diff --git a/vlib/v/ast/comptime_valid_idents.v b/vlib/v/ast/comptime_valid_idents.v
index 3d9e00d126..2a242adb53 100644
--- a/vlib/v/ast/comptime_valid_idents.v
+++ b/vlib/v/ast/comptime_valid_idents.v
@@ -1,5 +1,7 @@
 module ast
 
+import v.pref
+
 pub const valid_comptime_if_os = ['windows', 'ios', 'macos', 'mach', 'darwin', 'hpux', 'gnu', 'qnx',
 	'linux', 'freebsd', 'openbsd', 'netbsd', 'bsd', 'dragonfly', 'android', 'termux', 'solaris',
 	'haiku', 'serenity', 'vinix', 'plan9', 'wasm32_emscripten']
@@ -22,3 +24,225 @@ fn all_valid_comptime_idents() []string {
 	res << valid_comptime_if_other
 	return res
 }
+
+pub fn eval_comptime_not_user_defined_ident(ident string, the_pref &pref.Preferences) !bool {
+	mut is_true := false
+	if ident in valid_comptime_if_os {
+		if ident_enum_val := pref.os_from_string(ident) {
+			if ident_enum_val == the_pref.os {
+				is_true = true
+			}
+		}
+	} else if ident in valid_comptime_if_compilers {
+		is_true = pref.cc_from_string(ident) == the_pref.ccompiler_type
+	} else if ident in valid_comptime_if_platforms {
+		match ident {
+			'amd64' {
+				is_true = the_pref.arch == .amd64
+			}
+			'i386' {
+				is_true = the_pref.arch == .i386
+			}
+			'aarch64' {
+				is_true = the_pref.arch == .arm64
+			}
+			'arm64' {
+				is_true = the_pref.arch == .arm64
+			}
+			'arm32' {
+				is_true = the_pref.arch == .arm32
+			}
+			'rv64' {
+				is_true = the_pref.arch == .rv64
+			}
+			'rv32' {
+				is_true = the_pref.arch == .rv32
+			}
+			's390x' {
+				is_true = the_pref.arch == .s390x
+			}
+			'ppc64le' {
+				is_true = the_pref.arch == .ppc64le
+			}
+			'loongarch64' {
+				is_true = the_pref.arch == .loongarch64
+			}
+			else {
+				return error('invalid \$if condition: unknown platforms `${ident}`')
+			}
+		}
+	} else if ident in valid_comptime_if_cpu_features {
+		match ident {
+			'x64' {
+				is_true = the_pref.m64
+			}
+			'x32' {
+				is_true = !the_pref.m64
+			}
+			'little_endian' {
+				is_true = $if little_endian { true } $else { false }
+			}
+			'big_endian' {
+				is_true = $if big_endian { true } $else { false }
+			}
+			else {
+				return error('invalid \$if condition: unknown cpu_features `${ident}`')
+			}
+		}
+	} else if ident in valid_comptime_if_other {
+		match ident {
+			'apk' {
+				is_true = the_pref.is_apk
+			}
+			'js' {
+				is_true = the_pref.backend.is_js()
+			}
+			'debug' {
+				is_true = the_pref.is_debug
+			}
+			'prod' {
+				is_true = the_pref.is_prod
+			}
+			'test' {
+				is_true = the_pref.is_test
+			}
+			'glibc' {
+				is_true = the_pref.is_glibc
+			}
+			'prealloc' {
+				is_true = the_pref.prealloc
+			}
+			'no_bounds_checking' {
+				is_true = the_pref.no_bounds_checking
+			}
+			'freestanding' {
+				is_true = the_pref.is_bare && !the_pref.output_cross_c
+			}
+			'threads' {
+				return error('threads should handle outside of `check_valid_ident()`')
+			}
+			'js_node' {
+				is_true = the_pref.backend == .js_node
+			}
+			'js_browser' {
+				is_true = the_pref.backend == .js_browser
+			}
+			'js_freestanding' {
+				is_true = the_pref.backend == .js_freestanding
