diff --git a/docs/elf-tls.md b/docs/elf-tls.md
index d408b3f..6b03841 100644
--- a/docs/elf-tls.md
+++ b/docs/elf-tls.md
@@ -1,9 +1,4 @@
-# Android ELF TLS (Draft)
-
-Internal links:
- * [go/android-elf-tls](http://go/android-elf-tls)
- * [One-pager](https://docs.google.com/document/d/1leyPTnwSs24P2LGiqnU6HetnN5YnDlZkihigi6qdf_M)
- * Tracking bugs: http://b/110100012, http://b/78026329
+# Android ELF TLS
 
 [TOC]
 
diff --git a/docs/status.md b/docs/status.md
index bc8ab6a..e0364a8 100644
--- a/docs/status.md
+++ b/docs/status.md
@@ -125,6 +125,7 @@
   * `getloadavg` (BSD/GNU extension in <stdlib.h>)
 
 New libc behavior in Q (API level 29):
+  * Support for [ELF TLS](elf-tls.md).
   * Whole printf family now supports the GNU `%m` extension, rather than a
     special-case hack in `syslog`.
   * `popen` now always uses `O_CLOEXEC`, not just with the `e` extension.
diff --git a/libc/bionic/locale.cpp b/libc/bionic/locale.cpp
index 2f4d206..a1d6909 100644
--- a/libc/bionic/locale.cpp
+++ b/libc/bionic/locale.cpp
@@ -35,17 +35,8 @@
 #include <time.h>
 #include <wchar.h>
 
-#include "platform/bionic/macros.h"
-
-#if defined(__BIONIC_BUILD_FOR_ANDROID_SUPPORT)
-#define USE_TLS_SLOT 0
-#else
-#define USE_TLS_SLOT 1
-#endif
-
-#if USE_TLS_SLOT
 #include "bionic/pthread_internal.h"
-#endif
+#include "platform/bionic/macros.h"
 
 // We only support two locales, the "C" locale (also known as "POSIX"),
 // and the "C.UTF-8" locale (also known as "en_US.UTF-8").
@@ -82,10 +73,6 @@
   return get_locale_mb_cur_max(uselocale(nullptr));
 }
 
-#if !USE_TLS_SLOT
-static thread_local locale_t g_current_locale;
-#endif
-
 static pthread_once_t g_locale_once = PTHREAD_ONCE_INIT;
 static lconv g_locale;
 
@@ -180,11 +167,7 @@
 }
 
 static locale_t* get_current_locale_ptr() {
-#if USE_TLS_SLOT
   return &__get_bionic_tls().locale;
-#else
-  return &g_current_locale;
-#endif
 }
 
 locale_t uselocale(locale_t new_locale) {
diff --git a/libc/include/math.h b/libc/include/math.h
index 3e80083..343ab98 100644
--- a/libc/include/math.h
+++ b/libc/include/math.h
@@ -68,10 +68,7 @@
 
 #define isnormal(x) __builtin_isnormal(x)
 
-#define signbit(x) \
-    ((sizeof(x) == sizeof(float)) ? __builtin_signbitf(x) \
-    : (sizeof(x) == sizeof(double)) ? __builtin_signbit(x) \
-    : __builtin_signbitl(x))
+#define signbit(x) __builtin_signbit(x)
 
 double acos(double __x);
 float acosf(float __x);
diff --git a/tests/math_test.cpp b/tests/math_test.cpp
index 7ca0e75..273ef97 100644
--- a/tests/math_test.cpp
+++ b/tests/math_test.cpp
@@ -17,36 +17,37 @@
 #define _GNU_SOURCE 1
 #include <math.h>
 
