Rollup merge of rust-lang#119574 - RalfJung:miri, r=oli-obk

Miri subtree update

r? `@ghost`

Author: matthiaskrgr

src/tools/miri/src/helpers.rs

@@ -6,6 +6,7 @@ use std::time::Duration;
 use log::trace;
 
 use rustc_apfloat::ieee::{Double, Single};
+use rustc_apfloat::Float;
 use rustc_hir::def::{DefKind, Namespace};
 use rustc_hir::def_id::{DefId, CRATE_DEF_INDEX};
 use rustc_index::IndexVec;
@@ -117,6 +118,50 @@ fn try_resolve_did(tcx: TyCtxt<'_>, path: &[&str], namespace: Option<Namespace>)
     }
 }
 
+/// Convert a softfloat type to its corresponding hostfloat type.
+pub trait ToHost {
+    type HostFloat;
+    fn to_host(self) -> Self::HostFloat;
+}
+
+/// Convert a hostfloat type to its corresponding softfloat type.
+pub trait ToSoft {
+    type SoftFloat;
+    fn to_soft(self) -> Self::SoftFloat;
+}
+
+impl ToHost for rustc_apfloat::ieee::Double {
+    type HostFloat = f64;
+
+    fn to_host(self) -> Self::HostFloat {
+        f64::from_bits(self.to_bits().try_into().unwrap())
+    }
+}
+
+impl ToSoft for f64 {
+    type SoftFloat = rustc_apfloat::ieee::Double;
+
+    fn to_soft(self) -> Self::SoftFloat {
+        Float::from_bits(self.to_bits().into())
+    }
+}
+
+impl ToHost for rustc_apfloat::ieee::Single {
+    type HostFloat = f32;
+
+    fn to_host(self) -> Self::HostFloat {
+        f32::from_bits(self.to_bits().try_into().unwrap())
+    }
+}
+
+impl ToSoft for f32 {
+    type SoftFloat = rustc_apfloat::ieee::Single;
+
+    fn to_soft(self) -> Self::SoftFloat {
+        Float::from_bits(self.to_bits().into())
+    }
+}
+
 impl<'mir, 'tcx: 'mir> EvalContextExt<'mir, 'tcx> for crate::MiriInterpCx<'mir, 'tcx> {}
 pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
     /// Checks if the given crate/module exists.
@@ -1188,11 +1233,3 @@ pub(crate) fn simd_element_to_bool(elem: ImmTy<'_, Provenance>) -> InterpResult<
         _ => throw_ub_format!("each element of a SIMD mask must be all-0-bits or all-1-bits"),
     })
 }
-
-// This looks like something that would be nice to have in the standard library...
-pub(crate) fn round_to_next_multiple_of(x: u64, divisor: u64) -> u64 {
-    assert_ne!(divisor, 0);
-    // divisor is nonzero; multiplication cannot overflow since we just divided
-    #[allow(clippy::arithmetic_side_effects)]
-    return (x.checked_add(divisor - 1).unwrap() / divisor) * divisor;
-}

src/tools/miri/src/lib.rs

@@ -11,6 +11,7 @@
 #![feature(round_ties_even)]
 #![feature(let_chains)]
 #![feature(lint_reasons)]
+#![feature(int_roundings)]
 // Configure clippy and other lints
 #![allow(
     clippy::collapsible_else_if,

src/tools/miri/src/operator.rs

@@ -118,4 +118,8 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
             nan
         }
     }
+
+    fn adjust_nan<F1: Float + FloatConvert<F2>, F2: Float>(&self, f: F2, inputs: &[F1]) -> F2 {
+        if f.is_nan() { self.generate_nan(inputs) } else { f }
+    }
 }

src/tools/miri/src/shims/foreign_items.rs

@@ -23,6 +23,7 @@ use rustc_target::{
 
 use super::backtrace::EvalContextExt as _;
 use crate::*;
+use helpers::{ToHost, ToSoft};
 
