diff --git a/rust-version b/rust-version
index b72e1f53ef..8ef35afca0 100644
--- a/rust-version
+++ b/rust-version
@@ -1 +1 @@
-1cbd8a4d686d1411105f26cddf876c5994e69593
+8e948df707ea8a3c88c65bf2ffdcb2f1cf5491be
diff --git a/src/fn_call.rs b/src/fn_call.rs
index e9377d89bc..3d2c523bf7 100644
--- a/src/fn_call.rs
+++ b/src/fn_call.rs
@@ -758,7 +758,7 @@ pub trait EvalContextExt<'a, 'mir, 'tcx: 'a + 'mir>: crate::MiriEvalContextExt<'
                 this.machine.last_error = err;
             }
             "GetLastError" => {
-                this.write_scalar(Scalar::from_uint(this.machine.last_error, Size::from_bits(32)), dest)?;
+                this.write_scalar(Scalar::from_u32(this.machine.last_error), dest)?;
             }
 
             "AddVectoredExceptionHandler" => {
@@ -854,7 +854,7 @@ pub trait EvalContextExt<'a, 'mir, 'tcx: 'a + 'mir>: crate::MiriEvalContextExt<'
                 };
                 // If there was no error, write back how much was written.
                 if let Some(n) = written {
-                    this.write_scalar(Scalar::from_uint(n, Size::from_bits(32)), written_place.into())?;
+                    this.write_scalar(Scalar::from_u32(n), written_place.into())?;
                 }
                 // Return whether this was a success.
                 this.write_scalar(
diff --git a/src/intrinsic.rs b/src/intrinsic.rs
index 822265bc21..451a97eeed 100644
--- a/src/intrinsic.rs
+++ b/src/intrinsic.rs
@@ -1,3 +1,4 @@
+use rustc_apfloat::Float;
 use rustc::mir;
 use rustc::mir::interpret::{InterpResult, PointerArithmetic};
 use rustc::ty::layout::{self, LayoutOf, Size};
@@ -186,7 +187,8 @@ pub trait EvalContextExt<'a, 'mir, 'tcx: 'a+'mir>: crate::MiriEvalContextExt<'a,
 
             "sinf32" | "fabsf32" | "cosf32" | "sqrtf32" | "expf32" | "exp2f32" | "logf32" |
             "log10f32" | "log2f32" | "floorf32" | "ceilf32" | "truncf32" => {
-                let f = this.read_scalar(args[0])?.to_f32()?;
+                // FIXME: Using host floats.
+                let f = f32::from_bits(this.read_scalar(args[0])?.to_u32()?);
                 let f = match intrinsic_name.get() {
                     "sinf32" => f.sin(),
                     "fabsf32" => f.abs(),
@@ -202,12 +204,13 @@ pub trait EvalContextExt<'a, 'mir, 'tcx: 'a+'mir>: crate::MiriEvalContextExt<'a,
                     "truncf32" => f.trunc(),
                     _ => bug!(),
                 };
-                this.write_scalar(Scalar::from_f32(f), dest)?;
+                this.write_scalar(Scalar::from_u32(f.to_bits()), dest)?;
             }
 
             "sinf64" | "fabsf64" | "cosf64" | "sqrtf64" | "expf64" | "exp2f64" | "logf64" |
             "log10f64" | "log2f64" | "floorf64" | "ceilf64" | "truncf64" => {
-                let f = this.read_scalar(args[0])?.to_f64()?;
+                // FIXME: Using host floats.
+                let f = f64::from_bits(this.read_scalar(args[0])?.to_u64()?);
                 let f = match intrinsic_name.get() {
                     "sinf64" => f.sin(),
                     "fabsf64" => f.abs(),
@@ -223,7 +226,7 @@ pub trait EvalContextExt<'a, 'mir, 'tcx: 'a+'mir>: crate::MiriEvalContextExt<'a,
                     "truncf64" => f.trunc(),
                     _ => bug!(),
                 };
-                this.write_scalar(Scalar::from_f64(f), dest)?;
+                this.write_scalar(Scalar::from_u64(f.to_bits()), dest)?;
             }
 
             "fadd_fast" | "fsub_fast" | "fmul_fast" | "fdiv_fast" | "frem_fast" => {
@@ -240,6 +243,28 @@ pub trait EvalContextExt<'a, 'mir, 'tcx: 'a+'mir>: crate::MiriEvalContextExt<'a,
                 this.binop_ignore_overflow(op, a, b, dest)?;
             }
 
