From f8e937fa466f721925073225a1a2177eee8b8e81 Mon Sep 17 00:00:00 2001
From: Andrey Zgarbul <zgarbul.andrey@gmail.com>
Date: Sun, 15 Jul 2018 07:01:26 +0300
Subject: [PATCH] sinf, fix constant in k_expo2f

---
 library/compiler-builtins/libm/src/lib.rs     |  2 --
 .../libm/src/math/k_expo2f.rs                 |  4 +--
 .../compiler-builtins/libm/src/math/mod.rs    |  2 ++
 .../compiler-builtins/libm/src/math/sinhf.rs  | 30 +++++++++++++++++++
 .../libm/test-generator/src/main.rs           |  2 +-
 5 files changed, 35 insertions(+), 5 deletions(-)
 create mode 100644 library/compiler-builtins/libm/src/math/sinhf.rs

diff --git a/library/compiler-builtins/libm/src/lib.rs b/library/compiler-builtins/libm/src/lib.rs
index 1ed07873421e..45213a25f7ab 100644
--- a/library/compiler-builtins/libm/src/lib.rs
+++ b/library/compiler-builtins/libm/src/lib.rs
@@ -108,7 +108,6 @@ pub trait F32Ext: private::Sealed {
 
     fn ln_1p(self) -> Self;
 
-    #[cfg(todo)]
     fn sinh(self) -> Self;
 
     fn cosh(self) -> Self;
@@ -284,7 +283,6 @@ impl F32Ext for f32 {
         log1pf(self)
     }
 
-    #[cfg(todo)]
     #[inline]
     fn sinh(self) -> Self {
         sinhf(self)
diff --git a/library/compiler-builtins/libm/src/math/k_expo2f.rs b/library/compiler-builtins/libm/src/math/k_expo2f.rs
index 031a0bdd0365..e2eaa4e6bb02 100644
--- a/library/compiler-builtins/libm/src/math/k_expo2f.rs
+++ b/library/compiler-builtins/libm/src/math/k_expo2f.rs
@@ -2,13 +2,13 @@ use super::expf;
 
 /* k is such that k*ln2 has minimal relative error and x - kln2 > log(FLT_MIN) */
 const K: i32 = 235;
-const K_LN2: f32 = 162.89; /* 0x1.45c778p+7f */
 
 /* expf(x)/2 for x >= log(FLT_MAX), slightly better than 0.5f*expf(x/2)*expf(x/2) */
 #[inline]
 pub(crate) fn k_expo2f(x: f32) -> f32 {
+    let k_ln2 = f32::from_bits(0x4322e3bc);
     /* note that k is odd and scale*scale overflows */
     let scale = f32::from_bits(((0x7f + K / 2) as u32) << 23);
     /* exp(x - k ln2) * 2**(k-1) */
-    expf(x - K_LN2) * scale * scale
+    expf(x - k_ln2) * scale * scale
 }
diff --git a/library/compiler-builtins/libm/src/math/mod.rs b/library/compiler-builtins/libm/src/math/mod.rs
index a29f2fb0ab43..eda6b5b72931 100644
--- a/library/compiler-builtins/libm/src/math/mod.rs
+++ b/library/compiler-builtins/libm/src/math/mod.rs
@@ -53,6 +53,7 @@ mod scalbnf;
 mod sin;
 mod sinf;
 mod sinh;
+mod sinhf;
 mod sqrt;
 mod sqrtf;
 mod tan;
@@ -108,6 +109,7 @@ pub use self::scalbnf::scalbnf;
 pub use self::sin::sin;
 pub use self::sinf::sinf;
 pub use self::sinh::sinh;
+pub use self::sinhf::sinhf;
 pub use self::sqrt::sqrt;
 pub use self::sqrtf::sqrtf;
 pub use self::tan::tan;
diff --git a/library/compiler-builtins/libm/src/math/sinhf.rs b/library/compiler-builtins/libm/src/math/sinhf.rs
new file mode 100644
index 000000000000..90c4b9312819
--- /dev/null
+++ b/library/compiler-builtins/libm/src/math/sinhf.rs
@@ -0,0 +1,30 @@
+use super::expm1f;
+use super::k_expo2f;
+
+#[inline]
+pub fn sinhf(x: f32) -> f32 {
+    let mut h = 0.5f32;
+    let mut ix = x.to_bits();
+    if (ix >> 31) != 0 {
+        h = -h;
+    }
+    /* |x| */
+    ix &= 0x7fffffff;
+    let absx = f32::from_bits(ix);
+    let w = ix;
+
+    /* |x| < log(FLT_MAX) */
+    if w < 0x42b17217 {
+        let t = expm1f(absx);
+        if w < 0x3f800000 {
+            if w < (0x3f800000 - (12 << 23)) {
+                return x;
+            }
+            return h * (2. * t - t * t / (t + 1.));
+        }
+        return h * (t + t / (t + 1.));
+    }
+
+    /* |x| > logf(FLT_MAX) or nan */
+    2. * h * k_expo2f(absx)
+}
diff --git a/library/compiler-builtins/libm/test-generator/src/main.rs b/library/compiler-builtins/libm/test-generator/src/main.rs
index 6708891f3ed3..7caada4ef3e9 100644
--- a/library/compiler-builtins/libm/test-generator/src/main.rs
+++ b/library/compiler-builtins/libm/test-generator/src/main.rs
@@ -669,7 +669,7 @@ f32_f32! {
     logf,
     roundf,
     sinf,
-    // sinhf,
+    sinhf,
     tanf,
     tanhf,
     fabsf,