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solsonsolson
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Merge pull request #42 from oli-obk/floating_in_space
implement floats by running the ops on the host architecture
2 parents a7cc77a + 7613ef0 commit f4afb59

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4 files changed

+114
-3
lines changed

4 files changed

+114
-3
lines changed

‎src/interpreter/mod.rs‎

Lines changed: 16 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -169,7 +169,7 @@ impl<'a, 'tcx> EvalContext<'a, 'tcx> {
169169
// TODO(solson): Try making const_to_primval instead.
170170
fn const_to_ptr(&mut self, const_val: &const_val::ConstVal) -> EvalResult<'tcx, Pointer> {
171171
use rustc::middle::const_val::ConstVal::*;
172-
use rustc_const_math::{ConstInt, ConstIsize, ConstUsize};
172+
use rustc_const_math::{ConstInt, ConstIsize, ConstUsize, ConstFloat};
173173
macro_rules! i2p {
174174
($i:ident, $n:expr) => {{
175175
let ptr = self.memory.allocate($n);
@@ -178,7 +178,17 @@ impl<'a, 'tcx> EvalContext<'a, 'tcx> {
178178
}}
179179
}
180180
match *const_val {
181-
Float(_f) => unimplemented!(),
181+
Float(ConstFloat::F32(f)) => {
182+
let ptr = self.memory.allocate(4);
183+
self.memory.write_f32(ptr, f)?;
184+
Ok(ptr)
185+
},
186+
Float(ConstFloat::F64(f)) => {
187+
let ptr = self.memory.allocate(8);
188+
self.memory.write_f64(ptr, f)?;
189+
Ok(ptr)
190+
},
191+
Float(ConstFloat::FInfer{..}) => unreachable!(),
182192
Integral(ConstInt::Infer(_)) => unreachable!(),
183193
Integral(ConstInt::InferSigned(_)) => unreachable!(),
184194
Integral(ConstInt::I8(i)) => i2p!(i, 1),
@@ -824,7 +834,7 @@ impl<'a, 'tcx> EvalContext<'a, 'tcx> {
824834
}
825835

826836
pub fn read_primval(&mut self, ptr: Pointer, ty: Ty<'tcx>) -> EvalResult<'tcx, PrimVal> {
827-
use syntax::ast::{IntTy, UintTy};
837+
use syntax::ast::{IntTy, UintTy, FloatTy};
828838
let val = match (self.memory.pointer_size(), &ty.sty) {
829839
(_, &ty::TyBool) => PrimVal::Bool(self.memory.read_bool(ptr)?),
830840
(_, &ty::TyChar) => {
@@ -849,6 +859,9 @@ impl<'a, 'tcx> EvalContext<'a, 'tcx> {
849859
(8, &ty::TyUint(UintTy::Us)) |
850860
(_, &ty::TyUint(UintTy::U64)) => PrimVal::U64(self.memory.read_uint(ptr, 8)? as u64),
851861

862+
(_, &ty::TyFloat(FloatTy::F32)) => PrimVal::F32(self.memory.read_f32(ptr)?),
863+
(_, &ty::TyFloat(FloatTy::F64)) => PrimVal::F64(self.memory.read_f64(ptr)?),
864+
852865
(_, &ty::TyFnDef(def_id, substs, fn_ty)) => {
853866
PrimVal::FnPtr(self.memory.create_fn_ptr(def_id, substs, fn_ty))
854867
},

‎src/memory.rs‎

Lines changed: 54 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -407,6 +407,8 @@ impl<'a, 'tcx> Memory<'a, 'tcx> {
407407
PrimVal::U64(n) => self.write_uint(ptr, n as u64, 8),
408408
PrimVal::Char(c) => self.write_uint(ptr, c as u64, 4),
409409
PrimVal::IntegerPtr(n) => self.write_uint(ptr, n as u64, pointer_size),
410+
PrimVal::F32(f) => self.write_f32(ptr, f),
411+
PrimVal::F64(f) => self.write_f64(ptr, f),
410412
PrimVal::FnPtr(_p) |
411413
PrimVal::AbstractPtr(_p) => unimplemented!(),
412414
}
@@ -464,6 +466,28 @@ impl<'a, 'tcx> Memory<'a, 'tcx> {
464466
let size = self.pointer_size();
465467
self.write_uint(ptr, n, size)
466468
}
469+
470+
pub fn write_f32(&mut self, ptr: Pointer, f: f32) -> EvalResult<'tcx, ()> {
471+
let endianess = self.endianess();
472+
let b = self.get_bytes_mut(ptr, 4)?;
473+
write_target_f32(endianess, b, f).unwrap();
474+
Ok(())
475+
}
476+
477+
pub fn write_f64(&mut self, ptr: Pointer, f: f64) -> EvalResult<'tcx, ()> {
478+
let endianess = self.endianess();
479+
let b = self.get_bytes_mut(ptr, 8)?;
480+
write_target_f64(endianess, b, f).unwrap();
481+
Ok(())
482+
}
483+
484+
pub fn read_f32(&self, ptr: Pointer) -> EvalResult<'tcx, f32> {
485+
self.get_bytes(ptr, 4).map(|b| read_target_f32(self.endianess(), b).unwrap())
486+
}
487+
488+
pub fn read_f64(&self, ptr: Pointer) -> EvalResult<'tcx, f64> {
489+
self.get_bytes(ptr, 8).map(|b| read_target_f64(self.endianess(), b).unwrap())
490+
}
467491
}
468492