+			}
+			'interpreter' {
+				is_true = the_pref.backend == .interpret
+			}
+			'es5' {
+				is_true = the_pref.output_es5
+			}
+			'profile' {
+				is_true = the_pref.is_prof
+			}
+			'wasm32' {
+				is_true = the_pref.arch == .wasm32
+			}
+			'wasm32_wasi' {
+				is_true = the_pref.os == .wasm32_wasi
+			}
+			'fast_math' {
+				is_true = the_pref.fast_math
+			}
+			'native' {
+				is_true = the_pref.backend == .native
+			}
+			'autofree' {
+				is_true = the_pref.autofree
+			}
+			else {
+				return error('invalid \$if condition: unknown other indent `${ident}`')
+			}
+		}
+	} else if ident in the_pref.compile_defines {
+		is_true = true
+	} else {
+		return error('invalid \$if condition: unknown indent `${ident}`')
+	}
+	return is_true
+}
+
+pub const system_ident_map = {
+	// OS
+	'windows':            '_WIN32'
+	'ios':                '__TARGET_IOS__'
+	'macos':              '__APPLE__'
+	'mach':               '__MACH__'
+	'darwin':             '__DARWIN__'
+	'hpux':               '__HPUX__'
+	'gnu':                '__GNU__'
+	'qnx':                '__QNX__'
+	'linux':              '__linux__'
+	'serenity':           '__serenity__'
+	'plan9':              '__plan9__'
+	'vinix':              '__vinix__'
+	'freebsd':            '__FreeBSD__'
+	'openbsd':            '__OpenBSD__'
+	'netbsd':             '__NetBSD__'
+	'bsd':                '__BSD__'
+	'dragonfly':          '__DragonFly__'
+	'android':            '__ANDROID__'
+	'termux':             '__TERMUX__'
+	'solaris':            '__sun'
+	'haiku':              '__HAIKU__'
+	// Backend
+	'js':                 '_VJS'
+	'wasm32_emscripten':  '__EMSCRIPTEN__'
+	'native':             '_VNATIVE'
+	// Compiler
+	'gcc':                '__V_GCC__'
+	'tinyc':              '__TINYC__'
+	'clang':              '__clang__'
+	'mingw':              '__MINGW32__'
+	'msvc':               '_MSC_VER'
+	'cplusplus':          '__cplusplus'
+	// Others
+	'threads':            '__VTHREADS__'
+	'gcboehm':            '_VGCBOEHM'
+	'debug':              '_VDEBUG'
+	'prod':               '_VPROD'
+	'profile':            '_VPROFILE'
+	'test':               '_VTEST'
+	'glibc':              '__GLIBC__'
+	'prealloc':           '_VPREALLOC'
+	'no_bounds_checking': 'CUSTOM_DEFINE_no_bounds_checking'
+	'freestanding':       '_VFREESTANDING'
+	'autofree':           '_VAUTOFREE'
+	// CPU
+	'amd64':              '__V_amd64'
+	'aarch64':            '__V_arm64'
+	'arm64':              '__V_arm64' // aarch64 alias
+	'arm32':              '__V_arm32'
+	'i386':               '__V_x86'
+	'rv64':               '__V_rv64'
+	'riscv64':            '__V_rv64' // rv64 alias
+	'rv32':               '__V_rv32'
+	'riscv32':            '__V_rv32' // rv32 alias
+	's390x':              '__V_s390x'
+	'ppc64le':            '__V_ppc64le'
+	'loongarch64':        '__V_loongarch64'
+	'x64':                'TARGET_IS_64BIT'
+	'x32':                'TARGET_IS_32BIT'
+	'little_endian':      'TARGET_ORDER_IS_LITTLE'
+	'big_endian':         'TARGET_ORDER_IS_BIG'
+}
+
+pub fn comptime_if_to_ifdef(name string, the_pref &pref.Preferences) !string {
