This is a retry of r284495 which was reverted at r284513 due to use-after-scope bugs
caused by faulty usage of StringRef.
This version also renames a pair of functions:
getRecipEstimateDivEnabled()
getRecipEstimateSqrtEnabled()
as suggested by Eric Christopher.
original commit msg:
[Target] remove TargetRecip class; move reciprocal estimate isel functionality to TargetLowering
This is a follow-up to https://reviews.llvm.org/D24816 - where we changed reciprocal estimates to be function attributes
rather than TargetOptions.
This patch is intended to be a structural, but not functional change. By moving all of the
TargetRecip functionality into TargetLowering, we can remove all of the reciprocal estimate
state, shield the callers from the string format implementation, and simplify/localize the
logic needed for a target to enable this.
If a function has a "reciprocal-estimates" attribute, those settings may override the target's
default reciprocal preferences for whatever operation and data type we're trying to optimize.
If there's no attribute string or specific setting for the op/type pair, just use the target
default settings.
As noted earlier, a better solution would be to move the reciprocal estimate settings to IR
instructions and SDNodes rather than function attributes, but that's a multi-step job that
requires infrastructure improvements. I intend to work on that, but it's not clear how long
it will take to get all the pieces in place.
Differential Revision: https://reviews.llvm.org/D25440
llvm-svn: 284746
All of these existed because MSVC 2013 was unable to synthesize default
move ctors. We recently dropped support for it so all that error-prone
boilerplate can go.
No functionality change intended.
llvm-svn: 284721
This is a follow-up to D24816 - where we changed reciprocal estimates to be function attributes
rather than TargetOptions.
This patch is intended to be a structural, but not functional change. By moving all of the
TargetRecip functionality into TargetLowering, we can remove all of the reciprocal estimate
state, shield the callers from the string format implementation, and simplify/localize the
logic needed for a target to enable this.
If a function has a "reciprocal-estimates" attribute, those settings may override the target's
default reciprocal preferences for whatever operation and data type we're trying to optimize.
If there's no attribute string or specific setting for the op/type pair, just use the target
default settings.
As noted earlier, a better solution would be to move the reciprocal estimate settings to IR
instructions and SDNodes rather than function attributes, but that's a multi-step job that
requires infrastructure improvements. I intend to work on that, but it's not clear how long
it will take to get all the pieces in place.
Differential Revision: https://reviews.llvm.org/D25440
llvm-svn: 284495
This is a patch to implement pr30640.
When a 64bit constant has the same hi/lo words, we can use rldimi to copy the low word into high word of the same register.
This optimization caused failure of test case bperm.ll because of not optimal heuristic in function SelectAndParts64. It chooses AND or ROTATE to extract bit groups from a register, and OR them together. This optimization lowers the cost of loading 64bit constant mask used in AND method, and causes different code sequence. But actually ROTATE method is better in this test case. The reason is in ROTATE method the final OR operation can be avoided since rldimi can insert the rotated bits into target register directly. So this patch also enhances SelectAndParts64 to prefer ROTATE method when the two methods have same cost and there are multiple bit groups need to be ORed together.
Differential Revision: https://reviews.llvm.org/D25521
llvm-svn: 284276
Summary:
In PPCMIPeephole, when we see two splat instructions, we can't simply do the following transformation:
B = Splat A
C = Splat B
=>
C = Splat A
because B may still be used between these two instructions. Instead, we should make the second Splat a PPC::COPY and let later passes decide whether to remove it or not:
B = Splat A
C = Splat B
=>
B = Splat A
C = COPY B
Fixes PR30663.
Reviewers: echristo, iteratee, kbarton, nemanjai
Subscribers: mehdi_amini, llvm-commits
Differential Revision: https://reviews.llvm.org/D25493
llvm-svn: 283961
Summary:
I had for the second time today a bug where llvm::format("%s", Str)
was called with Str being a StringRef. The Linux and MacOS bots were
fine, but windows having different calling convention, it printed
garbage.
