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Rust programs crash when dividing by zero #944

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Rust programs crash when dividing by zero#944
Labels
A-runtimeArea: std's runtime and "pre-main" init for handling backtraces, unwinds, stack overflowsE-easyCall for participation: Easy difficulty. Experience needed to fix: Not much. Good first issue.I-crashIssue: The compiler crashes (SIGSEGV, SIGABRT, etc). Use I-ICE instead when the compiler panics.
Milestone
0.3

Description

@jruderman
jruderman
opened on Sep 20, 2011
fn main() {
    let y = 0;
    assert 1 / y != 0;
}

SIGFPE / Floating point exception

Is this the intended behavior?

Activity

  1. jruderman commented on Sep 20, 2011

    @jruderman
    jruderman
    on Sep 20, 2011
    ContributorAuthor

    Task failure would be friendlier.

  2. mbrubeck commented on Nov 2, 2011

    @mbrubeck
    mbrubeck
    on Nov 2, 2011
    Contributor

    Rust uses the LLVM sdiv and udiv instructions for integer division, which have undefined results for division by zero. Using the current Rust compiler built from master on my 32-bit Linux machine, fn main() { log_err 1/0 } prints 0 when compiled with optimization. When compiled without optimization, it yields different results each time it is executed, for example 139268064.

    I'm kind of suprised by both of these results; I'd have expected a hardware exception like the one that jruderman reported. Does clang do anything different for integer division? See this thread for some discussion (but no current solutions) from the LLVM point of view.

  3. graydon commented on Feb 15, 2012

    @graydon
    graydon
    on Feb 15, 2012
    Contributor

    Should trap SIGFPE and route to failure. Runtime issue.

  4. graydon
    closed this as completedin aeb9a2bon Jun 14, 2012
  5. ZuseZ4
    added a commit that references this issue on Mar 7, 2023

    Update benchmark.yml (rust-lang#944)

    10dfcf9
  6. coastalwhite
    added a commit that references this issue on Aug 5, 2023

    Use black_box instead of llvm_asm (rust-lang#944)

    ca5aed8
  7. U007D
    added 2 commits that reference this issue on Aug 21, 2026

    Merge rust-lang#944

    711b82a

    Auto merge of rust-lang#944 - rust-lang:rustup, r=oli-obk

    dd94c7c
  8. rust-bors
    added a commit that references this issue on Sep 18, 2026

    Merge pull request #944 from rust-lang/remove-failing-tests

    e2cf8d9
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    A-runtimeArea: std's runtime and "pre-main" init for handling backtraces, unwinds, stack overflowsE-easyCall for participation: Easy difficulty. Experience needed to fix: Not much. Good first issue.I-crashIssue: The compiler crashes (SIGSEGV, SIGABRT, etc). Use I-ICE instead when the compiler panics.

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