+	if name == 'fast_math' {
+		return if the_pref.ccompiler_type == .msvc {
+			// turned on by: `-cflags /fp:fast`
+			'_M_FP_FAST'
+		} else {
+			// turned on by: `-cflags -ffast-math`
+			'__FAST_MATH__'
+		}
+	}
+	if ifdef := system_ident_map[name] {
+		return ifdef
+	}
+	return error('bad os ifdef name `${name}`')
+}
diff --git a/vlib/v/checker/comptime.v b/vlib/v/checker/comptime.v
index 1befa70d85..9567c77cf5 100644
--- a/vlib/v/checker/comptime.v
+++ b/vlib/v/checker/comptime.v
@@ -784,191 +784,6 @@ fn (mut c Checker) evaluate_once_comptime_if_attribute(mut node ast.Attr) bool {
 	return node.ct_skip
 }
 
-fn (mut c Checker) comptime_if_to_ifdef(name string) !string {
-	match name {
-		// platforms/os-es:
-		'windows' {
-			return '_WIN32'
-		}
-		'ios' {
-			return '__TARGET_IOS__'
-		}
-		'macos' {
-			return '__APPLE__'
-		}
-		'mach' {
-			return '__MACH__'
-		}
-		'darwin' {
-			return '__DARWIN__'
-		}
-		'hpux' {
-			return '__HPUX__'
-		}
-		'gnu' {
-			return '__GNU__'
-		}
-		'qnx' {
-			return '__QNX__'
-		}
-		'linux' {
-			return '__linux__'
-		}
-		'serenity' {
-			return '__serenity__'
-		}
-		'plan9' {
-			return '__plan9__'
-		}
-		'vinix' {
-			return '__vinix__'
-		}
-		'freebsd' {
-			return '__FreeBSD__'
-		}
-		'openbsd' {
-			return '__OpenBSD__'
-		}
-		'netbsd' {
-			return '__NetBSD__'
-		}
-		'bsd' {
-			return '__BSD__'
-		}
-		'dragonfly' {
-			return '__DragonFly__'
-		}
-		'android' {
-			return '__ANDROID__'
-		}
-		'termux' {
-			// Note: termux is running on Android natively so __ANDROID__ will also be defined
-			return '__TERMUX__'
-		}
-		'solaris' {
-			return '__sun'
-		}
-		'haiku' {
-			return '__HAIKU__'
-		}
-		//
-		'js' {
-			return '_VJS'
-		}
-		'wasm32_emscripten' {
-			return '__EMSCRIPTEN__'
-		}
-		'native' {
-			return '_VNATIVE' // when using the native backend, cgen is inactive
-		}
-		// compilers:
-		'gcc' {
-			return '__V_GCC__'
-		}
-		'tinyc' {
-			return '__TINYC__'
-		}
-		'clang' {
-			return '__clang__'
-		}
-		'mingw' {
-			return '__MINGW32__'
-		}
-		'msvc' {
-			return '_MSC_VER'
-		}
-		'cplusplus' {
-			return '__cplusplus'
-		}
-		// other:
-		'threads' {
-			return '__VTHREADS__'
-		}
-		'gcboehm' {
-			return '_VGCBOEHM'
-		}
-		'debug' {
-			return '_VDEBUG'
-		}
-		'prod' {
-			return '_VPROD'
-		}
-		'profile' {
-			return '_VPROFILE'
-		}
-		'test' {
-			return '_VTEST'
-		}
-		'glibc' {
-			return '__GLIBC__'
-		}
-		'prealloc' {
-			return '_VPREALLOC'
-		}
-		'no_bounds_checking' {
-			return 'CUSTOM_DEFINE_no_bounds_checking'
-		}
-		'freestanding' {
-			return '_VFREESTANDING'
-		}
-		'autofree' {
-			return '_VAUTOFREE'
-		}
-		// architectures:
-		'amd64' {
-			return '__V_amd64'
-		}
-		'aarch64', 'arm64' {
-			return '__V_arm64'
-		}
-		'arm32' {
-			return '__V_arm32'
-		}
-		'i386' {
-			return '__V_x86'
-		}
-		'rv64', 'riscv64' {
-			return '__V_rv64'
-		}
-		'rv32', 'riscv32' {
-			return '__V_rv32'
-		}
-		's390x' {
-			return '__V_s390x'
-		}
-		'ppc64le' {
-			return '__V_ppc64le'
-		}
-		'loongarch64' {
-			return '__V_loongarch64'
