta AMD\ 29000 9c 9l 9a
@@ -323,14 +323,14 @@
 The loader uses the library name to
 find libraries to load.
 If the name contains
-.CW %O ,
+.CW $O ,
 it is replaced with
 the single character object type of the compiler
 (e.g.,
 .CW v
 for the MIPS).
 If the name contains
-.CW %M ,
+.CW $M ,
 it is replaced with
 the architecture type for the compiler
 (e.g.,
@@ -343,7 +343,7 @@
 .CW .
 then it is searched for in the loader's current directory.
 Otherwise, the name is searched from
-.CW /%M/lib .
+.CW /$M/lib .
 Such
 .CW #pragma
 statements in header files guarantee that the correct
@@ -352,7 +352,7 @@
 .LP
 They also accept
 .CW #pragma
-.CW hjdicks
+.CW packed
 .CW on
 (or
 .CW yes
@@ -360,7 +360,7 @@
 .CW 1 )
 to cause subsequently declared data, until
 .CW #pragma
-.CW hjdicks
+.CW packed
 .CW off
 (or
 .CW no