From 36f09ee9e6ddb9309f28bcff918fb6a7c60a17b4 Mon Sep 17 00:00:00 2001
From: Doug Evans <xdje42@gmail.com>
Date: Fri, 20 Dec 2002 06:39:04 +0000
Subject: [PATCH] 	* mode.scm (mode-sem-mode): New fn. 	* operand.scm
 (op:new-mode): Update. mode-name. 	(op-natural-mode?) New fn. 	*
 rtl.scm (hw): Set hw-name,mode-name. plus some comment tweaks

---
 ChangeLog     |  5 +++++
 mode.scm      | 16 ++++++++++++++++
 operand.scm   |  9 +++++++++
 rtl.scm       |  2 ++
 semantics.scm |  2 +-
 types.scm     |  3 +++
 6 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/ChangeLog b/ChangeLog
index 9fb3d92..5b51f2c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,10 @@
 2002-12-19  Doug Evans  <dje@sebabeach.org>
 
+	* mode.scm (mode-sem-mode): New fn.
+	* operand.scm (op:new-mode): Update. mode-name.
+	(op-natural-mode?) New fn.
+	* rtl.scm (hw): Set hw-name,mode-name.
+
 	Back out sim*.scm changes of 2001-04-02  Ben Elliston  <bje@redhat.com>
 	Instead do:
 	* sim-decode.scm (-gen-decode-insn-globals): Use @PREFIX@_INSN__MAX
diff --git a/mode.scm b/mode.scm
index 5e0c69e..7fdbe5d 100644
--- a/mode.scm
+++ b/mode.scm
@@ -286,6 +286,22 @@
   (mode:lookup (mode-real-name m))
 )
 
+; Return the version of MODE to use in semantic expressions.
+; This (essentially) converts aliases to their real value and then uses
+; mode:sem-mode.  The implementation is the opposite but the effect is the
+; same.
+; ??? Less efficient than it should be.  One improvement would be to
+; disallow unsigned modes from being aliased and set sem-mode for aliased
+; modes.
+
+(define (mode-sem-mode m)
+  (let* ((m1 (mode:lookup m))
+	 (sm (mode:sem-mode m1)))
+    (if sm
+	sm
+	(mode-real-mode m1)))
+)
+
 ; Return #t if mode M1-NAME is bigger than mode M2-NAME.
 
 (define (mode-bigger? m1-name m2-name)
diff --git a/operand.scm b/operand.scm
index a3faf1d..df70133 100644
--- a/operand.scm
+++ b/operand.scm
@@ -261,6 +261,7 @@
 ; Mode support.
 
 ; Create a copy of operand OP in mode NEW-MODE-NAME.
+; NOTE: Even if the mode isn't changing this creates a copy.
 ; If OP has been subclassed the result must contain the complete class
 ; (e.g. the behaviour of `object-copy-top').
 
@@ -282,6 +283,7 @@
 	      (if (not new-mode)
 		  (error "op:new-mode: internal error, bad mode"
 			 new-mode-name))
+	      (elm-xset! result 'mode-name new-mode-name)
 	      (elm-xset! result 'mode new-mode)
 	      result)
 	    (parse-error "op:new-mode"
@@ -290,6 +292,13 @@
 					"'")
 			 new-mode-name))))
 )
+
+; Return #t if operand OP references its h/w element in its natural mode.
+
+(define (op-natural-mode? op)
+  (or (eq? (op:mode-name op) 'DFLT)
+      (mode-compatible? 'samesize (op:mode op) (hw-default-mode (op:type op))))
+)
 
 ; Ifield support.
 
diff --git a/rtl.scm b/rtl.scm
index d7d0025..7834ed9 100644
--- a/rtl.scm
+++ b/rtl.scm
@@ -2029,7 +2029,9 @@
       (if (not (hw-mode-ok? hw (obj:name mode) (elm-xget result 'index)))
 	  (parse-error "hw" "invalid mode for hardware" mode-name))
 
+      (elm-xset! result 'hw-name hw-name)
       (elm-xset! result 'type hw)
+      (elm-xset! result 'mode-name mode-name)
       (elm-xset! result 'mode mode)
 
       (op:set-pretty-sem-name! result hw-name)
diff --git a/semantics.scm b/semantics.scm
index 1159587..e614892 100644
--- a/semantics.scm
+++ b/semantics.scm
@@ -260,7 +260,7 @@
     (else #f))
 )
 
-; Simplify an rtl expresion.
+; Simplify an rtl expression.
 ; EXPR must be in source form.
 ; The result is a possibly simplified EXPR, still in source form.
 ;
diff --git a/types.scm b/types.scm
index eb8d2b5..27bf707 100644
--- a/types.scm
+++ b/types.scm
@@ -239,6 +239,9 @@
 )
 
 ; Return a boolean indicating if two bitranges overlap.
+;
+; lsb0? = #t: 31 ...  0
+; lsb0? = #f: 0  ... 31
 
 (define (bitrange-overlap? start1 length1 start2 length2 lsb0?)
   (if lsb0?
-- 
2.43.5