-		}
-		// bitness:
-		'x64' {
-			return 'TARGET_IS_64BIT'
-		}
-		'x32' {
-			return 'TARGET_IS_32BIT'
-		}
-		// endianness:
-		'little_endian' {
-			return 'TARGET_ORDER_IS_LITTLE'
-		}
-		'big_endian' {
-			return 'TARGET_ORDER_IS_BIG'
-		}
-		'fast_math' {
-			if c.pref.ccompiler_type == .msvc {
-				// turned on by: `-cflags /fp:fast`
-				return '_M_FP_FAST'
-			}
-			// turned on by: `-cflags -ffast-math`
-			return '__FAST_MATH__'
-		}
-		else {}
-	}
-	return error('bad os ifdef name "${name}"')
-}
-
 // check if `ident` is a function generic, such as `T`
 fn (mut c Checker) is_generic_ident(ident string) bool {
 	if !isnil(c.table.cur_fn) && ident in c.table.cur_fn.generic_names
@@ -1141,10 +956,6 @@ fn (mut c Checker) comptime_if_cond(mut cond ast.Expr, mut sb strings.Builder) (
 			should_record_ident = true
 			is_user_ident = true
 			ident_name = cname
-			// ifdef := c.comptime_if_to_ifdef(cname, true) or {
-			//	c.error(err.msg(), cond.pos)
-			//	return false, false
-			//}
 			sb.write_string('defined(CUSTOM_DEFINE_${cname})')
 			is_true = cname in c.pref.compile_defines
 			return is_true, false
@@ -1483,143 +1294,12 @@ fn (mut c Checker) comptime_if_cond(mut cond ast.Expr, mut sb strings.Builder) (
 			should_record_ident = true
 			is_user_ident = false
 			ident_name = cname
-			if cname in ast.valid_comptime_if_os {
-				if cname_enum_val := pref.os_from_string(cname) {
-					if cname_enum_val == c.pref.os {
-						is_true = true
-					}
-				}
-			} else if cname in ast.valid_comptime_if_compilers {
-				is_true = pref.cc_from_string(cname) == c.pref.ccompiler_type
-			} else if cname in ast.valid_comptime_if_platforms {
-				if cname == 'aarch64' {
-					c.note('use `arm64` instead of `aarch64`', cond.pos)
-				}
-				match cname {
-					'amd64' {
-						is_true = c.pref.arch == .amd64
-					}
-					'i386' {
-						is_true = c.pref.arch == .i386
-					}
-					'aarch64' {
-						is_true = c.pref.arch == .arm64
-					}
-					'arm64' {
-						is_true = c.pref.arch == .arm64
-					}
-					'arm32' {
-						is_true = c.pref.arch == .arm32
-					}
-					'rv64' {
-						is_true = c.pref.arch == .rv64
-					}
-					'rv32' {
-						is_true = c.pref.arch == .rv32
-					}
-					's390x' {
-						is_true = c.pref.arch == .s390x
-					}
-					'ppc64le' {
-						is_true = c.pref.arch == .ppc64le
-					}
-					'loongarch64' {
-						is_true = c.pref.arch == .loongarch64
-					}
-					else {
-						c.error('invalid \$if condition: unknown platforms `${cname}`',
-							cond.pos)
-						return false, false
-					}
-				}
-			} else if cname in ast.valid_comptime_if_cpu_features {
-				match cname {
-					'x64' {
-						is_true = c.pref.m64
-					}
-					'x32' {
-						is_true = !c.pref.m64
-					}
-					'little_endian' {
-						is_true = $if little_endian { true } $else { false }
-					}
-					'big_endian' {
-						is_true = $if big_endian { true } $else { false }
-					}
-					else {
-						c.error('invalid \$if condition: unknown cpu_features `${cname}`',
-							cond.pos)
-						return false, false
-					}
-				}