+            "minnumf32" | "maxnumf32" => {
+                let a = this.read_scalar(args[0])?.to_f32()?;
+                let b = this.read_scalar(args[1])?.to_f32()?;
+                let res = if intrinsic_name.get().starts_with("min") {
+                    a.min(b)
+                } else {
+                    a.max(b)
+                };
+                this.write_scalar(Scalar::from_f32(res), dest)?;
+            }
+
+            "minnumf64" | "maxnumf64" => {
+                let a = this.read_scalar(args[0])?.to_f64()?;
+                let b = this.read_scalar(args[1])?.to_f64()?;
+                let res = if intrinsic_name.get().starts_with("min") {
+                    a.min(b)
+                } else {
+                    a.max(b)
+                };
+                this.write_scalar(Scalar::from_f64(res), dest)?;
+            }
+
             "exact_div" => {
                 // Performs an exact division, resulting in undefined behavior where
                 // `x % y != 0` or `y == 0` or `x == T::min_value() && y == -1`
@@ -320,19 +345,21 @@ pub trait EvalContextExt<'a, 'mir, 'tcx: 'a+'mir>: crate::MiriEvalContextExt<'a,
             }
 
             "powf32" => {
-                let f = this.read_scalar(args[0])?.to_f32()?;
-                let f2 = this.read_scalar(args[1])?.to_f32()?;
+                // FIXME: Using host floats.
+                let f = f32::from_bits(this.read_scalar(args[0])?.to_u32()?);
+                let f2 = f32::from_bits(this.read_scalar(args[1])?.to_u32()?);
                 this.write_scalar(
-                    Scalar::from_f32(f.powf(f2)),
+                    Scalar::from_u32(f.powf(f2).to_bits()),
                     dest,
                 )?;
             }
 
             "powf64" => {
-                let f = this.read_scalar(args[0])?.to_f64()?;
-                let f2 = this.read_scalar(args[1])?.to_f64()?;
+                // FIXME: Using host floats.
+                let f = f64::from_bits(this.read_scalar(args[0])?.to_u64()?);
+                let f2 = f64::from_bits(this.read_scalar(args[1])?.to_u64()?);
                 this.write_scalar(
-                    Scalar::from_f64(f.powf(f2)),
+                    Scalar::from_u64(f.powf(f2).to_bits()),
                     dest,
                 )?;
             }
@@ -341,8 +368,9 @@ pub trait EvalContextExt<'a, 'mir, 'tcx: 'a+'mir>: crate::MiriEvalContextExt<'a,
                 let a = this.read_scalar(args[0])?.to_f32()?;
                 let b = this.read_scalar(args[1])?.to_f32()?;
                 let c = this.read_scalar(args[2])?.to_f32()?;
+                let res = a.mul_add(b, c).value;
                 this.write_scalar(
-                    Scalar::from_f32(a * b + c),
+                    Scalar::from_f32(res),
                     dest,
                 )?;
             }
@@ -351,26 +379,29 @@ pub trait EvalContextExt<'a, 'mir, 'tcx: 'a+'mir>: crate::MiriEvalContextExt<'a,
                 let a = this.read_scalar(args[0])?.to_f64()?;
                 let b = this.read_scalar(args[1])?.to_f64()?;
                 let c = this.read_scalar(args[2])?.to_f64()?;
+                let res = a.mul_add(b, c).value;
                 this.write_scalar(
-                    Scalar::from_f64(a * b + c),
+                    Scalar::from_f64(res),
                     dest,
                 )?;
             }
 
             "powif32" => {
-                let f = this.read_scalar(args[0])?.to_f32()?;
+                // FIXME: Using host floats.
+                let f = f32::from_bits(this.read_scalar(args[0])?.to_u32()?);
                 let i = this.read_scalar(args[1])?.to_i32()?;
                 this.write_scalar(
-                    Scalar::from_f32(f.powi(i)),
+                    Scalar::from_u32(f.powi(i).to_bits()),
                     dest,
                 )?;
             }
 