469493
/// Relocations
@@ -586,6 +610,36 @@ fn read_target_int(endianess: layout::Endian, mut source: &[u8]) -> Result<i64,
586610
}
587611
}
588612

613+
////////////////////////////////////////////////////////////////////////////////
614+
// Methods to access floats in the target endianess
615+
////////////////////////////////////////////////////////////////////////////////
616+
617+
fn write_target_f32(endianess: layout::Endian, mut target: &mut [u8], data: f32) -> Result<(), byteorder::Error> {
618+
match endianess {
619+
layout::Endian::Little => target.write_f32::<LittleEndian>(data),
620+
layout::Endian::Big => target.write_f32::<BigEndian>(data),
621+
}
622+
}
623+
fn write_target_f64(endianess: layout::Endian, mut target: &mut [u8], data: f64) -> Result<(), byteorder::Error> {
624+
match endianess {
625+
layout::Endian::Little => target.write_f64::<LittleEndian>(data),
626+
layout::Endian::Big => target.write_f64::<BigEndian>(data),
627+
}
628+
}
629+
630+
fn read_target_f32(endianess: layout::Endian, mut source: &[u8]) -> Result<f32, byteorder::Error> {
631+
match endianess {
632+
layout::Endian::Little => source.read_f32::<LittleEndian>(),
633+
layout::Endian::Big => source.read_f32::<BigEndian>(),
634+
}
635+
}
636+
fn read_target_f64(endianess: layout::Endian, mut source: &[u8]) -> Result<f64, byteorder::Error> {
637+
match endianess {
638+
layout::Endian::Little => source.read_f64::<LittleEndian>(),
639+
layout::Endian::Big => source.read_f64::<BigEndian>(),
640+
}
641+
}
642+
589643
////////////////////////////////////////////////////////////////////////////////
590644
// Undefined byte tracking
591645
////////////////////////////////////////////////////////////////////////////////

‎src/primval.rs‎

Lines changed: 33 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -13,6 +13,8 @@ pub enum PrimVal {
1313
FnPtr(Pointer),
1414
IntegerPtr(u64),
1515
Char(char),
16+
17+
F32(f32), F64(f64),
1618
}
1719

1820
/// returns the result of the operation and whether the operation overflowed
@@ -57,6 +59,32 @@ pub fn binary_op<'tcx>(bin_op: mir::BinOp, left: PrimVal, right: PrimVal) -> Eva
5759
})
5860
}
5961

62+
macro_rules! float_binops {
63+
($v:ident, $l:ident, $r:ident) => ({
64+
match bin_op {
65+
Add => $v($l + $r),
66+
Sub => $v($l - $r),
67+
Mul => $v($l * $r),
68+
Div => $v($l / $r),
69+
Rem => $v($l % $r),
70+
71+
// invalid float ops
72+
BitXor => unreachable!(),
73+
BitAnd => unreachable!(),
74+
BitOr => unreachable!(),
75+
Shl => unreachable!(),
76+
Shr => unreachable!(),
77+
78+
Eq => Bool($l == $r),
79+
Ne => Bool($l != $r),
80+
Lt => Bool($l < $r),
81+
Le => Bool($l <= $r),
82+
Gt => Bool($l > $r),
83+
Ge => Bool($l >= $r),
84+
}
85+
})
86+
}
87+
6088
fn unrelated_ptr_ops<'tcx>(bin_op: mir::BinOp) -> EvalResult<'tcx, PrimVal> {
6189
use rustc::mir::repr::BinOp::*;
6290
match bin_op {
@@ -128,6 +156,8 @@ pub fn binary_op<'tcx>(bin_op: mir::BinOp, left: PrimVal, right: PrimVal) -> Eva
128156
(U16(l), U16(r)) => int_binops!(U16, l, r),
129157
(U32(l), U32(r)) => int_binops!(U32, l, r),
130158
(U64(l), U64(r)) => int_binops!(U64, l, r),
159+
(F32(l), F32(r)) => float_binops!(F32, l, r),
160+
(F64(l), F64(r)) => float_binops!(F64, l, r),
131161
(Char(l), Char(r)) => match bin_op {
132162
Eq => Bool(l == r),
133163
Ne => Bool(l != r),
@@ -211,6 +241,9 @@ pub fn unary_op<'tcx>(un_op: mir::UnOp, val: PrimVal) -> EvalResult<'tcx, PrimVa
211241
(Not, U16(n)) => Ok(U16(!n)),
212242
(Not, U32(n)) => Ok(U32(!n)),
213243
(Not, U64(n)) => Ok(U64(!n)),
244+
245+
(Neg, F64(n)) => Ok(F64(-n)),
246+
(Neg, F32(n)) => Ok(F32(-n)),
214247
_ => Err(EvalError::Unimplemented(format!("unimplemented unary op: {:?}, {:?}", un_op, val))),
215248
}
216249
}

‎tests/run-pass/floats.rs‎

Lines changed: 11 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,11 @@
1+
2+
fn main() {
3+
assert_eq!(6.0_f32*6.0_f32, 36.0_f32);
4+
assert_eq!(6.0_f64*6.0_f64, 36.0_f64);
5+
assert_eq!(-{5.0_f32}, -5.0_f32);
6+
assert!((5.0_f32/0.0).is_infinite());
7+
assert!((-5.0_f32).sqrt().is_nan());
8+
let x: u64 = unsafe { std::mem::transmute(42.0_f64) };
9+
let y: f64 = unsafe { std::mem::transmute(x) };
10+
assert_eq!(y, 42.0_f64);
11+
}

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