From 9f5f3caa74d66d5cc90eebec71a5e743f7c5a970 Mon Sep 17 00:00:00 2001
From: kvigor <kvigor@4a8a32a2-be11-0410-ad9d-d568d2c75423>
Date: Tue, 4 Feb 2003 05:52:45 +0000
Subject: [PATCH] Minor ds390 performance enhancement on generic pointer reads

git-svn-id: https://sdcc.svn.sourceforge.net/svnroot/sdcc/trunk/sdcc@2214 4a8a32a2-be11-0410-ad9d-d568d2c75423
---
 device/lib/_gptrget.c | 76 +++++++++++++++++++++++++++++++++++++++++++
 src/ds390/gen.c       | 23 +++++++------
 2 files changed, 89 insertions(+), 10 deletions(-)

diff --git a/device/lib/_gptrget.c b/device/lib/_gptrget.c
index 7eaca491..ca8bc1bd 100644
--- a/device/lib/_gptrget.c
+++ b/device/lib/_gptrget.c
@@ -84,3 +84,79 @@ unsigned char _gptrget ()
      _endasm ;
 
 }
+
+#ifdef SDCC_ds390
+unsigned int _gptrgetWord ()
+{
+    _asm
+    ;
+    ;   depending on the pointer type acc. to SDCCsymt.h
+    ;
+        mov     a,b
+        jz      00001$	; 0 near
+	dec     a
+	jz      00002$	; 1 far
+        dec     a
+        jz      00003$	; 2 code
+	dec     a
+	jz      00004$
+	dec     a	; 4 skip generic pointer
+	dec     a
+	jz      00001$	; 5 idata
+    ;
+    ;   any other value for type
+    ;   return xFF
+	mov     a,#0xff
+	sjmp    00006$
+    ;
+    ;   Pointer to data space
+    ;
+ 00001$:
+        push 	ar0
+	mov     r0,dpl     ; use only low order address
+	mov     _ap,@r0
+	inc	r0
+	mov	a,@r0
+	inc     dpl
+        sjmp    00005$
+    ;
+    ;   pointer to xternal data
+    ;
+ 00002$:
+        movx    a,@dptr
+	mov	_ap,a
+	inc     dptr
+	movx    a,@dptr
+        sjmp    00006$
+;
+;   pointer to code area
+;
+ 00003$:
+	; clr     a  is already 0
+        movc    a,@a+dptr
+	mov     _ap,a
+	clr	a
+	inc 	dptr
+	movc 	a,@a+dptr
+        sjmp    00006$
+;
+;   pointer to xternal stack
+;
+ 00004$:
+    	push 	ar0
+	mov     r0,dpl
+        movx    a,@r0
+	mov 	_ap,a
+	inc 	r0
+	movx    a,@r0
+	inc 	dpl
+;
+;   restore and return
+;
+00005$:
+    pop ar0
+00006$:	
+     _endasm ;
+
+}
+#endif
diff --git a/src/ds390/gen.c b/src/ds390/gen.c
index ecf14b94..e87d5855 100644
--- a/src/ds390/gen.c
+++ b/src/ds390/gen.c
@@ -9510,29 +9510,32 @@ genGenPointerGet (operand * left,
 
   /* if bit then unpack */
   if (IS_BITVAR (retype) || IS_BITVAR (letype))
+  {
     genUnpackBits (result, "dptr", GPOINTER);
+  }
   else
     {
-      size = AOP_SIZE (result);
-      offset = 0;
+	size = AOP_SIZE (result);
+	offset = 0;
 
-      while (size--)
+	while (size--)
 	{
-// Whoops; uncooked experimental code which was accidentally committed.
-// Kevin should either finish cooking this or yank it soon.
-#if 0
 	    if (size)
 	    {
-		emitcode("push", "b");
+		// Get two bytes at a time, results in _AP & A.
+		// dptr will be incremented ONCE by __gptrgetWord.
+		//
+		// Note: any change here must be coordinated
+		// with the implementation of __gptrgetWord
+		// in device/lib/_gptrget.c
 		emitcode ("lcall", "__gptrgetWord");
-		aopPut (AOP (result), "b", offset++);
+		aopPut (AOP (result), DP2_RESULT_REG, offset++);
 		aopPut (AOP (result), "a", offset++);
-		emitcode("pop", "b");
 		size--;
 	    }
 	    else
-#endif		
 	    {
+		// Only one byte to get.
 		emitcode ("lcall", "__gptrget");
 		aopPut (AOP (result), "a", offset++);
 	    }
-- 
2.47.2