From b77f254ab14cb0fd91a8e1a9bd5ef7211db86b85 Mon Sep 17 00:00:00 2001
From: Dmitry Atamanov <dataman@tutanota.com>
Date: Thu, 24 Aug 2023 17:19:09 +0500
Subject: [PATCH] Tune `@expect`, `@likely`, `@unlikely` and `@prefetch`
 macros.

---
 lib/std/core/builtin.c3               | 45 +++++++++++++++++----------
 lib/std/core/env.c3                   |  3 ++
 test/test_suite/builtins/prefetch.c3t |  2 +-
 test/unit/stdlib/core/builtintests.c3 |  2 +-
 4 files changed, 33 insertions(+), 19 deletions(-)

diff --git a/lib/std/core/builtin.c3 b/lib/std/core/builtin.c3
index 774f6b41a..99273abec 100644
--- a/lib/std/core/builtin.c3
+++ b/lib/std/core/builtin.c3
@@ -193,11 +193,14 @@ macro enum_by_name($Type, String enum_name) @builtin
  **/
 macro bool @likely(bool #value, $probability = 1.0) @builtin
 {
-	$if $probability == 1.0:
-		return $$expect(#value, true);
-	$else
-		return $$expect_with_probability(#value, true, $probability);
-	$endif
+    $switch
+    $case env::BUILTIN_EXPECT_IS_DISABLED:
+	return #value;
+    $case $probability == 1.0:
+	return $$expect(#value, true);
+    $default:
+	return $$expect_with_probability(#value, true, $probability);
+    $endswitch
 }
 
 /**
@@ -209,11 +212,14 @@ macro bool @likely(bool #value, $probability = 1.0) @builtin
  **/
 macro bool @unlikely(bool #value, $probability = 1.0) @builtin
 {
-	$if $probability == 1.0:
-		return $$expect(#value, false);
-	$else
-		return $$expect_with_probability(#value, false, $probability);
-	$endif
+    $switch
+    $case env::BUILTIN_EXPECT_IS_DISABLED:
+	return #value;
+    $case $probability == 1.0:
+	return $$expect(#value, false);
+    $default:
+	return $$expect_with_probability(#value, false, $probability);
+    $endswitch
 }
 
 /**
@@ -223,11 +229,14 @@ macro bool @unlikely(bool #value, $probability = 1.0) @builtin
  **/
 macro @expect(#value, expected, $probability = 1.0) @builtin
 {
-	$if $probability == 1.0:
-		return $$expect(#value, ($typeof(#value))expected);
-	$else
-		return $$expect_with_probability(#value, expected, $probability);
-	$endif
+    $switch
+    $case env::BUILTIN_EXPECT_IS_DISABLED:
+	return #value == expected;
+    $case $probability == 1.0:
+	return $$expect(#value, ($typeof(#value))expected);
+    $default:
+	return $$expect_with_probability(#value, expected, $probability);
+    $endswitch
 }
 
 /**
@@ -249,9 +258,11 @@ enum PrefetchLocality
  * @param $locality `Locality ranging from none to extremely local`
  * @param $write `Prefetch for write, otherwise prefetch for read.`
  **/
-macro prefetch(void* ptr, PrefetchLocality $locality = VERY_NEAR, bool $write = false) @builtin
+macro @prefetch(void* ptr, PrefetchLocality $locality = VERY_NEAR, bool $write = false) @builtin
 {
-	$$prefetch(ptr, $write ? 1 : 0, $locality.ordinal);
+	$if !env::BUILTIN_PREFETCH_IS_DISABLED:
+		$$prefetch(ptr, $write ? 1 : 0, $locality.ordinal);
+	$endif
 }
 
 macro swizzle(v, ...) @builtin
diff --git a/lib/std/core/env.c3 b/lib/std/core/env.c3
index 59623cd2d..154a79159 100644
--- a/lib/std/core/env.c3
+++ b/lib/std/core/env.c3
@@ -179,3 +179,6 @@ macro bool os_is_posix()
 		return false;
 	$endswitch
 }
+
+const BUILTIN_EXPECT_IS_DISABLED = $feature(DISABLE_BUILTIN_EXPECT);
+const BUILTIN_PREFETCH_IS_DISABLED = $feature(DISABLE_BUILTIN_PREFETCH);
diff --git a/test/test_suite/builtins/prefetch.c3t b/test/test_suite/builtins/prefetch.c3t
index b2efdfc42..4bb042e60 100644
--- a/test/test_suite/builtins/prefetch.c3t
+++ b/test/test_suite/builtins/prefetch.c3t
@@ -7,7 +7,7 @@ fn void main()
 	int a;
 	$$prefetch(&a, 1, 3);
 	$$prefetch(&a, 0, 1);
-	prefetch(&a);
+	@prefetch(&a);
 }
 
 /* #expect: test.ll
diff --git a/test/unit/stdlib/core/builtintests.c3 b/test/unit/stdlib/core/builtintests.c3
index 7b0f886c8..a1abe2945 100644
--- a/test/unit/stdlib/core/builtintests.c3
+++ b/test/unit/stdlib/core/builtintests.c3
@@ -57,7 +57,7 @@ int abc;
 
 fn void test_prefetch()
 {
-	prefetch(&abc);
+	@prefetch(&abc);
 }
 
 fn void test_hash()