rust/src/test/run-pass/saturating-float-casts.rs
Alex Crichton 666bb90300 wasm: Update LLVM to fix a test
This commit updates LLVM with some tweaks to the integer <-> floating point
conversion instructions to ensure that `as` in Rust doesn't trap.

Closes #46298
2017-11-30 05:39:57 -08:00

145 lines
5.2 KiB
Rust

// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
// Tests saturating float->int casts. See u128-as-f32.rs for the opposite direction.
// compile-flags: -Z saturating-float-casts
#![feature(test, i128, i128_type, stmt_expr_attributes)]
#![deny(overflowing_literals)]
extern crate test;
use std::{f32, f64};
use std::{u8, i8, u16, i16, u32, i32, u64, i64};
#[cfg(not(target_os="emscripten"))]
use std::{u128, i128};
use test::black_box;
macro_rules! test {
($val:expr, $src_ty:ident -> $dest_ty:ident, $expected:expr) => (
// black_box disables constant evaluation to test run-time conversions:
assert_eq!(black_box::<$src_ty>($val) as $dest_ty, $expected,
"run-time {} -> {}", stringify!($src_ty), stringify!($dest_ty));
);
($fval:expr, f* -> $ity:ident, $ival:expr) => (
test!($fval, f32 -> $ity, $ival);
test!($fval, f64 -> $ity, $ival);
)
}
// This macro tests const eval in addition to run-time evaluation.
// If and when saturating casts are adopted, this macro should be merged with test!() to ensure
// that run-time and const eval agree on inputs that currently trigger a const eval error.
macro_rules! test_c {
($val:expr, $src_ty:ident -> $dest_ty:ident, $expected:expr) => ({
test!($val, $src_ty -> $dest_ty, $expected);
{
const X: $src_ty = $val;
const Y: $dest_ty = X as $dest_ty;
assert_eq!(Y, $expected,
"const eval {} -> {}", stringify!($src_ty), stringify!($dest_ty));
}
});
($fval:expr, f* -> $ity:ident, $ival:expr) => (
test_c!($fval, f32 -> $ity, $ival);
test_c!($fval, f64 -> $ity, $ival);
)
}
macro_rules! common_fptoi_tests {
($fty:ident -> $($ity:ident)+) => ({ $(
test!($fty::NAN, $fty -> $ity, 0);
test!($fty::INFINITY, $fty -> $ity, $ity::MAX);
test!($fty::NEG_INFINITY, $fty -> $ity, $ity::MIN);
// These two tests are not solely float->int tests, in particular the latter relies on
// `u128::MAX as f32` not being UB. But that's okay, since this file tests int->float
// as well, the test is just slightly misplaced.
test!($ity::MIN as $fty, $fty -> $ity, $ity::MIN);
test!($ity::MAX as $fty, $fty -> $ity, $ity::MAX);
test_c!(0., $fty -> $ity, 0);
test_c!($fty::MIN_POSITIVE, $fty -> $ity, 0);
test!(-0.9, $fty -> $ity, 0);
test_c!(1., $fty -> $ity, 1);
test_c!(42., $fty -> $ity, 42);
)+ });
(f* -> $($ity:ident)+) => ({
common_fptoi_tests!(f32 -> $($ity)+);
common_fptoi_tests!(f64 -> $($ity)+);
})
}
macro_rules! fptoui_tests {
($fty: ident -> $($ity: ident)+) => ({ $(
test!(-0., $fty -> $ity, 0);
test!(-$fty::MIN_POSITIVE, $fty -> $ity, 0);
test!(-0.99999994, $fty -> $ity, 0);
test!(-1., $fty -> $ity, 0);
test!(-100., $fty -> $ity, 0);
test!(#[allow(overflowing_literals)] -1e50, $fty -> $ity, 0);
test!(#[allow(overflowing_literals)] -1e130, $fty -> $ity, 0);
)+ });
(f* -> $($ity:ident)+) => ({
fptoui_tests!(f32 -> $($ity)+);
fptoui_tests!(f64 -> $($ity)+);
})
}
pub fn main() {
common_fptoi_tests!(f* -> i8 i16 i32 i64 u8 u16 u32 u64);
fptoui_tests!(f* -> u8 u16 u32 u64);
// FIXME emscripten does not support i128
#[cfg(not(target_os="emscripten"))] {
common_fptoi_tests!(f* -> i128 u128);
fptoui_tests!(f* -> u128);
}
// The following tests cover edge cases for some integer types.
// # u8
test_c!(254., f* -> u8, 254);
test!(256., f* -> u8, 255);
// # i8
test_c!(-127., f* -> i8, -127);
test!(-129., f* -> i8, -128);
test_c!(126., f* -> i8, 126);
test!(128., f* -> i8, 127);
// # i32
// -2147483648. is i32::MIN (exactly)
test_c!(-2147483648., f* -> i32, i32::MIN);
// 2147483648. is i32::MAX rounded up
test!(2147483648., f32 -> i32, 2147483647);
// With 24 significand bits, floats with magnitude in [2^30 + 1, 2^31] are rounded to
// multiples of 2^7. Therefore, nextDown(round(i32::MAX)) is 2^31 - 128:
test_c!(2147483520., f32 -> i32, 2147483520);
// Similarly, nextUp(i32::MIN) is i32::MIN + 2^8 and nextDown(i32::MIN) is i32::MIN - 2^7
test!(-2147483904., f* -> i32, i32::MIN);
test_c!(-2147483520., f* -> i32, -2147483520);
// # u32
// round(MAX) and nextUp(round(MAX))
test_c!(4294967040., f* -> u32, 4294967040);
test!(4294967296., f* -> u32, 4294967295);
// # u128
#[cfg(not(target_os="emscripten"))]
{
// float->int:
test_c!(f32::MAX, f32 -> u128, 0xffffff00000000000000000000000000);
// nextDown(f32::MAX) = 2^128 - 2 * 2^104
const SECOND_LARGEST_F32: f32 = 340282326356119256160033759537265639424.;
test_c!(SECOND_LARGEST_F32, f32 -> u128, 0xfffffe00000000000000000000000000);
}
}