rust/src/test/codegen, branch 1.45.2

Revert "Defer creating drop trees in MIR lowering until leaving that scope"

2020-06-13T19:50:29+00:00

This reverts commit 611988551fba1bcbb33ae2e1e0171cb8d2e70d5a.

Added a codegen test for a recent optimization for overflow-checks=on

2020-05-24T20:20:02+00:00

Closes #58692

Auto merge of #71718 - NeoRaider:ffi_const_pure, r=Amanieu

2020-05-21T15:02:08+00:00

Experimentally add `ffi_const` and `ffi_pure` extern fn attributes Add FFI function attributes corresponding to clang/gcc/... `const` and `pure`. Rebased version of #58327 by @gnzlbg with the following changes: - Switched back from the `c_ffi_const` and `c_ffi_pure` naming to `ffi_const` and `ffi_pure`, as I agree with https://github.com/rust-lang/rust/pull/58327#issuecomment-462718772 and this nicely aligns with `ffi_returns_twice` - (Hopefully) took care of all of @hanna-kruppe's change requests in the original PR r? @hanna-kruppe

Auto merge of #72205 - ecstatic-morse:nrvo, r=oli-obk

2020-05-21T07:16:44+00:00

Dumb NRVO This is a very simple version of an NRVO pass, which scans backwards from the `return` terminator to see if there is an an assignment like `_0 = _1`. If a basic block with two or more predecessors is encountered during this scan without first seeing an assignment to the return place, we bail out. This avoids running a full "reaching definitions" dataflow analysis. I wanted to see how much `rustc` would benefit from even a very limited version of this optimization. We should be able to use this as a point of comparison for more advanced versions that are based on live ranges. r? @ghost

Rollup merge of #72139 - nnethercote:standalone-fold, r=cuviper

2020-05-20T12:21:06+00:00

Make `fold` standalone. `fold` is currently implemented via `try_fold`, but implementing it directly results in slightly less LLVM IR being generated, speeding up compilation of some benchmarks. r? @cuviper

Add tests for `#[ffi_const]` and `#[ffi_pure]` function attributes

2020-05-19T23:16:11+00:00

Based on the work of gnzlbg .

Add tests for asm!

2020-05-18T13:41:32+00:00

Make `fold` standalone.

2020-05-17T19:41:59+00:00

`fold` is currently implemented via `try_fold`, but implementing it directly results in slightly less LLVM IR being generated, speeding up compilation of some benchmarks. (And likewise for `rfold`.) The commit adds `fold` implementations to all the iterators that lack one but do have a `try_fold` implementation. Most of these just call the `try_fold` implementation directly.

Test that NRVO elides the call to `memcpy`

2020-05-17T17:24:06+00:00

Disable MIR optimization for alignment codegen tests

2020-05-17T00:15:24+00:00

NRVO optimizes away the locals whose alignment is tested. I don't think this affects the purpose of the test.