From 9c9be62b02eccd177db2311c337c7b469cd19e62 Mon Sep 17 00:00:00 2001
From: Stefan Plantikow <stefan.plantikow@googlemail.com>
Date: Tue, 22 Nov 2011 18:08:26 +0100
Subject: [PATCH] std: rewrote math to support most C95 libmath calls on f32,
 f64 and float

---
 src/lib/ctypes.rs        |   4 +
 src/lib/math.rs          | 389 +++++++++++++++++++++++++++++++--------
 src/test/stdtest/math.rs |  12 +-
 3 files changed, 323 insertions(+), 82 deletions(-)

diff --git a/src/lib/ctypes.rs b/src/lib/ctypes.rs
index c48a2c8c073..890300ce781 100644
--- a/src/lib/ctypes.rs
+++ b/src/lib/ctypes.rs
@@ -5,6 +5,7 @@ Definitions useful for C interop
 */
 
 type c_int = i32;
+
 type long = int;
 type unsigned = u32;
 type ulong = uint;
@@ -13,6 +14,9 @@ type intptr_t = uint;
 type uintptr_t = uint;
 type uint32_t = u32;
 
+// This *must* match with "import c_float = fXX" in std::math per arch
+type c_float = f64;
+
 type size_t = uint;
 type ssize_t = int;
 type off_t = uint;
diff --git a/src/lib/math.rs b/src/lib/math.rs
index 5d826d5ce32..339e6308651 100644
--- a/src/lib/math.rs
+++ b/src/lib/math.rs
@@ -1,77 +1,173 @@
 /* Module: math */
 
-#[link_name = ""]
+export consts;
+export min, max;
+
+export f32, f64;
+
+// Currently this module supports from -lmath
+// C95 - frexp - ldexp - fmod - modf + log2 + log1p
+
+export
+    acos, asin, atan, atan2, ceil, cos, cosh, exp, abs, floor,
+    ln, ln1p, log10, log2, pow, sin, sinh, sqrt, tan, tanh;
+
+// These two must match in width according to architecture
+
+import ctypes::c_float;
+import c_float = f64;
+
+
+#[link_name = "m"]
 #[abi = "cdecl"]
-native mod libc {
-    fn sqrt(n: float) -> float;
-    fn sin(n: float) -> float;
-    fn asin(n: float) -> float;
-    fn cos(n: float) -> float;
-    fn acos(n: float) -> float;
-    fn tan(n: float) -> float;
-    fn atan(n: float) -> float;
-    #[link_name="log"]
-    fn ln(n: float) -> float;
-    fn log2(n: float) -> float;
-    fn log10(n: float) -> float;
-    fn log1p(n: float) -> float;
+native mod f64 {
+
+    // Alpabetically sorted by link_name
+
+    fn acos(n: f64) -> f64;
+    fn asin(n: f64) -> f64;
+    fn atan(n: f64) -> f64;
+    fn atan2(a: f64, b: f64) -> f64;
+    fn ceil(n: f64) -> f64;
+    fn cos(n: f64) -> f64;
+    fn cosh(n: f64) -> f64;
+    fn exp(n: f64) -> f64;
+    #[link_name="fabs"] fn abs(n: f64) -> f64; 
+    fn floor(n: f64) -> f64;
+    #[link_name="log"] fn ln(n: f64) -> f64;
+    #[link_name="log1p"] fn ln1p(n: f64) -> f64;
+    fn log10(n: f64) -> f64;
+    fn log2(n: f64) -> f64;
+    fn pow(n: f64, e: f64) -> f64;
+    fn sin(n: f64) -> f64;
+    fn sinh(n: f64) -> f64;
+    fn sqrt(n: f64) -> f64;
+    fn tan(n: f64) -> f64;
+    fn tanh(n: f64) -> f64;
 }
 
-/*
-Function: sqrt
+#[link_name = "m"]
+#[abi = "cdecl"]
+native mod f32 {
 
-Returns the square root
-*/
-pure fn sqrt(x: float) -> float { unsafe { libc::sqrt(x) } }
+    // Alpabetically sorted by link_name
 
-/*
-Function: sin
+    #[link_name="acosf"] fn acos(n: f32) -> f32;
+    #[link_name="asinf"] fn asin(n: f32) -> f32;
+    #[link_name="atanf"] fn atan(n: f32) -> f32;
+    #[link_name="atan2f"] fn atan2(a: f32, b: f32) -> f32;
+    #[link_name="ceilf"] fn ceil(n: f32) -> f32;
+    #[link_name="cosf"] fn cos(n: f32) -> f32;
+    #[link_name="coshf"] fn cosh(n: f32) -> f32;
+    #[link_name="expf"] fn exp(n: f32) -> f32;
+    #[link_name="fabsf"] fn abs(n: f32) -> f32;
+    #[link_name="floorf"] fn floor(n: f32) -> f32;
+    #[link_name="powf"] fn pow(n: f32, e: f32) -> f32;
+    #[link_name="sinf"] fn sin(n: f32) -> f32;
+    #[link_name="sinhf"] fn sinh(n: f32) -> f32;
+    #[link_name="sqrtf"] fn sqrt(n: f32) -> f32;
+    #[link_name="tanf"] fn tan(n: f32) -> f32;
+    #[link_name="tanhf"] fn tanh(n: f32) -> f32;
+    #[link_name="logf"] fn ln(n: f32) -> f32;
+    #[link_name="log1p"] fn ln1p(n: f64) -> f64;
+    #[link_name="log2f"] fn log2(n: f32) -> f32;
+    #[link_name="log10f"] fn log10(n: f32) -> f32;
+}
 
