Commit Graph

5 Commits

Author SHA1 Message Date
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
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
Yunzhong Gao d290eb4565 Fix the test case to handle different IR variable names.
llvm-svn: 239457
2015-06-10 03:19:08 +00:00
Yunzhong Gao cb77930d6b Implementing C99 partial re-initialization behavior (DR-253)
Based on previous discussion on the mailing list, clang currently lacks support
for C99 partial re-initialization behavior:
Reference: http://lists.cs.uiuc.edu/pipermail/cfe-dev/2013-April/029188.html
Reference: http://www.open-std.org/jtc1/sc22/wg14/www/docs/dr_253.htm

This patch attempts to fix this problem.

Given the following code snippet,

struct P1 { char x[6]; };
struct LP1 { struct P1 p1; };

struct LP1 l = { .p1 = { "foo" }, .p1.x[2] = 'x' };
// this example is adapted from the example for "struct fred x[]" in DR-253;
// currently clang produces in l: { "\0\0x" },
//   whereas gcc 4.8 produces { "fox" };
// with this fix, clang will also produce: { "fox" };


Differential Review: http://reviews.llvm.org/D5789

llvm-svn: 239446
2015-06-10 00:27:52 +00:00