-			} else if cname in ast.valid_comptime_if_other {
-				match cname {
-					'apk' {
-						is_true = c.pref.is_apk
-					}
-					'js' {
-						is_true = c.pref.backend.is_js()
-					}
-					'debug' {
-						is_true = c.pref.is_debug
-					}
-					'prod' {
-						is_true = c.pref.is_prod
-					}
-					'test' {
-						is_true = c.pref.is_test
-					}
-					'glibc' {
-						is_true = c.pref.is_glibc
-					}
-					'prealloc' {
-						is_true = c.pref.prealloc
-					}
-					'no_bounds_checking' {
-						is_true = c.pref.no_bounds_checking
-					}
-					'freestanding' {
-						is_true = c.pref.is_bare && !c.pref.output_cross_c
-					}
-					'threads' {
-						is_true = c.table.gostmts > 0
-					}
-					'js_node' {
-						is_true = c.pref.backend == .js_node
-					}
-					'js_browser' {
-						is_true = c.pref.backend == .js_browser
-					}
-					'js_freestanding' {
-						is_true = c.pref.backend == .js_freestanding
-					}
-					'interpreter' {
-						is_true = c.pref.backend == .interpret
-					}
-					'es5' {
-						is_true = c.pref.output_es5
-					}
-					'profile' {
-						is_true = c.pref.is_prof
-					}
-					'wasm32' {
-						is_true = c.pref.arch == .wasm32
-					}
-					'wasm32_wasi' {
-						is_true = c.pref.os == .wasm32_wasi
-					}
-					'fast_math' {
-						is_true = c.pref.fast_math
-					}
-					'native' {
-						is_true = c.pref.backend == .native
-					}
-					'autofree' {
-						is_true = c.pref.autofree
-					}
-					else {
-						c.error('invalid \$if condition: unknown other indent `${cname}`',
-							cond.pos)
+			if cname in ast.valid_comptime_not_user_defined {
+				if cname == 'threads' {
+					is_true = c.table.gostmts > 0
+				} else {
+					is_true = ast.eval_comptime_not_user_defined_ident(cname, c.pref) or {
+						c.error(err.msg(), cond.pos)
 						return false, false
 					}
 				}
@@ -1655,7 +1335,7 @@ fn (mut c Checker) comptime_if_cond(mut cond ast.Expr, mut sb strings.Builder) (
 				c.error('invalid \$if condition: unknown indent `${cname}`', cond.pos)
 				return false, false
 			}
-			if ifdef := c.comptime_if_to_ifdef(cname) {
+			if ifdef := ast.comptime_if_to_ifdef(cname, c.pref) {
 				sb.write_string('defined(${ifdef})')
 			} else {
 				sb.write_string('${is_true}')
diff --git a/vlib/v/parser/if_match.v b/vlib/v/parser/if_match.v
index 3578481a06..260be280f4 100644
--- a/vlib/v/parser/if_match.v
+++ b/vlib/v/parser/if_match.v
@@ -5,7 +5,6 @@ module parser
 
 import v.ast
 import v.token
-import v.pref
 import v.pkgconfig
 
 fn (mut p Parser) if_expr(is_comptime bool, is_expr bool) ast.IfExpr {
@@ -724,140 +723,12 @@ fn (mut p Parser) comptime_if_cond(mut cond ast.Expr) bool {
 		}
 		ast.Ident {
 			cname := cond.name
-			if cname in ast.valid_comptime_if_os {
-				if cname_enum_val := pref.os_from_string(cname) {
-					if cname_enum_val == p.pref.os {
-						is_true = true
-					}
-				}
-			} else if cname in ast.valid_comptime_if_compilers {
-				is_true = pref.cc_from_string(cname) == p.pref.ccompiler_type
-			} else if cname in ast.valid_comptime_if_platforms {
-				if cname == 'aarch64' {