-Returns the sine of an angle
-*/
-pure fn sin(x: float) -> float { unsafe { libc::sin(x) } }
 
-/*
-Function: cos
+mod consts {
+    /*
+    Const: pi
 
-Returns the cosine of an angle
-*/
-pure fn cos(x: float) -> float { unsafe { libc::cos(x) } }
+    Archimedes' constant
+    */
+    const pi: float = 3.14159265358979323846264338327950288;
 
-/*
-Function: tan
+    /*
+    Const: frac_pi_2
 
-Returns the tangent of an angle
-*/
-pure fn tan(x: float) -> float { unsafe { libc::tan(x) } }
+    pi/2.0
+    */
+    const frac_pi_2: float = 1.57079632679489661923132169163975144;
 
-/*
-Function: asin
+    /*
+    Const: frac_pi_4
 
-Returns the arcsine of an angle
-*/
-pure fn asin(x: float) -> float { unsafe { libc::asin(x) } }
+    pi/4.0
+    */
+    const frac_pi_4: float = 0.785398163397448309615660845819875721;
 
-/*
-Function: acos
+    /*
+    Const: frac_1_pi
 
-Returns the arccosine of an angle
-*/
-pure fn acos(x: float) -> float { unsafe { libc::acos(x) } }
+    1.0/pi
+    */
+    const frac_1_pi: float = 0.318309886183790671537767526745028724;
 
-/*
-Function: atan
+    /*
+    Const: frac_2_pi
 
-Returns the arctangent of an angle
-*/
-pure fn atan(x: float) -> float { unsafe { libc::atan(x) } }
+    2.0/pi
+    */
+    const frac_2_pi: float = 0.636619772367581343075535053490057448;
 
-/*
-Const: pi
+    /*
+    Const: frac_2_sqrtpi
 
-Archimedes' constant
-*/
-const pi: float = 3.141592653589793;
+    2.0/sqrt(pi)
+    */
+    const frac_2_sqrtpi: float = 1.12837916709551257389615890312154517;
+
+    /*
+    Const: sqrt2
+
+    sqrt(2.0)
+    */
+    const sqrt2: float = 1.41421356237309504880168872420969808;
+
+    /*
+    Const: frac_1_sqrt2
+
+    1.0/sqrt(2.0)
+    */
+    const frac_1_sqrt2: float = 0.707106781186547524400844362104849039;
+
+    /*
+    Const: e
+
+    Euler's number
+    */
+    const e: float = 2.71828182845904523536028747135266250;
+
+    /*
+    Const: log2_e
+
+    log2(e)
+    */
+    const log2_e: float = 1.44269504088896340735992468100189214;
+
+    /*
+    Const: log10_e
+
+    log10(e)
+    */
+    const log10_e: float = 0.434294481903251827651128918916605082;
+
+    /*
+    Const: ln_2
+
+    ln(2.0)
+    */
+    const ln_2: float = 0.693147180559945309417232121458176568;
+
+    /*
+    Const: ln_10
+
+    ln(10.0)
+    */
+    const ln_10: float = 2.30258509299404568401799145468436421;
+
+}
 
 /*
 Function: min
@@ -88,38 +184,179 @@ Returns the maximum of two values
 pure fn max<copy T>(x: T, y: T) -> T { x < y ? y : x }
 
 /*
-Const: e
+Function: acos
 
-Euler's number
+Returns the arccosine of an angle (measured in rad)
 */
-const e: float = 2.718281828459045235;
+pure fn acos(x: float) -> float
+    { unsafe { c_float::acos(x as c_float) as float } }
+
+/*
+Function: asin
+
+Returns the arcsine of an angle (measured in rad)
+*/
+pure fn asin(x: float) -> float
+    { unsafe { c_float::asin(x as c_float) as float } }
+
+/*
+Function: atan
+
+Returns the arctangents of an angle (measured in rad)
+*/
+pure fn atan(x: float) -> float
+    { unsafe { c_float::atan(x as c_float) as float } }
+
+
+/*
+Function: atan2
+
+Returns the arctangent of an angle (measured in rad)
+*/
+pure fn atan2(y: float, x: float) -> float
+    { unsafe { c_float::atan2(y as c_float, x as c_float) as float } }
+
+/*
+Function: ceil
+
+Returns:
+
+The smallest integral value less than or equal to `n`
+*/
+pure fn ceil(n: float) -> float
+    { unsafe { c_float::ceil(n as c_float) as float } }
+
+/*
+Function: cos
+
+Returns the cosine of an angle `x` (measured in rad)
+*/
+pure fn cos(x: float) -> float
+    { unsafe { c_float::cos(x as c_float) as float } }
+
+/*
+Function: cosh
+
+Returns the hyperbolic cosine of `x`
+
+*/
+pure fn cosh(x: float) -> float
+    { unsafe { c_float::cosh(x as c_float) as float } }
+
+
+/*
+Function: exp
+
+Returns:
+
+e to the power of `n*
+*/
+pure fn exp(n: float) -> float
+    { unsafe { c_float::exp(n as c_float) as float } }
+
+/*
+Function: abs
+
+Returns:
+
+The absolute value of  `n`
+
+*/
+pure fn abs(n: float) -> float
+    { unsafe { c_float::abs(n as c_float) as float } }
+
+/*
+Function: floor
+
+Returns:
+
+The largest integral value less than or equal to `n`
+*/
+pure fn floor(n: float) -> float
+    { unsafe { c_float::floor(n as c_float) as float } }
 
