From 5f7b1107d177ea7c0e71211c53ec7bdf811e72d3 Mon Sep 17 00:00:00 2001
From: Judah Caruso <judah@tuta.io>
Date: Tue, 27 May 2025 16:09:05 -0600
Subject: [PATCH] improve meta.unroll

---
 meta/macros.jai | 63 ++++++++++++++-----------------------------------
 1 file changed, 18 insertions(+), 45 deletions(-)

diff --git a/meta/macros.jai b/meta/macros.jai
index 8e99090..c38fb15 100644
--- a/meta/macros.jai
+++ b/meta/macros.jai
@@ -140,51 +140,19 @@ for_expansion :: (v: *Named_Block, code: Code, _: For_Flags) #expand {
 }
 
 for_expansion :: (loop: *Unrolled_Loop, body: Code, flags: For_Flags, loc := #caller_location) #expand {
-   #assert flags & .REVERSE == 0 "reverse iteration not supported with loop unrolling (for now)";
-   #assert flags & .POINTER == 0 "pointer iteration not supported with loop unrolling (for now)";
-
    // runtime unroll
    #if loop.N == -1 {
-      for i: 0..loop.array.count - 1 {
-         `it := #no_abc loop.array[i];
+      for #v2 <=(flags & .REVERSE == .REVERSE) i: 0..loop.array.count - 1 {
+         #if flags & .POINTER {
+            `it := *(#no_abc loop.array[i]);
+         }
+         else {
+            `it := #no_abc loop.array[i];
+         }
+
          `it_index := i;
          #insert,scope(body) body;
       }
-
-      // @todo(judah): below doesn't properly handle counts not divisible by 4,
-      // so we end up going over the bounds of the array.
-
-      // UNROLL_AMOUNT :: 4; // @todo(judah): make this configurable?
-      // unrolled_loops  := loop.array.count / UNROLL_AMOUNT;
-      // remainder_loops := loop.array.count % UNROLL_AMOUNT;
-      // `it: loop.T;
-      // for i: 0..unrolled_loops #no_abc {
-      //    basic.print("I: %\n", i);
-      //    index := i * UNROLL_AMOUNT;
-
-      //    it_index = index + 0;
-      //    it       = loop.array[it_index];
-      //    #insert,scope(body) body;
-
-      //    it_index = index + 1;
-      //    it       = loop.array[it_index];
-      //    #insert,scope(body) body;
-
-      //    it_index = index + 2;
-      //    it       = loop.array[it_index];
-      //    #insert,scope(body) body;
-
-      //    it_index = index + 3;
-      //    it       = loop.array[it_index];
-      //    #insert,scope(body) body;
-      // }
-
-      // after_big_loop := it_index;
-      // for i: 0..remainder_loops  #no_abc {
-      //    it_index = after_big_loop + i;
-      //    it       = loop.array[it_index];
-      //    #insert,scope(body) body;
-      // }
    }
    // compile-time unroll
    else {
@@ -201,14 +169,19 @@ for_expansion :: (loop: *Unrolled_Loop, body: Code, flags: For_Flags, loc := #ca
             basic.append(*b, "`it: loop.T = ---;\n");
          }
 
-         for 0..loop.N - 1 {
+         for #v2 <=(flags & .REVERSE == .REVERSE) 0..loop.N - 1 {
             basic.append(*b, "{\n");
 
             if loop.T == void {
                basic.print_to_builder(*b, "\tit = %;\n", it);
             }
             else {
-               basic.print_to_builder(*b, "\tit = #no_abc loop.array[%];\n", it);
+               #if flags & .POINTER {
+                  basic.print_to_builder(*b, "\tit = *(#no_abc loop.array[%]);\n", it);
+               }
+               else {
+                  basic.print_to_builder(*b, "\tit = #no_abc loop.array[%];\n", it);
+               }
             }
 
             basic.print_to_builder(*b, "\tit_index = %;\n", it);
@@ -221,9 +194,6 @@ for_expansion :: (loop: *Unrolled_Loop, body: Code, flags: For_Flags, loc := #ca
    }
 }
 
-
-#scope_file;
-
 Default_Name :: "block";
 Named_Block  :: struct(NAME: string) {}
 
@@ -242,6 +212,9 @@ Unrolled_Loop :: struct(N: int, T: Type = void) {
    }
 }
 
+
+#scope_file;
+
 basic    :: #import "Basic"; // @future
 pp       :: #import "Program_Print"; // @future
 compiler :: #import "Compiler"; // @future