 /// Type of dynamic symbols (for `dlsym` et al)
 #[derive(Debug, Copy, Clone)]
@@ -886,23 +887,26 @@ trait EvalContextExtPriv<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
             | "tgammaf"
             => {
                 let [f] = this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?;
+                let f = this.read_scalar(f)?.to_f32()?;
                 // FIXME: Using host floats.
-                let f = f32::from_bits(this.read_scalar(f)?.to_u32()?);
+                let f_host = f.to_host();
                 let res = match link_name.as_str() {
-                    "cbrtf" => f.cbrt(),
-                    "coshf" => f.cosh(),
-                    "sinhf" => f.sinh(),
-                    "tanf" => f.tan(),
-                    "tanhf" => f.tanh(),
-                    "acosf" => f.acos(),
-                    "asinf" => f.asin(),
-                    "atanf" => f.atan(),
-                    "log1pf" => f.ln_1p(),
-                    "expm1f" => f.exp_m1(),
-                    "tgammaf" => f.gamma(),
+                    "cbrtf" => f_host.cbrt(),
+                    "coshf" => f_host.cosh(),
+                    "sinhf" => f_host.sinh(),
+                    "tanf" => f_host.tan(),
+                    "tanhf" => f_host.tanh(),
+                    "acosf" => f_host.acos(),
+                    "asinf" => f_host.asin(),
+                    "atanf" => f_host.atan(),
+                    "log1pf" => f_host.ln_1p(),
+                    "expm1f" => f_host.exp_m1(),
+                    "tgammaf" => f_host.gamma(),
                     _ => bug!(),
                 };
-                this.write_scalar(Scalar::from_u32(res.to_bits()), dest)?;
+                let res = res.to_soft();
+                let res = this.adjust_nan(res, &[f]);
+                this.write_scalar(res, dest)?;
             }
             #[rustfmt::skip]
             | "_hypotf"
@@ -911,19 +915,20 @@ trait EvalContextExtPriv<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
             | "fdimf"
             => {
                 let [f1, f2] = this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?;
+                let f1 = this.read_scalar(f1)?.to_f32()?;
+                let f2 = this.read_scalar(f2)?.to_f32()?;
                 // underscore case for windows, here and below
                 // (see https://docs.microsoft.com/en-us/cpp/c-runtime-library/reference/floating-point-primitives?view=vs-2019)
                 // FIXME: Using host floats.
-                let f1 = f32::from_bits(this.read_scalar(f1)?.to_u32()?);
-                let f2 = f32::from_bits(this.read_scalar(f2)?.to_u32()?);
                 let res = match link_name.as_str() {
-                    "_hypotf" | "hypotf" => f1.hypot(f2),
-                    "atan2f" => f1.atan2(f2),
+                    "_hypotf" | "hypotf" => f1.to_host().hypot(f2.to_host()).to_soft(),
+                    "atan2f" => f1.to_host().atan2(f2.to_host()).to_soft(),
                     #[allow(deprecated)]
-                    "fdimf" => f1.abs_sub(f2),
+                    "fdimf" => f1.to_host().abs_sub(f2.to_host()).to_soft(),
                     _ => bug!(),
                 };
-                this.write_scalar(Scalar::from_u32(res.to_bits()), dest)?;
+                let res = this.adjust_nan(res, &[f1, f2]);
+                this.write_scalar(res, dest)?;
             }
             #[rustfmt::skip]
             | "cbrt"
@@ -939,23 +944,26 @@ trait EvalContextExtPriv<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
             | "tgamma"
             => {
                 let [f] = this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?;
+                let f = this.read_scalar(f)?.to_f64()?;
                 // FIXME: Using host floats.
-                let f = f64::from_bits(this.read_scalar(f)?.to_u64()?);
+                let f_host = f.to_host();
                 let res = match link_name.as_str() {
-                    "cbrt" => f.cbrt(),
-                    "cosh" => f.cosh(),
-                    "sinh" => f.sinh(),
-                    "tan" => f.tan(),
-                    "tanh" => f.tanh(),
-                    "acos" => f.acos(),
-                    "asin" => f.asin(),
-                    "atan" => f.atan(),
-                    "log1p" => f.ln_1p(),
-                    "expm1" => f.exp_m1(),
-                    "tgamma" => f.gamma(),
+                    "cbrt" => f_host.cbrt(),
+                    "cosh" => f_host.cosh(),
+                    "sinh" => f_host.sinh(),
+                    "tan" => f_host.tan(),
+                    "tanh" => f_host.tanh(),
+                    "acos" => f_host.acos(),
+                    "asin" => f_host.asin(),
+                    "atan" => f_host.atan(),
+                    "log1p" => f_host.ln_1p(),
+                    "expm1" => f_host.exp_m1(),
+                    "tgamma" => f_host.gamma(),
                     _ => bug!(),
                 };
-                this.write_scalar(Scalar::from_u64(res.to_bits()), dest)?;
+                let res = res.to_soft();
+                let res = this.adjust_nan(res, &[f]);
+                this.write_scalar(res, dest)?;
             }
             #[rustfmt::skip]
             | "_hypot"
@@ -964,17 +972,20 @@ trait EvalContextExtPriv<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
             | "fdim"
             => {
                 let [f1, f2] = this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?;
+                let f1 = this.read_scalar(f1)?.to_f64()?;
+                let f2 = this.read_scalar(f2)?.to_f64()?;
+                // underscore case for windows, here and below
+                // (see https://docs.microsoft.com/en-us/cpp/c-runtime-library/reference/floating-point-primitives?view=vs-2019)
                 // FIXME: Using host floats.
-                let f1 = f64::from_bits(this.read_scalar(f1)?.to_u64()?);
-                let f2 = f64::from_bits(this.read_scalar(f2)?.to_u64()?);
                 let res = match link_name.as_str() {
-                    "_hypot" | "hypot" => f1.hypot(f2),
-                    "atan2" => f1.atan2(f2),
+                    "_hypot" | "hypot" => f1.to_host().hypot(f2.to_host()).to_soft(),
+                    "atan2" => f1.to_host().atan2(f2.to_host()).to_soft(),
                     #[allow(deprecated)]
-                    "fdim" => f1.abs_sub(f2),
+                    "fdim" => f1.to_host().abs_sub(f2.to_host()).to_soft(),
                     _ => bug!(),
                 };
-                this.write_scalar(Scalar::from_u64(res.to_bits()), dest)?;
+                let res = this.adjust_nan(res, &[f1, f2]);
+                this.write_scalar(res, dest)?;
             }
             #[rustfmt::skip]
             | "_ldexp"
@@ -987,27 +998,30 @@ trait EvalContextExtPriv<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                 let exp = this.read_scalar(exp)?.to_i32()?;
 
