This patch is a part one of two reviews, one for the clang and the other for LLVM.
The patch deletes the back-end intrinsics and adds support for them in the auto upgrade.
Differential Revision: https://reviews.llvm.org/D31393
llvm-svn: 299432
We've had several bugs(PR32256, PR32241) recently that resulted from usages of AH/BH/CH/DH either before or after a copy to/from a mask register.
This ultimately occurs because we create COPY_TO_REGCLASS with VK1 and GR8. Then in CopyToFromAsymmetricReg in X86InstrInfo we find a 32-bit super register for the GR8 to emit the KMOV with. But as these tests are demonstrating, its possible for the GR8 register to be a high register and we end up doing an accidental extra or insert from bits 15:8.
I think the best way forward is to stop making copies directly between mask registers and GR8/GR16. Instead I think we should restrict to only copies between mask registers and GR32/GR64 and use EXTRACT_SUBREG/INSERT_SUBREG to handle the conversion from GR32 to GR16/8 or vice versa.
Unfortunately, this complicates fastisel a bit more now to create the subreg extracts where we used to create GR8 copies. We can probably make a helper function to bring down the repitition.
This does result in KMOVD being used for copies when BWI is available because we don't know the original mask register size. This caused a lot of deltas on tests because we have to split the checks for KMOVD vs KMOVW based on BWI.
Differential Revision: https://reviews.llvm.org/D30968
llvm-svn: 298928
SUBREG_TO_REG is supposed to indicate that the super register has been zeroed, but we can't prove that if we don't know where it came from.
llvm-svn: 281885
This reverts most of r274613 (AKA r274626) and its follow-ups (r276347, r277289),
due to miscompiles in the test suite. The FastISel change was left in, because
it apparently fixes an unrelated issue.
(Recommit of r279782 which was broken due to a bad merge.)
This fixes 4 out of the 5 test failures in PR29112.
llvm-svn: 279788
This reverts most of r274613 and its follow-ups (r276347, r277289), due to
miscompiles in the test suite. The FastISel change was left in, because it
apparently fixes an unrelated issue.
This fixes 4 out of the 5 test failures in PR29112.
llvm-svn: 279782
Optimized lowering of BITCAST node. The BITCAST node can be replaced with COPY_TO_REG instead of KMOV.
It allows to suppress two opposite BITCAST operations and avoid redundant "movs".
Differential Revision: https://reviews.llvm.org/D23247
llvm-svn: 277958
An identity COPY like this:
%AL = COPY %AL, %EAX<imp-def>
has no semantic effect, but encodes liveness information: Further users
of %EAX only depend on this instruction even though it does not define
the full register.
Replace the COPY with a KILL instruction in those cases to maintain this
liveness information. (This reverts a small part of r238588 but this
time adds a comment explaining why a KILL instruction is useful).
llvm-svn: 274952
The patch removes redundant kmov instructions (not all, we still have a lot of work here) and redundant "and" instructions after "setcc".
I use "AssertZero" marker between X86ISD::SETCC node and "truncate" to eliminate extra "and $1" instruction.
I also changed zext, aext and trunc patterns in the .td file. It allows to remove extra "kmov" instruictions.
This patch fixes https://llvm.org/bugs/show_bug.cgi?id=28173.
Fast ISEL mode is not supported correctly for AVX-512. ICMP/FCMP scalar instruction should return result in k-reg. It will be fixed in one of the next patches. I redirected handling of "cmp" to the DAG builder mode. (The code looks worse in one specific test case, but without this fix the new patch fails).
Differential revision: http://reviews.llvm.org/D21956
llvm-svn: 274613
lower broadcast<type>x<vector> to shuffles.
there are two cases:
1.src is 128 bits and dest is 512 bits: in this case we will lower it to shuffle with imm = 0.
2.src is 256 bit and dest is 512 bits: in this case we will lower it to shuffle with imm = 01000100b (0x44) that way we will broadcast the 256bit source: ymm[0,1,2,3] => zmm[0,1,2,3,0,1,2,3] then it will mask it with the passthru value (in case it's mask op).
Differential Revision: http://reviews.llvm.org/D15790
llvm-svn: 256490
Fix TRUNCATE lowering vector to vector i1, use LSB and not MSB.
Implement VPMOVB/W/D/Q2M intrinsic.
Differential Revision: http://reviews.llvm.org/D15675
llvm-svn: 256470
Copying one mask register to another under BW should be done with kmovq instruction, otherwise we can loose some bits.
Copying 8 bits under DQ may be done with kmovb.
Differential Revision: http://reviews.llvm.org/D14812
llvm-svn: 253563
Michael Zuckerman