From 3034869230b581367d39fca3ae635e75563d795f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Remko=20Tron=C3=A7on?= <remko@el-tramo.be>
Date: Sun, 24 Apr 2022 10:58:35 +0200
Subject: [PATCH] compiler: compile push & pop inline (infrastructure)

---
 scripts/word.wat | 10 +++++++++-
 src/waforth.wat  | 46 ++++++++++++++++++++++++++++++++++++++++++----
 2 files changed, 51 insertions(+), 5 deletions(-)

diff --git a/scripts/word.wat b/scripts/word.wat
index 66e47b9..1b0d1fd 100644
--- a/scripts/word.wat
+++ b/scripts/word.wat
@@ -16,11 +16,19 @@
     (get_local $tos)  
 
     ;; Push
-    (call_indirect (type $push) (i32.const 43) (i32.const 1))
+    (set_local $tos)
+    (i32.store (local.get $tos) (i32.const 43))
+    (i32.add (local.get $tos) (i32.const 4))
 
     ;; Word call
     (call_indirect (type $push) (i32.const 10) (i32.const 9))
 
+    ;; Pop   
+    (tee_local $tos (i32.sub (i32.const 4)))
+    (local.get $tos)
+    (i32.load)
+    (drop)
+
     ;; Conditional
     (if (param i32) (result i32) (i32.ne (call_indirect (type $pop) (i32.const 2)) (i32.const 0))
       (then
diff --git a/src/waforth.wat b/src/waforth.wat
index 041cbd0..eb322d0 100644
--- a/src/waforth.wat
+++ b/src/waforth.wat
@@ -2071,12 +2071,22 @@
 
 
 (func $compilePushConst (param $n i32)
+  (call $emitSetLocal (i32.const 0)) ;; Save tos currently on operand stack
+  (call $emitGetLocal (i32.const 0)) ;; Put tos on operand stack again
   (call $emitConst (local.get $n))
-  (call $emitICall (i32.const 1) (i32.const 1 (; = PUSH_INDEX ;))))
+  (call $compilePush))
 
 (func $compilePushLocal (param $n i32)
+  (call $emitSetLocal (i32.const 0)) ;; Save tos currently on operand stack
+  (call $emitGetLocal (i32.const 0)) ;; Put tos on operand stack again
   (call $emitGetLocal (local.get $n))
-  (call $emitICall (i32.const 1) (i32.const 1 (; = PUSH_INDEX ;))))
+  (call $compilePush))
+
+(func $compilePush
+  (call $emitStore)
+  (call $emitGetLocal (i32.const 0)) ;; Put $tos+4 on operand stack
+  (call $emitConst (i32.const 4))
+  (call $emitAdd))
 
 (func $compileIf
   (call $compilePop)
@@ -2187,8 +2197,12 @@
   (global.set $cp (i32.add (global.get $cp) (i32.const 1))))
 
 (func $compilePop
-  (call $emitICall (i32.const 2) (i32.const 2 (; = POP_INDEX ;))))
-
+  (call $emitConst (i32.const 4))
+  (call $emitSub)
+  (call $emitTeeLocal (i32.const 0))
+  (call $emitGetLocal (i32.const 0))
+  (call $emitLoad))
+  
 (func $compileCall (param $tos i32) (param $FINDToken i32) (result i32)
   (local $body i32)
   (local.set $body (call $body (local.get $FINDToken)))
@@ -2265,10 +2279,19 @@
   (global.set $cp (i32.add (global.get $cp) (i32.const 1)))
   (global.set $cp (call $leb128 (global.get $cp) (local.get $n))))
 
+(func $emitTeeLocal (param $n i32)
+  (i32.store8 (global.get $cp) (i32.const 0x22))
+  (global.set $cp (i32.add (global.get $cp) (i32.const 1)))
+  (global.set $cp (call $leb128 (global.get $cp) (local.get $n))))
+
 (func $emitAdd
   (i32.store8 (global.get $cp) (i32.const 0x6a))
   (global.set $cp (i32.add (global.get $cp) (i32.const 1))))
 
+(func $emitSub
+  (i32.store8 (global.get $cp) (i32.const 0x6b))
+  (global.set $cp (i32.add (global.get $cp) (i32.const 1))))
+
 (func $emitEqualsZero
   (i32.store8 (global.get $cp) (i32.const 0x45))
   (global.set $cp (i32.add (global.get $cp) (i32.const 1))))
@@ -2289,6 +2312,21 @@
   (i32.store8 (global.get $cp) (i32.const 0x0f))
   (global.set $cp (i32.add (global.get $cp) (i32.const 1))))
 
+(func $emitStore
+  (i32.store8 (global.get $cp) (i32.const 0x36))
+  (global.set $cp (i32.add (global.get $cp) (i32.const 1)))
+  (i32.store8 (global.get $cp) (i32.const 0x02)) ;; Alignment
+  (global.set $cp (i32.add (global.get $cp) (i32.const 1)))
+  (i32.store8 (global.get $cp) (i32.const 0x00)) ;; Offset
+  (global.set $cp (i32.add (global.get $cp) (i32.const 1))))
+
+(func $emitLoad
+  (i32.store8 (global.get $cp) (i32.const 0x28))
+  (global.set $cp (i32.add (global.get $cp) (i32.const 1)))
+  (i32.store8 (global.get $cp) (i32.const 0x02)) ;; Alignment
+  (global.set $cp (i32.add (global.get $cp) (i32.const 1)))
+  (i32.store8 (global.get $cp) (i32.const 0x00)) ;; Offset
+  (global.set $cp (i32.add (global.get $cp) (i32.const 1))))
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;; Compilation state