unroll macro

_run_all_tests.jai

@@ -7,8 +7,8 @@
    #import,file "./hash/module.jai"(true);
 
    rmath :: #import,file "./math/module.jai"(.radians, true);
-   dmath :: #import,file "./math/module.jai"(.degrees, true);
-   tmath :: #import,file "./math/module.jai"(.turns, true);
+   // dmath :: #import,file "./math/module.jai"(.degrees, true);
+   // tmath :: #import,file "./math/module.jai"(.turns, true);
 }
 
 

macros.jai

@@ -71,25 +71,49 @@ operator | :: with;
 
 
 /*
-Creates a named block that can exit early (via 'break' or 'continue').
+   Creates a named block that can exit early (via 'break' or 'continue').
 
-This mostly replaces the case where you'd like to jump to
-the end of a scope based on some logic within. Without
-gotos, this is the next best thing.
+   This mostly replaces the case where you'd like to jump to
+   the end of a scope based on some logic within. Without
+   gotos, this is the next best thing.
 
-Usage:
-   // within a loop
-   for this_block() { // this is named 'block' by default
-      if !moving break;
-      // do movement here
-   }
-   for this_block("render_player") {
-      if invisible break render_player;
-      // do rendering here
-   }
+   Usage:
+      // within a loop
+      for this_block() { // this is named 'block' by default
+         if !moving break;
+         // do movement here
+      }
+      for this_block("render_player") {
+         if invisible break render_player;
+         // do rendering here
+      }
 */
 this_block :: ($name: string = Default_Name) -> Named_Block(name) #expand { return .{}; }
 
+/*
+   Drop-in loop unrolling macro.
+
+   Usage:
+      for unroll(5) {
+         // duplicates this body 5 times exactly
+      }
+
+      known_size: [3]float;
+      for unroll(known_size) {
+         // duplicates this body 3 times exactly
+      }
+
+      var_size: []float;
+      for unroll(var_size) {
+         // duplicates this body a set number of times,
+         // falling back to a regular for loop to handle
+         // the remaining iterations.
+      }
+*/
+unroll :: ($count: int) -> Unrolled_Loop(count) { return .{}; }
+unroll :: (arr: [$N]$T) -> Unrolled_Loop(N, T)  { return .{ array = arr }; }
+unroll :: (arr: []$T)   -> Unrolled_Loop(-1, T) { return .{ array = arr }; }
+
 // Call #c_call procedures inline with the current context: 'c_call(some_c_call_proc(10, 20))'
 c_call :: (call: Code) #expand {
    push_context context { #insert,scope(call) call; }
@@ -118,6 +142,104 @@ for_expansion :: (v: *Named_Block, code: Code, _: For_Flags) #expand {
    ifx v.NAME.count != 0 v.NAME else Default_Name);
 }
 
+Unrolled_Loop :: struct(N: int, T: Type = void) {
+   // Only store arrays when we absolutely have to.
+   #if T != void {
+      // @todo(judah): because this will only be created via 'unroll',
+      // should these be pointers to the underlying arrays so we don't
+      // pay for a copy?
+      #if N == -1 {
+         array: []T = ---;
+      }
+      else {
+         array: [N]T = ---;
+      }
+   }
+}
+
+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];
+         `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 {
+      `it_index := 0;
+
+      #insert -> string {
+         b: basic.String_Builder;
+         basic.print_to_builder(*b, "// inserted unrolled loop (N = %) at %:%\n", loop.N, loc.fully_pathed_filename, loc.line_number);
+
+         if loop.T == void {
+            basic.append(*b, "`it: int = ---;\n");
+         }
+         else {
+            basic.append(*b, "`it: loop.T = ---;\n");
+         }
+
+         for 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);
+            }
+
+            basic.print_to_builder(*b, "\tit_index = %;\n", it);
+            basic.append(*b, "\t#insert,scope(body) body;\n");
+            basic.append(*b, "}\n");
+         }
+
+         return basic.builder_to_string(*b);
+      }
+   }
+}
+
+
 pp       :: #import "Program_Print";
 compiler :: #import "Compiler";
 

math/vec.jai

@@ -97,24 +97,28 @@ for_expansion :: (v: *Vec, body: Code, flags: For_Flags) #expand {
 
 operator + :: inline (l: Vec, r: Vec(l.N, l.T)) -> Vec(l.N, l.T) #no_abc {
    res: Vec(l.N, l.T) = ---;
+   // @todo(judah): unroll for N <= 4
    for l res[it_index] = it + r[it_index];
    return res;
 }
 
 operator - :: inline (l: Vec, r: Vec(l.N, l.T)) -> Vec(l.N, l.T) #no_abc {
    res: Vec(l.N, l.T) = ---;
+   // @todo(judah): unroll for N <= 4
    for l res[it_index] = it - r[it_index];
    return res;
 }
 
 operator * :: inline (l: Vec, r: Vec(l.N, l.T)) -> Vec(l.N, l.T) #no_abc {
    res: Vec(l.N, l.T) = ---;
+   // @todo(judah): unroll for N <= 4
    for l res[it_index] = it * r[it_index];
    return res;
 }
 
 operator / :: inline (l: Vec, r: Vec(l.N, l.T)) -> Vec(l.N, l.T) #no_abc {
    res: Vec(l.N, l.T) = ---;
+   // @todo(judah): unroll for N <= 4
    for l res[it_index] = it / r[it_index];
    return res;
 }
@@ -165,3 +169,18 @@ v4i :: (x: $T = 0, y: T = 0, z: T = 0, w: T = 0) -> Vec(4, T)
 quat :: (x: float = 0, y: float = 0, z: float = 0, w: float = 0) -> Quat #expand {
    return .{ x = x, y = y, z = z, w = w };
 }
+
+
+#if RUN_TESTS #run,stallable {
+   test.run("vec2:ops", t => {
+      a := v2f(10.0, 1);
+      b := v2f(20.0, 2);
+      c := a + b;
+
+      test.expect(t, c.x == 30 && c.y == 3);
+   });
+}
+
+#scope_file;
+
+jx :: #import,file "../module.jai";