Commit Graph

9 Commits

Author SHA1 Message Date
Daniel Neilson c8bdc8db73 Change memcpy/memove/memset to have dest and source alignment attributes.
Summary:
  This change is step three in the series of changes to remove alignment argument from
memcpy/memmove/memset in favour of alignment attributes. Steps:

Step 1) Remove alignment parameter and create alignment parameter attributes for
memcpy/memmove/memset. ( rL322965, rC322964, rL322963 )
Step 2) Expand the IRBuilder API to allow creation of memcpy/memmove with differing
source and dest alignments. ( rL323597 )
Step 3) Update Clang to use the new IRBuilder API.
Step 4) Update Polly to use the new IRBuilder API.
Step 5) Update LLVM passes that create memcpy/memmove calls to use the new IRBuilder API,
and those that use use MemIntrinsicInst::[get|set]Alignment() to use getDestAlignment()
and getSourceAlignment() instead.
Step 6) Remove the single-alignment IRBuilder API for memcpy/memmove, and the
MemIntrinsicInst::[get|set]Alignment() methods.

Reference
   http://lists.llvm.org/pipermail/llvm-dev/2015-August/089384.html
   http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20151109/312083.html

Reviewers: rjmccall

Subscribers: jyknight, nemanjai, nhaehnle, javed.absar, sbc100, aheejin, kbarton, fedor.sergeev, cfe-commits

Differential Revision: https://reviews.llvm.org/D41677

llvm-svn: 323617
2018-01-28 17:27:45 +00:00
Daniel Neilson 6e938effaa Change memcpy/memove/memset to have dest and source alignment attributes (Step 1).
Summary:
  Upstream LLVM is changing the the prototypes of the @llvm.memcpy/memmove/memset
intrinsics. This change updates the Clang tests for this change.

  The @llvm.memcpy/memmove/memset intrinsics currently have an explicit argument
which is required to be a constant integer. It represents the alignment of the
dest (and source), and so must be the minimum of the actual alignment of the
two.

 This change removes the alignment argument in favour of placing the alignment
attribute on the source and destination pointers of the memory intrinsic call.

 For example, code which used to read:
   call void @llvm.memcpy.p0i8.p0i8.i32(i8* %dest, i8* %src, i32 100, i32 4, i1 false)
will now read
   call void @llvm.memcpy.p0i8.p0i8.i32(i8* align 4 %dest, i8* align 4 %src, i32 100, i1 false)

 At this time the source and destination alignments must be the same (Step 1).
Step 2 of the change, to be landed shortly, will relax that contraint and allow
the source and destination to have different alignments.

llvm-svn: 322964
2018-01-19 17:12:54 +00:00
Tim Northover 58672974a9 ARM & AArch64: convert asm tests to LLVM IR and restrict optimizations.
This is mostly a one-time autoconversion of tests that checked assembly after
"-Owhatever" compiles to only run "opt -mem2reg" and check the assembly. This
should make them much more stable to changes in LLVM so they won't break on
unrelated changes.

"opt -mem2reg" is a compromise designed to increase the readability of tests
that check dataflow, while minimizing dependency on LLVM. Hopefully mem2reg is
stable enough that no surpises will come along.

Should address http://llvm.org/PR26815.

llvm-svn: 263048
2016-03-09 18:54:42 +00:00
Pete Cooper 3b39e88ae0 Revert "Change memcpy/memset/memmove to have dest and source alignments."
This reverts commit r253512.

This likely broke the bots in:
http://lab.llvm.org:8011/builders/clang-ppc64-elf-linux2/builds/20202
http://bb.pgr.jp/builders/clang-3stage-i686-linux/builds/3787

llvm-svn: 253542
2015-11-19 05:55:59 +00:00
Pete Cooper 7bfd5cb7be Change memcpy/memset/memmove to have dest and source alignments.
This is a follow on from a similar LLVM commit: r253511.

Note, this was reviewed (and more details are in) http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20151109/312083.html

These intrinsics currently have an explicit alignment argument which is
required to be a constant integer.  It represents the alignment of the
source and dest, and so must be the minimum of those.

This change allows source and dest to each have their own alignments
by using the alignment attribute on their arguments.  The alignment
argument itself is removed.

The only code change to clang is hidden in CGBuilder.h which now passes
both dest and source alignment to IRBuilder, instead of taking the minimum of
dest and source alignments.

Reviewed by Hal Finkel.

llvm-svn: 253512
2015-11-18 22:18:45 +00:00
Ulrich Weigand 6e2cea6f0c Respect alignment when loading up a coerced function argument
Code in CGCall.cpp that loads up function arguments that need to be
coerced to a different type may in some cases ignore the fact that
the source of the argument is not naturally aligned. This may cause
incorrect code to be generated. In some places in CreateCoercedLoad,
we already have setAlignment calls to address this, but I ran into one
where it was missing, causing wrong code generation on SystemZ.

However, in that location, we do not actually know what alignment of
the source location we can rely on; the callers do not pass anything
to this routine. This is already an issue in other places in
CreateCoercedLoad; and the same problem exists for CreateCoercedStore.

To avoid pessimising code, and to fix the FIXMEs already in place,
this patch also adds an alignment argument to the CreateCoerced*
routines and uses it instead of forcing an alignment of 1. The
callers are changed to pass in the best information they have.

This actually requires changes in a number of existing test cases
since we now get better alignment in many places.

Differential Revision: http://reviews.llvm.org/D11033

llvm-svn: 241898
2015-07-10 11:31:43 +00:00
James Molloy 90d6101410 Use store size instead of alloc size when coercing.
Previously, EnterStructPointerForCoercedAccess used Alloc size when determining how to convert. This was problematic, because there were situations were the alloc size was larger than the store size. For example, if the first element of a structure were i24 and the destination type were i32, the old code would generate a GEP and a load i24. The code should compare store sizes to ensure the whole object is loaded. I have attached a test case.

This patch modifies the output of arm64-be-bitfield.c test case, but the new IR seems to be equivalent, and after -O3, the compiler generates identical ARM assembly. (asr x0, x0, #54)

Patch by Thomas Jablin!

llvm-svn: 216722
2014-08-29 10:17:52 +00:00
Tim Northover 18b7512faa AArch64: use aarch64_be instead of arm64_be in all tests.
arm64_be doesn't really exist; it was useful for testing while AArch64 and
ARM64 were separate, but now the only real way to refer to the system is
aarch64_be.

llvm-svn: 213747
2014-07-23 12:57:31 +00:00
James Molloy 491cefbe7a When doing int<->ptr coercion for big-endian, calculate the shift amount correctly.
Previously we calculated the shift amount based upon DataLayout::getTypeAllocSizeInBits.
This will only work for legal types - types such as i24 that are created as part of
structs for bitfields will return "32" from that function. Change to using
getTypeSizeInBits.

It turns out that AArch64 didn't run across this problem because it always returned
[1 x i64] as the type for a bitfield, whereas ARM64 returns i64 so goes down this
(better, but wrong) codepath.

llvm-svn: 208231
2014-05-07 17:41:15 +00:00