-// This include (and the associated definition of __test_capture_signbit)
-// must be placed before any files that include <cmath> (gtest.h in this case).
+// <math.h> is required to define type-generic macros: fpclassify, signbit,
+// isfinite, isinf, isnan, isnormal, isgreater, isgreaterequal, isless,
+// islessequal, islessgreater, and isunordered.
 //
-// <math.h> is required to define generic macros signbit, isfinite and
-// several other such functions.
+// <cmath> is required to #undef these macros and make equivalent sets of
+// _overloaded_ functions available in namespace std. So the isnan() macro,
+// for example, is replaced by std::isnan(float), std::isnan(double),
+// and std::isnan(long double).
 //
-// <cmath> is required to undef declarations of these macros in the global
-// namespace and make equivalent functions available in namespace std. Our
-// stlport implementation does this only for signbit, isfinite, isinf and
-// isnan.
-//
-// NOTE: We don't write our test using std::signbit because we want to be
-// sure that we're testing the bionic version of signbit. The C++ libraries
-// are free to reimplement signbit or delegate to compiler builtins if they
-// please.
+// We're trying to test the bionic macros rather than whatever libc++'s
+// implementation happens to be, so we #include <math.h> and "capture" the
+// macros in our own _template_ functions in the global namespace before
+// we #include any files that include <cmath>, such as <gtest.h>.
 
-namespace {
-template<typename T> inline int test_capture_signbit(const T in) {
-  return signbit(in);
-}
-template<typename T> inline int test_capture_isfinite(const T in) {
-  return isfinite(in);
-}
-template<typename T> inline int test_capture_isnan(const T in) {
-  return isnan(in);
-}
-template<typename T> inline int test_capture_isinf(const T in) {
-  return isinf(in);
-}
-}
+#define capture_generic_macro(capture_function_name, generic_macro_name) \
+  template <typename T> inline int capture_function_name(const T in) { \
+    return generic_macro_name(in); \
+  }
+
+capture_generic_macro(test_capture_fpclassify, fpclassify)
+capture_generic_macro(test_capture_signbit, signbit)
+capture_generic_macro(test_capture_isfinite, isfinite)
+capture_generic_macro(test_capture_isinf, isinf)
+capture_generic_macro(test_capture_isnan, isnan)
+capture_generic_macro(test_capture_isnormal, isnormal)
+capture_generic_macro(test_capture_isgreater, isgreater)
+capture_generic_macro(test_capture_isgreaterequal, isgreaterequal)
+capture_generic_macro(test_capture_isless, isless)
+capture_generic_macro(test_capture_islessequal, islessequal)
+capture_generic_macro(test_capture_islessgreater, islessgreater)
+capture_generic_macro(test_capture_isunordered, isunordered)
 
 #include "math_data_test.h"
 
@@ -60,6 +61,22 @@
 
 #include <android-base/scopeguard.h>
 
+// Now we've included all the headers we need, we can redefine the generic
+// function-like macros to point to the bionic <math.h> versions we captured
+// earlier.
+#define fpclassify test_capture_fpclassify
+#define signbit test_capture_signbit
+#define isfinite test_capture_isfinite
+#define isinf test_capture_isinf
+#define isnan test_capture_isnan
+#define isnormal test_capture_isnormal
+#define isgreater test_capture_isgreater
+#define isgreaterequal test_capture_isgreaterequal
+#define isless test_capture_isless
+#define islessequal test_capture_islessequal
+#define islessgreater test_capture_islessgreater
+#define isunordered test_capture_isunordered
+
 static float float_subnormal() {
   union {
     float f;
@@ -124,36 +141,36 @@
 }
 
 TEST(math_h, isfinite) {
-  ASSERT_TRUE(test_capture_isfinite(123.0f));
-  ASSERT_TRUE(test_capture_isfinite(123.0));
-  ASSERT_TRUE(test_capture_isfinite(123.0L));
-  ASSERT_FALSE(test_capture_isfinite(HUGE_VALF));
-  ASSERT_FALSE(test_capture_isfinite(-HUGE_VALF));
-  ASSERT_FALSE(test_capture_isfinite(HUGE_VAL));
-  ASSERT_FALSE(test_capture_isfinite(-HUGE_VAL));
-  ASSERT_FALSE(test_capture_isfinite(HUGE_VALL));
-  ASSERT_FALSE(test_capture_isfinite(-HUGE_VALL));
+  ASSERT_TRUE(isfinite(123.0f));
+  ASSERT_TRUE(isfinite(123.0));
+  ASSERT_TRUE(isfinite(123.0L));
+  ASSERT_FALSE(isfinite(HUGE_VALF));
+  ASSERT_FALSE(isfinite(-HUGE_VALF));
+  ASSERT_FALSE(isfinite(HUGE_VAL));
+  ASSERT_FALSE(isfinite(-HUGE_VAL));
+  ASSERT_FALSE(isfinite(HUGE_VALL));
+  ASSERT_FALSE(isfinite(-HUGE_VALL));
 }
 
