diff --git a/src/library.js b/src/library.js
index a33d875c347bb..1439550613a31 100644
--- a/src/library.js
+++ b/src/library.js
@@ -946,6 +946,22 @@ LibraryManager.library = {
     {{{ makeStructuralReturn(['retl', 'reth']) }}};
   },
 
+  llvm_ctlz_i8__asm: true,
+  llvm_ctlz_i8__sig: 'ii',
+  llvm_ctlz_i8: function(x, isZeroUndef) {
+    x = x | 0;
+    isZeroUndef = isZeroUndef | 0;
+    return (Math_clz32(x) | 0) - 24 | 0;
+  },
+
+  llvm_ctlz_i16__asm: true,
+  llvm_ctlz_i16__sig: 'ii',
+  llvm_ctlz_i16: function(x, isZeroUndef) {
+    x = x | 0;
+    isZeroUndef = isZeroUndef | 0;
+    return (Math_clz32(x) | 0) - 16 | 0
+  },
+
   llvm_ctlz_i64__asm: true,
   llvm_ctlz_i64__sig: 'iii',
   llvm_ctlz_i64: function(l, h, isZeroUndef) {
@@ -1462,6 +1478,21 @@ LibraryManager.library = {
   llvm_floor_f32: 'Math_floor',
   llvm_floor_f64: 'Math_floor',
 
+  llvm_exp2_f32: function(x) {
+    return Math.pow(2, x);
+  },
+  llvm_exp2_f64: 'llvm_exp2_f32',
+
+  llvm_log2_f32: function(x) {
+    return Math.log(x) / Math.LN2; // TODO: Math.log2, when browser support is there
+  },
+  llvm_log2_f64: 'llvm_log2_f32',
+
+  llvm_log10_f32: function(x) {
+    return Math.log(x) / Math.LN10; // TODO: Math.log10, when browser support is there
+  },
+  llvm_log10_f64: 'llvm_log10_f32',
+
   llvm_copysign_f32: function(x, y) {
     return y < 0 || (y === 0 && 1/y < 0) ? -Math_abs(x) : Math_abs(x);
   },
diff --git a/tests/core/test_llvm_intrinsics.c b/tests/core/test_llvm_intrinsics.c
index a0df641f786d6..5556d89f746e4 100644
--- a/tests/core/test_llvm_intrinsics.c
+++ b/tests/core/test_llvm_intrinsics.c
@@ -4,6 +4,8 @@
 extern "C" {
 extern unsigned short llvm_bswap_i16(unsigned short x);
 extern unsigned int llvm_bswap_i32(unsigned int x);
+extern int32_t llvm_ctlz_i8(int8_t x, int izZeroUndef);
+extern int32_t llvm_ctlz_i16(int16_t x, int izZeroUndef);
 extern int32_t llvm_ctlz_i32(int32_t x, int izZeroUndef);
 extern int64_t llvm_ctlz_i64(int64_t x, int izZeroUndef);
 extern int32_t llvm_cttz_i32(int32_t x, int izZeroUndef);
@@ -19,6 +21,12 @@ extern float llvm_floor_f32(float x);
 extern double llvm_floor_f64(double x);
 extern float llvm_sin_f32(float x);
 extern double llvm_sin_f64(double x);
+extern float llvm_exp2_f32(float x);
+extern double llvm_exp2_f64(double x);
+extern float llvm_log2_f32(float x);
+extern double llvm_log2_f64(double x);
+extern float llvm_log10_f32(float x);
+extern double llvm_log10_f64(double x);
 }
 
 int main(void) {
@@ -41,6 +49,8 @@ int main(void) {
   printf("%d,%d\n", (int)llvm_ctpop_i64((0x3101ULL << 32) | 1),
          llvm_ctpop_i32(0x3101));
 
+  printf("small ctlz: %d,%d\n", (int)llvm_ctlz_i8(2, 0), llvm_ctlz_i16(2, 0));
+
   printf("llvm_ctpop_i32:\n");
   printf("%d\n", (int)llvm_ctpop_i32(-594093059)); // 22
   printf("%d\n", (int)llvm_ctpop_i32(0xdeadbeef)); // 24
@@ -67,5 +77,14 @@ int main(void) {
   printf("%.1f\n", llvm_sin_f32(90.0f * 3.14/180));
   printf("%.1f\n", llvm_sin_f64(270.0 * 3.14/180));
 
+  printf("exp2_f32 %.1f\n", llvm_exp2_f32(3));
+  printf("exp2_f64 %.1f\n", llvm_exp2_f64(4.5));
+  printf("log2_f32 %.1f\n", llvm_log2_f32(16));
+  printf("log2_f64 %.1f\n", llvm_log2_f64(20));
+  printf("log10_f32 %.1f\n", llvm_log10_f32(1000));
+  printf("log10_f64 %.1f\n", llvm_log10_f64(2000));
+
+  printf("ok.\n");
+
   return 0;
 }
diff --git a/tests/core/test_llvm_intrinsics.out b/tests/core/test_llvm_intrinsics.out
index 157433ceb7a6e..0cb78114afa9c 100644
--- a/tests/core/test_llvm_intrinsics.out
+++ b/tests/core/test_llvm_intrinsics.out
@@ -5,6 +5,7 @@ c5,de,15,8a
 23,21
 40,10
 5,4
+small ctlz: 6,14
 llvm_ctpop_i32:
 22
 24
@@ -26,3 +27,10 @@ llvm_expect_i32:
 -9
 1.0
 -1.0
+exp2_f32 8.0
+exp2_f64 22.6
+log2_f32 4.0
+log2_f64 4.3
+log10_f32 3.0
+log10_f64 3.3
+ok.