add some llvm math funcs for rust #4543

Author: kripken

src/library.js

@@ -1462,6 +1462,21 @@ 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);
   },

tests/core/test_llvm_intrinsics.c

@@ -19,6 +19,12 @@ 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) {
@@ -67,5 +73,14 @@ 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;
 }

tests/core/test_llvm_intrinsics.out

@@ -26,3 +26,10 @@ 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.