 /*
 Function: ln
 
-Returns the natural logaritm
+Returns the natural logaritm of `n`
 */
-pure fn ln(n: float) -> float { unsafe { libc::ln(n) } }
+pure fn ln(n: float) -> float
+    { unsafe { c_float::ln(n as c_float) as float } }
 
 /*
-Function: log2
-
-Returns the logarithm to base 2
-*/
-pure fn log2(n: float) -> float { unsafe { libc::log2(n) } }
-
-/*
-Function: log2
-
-Returns the logarithm to base 10
-*/
-pure fn log10(n: float) -> float { unsafe { libc::log10(n) } }
-
-
-/*
-Function: log1p
+Function: ln1p
 
 Returns the natural logarithm of `1+n` accurately,
 even for very small values of `n`
 */
-pure fn ln1p(n: float) -> float { unsafe { libc::log1p(n) } }
+pure fn ln1p(n: float) -> float
+    { unsafe { c_float::ln1p(n as c_float) as float } }
+
+/*
+Function: log10
+
+Returns the logarithm to base 10 of `n`
+*/
+pure fn log10(n: float) -> float
+    { unsafe { c_float::log10(n as c_float) as float } }
+
+/*
+Function: log2
+
+Returns the logarithm to base 2 of `n`
+*/
+pure fn log2(n: float) -> float
+    { unsafe { c_float::log2(n as c_float) as float } }
+
+/*
+Function: pow
+*/
+pure fn pow(v: float, e: float) -> float
+    { unsafe { c_float::pow(v as c_float, e as c_float) as float } }
+
+
+/*
+Function: sin
+
+Returns the sine of an angle `x` (measured in rad)
+*/
+pure fn sin(x: float) -> float
+    { unsafe { c_float::sin(x as c_float) as float } }
+
+/*
+Function: sinh
+
+Returns the hyperbolic sine of an angle `x` (measured in rad)
+*/
+pure fn sinh(x: float) -> float
+    { unsafe { c_float::sinh(x as c_float) as float } }
+
+/*
+Function: sqrt
+
+Returns the square root of `x`
+*/
+pure fn sqrt(x: float) -> float
+    { unsafe { c_float::sqrt(x as c_float) as float } }
+
+/*
+Function: tan
+
+Returns the tangent of an angle `x` (measured in rad)
+
+*/
+pure fn tan(x: float) -> float
+    { unsafe { c_float::tan(x as c_float) as float } }
+
+/*
+Function: tanh
+
+Returns the hyperbolic tangent of an angle `x` (measured in rad)
+
+*/
+pure fn tanh(x: float) -> float
+    { unsafe { c_float::tanh(x as c_float) as float } }
+
+
+
+
diff --git a/src/test/stdtest/math.rs b/src/test/stdtest/math.rs
index 12bc31bb0e5..53d93ae3077 100644
--- a/src/test/stdtest/math.rs
+++ b/src/test/stdtest/math.rs
@@ -24,14 +24,14 @@ fn test_max_min() {
 fn test_angle() {
     fn angle(vec: (float, float)) -> float {
         alt vec {
-          (0f, y) when y < 0f { 1.5 * std::math::pi }
-          (0f, y) { 0.5 * std::math::pi }
+          (0f, y) when y < 0f { 1.5 * consts::pi }
+          (0f, y) { 0.5 * consts::pi }
           (x, y) { std::math::atan(y / x) }
         }
     }
     assert angle((1f, 0f)) == 0f;
-    assert angle((1f, 1f)) == 0.25 * pi;
-    assert angle((0f, 1f)) == 0.5 * pi;
+    assert angle((1f, 1f)) == 0.25 * consts::pi;
+    assert angle((0f, 1f)) == 0.5 * consts::pi;
 }
 
 
@@ -42,11 +42,11 @@ fn test_log_functions() {
     assert log2(1.0) == 0.0;
     assert log10(1.0) == 0.0;
 
-    assert ln(e) == 1.0;
+    assert ln(consts::e) == 1.0;
     assert log2(2.0) == 1.0;
     assert log10(10.0) == 1.0;
 
-    assert ln(e*e*e*e) == 4.0;
+    assert ln(consts::e*consts::e*consts::e*consts::e) == 4.0;
     assert log2(256.0) == 8.0;
     assert log10(1000.0) == 3.0;