-					p.note('use `arm64` instead of `aarch64`')
-				}
-				match cname {
-					'amd64' {
-						is_true = p.pref.arch == .amd64
-					}
-					'i386' {
-						is_true = p.pref.arch == .i386
-					}
-					'aarch64' {
-						is_true = p.pref.arch == .arm64
-					}
-					'arm64' {
-						is_true = p.pref.arch == .arm64
-					}
-					'arm32' {
-						is_true = p.pref.arch == .arm32
-					}
-					'rv64' {
-						is_true = p.pref.arch == .rv64
-					}
-					'rv32' {
-						is_true = p.pref.arch == .rv32
-					}
-					's390x' {
-						is_true = p.pref.arch == .s390x
-					}
-					'ppc64le' {
-						is_true = p.pref.arch == .ppc64le
-					}
-					'loongarch64' {
-						is_true = p.pref.arch == .loongarch64
-					}
-					else {
-						p.error('invalid \$if condition: unknown platforms `${cname}`')
-						return false
-					}
-				}
-			} else if cname in ast.valid_comptime_if_cpu_features {
-				match cname {
-					'x64' {
-						is_true = p.pref.m64
-					}
-					'x32' {
-						is_true = !p.pref.m64
-					}
-					'little_endian' {
-						is_true = $if little_endian { true } $else { false }
-					}
-					'big_endian' {
-						is_true = $if big_endian { true } $else { false }
-					}
-					else {
-						p.error('invalid \$if condition: unknown cpu_features `${cname}`')
-						return false
-					}
-				}
-			} else if cname in ast.valid_comptime_if_other {
-				match cname {
-					'apk' {
-						is_true = p.pref.is_apk
-					}
-					'js' {
-						is_true = p.pref.backend.is_js()
-					}
-					'debug' {
-						is_true = p.pref.is_debug
-					}
-					'prod' {
-						is_true = p.pref.is_prod
-					}
-					'test' {
-						is_true = p.pref.is_test
-					}
-					'glibc' {
-						is_true = p.pref.is_glibc
-					}
-					'prealloc' {
-						is_true = p.pref.prealloc
-					}
-					'no_bounds_checking' {
-						is_true = p.pref.no_bounds_checking
-					}
-					'freestanding' {
-						is_true = p.pref.is_bare && !p.pref.output_cross_c
-					}
-					'threads' {
-						is_true = p.table.gostmts > 0
-					}
-					'js_node' {
-						is_true = p.pref.backend == .js_node
-					}
-					'js_browser' {
-						is_true = p.pref.backend == .js_browser
-					}
-					'js_freestanding' {
-						is_true = p.pref.backend == .js_freestanding
-					}
-					'interpreter' {
-						is_true = p.pref.backend == .interpret
-					}
-					'es5' {
-						is_true = p.pref.output_es5
-					}
-					'profile' {
-						is_true = p.pref.is_prof
-					}
-					'wasm32' {
-						is_true = p.pref.arch == .wasm32
-					}
-					'wasm32_wasi' {
-						is_true = p.pref.os == .wasm32_wasi
-					}
-					'fast_math' {
-						is_true = p.pref.fast_math
-					}
-					'native' {
-						is_true = p.pref.backend == .native
-					}
-					'autofree' {
-						is_true = p.pref.autofree
-					}
-					else {
-						p.error('invalid \$if condition: unknown other indent `${cname}`')
+			if cname in ast.valid_comptime_not_user_defined {
+				if cname == 'threads' {
+					is_true = p.table.gostmts > 0
+				} else {
+					is_true = ast.eval_comptime_not_user_defined_ident(cname, p.pref) or {
+						p.error(err.msg())
 						return false
 					}
 				}