Commit Graph

10 Commits

Author SHA1 Message Date
Benjamin Kramer 6293429b51 X86: Enable SSE memory intrinsics even when stack alignment is less than 16 bytes.
The stack realignment code was fixed to work when there is stack realignment and
a dynamic alloca is present so this shouldn't cause correctness issues anymore.

Note that this also enables generation of AVX instructions for memset
under the assumptions:
- Unaligned loads/stores are always fast on CPUs supporting AVX
- AVX is not slower than SSE
We may need some tweaked heuristics if one of those assumptions turns out not to
be true.

Effectively reverts r58317. Part of PR2962.

llvm-svn: 167967
2012-11-14 20:08:40 +00:00
Chris Lattner 80ed9dc9e5 rip out a ton of intrinsic modernization logic from AutoUpgrade.cpp, which is
for pre-2.9 bitcode files.  We keep x86 unaligned loads, movnt, crc32, and the
target indep prefetch change.

As usual, updating the testsuite is a PITA.

llvm-svn: 133337
2011-06-18 06:05:24 +00:00
Evan Cheng a048c83fe4 Revert r122955. It seems using movups to lower memcpy can cause massive regression (even on Nehalem) in edge cases. I also didn't see any real performance benefit.
llvm-svn: 123015
2011-01-07 19:35:30 +00:00
Evan Cheng 7998b1d6fe Use movups to lower memcpy and memset even if it's not fast (like corei7).
The theory is it's still faster than a pair of movq / a quad of movl. This
will probably hurt older chips like P4 but should run faster on current
and future Intel processors. rdar://8817010

llvm-svn: 122955
2011-01-06 07:58:36 +00:00
Dale Johannesen ed0d840838 Do not throw away alignment when generating the DAG for
memset; we may need it to decide between MOVAPS and MOVUPS
later.  Adjust a test that was looking for wrong code.
PR 3866 / 8675131.

llvm-svn: 119605
2010-11-18 01:35:23 +00:00
Evan Cheng 1e8ee79957 Add -mcpu to memcpy / memset tests to ensure they behave the same on all hosts / targets.
llvm-svn: 100101
2010-04-01 08:25:26 +00:00
Evan Cheng 43cd9e3845 Fix sdisel memcpy, memset, memmove lowering:
1. Makes it possible to lower with floating point loads and stores.
2. Avoid unaligned loads / stores unless it's fast.
3. Fix some memcpy lowering logic bug related to when to optimize a
   load from constant string into a constant.
4. Adjust x86 memcpy lowering threshold to make it more sane.
5. Fix x86 target hook so it uses vector and floating point memory
   ops more effectively.
rdar://7774704

llvm-svn: 100090
2010-04-01 06:04:33 +00:00
Dan Gohman 40503396da Eliminate more uses of llvm-as and llvm-dis.
llvm-svn: 81290
2009-09-08 23:54:48 +00:00
Evan Cheng 9534ea03e8 Fix a number of byval / memcpy / memset related codegen issues.
1. x86-64 byval alignment should be max of 8 and alignment of type. Previously the code was not doing what the commit message was saying.
2. Do not use byte repeat move and store operations. These are slow.

llvm-svn: 55139
2008-08-21 21:00:15 +00:00
Dan Gohman 8c99ccaf96 Recreate the size SDNode instead of reusing the old one in the x86
memcpy lowering code; this ensures that the size node has the desired
result type. This fixes a regression from r49572 with @llvm.memcpy.i64
on x86-32.

llvm-svn: 49761
2008-04-16 01:32:32 +00:00