Fix typo and add ADD-PSEUDO-REGISTER-ALIAS!

diff --git a/v7/src/compiler/documentation/porting.guide b/v7/src/compiler/documentation/porting.guide
index d7ba7061fa56a7d83cfab33936e79e2902c77d0c..8f7663283882a2de4212b69e9ce885dbe50e0258 100644 (file)
--- a/v7/src/compiler/documentation/porting.guide
+++ b/v7/src/compiler/documentation/porting.guide
@@ -1,6 +1,6 @@
 Emacs: Please use -*- Text -*- mode.  Thank you.
 
-$Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/compiler/documentation/porting.guide,v 1.17 1991/03/05 20:54:36 jinx Exp $
+$Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/compiler/documentation/porting.guide,v 1.18 1991/03/06 03:46:47 jinx Exp $
 
 Copyright (c) 1991 Massachusetts Institute of Technology
 
@@ -1520,7 +1520,7 @@ REUSE-PSEUDO-REGISTER-ALIAS! but occasionally neither meets the
 requirements.
 [*Markf: continuations? really?]
 
-* NEED-REGISTER! expects and RTL machine register and informs the
+* NEED-REGISTER! expects an RTL machine register and informs the
 register allocator that the rule in use requires that register so it
 should not be available for subsequent requests while translating the
 current RTL statement or expression.  The register is available for
@@ -1536,6 +1536,10 @@ registers to out-of-line code, typically in the compiled code runtime
 library.
 [*Markf: Explain the register map.]
 
+* ADD-PSEUDO-REGISTER-ALIAS! expects an RTL pseudo-register and an
+available machine register (no longer an alias), and makes the
+specified machine register an alias for the pseudo-register.
+
 * CLEAR-REGISTERS! expects any number of RTL registers and clears them
 from the register map, pushing their current contents to memory if
 needed.  It returns the code that will perform the required motion at