diff --git a/ci/run.sh b/ci/run.sh index 7dc9be1..3846049 100755 --- a/ci/run.sh +++ b/ci/run.sh @@ -28,6 +28,19 @@ case $1 in ;; esac +# Verify that there are no undefined symbols to `panic` within our implementations +# TODO(#79) fix the undefined references problem for debug-assertions+lto +case $1 in + thumb*) + RUSTFLAGS="-C debug-assertions=no -C link-arg=-nostartfiles" xargo rustc --features c --target $1 --bin intrinsics -- -C lto + xargo rustc --features c --target $1 --bin intrinsics --release -- -C lto + ;; + *) + RUSTFLAGS="-C debug-assertions=no" cargo rustc --features c --target $1 --bin intrinsics -- -C lto + cargo rustc --features c --target $1 --bin intrinsics --release -- -C lto + ;; +esac + # Look out for duplicated symbols when we include the compiler-rt (C) implementation PREFIX=$(echo $1 | sed -e 's/unknown-//')- case $1 in diff --git a/src/bin/intrinsics.rs b/src/bin/intrinsics.rs index 5e23485..e11e415 100644 --- a/src/bin/intrinsics.rs +++ b/src/bin/intrinsics.rs @@ -4,13 +4,14 @@ // to link due to the missing intrinsic (symbol). #![allow(unused_features)] +#![cfg_attr(thumb, no_main)] #![deny(dead_code)] +#![feature(asm)] #![feature(core_float)] #![feature(lang_items)] #![feature(libc)] #![feature(start)] #![no_std] -#![cfg_attr(thumb, no_main)] #[cfg(not(thumb))] extern crate libc; @@ -304,50 +305,56 @@ mod intrinsics { fn run() { use intrinsics::*; - aeabi_d2f(2.); - aeabi_d2i(2.); - aeabi_d2l(2.); - aeabi_d2uiz(2.); - aeabi_d2ulz(2.); - aeabi_dadd(2., 3.); - aeabi_dcmpeq(2., 3.); - aeabi_dcmpgt(2., 3.); - aeabi_dcmplt(2., 3.); - aeabi_ddiv(2., 3.); - aeabi_dmul(2., 3.); - aeabi_dsub(2., 3.); - aeabi_f2d(2.); - aeabi_f2iz(2.); - aeabi_f2lz(2.); - aeabi_f2uiz(2.); - aeabi_f2ulz(2.); - aeabi_fadd(2., 3.); - aeabi_fcmpeq(2., 3.); - aeabi_fcmpgt(2., 3.); - aeabi_fcmplt(2., 3.); - aeabi_fdiv(2., 3.); - aeabi_fmul(2., 3.); - aeabi_fsub(2., 3.); - aeabi_i2d(2); - aeabi_i2f(2); - aeabi_idiv(2, 3); - aeabi_idivmod(2, 3); - aeabi_l2d(2); - aeabi_l2f(2); - aeabi_ldivmod(2, 3); - aeabi_lmul(2, 3); - aeabi_ui2d(2); - aeabi_ui2f(2); - aeabi_uidiv(2, 3); - aeabi_uidivmod(2, 3); - aeabi_ul2d(2); - aeabi_ul2f(2); - aeabi_uldivmod(2, 3); - moddi3(2, 3); - mulodi4(2, 3); - powidf2(2., 3); - powisf2(2., 3); - umoddi3(2, 3); + // A copy of "test::black_box". Used to prevent LLVM from optimizing away the intrinsics during LTO + fn bb(dummy: T) -> T { + unsafe { asm!