From aaa52607489e964eafb369904f23246edd1ec402 Mon Sep 17 00:00:00 2001
From: Trevor Gross <tmgross@umich.edu>
Date: Sat, 11 May 2024 01:18:38 -0500
Subject: [PATCH] Implement `f128` comparison

---
 library/compiler-builtins/README.md           |  2 +-
 library/compiler-builtins/src/float/cmp.rs    | 83 +++++++++++++++++++
 .../compiler-builtins/testcrate/tests/cmp.rs  | 40 +++++++++
 3 files changed, 124 insertions(+), 1 deletion(-)

diff --git a/library/compiler-builtins/README.md b/library/compiler-builtins/README.md
index 1986c21c6692..37d7ab2e6718 100644
--- a/library/compiler-builtins/README.md
+++ b/library/compiler-builtins/README.md
@@ -233,7 +233,7 @@ These builtins are needed to support 128-bit integers.
 These builtins are needed to support `f16` and `f128`, which are in the process of being added to Rust.
 
 - [x] addtf3.c
-- [ ] comparetf2.c
+- [x] comparetf2.c
 - [ ] divtf3.c
 - [x] extenddftf2.c
 - [x] extendhfsf2.c
diff --git a/library/compiler-builtins/src/float/cmp.rs b/library/compiler-builtins/src/float/cmp.rs
index 193c5df368c8..44ebf6262ea4 100644
--- a/library/compiler-builtins/src/float/cmp.rs
+++ b/library/compiler-builtins/src/float/cmp.rs
@@ -172,6 +172,89 @@ intrinsics! {
     }
 }
 
+#[cfg(not(any(
+    feature = "no-f16-f128",
+    target_arch = "powerpc",
+    target_arch = "powerpc64"
+)))]
+intrinsics! {
+    #[avr_skip]
+    pub extern "C" fn __letf2(a: f128, b: f128) -> i32 {
+        cmp(a, b).to_le_abi()
+    }
+
+    #[avr_skip]
+    pub extern "C" fn __getf2(a: f128, b: f128) -> i32 {
+        cmp(a, b).to_ge_abi()
+    }
+
+    #[avr_skip]
+    pub extern "C" fn __unordtf2(a: f128, b: f128) -> i32 {
+        unord(a, b) as i32
+    }
+
+    #[avr_skip]
+    pub extern "C" fn __eqtf2(a: f128, b: f128) -> i32 {
+        cmp(a, b).to_le_abi()
+    }
+
+    #[avr_skip]
+    pub extern "C" fn __lttf2(a: f128, b: f128) -> i32 {
+        cmp(a, b).to_le_abi()
+    }
+
+    #[avr_skip]
+    pub extern "C" fn __netf2(a: f128, b: f128) -> i32 {
+        cmp(a, b).to_le_abi()
+    }
+
+    #[avr_skip]
+    pub extern "C" fn __gttf2(a: f128, b: f128) -> i32 {
+        cmp(a, b).to_ge_abi()
+    }
+}
+
+#[cfg(all(
+    not(feature = "no-f16-f128"),
+    any(target_arch = "powerpc", target_arch = "powerpc64")
+))]
+intrinsics! {
+    #[avr_skip]
+    pub extern "C" fn __lekf2(a: f128, b: f128) -> i32 {
+        cmp(a, b).to_le_abi()
+    }
+
+    #[avr_skip]
+    pub extern "C" fn __gekf2(a: f128, b: f128) -> i32 {
+        cmp(a, b).to_ge_abi()
+    }
+
+    #[avr_skip]
+    pub extern "C" fn __unordkf2(a: f128, b: f128) -> i32 {
+        unord(a, b) as i32
+    }
+
+    #[avr_skip]
+    pub extern "C" fn __eqkf2(a: f128, b: f128) -> i32 {
+        cmp(a, b).to_le_abi()
+    }
+
+    #[avr_skip]
+    pub extern "C" fn __ltkf2(a: f128, b: f128) -> i32 {
+        cmp(a, b).to_le_abi()
+    }
+
+    #[avr_skip]
+    pub extern "C" fn __nekf2(a: f128, b: f128) -> i32 {
+        cmp(a, b).to_le_abi()
+    }
+
+    #[avr_skip]
+    pub extern "C" fn __gtkf2(a: f128, b: f128) -> i32 {
+        cmp(a, b).to_ge_abi()
+    }
+}
+
 #[cfg(target_arch = "arm")]
 intrinsics! {
     pub extern "aapcs" fn __aeabi_fcmple(a: f32, b: f32) -> i32 {
diff --git a/library/compiler-builtins/testcrate/tests/cmp.rs b/library/compiler-builtins/testcrate/tests/cmp.rs
index 20915b25d120..0d15f5d421f0 100644
--- a/library/compiler-builtins/testcrate/tests/cmp.rs
+++ b/library/compiler-builtins/testcrate/tests/cmp.rs
@@ -1,5 +1,7 @@
 #![allow(unused_macros)]
 #![allow(unreachable_code)]
+#![feature(f128)]
+#![feature(f16)]
 
 #[cfg(not(target_arch = "powerpc64"))]
 use testcrate::*;
@@ -79,6 +81,44 @@ fn float_comparisons() {
             1, __nedf2;
         );
     });
+
+    #[cfg(not(feature = "no-f16-f128"))]
+    {
+        #[cfg(any(target_arch = "powerpc", target_arch = "powerpc64"))]
+        use compiler_builtins::float::cmp::{
+            __eqkf2 as __eqtf2, __gekf2 as __getf2, __gtkf2 as __gttf2, __lekf2 as __letf2,
+            __ltkf2 as __lttf2, __nekf2 as __netf2, __unordkf2 as __unordtf2,
+        };
+
+        #[cfg(not(any(target_arch = "powerpc", target_arch = "powerpc64")))]
+        use compiler_builtins::float::cmp::{
+            __eqtf2, __getf2, __gttf2, __letf2, __lttf2, __netf2, __unordtf2,
+        };
+
+        fuzz_float_2(N, |x: f128, y: f128| {
+            let x_is_nan = apfloat_fallback!(
+                f128, Quad, not(feature = "no-sys-f128"),
+                |x: FloatTy| x.is_nan() => no_convert,
+                x
+            );
+            let y_is_nan = apfloat_fallback!(
+                f128, Quad, not(feature = "no-sys-f128"),
+                |x: FloatTy| x.is_nan() => no_convert,
+                y
+            );
+
+            assert_eq!(__unordtf2(x, y) != 0, x_is_nan || y_is_nan);
+
+            cmp!(f128, x, y, Quad, not(feature = "no-sys-f128"),
+                1, __lttf2;
+                1, __letf2;
+                1, __eqtf2;
+                -1, __getf2;
+                -1, __gttf2;
+                1, __netf2;
+            );
+        });
+    }
 }
 
 macro_rules! cmp2 {