interpret: ensure that Place is never used for a different frame

[RalfJung]

We store the address where the stack frame stores its locals. The idea is that even if we pop and push, or switch to a different thread with a larger number of frames, then the locals address will most likely change so we'll notice that problem. This is made possible by some recent changes by @WaffleLapkin, where we no longer use Place across things that change the number of stack frames.

I made these debug assertions for now, just to make sure this can't cost us any perf.

The first commit is unrelated but it's a one-line comment change so it didn't warrant a separate PR...

r? @oli-obk

[rustbot]

The Miri subtree was changed

cc @rust-lang/miri

Some changes occurred to MIR optimizations

cc @rust-lang/wg-mir-opt

Some changes occurred to the CTFE / Miri engine

cc @rust-lang/miri

[RalfJung]

@bors try @rust-timer queue

[bors]

⌛ Trying commit 141ebf8 with merge dae6eba...

[bors]

☀️ Try build successful - checks-actions
Build commit: dae6eba (dae6eba43a658f72e2e5d69563db21182125db32)

[rust-timer]

Finished benchmarking commit (dae6eba): comparison URL.

Overall result: ✅ improvements - no action needed

Benchmarking this pull request likely means that it is perf-sensitive, so we're automatically marking it as not fit for rolling up. While you can manually mark this PR as fit for rollup, we strongly recommend not doing so since this PR may lead to changes in compiler perf.

@bors rollup=never
@rustbot label: -S-waiting-on-perf -perf-regression

Instruction count

This is a highly reliable metric that was used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-0.3%	[-0.3%, -0.3%]	1
All ❌✅ (primary)	-	-	0

Max RSS (memory usage)

This benchmark run did not return any relevant results for this metric.

Cycles

Results

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	2.2%	[2.2%, 2.2%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Binary size

This benchmark run did not return any relevant results for this metric.

Bootstrap: 649.076s -> 649.815s (0.11%)
Artifact size: 172.58 MiB -> 310.37 MiB (79.84%)

[oli-obk]

Since you're getting the address of the locals Vec, and not the address of where its locals are stored, popping then pushing will pass the assert, as the stack frame Vec doesn't reallocate.

[RalfJung]

Ah, damn, yes I should get the buffer address of course. Good thing I made this a helper function :D

[RalfJung]

Checking if enabling the assertions in release builds makes a perf difference.

@bors try @rust-timer queue

[bors]

⌛ Trying commit a566f90 with merge cde8b4d...

[bors]

☀️ Try build successful - checks-actions
Build commit: cde8b4d (cde8b4d6972edd365d89d64f52dea5abc94df774)

[rust-timer]

Finished benchmarking commit (cde8b4d): comparison URL.

Overall result: ❌ regressions - ACTION NEEDED

Benchmarking this pull request likely means that it is perf-sensitive, so we're automatically marking it as not fit for rolling up. While you can manually mark this PR as fit for rollup, we strongly recommend not doing so since this PR may lead to changes in compiler perf.

Next Steps: If you can justify the regressions found in this try perf run, please indicate this with @rustbot label: +perf-regression-triaged along with sufficient written justification. If you cannot justify the regressions please fix the regressions and do another perf run. If the next run shows neutral or positive results, the label will be automatically removed.

@bors rollup=never
@rustbot label: -S-waiting-on-perf +perf-regression

Instruction count

This is a highly reliable metric that was used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	0.8%	[0.8%, 0.9%]	4
Regressions ❌ (secondary)	0.7%	[0.6%, 0.8%]	5
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.8%	[0.8%, 0.9%]	4

Max RSS (memory usage)

Results

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	3.1%	[1.7%, 4.7%]	7
Regressions ❌ (secondary)	2.4%	[0.8%, 4.1%]	32
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-3.5%	[-4.0%, -3.0%]	2
All ❌✅ (primary)	3.1%	[1.7%, 4.7%]	7

Cycles

Results

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	1.9%	[1.3%, 2.5%]	6
Regressions ❌ (secondary)	0.9%	[0.9%, 0.9%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	1.9%	[1.3%, 2.5%]	6

Binary size

This benchmark run did not return any relevant results for this metric.

Bootstrap: 648.949s -> 647.618s (-0.21%)
Artifact size: 310.01 MiB -> 309.97 MiB (-0.01%)

[RalfJung]

Okay, the assertions can definitely be measured, so let's keep them as debug assertions.

[oli-obk]

@bors r+

[bors]

📌 Commit c3342b4 has been approved by oli-obk

It is now in the queue for this repository.

[bors]

⌛ Testing commit c3342b4 with merge b9d2b00...

[bors]

💥 Test timed out

[rust-log-analyzer]

A job failed! Check out the build log: (web) (plain)

Click to see the possible cause of the failure (guessed by this bot)

[RalfJung]

@bors retry timeout

[bors]

⌛ Testing commit c3342b4 with merge cb580ff...

[bors]

☀️ Test successful - checks-actions
Approved by: oli-obk
Pushing cb580ff to master...

[rust-timer]

Finished benchmarking commit (cb580ff): comparison URL.

Overall result: no relevant changes - no action needed

@rustbot label: -perf-regression

Instruction count

This benchmark run did not return any relevant results for this metric.

Max RSS (memory usage)

Results

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	4.3%	[2.7%, 5.8%]	2
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	4.3%	[2.7%, 5.8%]	2

Cycles

This benchmark run did not return any relevant results for this metric.

Binary size

This benchmark run did not return any relevant results for this metric.

Bootstrap: 670.21s -> 669.949s (-0.04%)
Artifact size: 310.75 MiB -> 310.79 MiB (0.01%)