                 let res = x.scalbn(exp);
-                this.write_scalar(Scalar::from_f64(res), dest)?;
+                let res = this.adjust_nan(res, &[x]);
+                this.write_scalar(res, dest)?;
             }
             "lgammaf_r" => {
                 let [x, signp] = this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?;
-                // FIXME: Using host floats.
-                let x = f32::from_bits(this.read_scalar(x)?.to_u32()?);
+                let x = this.read_scalar(x)?.to_f32()?;
                 let signp = this.deref_pointer(signp)?;
 
-                let (res, sign) = x.ln_gamma();
+                // FIXME: Using host floats.
+                let (res, sign) = x.to_host().ln_gamma();
                 this.write_int(sign, &signp)?;
-                this.write_scalar(Scalar::from_u32(res.to_bits()), dest)?;
+                let res = this.adjust_nan(res.to_soft(), &[x]);
+                this.write_scalar(res, dest)?;
             }
             "lgamma_r" => {
                 let [x, signp] = this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?;
-                // FIXME: Using host floats.
-                let x = f64::from_bits(this.read_scalar(x)?.to_u64()?);
+                let x = this.read_scalar(x)?.to_f64()?;
                 let signp = this.deref_pointer(signp)?;
 
-                let (res, sign) = x.ln_gamma();
+                // FIXME: Using host floats.
+                let (res, sign) = x.to_host().ln_gamma();
                 this.write_int(sign, &signp)?;
-                this.write_scalar(Scalar::from_u64(res.to_bits()), dest)?;
+                let res = this.adjust_nan(res.to_soft(), &[x]);
+                this.write_scalar(res, dest)?;
             }
 
             // LLVM intrinsics