From c5d842b7913483bccbb87d9f6578fdf4d292eab8 Mon Sep 17 00:00:00 2001
From: Folkert de Vries <folkert@folkertdev.nl>
Date: Sat, 14 Mar 2026 16:35:00 +0100
Subject: [PATCH] add fixmes for f128

also implement sqrt for f128 (using softfloat) and test sqrt for f16 and f128
---
 src/intrinsics/math.rs                 |  2 ++
 src/intrinsics/simd.rs                 |  6 +++---
 tests/pass/intrinsics/portable-simd.rs | 12 ++++++++++++
 3 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/src/intrinsics/math.rs b/src/intrinsics/math.rs
index fbd2aff4b5..fc7101df9e 100644
--- a/src/intrinsics/math.rs
+++ b/src/intrinsics/math.rs
@@ -192,10 +192,12 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
             "powf16" => pow_intrinsic::<HalfS>(this, args, dest)?,
             "powf32" => pow_intrinsic::<SingleS>(this, args, dest)?,
             "powf64" => pow_intrinsic::<DoubleS>(this, args, dest)?,
+            "powf128" => todo!("f128"), // FIXME(f128)
 
             "powif16" => powi_intrinsic::<HalfS>(this, args, dest)?,
             "powif32" => powi_intrinsic::<SingleS>(this, args, dest)?,
             "powif64" => powi_intrinsic::<DoubleS>(this, args, dest)?,
+            "powif128" => todo!("f128"), // FIXME(f128)
 
             _ => return interp_ok(EmulateItemResult::NotSupported),
         }
diff --git a/src/intrinsics/simd.rs b/src/intrinsics/simd.rs
index 235f815ba2..74582bc589 100644
--- a/src/intrinsics/simd.rs
+++ b/src/intrinsics/simd.rs
@@ -1,4 +1,4 @@
-use rustc_apfloat::ieee::{DoubleS, HalfS, IeeeFloat, SingleS};
+use rustc_apfloat::ieee::{DoubleS, HalfS, IeeeFloat, QuadS, SingleS};
 use rustc_middle::ty;
 use rustc_middle::ty::FloatTy;
 
@@ -36,7 +36,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
                         FloatTy::F16 => math::sqrt_op::<IeeeFloat<HalfS>>(this, &op, &dest)?,
                         FloatTy::F32 => math::sqrt_op::<IeeeFloat<SingleS>>(this, &op, &dest)?,
                         FloatTy::F64 => math::sqrt_op::<IeeeFloat<DoubleS>>(this, &op, &dest)?,
-                        FloatTy::F128 => unimplemented!("f128"),
+                        FloatTy::F128 => math::sqrt_op::<IeeeFloat<QuadS>>(this, &op, &dest)?,
                     };
                 }
             }
@@ -72,7 +72,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
                         FloatTy::F16 => host_unary_float_op::<HalfS>(this, &op, host_op, &dest)?,
                         FloatTy::F32 => host_unary_float_op::<SingleS>(this, &op, host_op, &dest)?,
                         FloatTy::F64 => host_unary_float_op::<DoubleS>(this, &op, host_op, &dest)?,
-                        FloatTy::F128 => unimplemented!("f128"),
+                        FloatTy::F128 => unimplemented!("f128"), // FIXME(f128)
                     }
                 }
             }
diff --git a/tests/pass/intrinsics/portable-simd.rs b/tests/pass/intrinsics/portable-simd.rs
index 554011dd02..b4fd8e2165 100644
--- a/tests/pass/intrinsics/portable-simd.rs
+++ b/tests/pass/intrinsics/portable-simd.rs
@@ -17,6 +17,7 @@ use std::ptr;
 use std::simd::StdFloat;
 use std::simd::prelude::*;
 
+// The `portable_simd` crate currently does not support f16 or f128 vectors, so we define our own.
 #[repr(simd, packed)]
 #[derive(Copy)]
 struct PackedSimd<T, const N: usize>([T; N]);
@@ -113,6 +114,9 @@ fn simd_ops_f16() {
             f16x4::splat(f16::NEG_INFINITY)
         );
 
+        assert_eq!(simd_fsqrt(simd_mul(a, a)), a);
+        assert_eq!(simd_fsqrt(simd_mul(b, b)), simd_fabs(b));
+
         assert_eq!(simd_eq(a, simd_mul(f16x4::splat(5.0), b)), i32x4::from_array([0, !0, 0, 0]));
         assert_eq!(simd_ne(a, simd_mul(f16x4::splat(5.0), b)), i32x4::from_array([!0, 0, !0, !0]));
         assert_eq!(simd_le(a, simd_mul(f16x4::splat(5.0), b)), i32x4::from_array([0, !0, !0, 0]));
@@ -324,6 +328,9 @@ fn simd_ops_f128() {
             f128x4::splat(f128::NEG_INFINITY)
         );
 
+        assert_eq!(simd_fsqrt(simd_mul(a, a)), a);
+        assert_eq!(simd_fsqrt(simd_mul(b, b)), simd_fabs(b));
+
         assert_eq!(simd_eq(a, simd_mul(f128x4::splat(5.0), b)), i32x4::from_array([0, !0, 0, 0]));
         assert_eq!(simd_ne(a, simd_mul(f128x4::splat(5.0), b)), i32x4::from_array([!0, 0, !0, !0]));
         assert_eq!(simd_le(a, simd_mul(f128x4::splat(5.0), b)), i32x4::from_array([0, !0, !0, 0]));
@@ -970,6 +977,11 @@ fn simd_float_intrinsics() {
         simd_flog2(a);
         simd_flog10(a);
     }
+
+    unsafe {
+        let a = f128x2::splat(10.0);
+        simd_fsqrt(a);
+    }
 }
 
 fn simd_masked_loadstore() {