("" : : "r"(&dummy)) } + dummy + } + + bb(aeabi_d2f(bb(2.))); + bb(aeabi_d2i(bb(2.))); + bb(aeabi_d2l(bb(2.))); + bb(aeabi_d2uiz(bb(2.))); + bb(aeabi_d2ulz(bb(2.))); + bb(aeabi_dadd(bb(2.), bb(3.))); + bb(aeabi_dcmpeq(bb(2.), bb(3.))); + bb(aeabi_dcmpgt(bb(2.), bb(3.))); + bb(aeabi_dcmplt(bb(2.), bb(3.))); + bb(aeabi_ddiv(bb(2.), bb(3.))); + bb(aeabi_dmul(bb(2.), bb(3.))); + bb(aeabi_dsub(bb(2.), bb(3.))); + bb(aeabi_f2d(bb(2.))); + bb(aeabi_f2iz(bb(2.))); + bb(aeabi_f2lz(bb(2.))); + bb(aeabi_f2uiz(bb(2.))); + bb(aeabi_f2ulz(bb(2.))); + bb(aeabi_fadd(bb(2.), bb(3.))); + bb(aeabi_fcmpeq(bb(2.), bb(3.))); + bb(aeabi_fcmpgt(bb(2.), bb(3.))); + bb(aeabi_fcmplt(bb(2.), bb(3.))); + bb(aeabi_fdiv(bb(2.), bb(3.))); + bb(aeabi_fmul(bb(2.), bb(3.))); + bb(aeabi_fsub(bb(2.), bb(3.))); + bb(aeabi_i2d(bb(2))); + bb(aeabi_i2f(bb(2))); + bb(aeabi_idiv(bb(2), bb(3))); + bb(aeabi_idivmod(bb(2), bb(3))); + bb(aeabi_l2d(bb(2))); + bb(aeabi_l2f(bb(2))); + bb(aeabi_ldivmod(bb(2), bb(3))); + bb(aeabi_lmul(bb(2), bb(3))); + bb(aeabi_ui2d(bb(2))); + bb(aeabi_ui2f(bb(2))); + bb(aeabi_uidiv(bb(2), bb(3))); + bb(aeabi_uidivmod(bb(2), bb(3))); + bb(aeabi_ul2d(bb(2))); + bb(aeabi_ul2f(bb(2))); + bb(aeabi_uldivmod(bb(2), bb(3))); + bb(moddi3(bb(2), bb(3))); + bb(mulodi4(bb(2), bb(3))); + bb(powidf2(bb(2.), bb(3))); + bb(powisf2(bb(2.), bb(3))); + bb(umoddi3(bb(2), bb(3))); } #[cfg(all(feature = "c", not(thumb)))] diff --git a/src/float/mod.rs b/src/float/mod.rs index 8bd574d..7dc084d 100644 --- a/src/float/mod.rs +++ b/src/float/mod.rs @@ -1,4 +1,5 @@ use core::mem; +#[cfg(test)] use core::fmt; pub mod add; diff --git a/src/float/pow.rs b/src/float/pow.rs index 14b3b9a..838805f 100644 --- a/src/float/pow.rs +++ b/src/float/pow.rs @@ -1,6 +1,5 @@ - macro_rules! pow { - ($intrinsic:ident: $fty:ty, $ity:ty) => { + ($intrinsic:ident: $fty:ty, $ity:ident) => { /// Returns `a` raised to the power `b` #[cfg_attr(not(test), no_mangle)] pub extern "C" fn $intrinsic(a: $fty, b: $ity) -> $fty { @@ -11,7 +10,7 @@ macro_rules! pow { if (b & 1) != 0 { r *= a; } - b /= 2; + b = sdiv!($ity, b, 2); if b == 0 { break; } diff --git a/src/int/sdiv.rs b/src/int/sdiv.rs index 37f5dd7..a1d119f 100644 --- a/src/int/sdiv.rs +++ b/src/int/sdiv.rs @@ -10,7 +10,8 @@ macro_rules! div { let a = (a ^ s_a) - s_a; let b = (b ^ s_b) - s_b; let s = s_a ^ s_b; - let r = (a as $uty) / (b as $uty); + + let r = udiv!(a as $uty, b as $uty); (r as $ty ^ s) - s } } @@ -25,7 +26,8 @@ macro_rules! mod_ { let b = (b ^ s) - s; let s = a >> (<$ty>::bits() - 1); let a = (a ^ s) - s; - let r = (a as $uty) % (b as $uty); + + let r = urem!(a as $uty, b as $uty); (r as $ty ^ s) - s } } diff --git a/src/int/udiv.rs b/src/int/udiv.rs index 3de18b4..999dcec 100644 --- a/src/int/udiv.rs +++ b/src/int/udiv.rs @@ -1,4 +1,4 @@ -use core::mem; +use core::{intrinsics, mem}; use int::{Int, LargeInt}; /// Returns `n / d` @@ -7,7 +7,11 @@ use int::{Int, LargeInt}; pub extern "C" fn __udivsi3(n: u32, d: u32) -> u32 { // Special cases if d == 0 { - panic!