 TEST(math_h, isinf) {
-  ASSERT_FALSE(test_capture_isinf(123.0f));
-  ASSERT_FALSE(test_capture_isinf(123.0));
-  ASSERT_FALSE(test_capture_isinf(123.0L));
-  ASSERT_TRUE(test_capture_isinf(HUGE_VALF));
-  ASSERT_TRUE(test_capture_isinf(-HUGE_VALF));
-  ASSERT_TRUE(test_capture_isinf(HUGE_VAL));
-  ASSERT_TRUE(test_capture_isinf(-HUGE_VAL));
-  ASSERT_TRUE(test_capture_isinf(HUGE_VALL));
-  ASSERT_TRUE(test_capture_isinf(-HUGE_VALL));
+  ASSERT_FALSE(isinf(123.0f));
+  ASSERT_FALSE(isinf(123.0));
+  ASSERT_FALSE(isinf(123.0L));
+  ASSERT_TRUE(isinf(HUGE_VALF));
+  ASSERT_TRUE(isinf(-HUGE_VALF));
+  ASSERT_TRUE(isinf(HUGE_VAL));
+  ASSERT_TRUE(isinf(-HUGE_VAL));
+  ASSERT_TRUE(isinf(HUGE_VALL));
+  ASSERT_TRUE(isinf(-HUGE_VALL));
 }
 
 TEST(math_h, isnan) {
-  ASSERT_FALSE(test_capture_isnan(123.0f));
-  ASSERT_FALSE(test_capture_isnan(123.0));
-  ASSERT_FALSE(test_capture_isnan(123.0L));
-  ASSERT_TRUE(test_capture_isnan(nanf("")));
-  ASSERT_TRUE(test_capture_isnan(nan("")));
-  ASSERT_TRUE(test_capture_isnan(nanl("")));
+  ASSERT_FALSE(isnan(123.0f));
+  ASSERT_FALSE(isnan(123.0));
+  ASSERT_FALSE(isnan(123.0L));
+  ASSERT_TRUE(isnan(nanf("")));
+  ASSERT_TRUE(isnan(nan("")));
+  ASSERT_TRUE(isnan(nanl("")));
 }
 
 TEST(math_h, isnormal) {
@@ -167,17 +184,17 @@
 
 // TODO: isgreater, isgreaterequals, isless, islessequal, islessgreater, isunordered
 TEST(math_h, signbit) {
-  ASSERT_EQ(0, test_capture_signbit(0.0f));
-  ASSERT_EQ(0, test_capture_signbit(0.0));
-  ASSERT_EQ(0, test_capture_signbit(0.0L));
+  ASSERT_EQ(0, signbit(0.0f));
+  ASSERT_EQ(0, signbit(0.0));
+  ASSERT_EQ(0, signbit(0.0L));
 
-  ASSERT_EQ(0, test_capture_signbit(1.0f));
-  ASSERT_EQ(0, test_capture_signbit(1.0));
-  ASSERT_EQ(0, test_capture_signbit(1.0L));
+  ASSERT_EQ(0, signbit(1.0f));
+  ASSERT_EQ(0, signbit(1.0));
+  ASSERT_EQ(0, signbit(1.0L));
 
-  ASSERT_NE(0, test_capture_signbit(-1.0f));
-  ASSERT_NE(0, test_capture_signbit(-1.0));
-  ASSERT_NE(0, test_capture_signbit(-1.0L));
+  ASSERT_NE(0, signbit(-1.0f));
+  ASSERT_NE(0, signbit(-1.0));
+  ASSERT_NE(0, signbit(-1.0L));
 }
 
 // Historical BSD cruft that isn't exposed in <math.h> any more.