Instead we can catch this at compile-time: it is never expected to
call a C vararg printf-like function with non scalar type I believe.
Reviewers: bogner, Bigcheese, dexonsmith
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D25266
llvm-svn: 283509
The motivation for the change is that we can't have pseudo-global settings for
codegen living in TargetOptions because that doesn't work with LTO.
Ideally, these reciprocal attributes will be moved to the instruction-level via
FMF, metadata, or something else. But making them function attributes is at least
an improvement over the current state.
The ingredients of this patch are:
Remove the reciprocal estimate command-line debug option.
Add TargetRecip to TargetLowering.
Remove TargetRecip from TargetOptions.
Clean up the TargetRecip implementation to work with this new scheme.
Set the default reciprocal settings in TargetLoweringBase (everything is off).
Update the PowerPC defaults, users, and tests.
Update the x86 defaults, users, and tests.
Note that if this patch needs to be reverted, the related clang patch checked in
at r283251 should be reverted too.
Differential Revision: https://reviews.llvm.org/D24816
llvm-svn: 283252
This patch corresponds to review:
The newly added VSX D-Form (register + offset) memory ops target the upper half
of the VSX register set. The existing ones target the lower half. In order to
unify these and have the ability to target all the VSX registers using D-Form
operations, this patch defines Pseudo-ops for the loads/stores which are
expanded post-RA. The expansion then choses the correct opcode based on the
register that was allocated for the operation.
llvm-svn: 283212
This patch corresponds to review:
https://reviews.llvm.org/D23155
This patch removes the VSHRC register class (based on D20310) and adds
exploitation of the Power9 sub-word integer loads into VSX registers as well
as vector sign extensions.
The new instructions are useful for a few purposes:
Int to Fp conversions of 1 or 2-byte values loaded from memory
Building vectors of 1 or 2-byte integers with values loaded from memory
Storing individual 1 or 2-byte elements from integer vectors
This patch implements all of those uses.
llvm-svn: 283190
The PPC branch-selection pass, which performs branch relaxation, needs to
account for the padding that might be introduced to satisfy block alignment
requirements. We were assuming that the first block was at offset zero (i.e.
had the alignment of the function itself), but under the ELFv2 ABI, a global
entry function prologue is added to the first block, and it is a
two-instruction sequence (i.e. eight-bytes long). If the function has 16-byte
alignment, the fact that the first block is eight bytes offset from the start
of the function is relevant to calculating where padding will be added in
between later blocks.
Unfortunately, I don't have a small test case.
llvm-svn: 283086
This change enables soft-float for PowerPC64, and also makes soft-float disable
all vector instruction sets for both 32-bit and 64-bit modes. This latter part
is necessary because the PPC backend canonicalizes many Altivec vector types to
floating-point types, and so soft-float breaks scalarization support for many
operations. Both for embedded targets and for operating-system kernels desiring
soft-float support, it seems reasonable that disabling hardware floating-point
also disables vector instructions (embedded targets without hardware floating
point support are unlikely to have Altivec, etc. and operating system kernels
desiring not to use floating-point registers to lower syscall cost are unlikely
to want to use vector registers either). If someone needs this to work, we'll
need to change the fact that we promote many Altivec operations to act on
v4f32. To make it possible to disable Altivec when soft-float is enabled,
hardware floating-point support needs to be expressed as a positive feature,
like the others, and not a negative feature, because target features cannot
have dependencies on the disabling of some other feature. So +soft-float has
now become -hard-float.