("Division by zero"); + // NOTE This should be unreachable in safe Rust because the program will panic before + // this intrinsic is called + unsafe { + intrinsics::abort() + } } if n == 0 { @@ -105,10 +109,11 @@ pub extern "C" fn __udivmoddi4(n: u64, d: u64, rem: Option<&mut u64>) -> u64 { // 0 X // --- // 0 X + if let Some(rem) = rem { - *rem = u64::from(n.low() % d.low()); + *rem = u64::from(urem!(n.low(), d.low())); } - return u64::from(n.low() / d.low()); + return u64::from(udiv!(n.low(), d.low())); } else { // 0 X // --- @@ -129,7 +134,11 @@ pub extern "C" fn __udivmoddi4(n: u64, d: u64, rem: Option<&mut u64>) -> u64 { // K X // --- // 0 0 - panic!("Division by zero"); + // NOTE This should be unreachable in safe Rust because the program will panic before + // this intrinsic is called + unsafe { + intrinsics::abort() + } } if n.low() == 0 { @@ -137,9 +146,9 @@ pub extern "C" fn __udivmoddi4(n: u64, d: u64, rem: Option<&mut u64>) -> u64 { // --- // K 0 if let Some(rem) = rem { - *rem = u64::from_parts(0, n.high() % d.high()); + *rem = u64::from_parts(0, urem!(n.high(), d.high())); } - return u64::from(n.high() / d.high()); + return u64::from(udiv!(n.high(), d.high())); } // K K diff --git a/src/lib.rs b/src/lib.rs index acc56c9..f5a12af 100644 --- a/src/lib.rs +++ b/src/lib.rs @@ -13,6 +13,67 @@ // NOTE cfg(all(feature = "c", ..)) indicate that compiler-rt provides an arch optimized // implementation of that intrinsic and we'll prefer to use that +// TODO(rust-lang/rust#37029) use e.g. checked_div(_).unwrap_or_else(|| abort()) +macro_rules! udiv { + ($a:expr, $b:expr) => { + unsafe { + let a = $a; + let b = $b; + + if b == 0 { + ::core::intrinsics::abort() + } else { + ::core::intrinsics::unchecked_div(a, b) + } + } + } +} + +macro_rules! sdiv { + ($sty:ident, $a:expr, $b:expr) => { + unsafe { + let a = $a; + let b = $b; + + if b == 0 || (b == -1 && a == $sty::min_value()) { + ::core::intrinsics::abort() + } else { + ::core::intrinsics::unchecked_div(a, b) + } + } + } +} + +macro_rules! urem { + ($a:expr, $b:expr) => { + unsafe { + let a = $a; + let b = $b; + + if b == 0 { + ::core::intrinsics::abort() + } else { + ::core::intrinsics::unchecked_rem(a, b) + } + } + } +} + +macro_rules! srem { + ($sty:ty, $a:expr, $b:expr) => { + unsafe { + let a = $a; + let b = $b; + + if b == 0 || (b == -1 && a == $sty::min_value()) { + ::core::intrinsics::abort() + } else { + ::core::intrinsics::unchecked_rem(a, b) + } + } + } +} + #[cfg(test)] #[macro_use] extern crate quickcheck;