Summary:
When constructing an APSInt from a string, the constructor doesn't correctly
truncate the bit width of the result if the passed in string was "0" (or any
alternative way to express 0 like "-0" or "000"). Instead of 1 (which is the
smallest allowed bit width) it returns an APSInt with a bit width of 5.
The reason is that the constructor checks that it never truncates the result to
the invalid bit width of 0, so when it calculates that storing a "0" doesn't
require any bits it just keeps the original overestimated bit width (which
happens to be 5).
This patch just sets the bit width of the result to 1 if the required bit width
is 0.
Reviewers: arphaman, dexonsmith
Reviewed By: dexonsmith
Subscribers: hiraditya, dexonsmith, JDevlieghere, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D81329
to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351636
This commit moves the APSInt initialization code that's used by
the LLLexer class into a new APSInt constructor that constructs
APSInts from strings.
This change is useful for MIR Serialization, as it would allow
the MILexer class to use the same APSInt initialization as
LLexer when parsing immediate machine operands.
llvm-svn: 240436
