Add f128 division

Use the new generic division algorithm to expose `__divtf3` and
`__divkf3`.

Author: tgross35

README.md

@@ -222,7 +222,7 @@ of being added to Rust.
 
 - [x] addtf3.c
 - [x] comparetf2.c
-- [ ] divtf3.c
+- [x] divtf3.c
 - [x] extenddftf2.c
 - [x] extendhfsf2.c
 - [x] extendhftf2.c

build.rs

@@ -526,7 +526,6 @@ mod c {
                 ("__floatsitf", "floatsitf.c"),
                 ("__floatunditf", "floatunditf.c"),
                 ("__floatunsitf", "floatunsitf.c"),
-                ("__divtf3", "divtf3.c"),
                 ("__powitf2", "powitf2.c"),
                 ("__fe_getround", "fp_mode.c"),
                 ("__fe_raise_inexact", "fp_mode.c"),

examples/intrinsics.rs

@@ -256,6 +256,10 @@ mod intrinsics {
         a * b
     }
 
+    pub fn divtf(a: f128, b: f128) -> f128 {
+        a / b
+    }
+
     pub fn subtf(a: f128, b: f128) -> f128 {
         a - b
     }
@@ -440,6 +444,7 @@ fn run() {
     bb(aeabi_uldivmod(bb(2), bb(3)));
     bb(ashlti3(bb(2), bb(2)));
     bb(ashrti3(bb(2), bb(2)));
+    bb(divtf(bb(2.), bb(2.)));
     bb(divti3(bb(2), bb(2)));
     bb(eqtf(bb(2.), bb(2.)));
     bb(extendhfdf(bb(2.)));

src/float/div.rs

@@ -617,4 +617,21 @@ intrinsics! {
     pub extern "C" fn __divdf3(a: f64, b: f64) -> f64 {
         div(a, b)
     }
+
+    #[avr_skip]
+    #[ppc_alias = __divkf3]
+    #[cfg(not(feature = "no-f16-f128"))]
+    pub extern "C" fn __divtf3(a: f128, b: f128) -> f128 {
+        div(a, b)
+    }
+
+    #[cfg(target_arch = "arm")]
+    pub extern "C" fn __divsf3vfp(a: f32, b: f32) -> f32 {
+        a / b
+    }
+
+    #[cfg(target_arch = "arm")]
+    pub extern "C" fn __divdf3vfp(a: f64, b: f64) -> f64 {
+        a / b
+    }
 }

testcrate/tests/div_rem.rs

@@ -1,3 +1,4 @@
+#![feature(f128)]
 #![allow(unused_macros)]
 
 use compiler_builtins::int::sdiv::{__divmoddi4, __divmodsi4, __divmodti4};
@@ -146,4 +147,19 @@ mod float_div {
         f32, __divsf3, Single, all();
         f64, __divdf3, Double, all();
     }
+
+    #[cfg(not(feature = "no-f16-f128"))]
+    #[cfg(not(any(target_arch = "powerpc", target_arch = "powerpc64")))]
+    float! {
+        f128, __divtf3, Quad,
+        // FIXME(llvm): there is a bug in LLVM rt.
+        // See <https://github.com/llvm/llvm-project/issues/91840>.
+        not(any(feature = "no-sys-f128", all(target_arch = "aarch64", target_os = "linux")));
+    }
+
+    #[cfg(not(feature = "no-f16-f128"))]
+    #[cfg(any(target_arch = "powerpc", target_arch = "powerpc64"))]
+    float! {
+        f128, __divkf3, Quad, not(feature = "no-sys-f128");
+    }
 }