[SMT] Parse SMT bitvector width as signed #8042
Open
+12
−5
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
maerhart
approved these changes
Jan 10, 2025
There was a problem hiding this comment.
It might be cleaner to write a custom parser that avoids the implicit conversion (basically parsing an APInt and doing the necessary checks before converting it to uint64_t).
When creating this type in C++ you probably give it an unsigned int, so the implicit conversion to a signed int could be a bit annoying there (but also only in corner cases).
But this approach is also fine for me.
I assume something like #8062 can still happen after this change (just the bitwidth to trigger it would be smaller)?
| @@ -89,8 +96,8 @@ func.func @repeat_count_too_large(%arg0: !smt.bv<32>) { | |||
|
|
|||
| // ----- | |||
|
|
|||
| func.func @repeat_result_type_bitwidth_too_large(%arg0: !smt.bv<18446744073709551612>) { | |||
| // expected-error @below {{result bit-width (provided integer times bit-width of the input type) must fit into 64 bits}} | |||
| smt.bv.repeat 2 times %arg0 : !smt.bv<18446744073709551612> | |||
There was a problem hiding this comment.
In the repeat parser, 64 is hardcoded as the width of the unsigned integer used. We'd need to adjust this and keep this error test but with a smaller number.
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Fixes an issue where SMT bitvector widths being parsed as unsigned meant that e.g. !smt.bv<-1> would wrap around and be interpreted as a 18446744073709551615-wide bitvector. The downside of this fix is that the error messages for bitvectors that are too wide become a little less clear (see the updated test) - does this still look like an ok fix to you @maerhart? Let me know if I should also drop the code that's emitting that error in the RepeatOp verifier, don't think it can be triggered after this but I may have missed a case.