MachineIRBuilder had weird before/after and beginning/end flags for the insert
point. Unfortunately the non-default means that instructions will be inserted
in reverse order which is almost never what anyone wants.
Really, I think we just want (like IRBuilder has) the ability to insert at any
C++ iterator-style point (i.e. before any instruction or before MBB.end()). So
this fixes MIRBuilders to behave like IRBuilders in this respect.
llvm-svn: 288980
If we don't skip over DEBUG_VALUEs, we get differences between -g and non-g
code.
This fixes PR31242.
Differential Revision: https://reviews.llvm.org/D27485
llvm-svn: 288965
The second operand of an "ri" instruction may be an immediate, but it may
also be a globalvariable, so we should make any assumptions.
This fixes PR31271.
Differential Revision: https://reviews.llvm.org/D27481
llvm-svn: 288964
We are being inconsistent with these instructions (and all their variants.....) with a random mix of them using the default float domain.
Differential Revision: https://reviews.llvm.org/D27419
llvm-svn: 288902
The non-constant pool version of DecodeVPERMIL2PMask was not offsetting correctly for the second input. I've updated the code to match the implementation in the constant-pool version.
Annoyingly this bug was hidden for so long as it's tricky to combine to useful variable shuffle masks that don't become constant-pool entries.
llvm-svn: 288898
Summary:
Prefer expansions such as: pmullw,pmulhw,unpacklwd,unpackhwd over pmulld.
On Silvermont [source: Optimization Reference Manual]:
PMULLD has a throughput of 1/11 [instruction/cycles].
PMULHUW/PMULHW/PMULLW have a throughput of 1/2 [instruction/cycles].
Fixes pr31202.
Analysis of this issue was done by Fahana Aleen.
Reviewers: wmi, delena, mkuper
Subscribers: RKSimon, llvm-commits
Differential Revision: https://reviews.llvm.org/D27203
llvm-svn: 288844
Handle the case where a sign extension has ended up being split into separate stages (typically to get around vector legal ops) and a zext + sext_in_reg gets inserted.
Differential Revision: https://reviews.llvm.org/D27461
llvm-svn: 288842
Check if a build_vector node includes a repeated constant pattern and replace it with a broadcast of that pattern.
For example:
"build_vector <0, 1, 2, 3, 0, 1, 2, 3>" would be replaced by "broadcast <0, 1, 2, 3>"
Differential Revision: https://reviews.llvm.org/D26802
llvm-svn: 288804
Summary: This patch makes sure FirstCSPop and MBBI never point to DBG_VALUE instructions, which affected the code generated.
Reviewers: mkuper, aprantl, MatzeB
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D27343
llvm-svn: 288794
This pattern turned a vector sqrt/rcp/rsqrt operation of sse_load_f32/f64 into the the scalar instruction for the operation and put undef into the upper bits. For correctness, the resulting code should still perform the sqrt/rcp/rsqrt on the upper bits after the load is extended since that's what the operation asked for. Particularly in the case where the upper bits are 0, in that case we need calculate the sqrt/rcp/rsqrt of the zeroes and keep the result in the upper-bits. This implies we should be using the packed instruction still.
The only test case for this pattern is one I just added so there was no coverage of this.
llvm-svn: 288784
This occurs due to a pattern that uses sse_load_f32/f64 with vector sqrt/rcp/rsqrt operations and turns them into scalar instructions. Perhaps for the case were the upper bits come from undef this is ok. I believe a (vzmovl load64) would do the same thing but those seems to become vzload instead and selectScalarSSELoad doesn't handle that today. In that case we should be performing the vector operation on the zeros in the upper bits which is not equivalent to using a scalar instruction.