             "powif64" => {
-                let f = this.read_scalar(args[0])?.to_f64()?;
+                // FIXME: Using host floats.
+                let f = f64::from_bits(this.read_scalar(args[0])?.to_u64()?);
                 let i = this.read_scalar(args[1])?.to_i32()?;
                 this.write_scalar(
-                    Scalar::from_f64(f.powi(i)),
+                    Scalar::from_u64(f.powi(i).to_bits()),
                     dest,
                 )?;
             }
diff --git a/src/lib.rs b/src/lib.rs
index d0b7111bb0..d2b20db06d 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -6,8 +6,8 @@
 extern crate log;
 // From rustc.
 extern crate syntax;
-#[macro_use]
-extern crate rustc;
+extern crate rustc_apfloat;
+#[macro_use] extern crate rustc;
 extern crate rustc_data_structures;
 extern crate rustc_mir;
 extern crate rustc_target;
diff --git a/tests/run-pass/c_enums.rs b/tests/run-pass/c_enums.rs
index 11897b73eb..16b795342e 100644
--- a/tests/run-pass/c_enums.rs
+++ b/tests/run-pass/c_enums.rs
@@ -11,11 +11,13 @@ enum Signed {
 }
 
 fn foo() -> [u8; 3] {
-    [Foo::Bar as u8, Foo::Baz as u8, Foo::Quux as u8]
+    let baz = Foo::Baz; // let-expansion changes the MIR significantly
+    [Foo::Bar as u8, baz as u8, Foo::Quux as u8]
 }
 
 fn signed() -> [i8; 3] {
-    [Signed::Bar as i8, Signed::Baz as i8, Signed::Quux as i8]
+    let baz = Signed::Baz; // let-expansion changes the MIR significantly
+    [Signed::Bar as i8, baz as i8, Signed::Quux as i8]
 }
 
 fn unsafe_match() -> bool {
diff --git a/tests/run-pass/floats.rs b/tests/run-pass/floats.rs
index 39fdbce492..c1588dae24 100644
--- a/tests/run-pass/floats.rs
+++ b/tests/run-pass/floats.rs
@@ -1,4 +1,3 @@
-
 fn main() {
     assert_eq!(6.0_f32*6.0_f32, 36.0_f32);
     assert_eq!(6.0_f64*6.0_f64, 36.0_f64);
@@ -12,4 +11,18 @@ fn main() {
     assert_eq!(5.0f32 as u32, 5);
     assert_eq!(5.0f32 as i32, 5);
     assert_eq!(-5.0f32 as i32, -5);
+
+    assert_eq!((1.0 as f32).max(-1.0), 1.0);
+    assert_eq!((1.0 as f32).min(-1.0), -1.0);
+    assert_eq!(std::f32::NAN.min(9.0), 9.0);
+    assert_eq!(std::f32::NAN.max(-9.0), -9.0);
+    assert_eq!((9.0 as f32).min(std::f32::NAN), 9.0);
+    assert_eq!((-9.0 as f32).max(std::f32::NAN), -9.0);
+
+    assert_eq!((1.0 as f64).max(-1.0), 1.0);
+    assert_eq!((1.0 as f64).min(-1.0), -1.0);
+    assert_eq!(std::f64::NAN.min(9.0), 9.0);
+    assert_eq!(std::f64::NAN.max(-9.0), -9.0);
+    assert_eq!((9.0 as f64).min(std::f64::NAN), 9.0);
+    assert_eq!((-9.0 as f64).max(std::f64::NAN), -9.0);
 }
diff --git a/tests/run-pass/intrinsics-math.rs b/tests/run-pass/intrinsics-math.rs
index a2c5563474..6b3d15a509 100644
--- a/tests/run-pass/intrinsics-math.rs
+++ b/tests/run-pass/intrinsics-math.rs
@@ -50,8 +50,10 @@ pub fn main() {
     assert_approx_eq!(8f32.log2(), 3f32);
     assert_approx_eq!(f64::consts::E.log2(), f64::consts::LOG2_E);
 
-    assert_approx_eq!(1.0f32.mul_add(2.0f32, 5.0f32), 7.0f32);
-    assert_approx_eq!(0.0f64.mul_add(-2.0f64, f64::consts::E), f64::consts::E);
+    assert_approx_eq!(3.0f32.mul_add(2.0f32, 5.0f32), 11.0);
+    assert_eq!(0.0f32.mul_add(-2.0, f32::consts::E), f32::consts::E);
+    assert_approx_eq!(3.0f64.mul_add(2.0, 5.0), 11.0);
+    assert_eq!(0.0f64.mul_add(-2.0f64, f64::consts::E), f64::consts::E);
 
     assert_approx_eq!((-1.0f32).abs(), 1.0f32);
     assert_approx_eq!(34.2f64.abs(), 34.2f64);