miri: shims for erf & friends

Author: GrigorenkoPV

src/tools/miri/src/lib.rs

@@ -2,6 +2,7 @@
 #![feature(rustc_private)]
 #![feature(cell_update)]
 #![feature(float_gamma)]
+#![feature(float_erf)]
 #![feature(map_try_insert)]
 #![feature(never_type)]
 #![feature(try_blocks)]

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

@@ -742,6 +742,8 @@ trait EvalContextExtPriv<'tcx>: crate::MiriInterpCxExt<'tcx> {
             | "log1pf"
             | "expm1f"
             | "tgammaf"
+            | "erff"
+            | "erfcf"
             => {
                 let [f] = this.check_shim(abi, Conv::C , link_name, args)?;
                 let f = this.read_scalar(f)?.to_f32()?;
@@ -759,6 +761,8 @@ trait EvalContextExtPriv<'tcx>: crate::MiriInterpCxExt<'tcx> {
                     "log1pf" => f_host.ln_1p(),
                     "expm1f" => f_host.exp_m1(),
                     "tgammaf" => f_host.gamma(),
+                    "erff" => f_host.erf(),
+                    "erfcf" => f_host.erfc(),
                     _ => bug!(),
                 };
                 let res = res.to_soft();
@@ -799,6 +803,8 @@ trait EvalContextExtPriv<'tcx>: crate::MiriInterpCxExt<'tcx> {
             | "log1p"
             | "expm1"
             | "tgamma"
+            | "erf"
+            | "erfc"
             => {
                 let [f] = this.check_shim(abi, Conv::C , link_name, args)?;
                 let f = this.read_scalar(f)?.to_f64()?;
@@ -816,6 +822,8 @@ trait EvalContextExtPriv<'tcx>: crate::MiriInterpCxExt<'tcx> {
                     "log1p" => f_host.ln_1p(),
                     "expm1" => f_host.exp_m1(),
                     "tgamma" => f_host.gamma(),
+                    "erf" => f_host.erf(),
+                    "erfc" => f_host.erfc(),
                     _ => bug!(),
                 };
                 let res = res.to_soft();

src/tools/miri/tests/pass/float.rs

@@ -1,4 +1,5 @@
 #![feature(stmt_expr_attributes)]
+#![feature(float_erf)]
 #![feature(float_gamma)]
 #![feature(core_intrinsics)]
 #![feature(f128)]
@@ -1076,6 +1077,11 @@ pub fn libm() {
     let (val, sign) = (-0.5f64).ln_gamma();
     assert_approx_eq!(val, (2.0 * f64::consts::PI.sqrt()).ln());
     assert_eq!(sign, -1);
+
+    assert_approx_eq!(1.0f32.erf(), 0.84270079294971486934122063508260926f32);
+    assert_approx_eq!(1.0f64.erf(), 0.84270079294971486934122063508260926f64);
+    assert_approx_eq!(1.0f32.erfc(), 0.15729920705028513065877936491739074f32);
+    assert_approx_eq!(1.0f64.erfc(), 0.15729920705028513065877936491739074f64);
 }
 
 fn test_fast() {