I will remove this pattern in a follow up patch. There appears to be no other test content for it.
llvm-svn: 288783
The intrinsics are supposed to pass the upper bits straight through to their output register. This means we need to make sure we still perform the 128-bit load to get those upper bits to pass to give to the instruction since the memory form of the instruction only reads 32 or 64 bits.
llvm-svn: 288781
The sqrtsd instruction only loads 64-bits and writes bits 63:0 with the sqrt result. Bits 127:64 are preserved in the destination register. The semantics of the intrinsic indicate bits 127:64 should come from the intrinsic argument which in this case is a 128-bit load. So the generated code should have a 128-bit load and use a register form of sqrtsd.
llvm-svn: 288780
The intrinsic takes one argument, the lower bits are affected by the operation and the upper bits should be passed through. The instruction itself takes two operands, the high bits of the first operand are passed through and the low bits of the second operand are modified by the operation. To match this to the intrinsic we should pass the single intrinsic input to both operands.
I had to remove the stack folding test for these instructions since they depended on the incorrect behavior. The same register is now used for both inputs so the load can't be folded.
llvm-svn: 288779
Summary:
This patch removes the scalar logical operation alias instructions. We can just use reg class copies and use the normal packed instructions instead. This removes the need for putting these instructions in the execution domain fixing tables as was done recently.
I removed the loadf64_128 and loadf32_128 patterns as DAG combine creates a narrower load for (extractelt (loadv4f32)) before we ever get to isel.
I plan to add similar patterns for AVX512DQ in a future commit to allow use of the larger register class when available.
Reviewers: spatel, delena, zvi, RKSimon
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D27401
llvm-svn: 288771
This changes the scalar non-intrinsic non-avx roundss/sd instruction
definitions not to read their destination register - allowing partial dependency
breaking.
This fixes PR31143.
Differential Revision: https://reviews.llvm.org/D27323
llvm-svn: 288703
so we can stop using DW_OP_bit_piece with the wrong semantics.
The entire back story can be found here:
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20161114/405934.html
The gist is that in LLVM we've been misinterpreting DW_OP_bit_piece's
offset field to mean the offset into the source variable rather than
the offset into the location at the top the DWARF expression stack. In
order to be able to fix this in a subsequent patch, this patch
introduces a dedicated DW_OP_LLVM_fragment operation with the
semantics that we used to apply to DW_OP_bit_piece, which is what we
actually need while inside of LLVM. This patch is complete with a
bitcode upgrade for expressions using the old format. It does not yet
fix the DWARF backend to use DW_OP_bit_piece correctly.
Implementation note: We discussed several options for implementing
this, including reserving a dedicated field in DIExpression for the
fragment size and offset, but using an custom operator at the end of
the expression works just fine and is more efficient because we then
only pay for it when we need it.
Differential Revision: https://reviews.llvm.org/D27361
rdar://problem/29335809
llvm-svn: 288683
We treat bitwise 'not' as a special operation and try not to reduce its all-ones mask.
Presumably, this is because a 'not' may be cheaper than a generic 'xor' or it may get
folded into another logic op if the target has those. However, if we can remove a logic
instruction by changing the xor's constant mask value, that should always be a win.
Note that the IR version of SimplifyDemandedBits() does not treat 'not' as a special-case
currently (although that's marked with a FIXME). So if you run this IR through -instcombine,
you should get the same end result. I'm hoping to add a different backend transform that
will expose this problem though, so I need to solve this first.
Differential Revision: https://reviews.llvm.org/D27356
llvm-svn: 288676
Currently the fast isel code emits an avx1 instruction sequence even with avx512. This is different than normal isel. A follow up commit will fix this.
llvm-svn: 288635
Summary:
When X = 0 and Y = inf, the original code produces inf, but the transformed
code produces nan. So this transform (and its relatives) should only be
used when the no-infs-fp-math flag is explicitly enabled.
Also disable the transform using fmad (intermediate rounding) when unsafe-math
is not enabled, since it can reduce the precision of the result; consider this
example with binary floating point numbers with two bits of mantissa:
x = 1.01
y = 111
x * (y + 1) = 1.01 * 1000 = 1010 (this is the exact result; no rounding occurs at any step)
x * y + x = 1000.11 + 1.01 =r 1000 + 1.01 = 1001.01 =r 1000 (with rounding towards zero)
The example relies on rounding towards zero at least in the second step.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=98578
Reviewers: RKSimon, tstellarAMD, spatel, arsenm
Subscribers: wdng, llvm-commits
Differential Revision: https://reviews.llvm.org/D26602
llvm-svn: 288506
Quentin Colombet