Fixes PR26970.
llvm-svn: 283060
This patch corresponds to review:
https://reviews.llvm.org/D24396
This patch adds support for the "vector count trailing zeroes",
"vector compare not equal" and "vector compare not equal or zero instructions"
as well as "scalar count trailing zeroes" instructions. It also changes the
vector negation to use XXLNOR (when VSX is enabled) so as not to increase
register pressure (previously this was done with a splat immediate of all
ones followed by an XXLXOR). This was done because the altivec.h
builtins (patch to follow) use vector negation and the use of an additional
register for the splat immediate is not optimal.
llvm-svn: 282478
This patch corresponds to review:
https://reviews.llvm.org/D21135
This patch exploits the following instructions:
mtvsrws
lxvwsx
mtvsrdd
mfvsrld
In order to improve some build_vector and extractelement patterns.
llvm-svn: 282246
Atomic comparison instructions use the sub-word load instruction on
Power8 and up but the value is not sign extended prior to the signed word
compare instruction. This patch adds that sign extension.
llvm-svn: 282182
This patch corresponds to:
https://reviews.llvm.org/D21409
The LXVD2X, LXVW4X, STXVD2X and STXVW4X instructions permute the two doublewords
in the vector register when in little-endian mode. Custom code ensures that the
necessary swaps are inserted for these. This patch simply removes the possibilty
that a load/store node will match one of these instructions in the SDAG as that
would not insert the necessary swaps.
llvm-svn: 282144
This patch corresponds to review:
https://reviews.llvm.org/D19825
The new lxvx/stxvx instructions do not require the swaps to line the elements
up correctly. In order to select them over the lxvd2x/lxvw4x instructions which
require swaps, the patterns for the old instruction have a predicate that
ensures they won't be selected on Power9 and newer CPUs.
llvm-svn: 282143
When a phi node is finally lowered to a machine instruction it is
important that the lowered "load" instruction is placed before the
associated DEBUG_VALUE entry describing the value loaded.
Renamed the existing SkipPHIsAndLabels to SkipPHIsLabelsAndDebug to
more fully describe that it also skips debug entries. Then used the
"new" function SkipPHIsAndLabels when the debug information should not
be skipped when placing the lowered "load" instructions so that it is
placed before the debug entries.
Differential Revision: https://reviews.llvm.org/D23760
llvm-svn: 281727
This patch corresponds to review:
https://reviews.llvm.org/D24021
In the initial implementation of this instruction, I forgot to account for
variable indices. This patch fixes PR30189 and should probably be merged into
3.9.1 (I'll open a bug according to the new instructions).
llvm-svn: 281479
There is currently no codegen for Power9 that depends on the directive
so this is NFC for now but will be important in the future. This was
missed in r268950 so I'm adding it now.
llvm-svn: 281473
Summary:
An IR load can be invariant, dereferenceable, neither, or both. But
currently, MI's notion of invariance is IR-invariant &&
IR-dereferenceable.
This patch splits up the notions of invariance and dereferenceability at
the MI level. It's NFC, so adds some probably-unnecessary
"is-dereferenceable" checks, which we can remove later if desired.
Reviewers: chandlerc, tstellarAMD
Subscribers: jholewinski, arsenm, nemanjai, llvm-commits
Differential Revision: https://reviews.llvm.org/D23371
llvm-svn: 281151
When folding an addi into a memory access that can take an immediate offset, we
were implicitly assuming that the existing offset was zero. This was incorrect.
If we're dealing with an addi with a plain constant, we can add it to the
existing offset (assuming that doesn't overflow the immediate, etc.), but if we
have anything else (i.e. something that will become a relocation expression),
we'll go back to requiring the existing immediate offset to be zero (because we
don't know what the requirements on that relocation expression might be - e.g.
maybe it is paired with some addis in some relevant way).
On the other hand, when dealing with a plain addi with a regular constant
immediate, the alignment restrictions (from the TOC base pointer, etc.) are
irrelevant.
I've added the test case from PR30280, which demonstrated the bug, but also
demonstrates a missed optimization opportunity (i.e. we don't need the memory
accesses at all).
Fixes PR30280.
llvm-svn: 280789
Unlike PPC64, PPC32/SVRV4 does not have red zone. In the absence of it
there is no guarantee that this part of the stack will not be modified
by any interrupt. To avoid this, make sure to claim the stack frame first
before storing into it.
