Commit Graph

11 Commits

Author SHA1 Message Date
Roman Lebedev 0a002f679b
[Sema] Try 2: Sanity-check alignment requested via `__attribute__((assume_aligned(imm)))`
Summary:
For `__builtin_assume_aligned()`, we do validate that the alignment
is not greater than `536870912` (D68824), but we don't do that for
`__attribute__((assume_aligned(N)))` attribute.
I suspect we should.

This was initially committed in a4cfb15d15
but reverted in 210f0882c9 due to
suspicious bot failures.

Reviewers: erichkeane, aaron.ballman, hfinkel, rsmith, jdoerfert

Reviewed By: erichkeane

Subscribers: cfe-commits, llvm-commits

Tags: #llvm, #clang

Differential Revision: https://reviews.llvm.org/D72994
2020-01-24 16:56:39 +03:00
Roman Lebedev 210f0882c9
Revert "[Sema] Sanity-check alignment requested via `__attribute__((assume_aligned(imm)))`"
Likely makes bots angry.

This reverts commit a4cfb15d15.

# Conflicts:
#	clang/lib/Sema/SemaDeclAttr.cpp
2020-01-23 23:10:35 +03:00
Roman Lebedev a4cfb15d15
[Sema] Sanity-check alignment requested via `__attribute__((assume_aligned(imm)))`
Summary:
For `__builtin_assume_aligned()`, we do validate that the alignment
is not greater than `536870912` (D68824), but we don't do that for
`__attribute__((assume_aligned(N)))` attribute.
I suspect we should.

Reviewers: erichkeane, aaron.ballman, hfinkel, rsmith, jdoerfert

Reviewed By: erichkeane

Subscribers: cfe-commits, llvm-commits

Tags: #llvm, #clang

Differential Revision: https://reviews.llvm.org/D72994
2020-01-23 22:50:48 +03:00
Erich Keane add0786dba Fix test failure with 374562 on Hexagon
__builtin_assume_aligned takes a size_t which is a 32 bit int on
hexagon.  Thus, the constant gets converted to a 32 bit value, resulting
in 0 not being a power of 2.  This patch changes the constant being
passed to 2**30 so that it fails, but doesnt exceed 30 bits.

llvm-svn: 374569
2019-10-11 16:30:45 +00:00
Erich Keane f759395994 Reland r374450 with Richard Smith's comments and test fixed.
The behavior from the original patch has changed, since we're no longer
allowing LLVM to just ignore the alignment.  Instead, we're just
assuming the maximum possible alignment.

Differential Revision: https://reviews.llvm.org/D68824

llvm-svn: 374562
2019-10-11 14:59:44 +00:00
Nico Weber b556085d81 Revert 374450 "Fix __builtin_assume_aligned with too large values."
The test fails on Windows, with

  error: 'warning' diagnostics expected but not seen:
    File builtin-assume-aligned.c Line 62: requested alignment
        must be 268435456 bytes or smaller; assumption ignored
  error: 'warning' diagnostics seen but not expected:
    File builtin-assume-aligned.c Line 62: requested alignment
        must be 8192 bytes or smaller; assumption ignored

llvm-svn: 374456
2019-10-10 21:34:32 +00:00
Erich Keane 31e454c1ec Fix __builtin_assume_aligned with too large values.
Code to handle __builtin_assume_aligned was allowing larger values, but
would convert this to unsigned along the way. This patch removes the
EmitAssumeAligned overloads that take unsigned to do away with this
problem.

Additionally, it adds a warning that values greater than 1 <<29 are
ignored by LLVM.

Differential Revision: https://reviews.llvm.org/D68824

llvm-svn: 374450
2019-10-10 21:08:28 +00:00
Aaron Ballman adf66b6174 Determine the attribute subject for diagnostics based on declarative information in DeclNodes.td. This greatly reduces the number of enumerated values used for more complex diagnostics; these are now only required when the "attribute only applies to" diagnostic needs to be generated manually as part of semantic processing.
This also clarifies some terminology used by the diagnostic (methods -> Objective-C methods, fields -> non-static data members, etc).

Many of the tests needed to be updated in multiple places for the diagnostic wording tweaks. The first instance of the diagnostic for that attribute is fully specified and subsequent instances cut off the complete list (to make it easier if additional subjects are added in the future for the attribute).

llvm-svn: 319002
2017-11-26 20:01:12 +00:00
Hal Finkel ee90a223ea Support the assume_aligned function attribute
In addition to __builtin_assume_aligned, GCC also supports an assume_aligned
attribute which specifies the alignment (and optional offset) of a function's
return value. Here we implement support for the assume_aligned attribute by making
use of the @llvm.assume intrinsic.

llvm-svn: 218500
2014-09-26 05:04:30 +00:00
Hal Finkel e65e0a1bc9 Don't test really-large alignments for now
Temporarily comment out the test for really-large powers of two. This seems to
be host-sensitive for some reason... trying to fix the clang-i386-freebsd
builder.

llvm-svn: 217351
2014-09-08 00:09:15 +00:00
Hal Finkel bcc06085a8 Add __builtin_assume and __builtin_assume_aligned using @llvm.assume.
This makes use of the recently-added @llvm.assume intrinsic to implement a
__builtin_assume(bool) intrinsic (to provide additional information to the
optimizer). This hooks up __assume in MS-compatibility mode to mirror
__builtin_assume (the semantics have been intentionally kept compatible), and
implements GCC's __builtin_assume_aligned as assume((p - o) & mask == 0). LLVM
now contains special logic to deal with assumptions of this form.

llvm-svn: 217349
2014-09-07 22:58:14 +00:00