This fixes https://llvm.org/bugs/show_bug.cgi?id=26519.
Differential Revision: https://reviews.llvm.org/D24093
llvm-svn: 280705
We used to compute the padding contributions to the block sizes during branch
relaxation only at the start of the transformation. As we perform branch
relaxation, we change the sizes of the blocks, and so the amount of inter-block
padding might change. Accordingly, we need to recompute the (alignment-based)
padding in between every iteration on our way toward the fixed point.
Unfortunately, I don't have a test case (and none was provided in the bug
report), and while this obviously seems needed, algorithmically, I don't have
any way of generating a small and/or non-fragile regression test.
llvm-svn: 280626
As it turns out, whether we zero-extend or sign-extend i8/i16 constants, which
are illegal types promoted to i32 on PowerPC, is a choice constrained by
assumptions within the infrastructure. Specifically, the logic in
FunctionLoweringInfo::ComputePHILiveOutRegInfo assumes that constant PHI
operands will be zero extended, and so, at least when materializing constants
that are PHI operands, we must do the same.
The rest of our fast-isel implementation does not appear to depend on the fact
that we were sign-extending i8/i16 constants, and all other targets also appear
to zero-extend small-bitwidth constants in fast-isel; we'll now do the same (we
had been doing this only for i1 constants, and sign-extending the others).
Fixes PR27721.
llvm-svn: 280614
PowerPC assembly code in the wild, so it seems, has things like this:
bc+ 12, 28, .L9
This is a bit odd because the '+' here becomes part of the BO field, and the BO
field is otherwise the first operand. Nevertheless, the ISA specification does
clearly say that the +- hint syntax applies to all conditional-branch mnemonics
(that test either CTR or a condition register, although not the forms which
check both), both basic and extended, so this is supposed to be valid.
This introduces some asm-parser-only definitions which take only the upper
three bits from the specified BO value, and the lower two bits are implied by
the +- suffix (via some associated aliases).
Fixes PR23646.
llvm-svn: 280571
dcbf has an optional hint-like field, add support for the extended form and the
associated mnemonics (dcbfl and dcbflp).
Partially fixes PR24796.
llvm-svn: 280559
When we have an offset into a global, etc. that is accessed relative to the TOC
base pointer, and the offset is larger than the minimum alignment of the global
itself and the TOC base pointer (which is 8-byte aligned), we can still fold
the @toc@ha into the memory access, but we must update the addis instruction's
symbol reference with the offset as the symbol addend. When there is only one
use of the addi to be folded and only one use of the addis that would need its
symbol's offset adjusted, then we can make the adjustment and fold the @toc@l
into the memory access.
llvm-svn: 280545
As Sanjay suggested when he added the hook, PPC should return true from
hasAndNotCompare. We have an efficient negated 'and' on PPC (which can feed a
compare).
Fixes PR27203.
llvm-svn: 280457
Following a suggestion by Sanjay, we should lower:
%shl = shl i32 1, %y
%and = and i32 %x, %shl
%cmp = icmp eq i32 %and, %shl
ret i1 %cmp
into:
subfic r4, r4, 32
rlwnm r3, r3, r4, 31, 31
Add this pattern and some associated patterns for the 64-bit case and the
not-equal case. Fixes PR27356.
llvm-svn: 280454
When applying our address-formation PPC64 peephole, we are reusing the @ha TOC
addis value with the low parts associated with different offsets (i.e.
different effective symbol addends). We were assuming this was okay so long as
the offsets were less than the alignment of the global variable being accessed.
This ignored the fact, however, that the TOC base pointer itself need only be
8-byte aligned. As a result, what we were doing is legal only for offsets less
than 8 regardless of the alignment of the object being accessed.
Fixes PR28727.
llvm-svn: 280441
Sanjay Patel