Similar to rL337966 - if the DAGCombiner's rotate matching was
working as expected, I don't think we'd see any test diffs here.
AArch only goes right, and PPC only goes left.
x86 has both, so no diffs there.
Differential Revision: https://reviews.llvm.org/D50091
llvm-svn: 339359
This patch aims to improve the codegen for vector loads involving the
scalar_to_vector (load X) sequence. Initially, ld->mv instructions were used
for scalar_to_vector (load X), so this patch allows scalar_to_vector (load X)
to utilize:
LXSD and LXSDX for i64 and f64
LXSIWAX for i32 (sign extension to i64)
LXSIWZX for i32 and f64
Committing on behalf of Amy Kwan.
Differential Revision: https://reviews.llvm.org/D48950
llvm-svn: 339260
Adding the FP_ROUND nodes when combining FP_TO_[SU]INT of elements
feeding a BUILD_VECTOR into an FP_TO_[SU]INT of the built vector
loses precision. This patch removes the code that adds these nodes
to true f64 operands. It also adds patterns required to ensure
the code is still vectorized rather than converting individual
elements and inserting into a vector.
Fixes https://bugs.llvm.org/show_bug.cgi?id=38342
Differential Revision: https://reviews.llvm.org/D50121
llvm-svn: 338658
The bug is visible in the constant-folded x86 tests. We can't use the
negated shift amount when the type is not power-of-2:
https://rise4fun.com/Alive/US1r
...so in that case, use the regular lowering that includes a select
to guard against a shift-by-bitwidth. This path is improved by only
calculating the modulo shift amount once now.
Also, improve the rotate (with power-of-2 size) lowering to use
a negate rather than subtract from bitwidth. This improves the
codegen whether we have a rotate instruction or not (although
we can still see that we're not matching to a legal rotate in
all cases).
llvm-svn: 338592
This is exchanging a sub-of-1 with add-of-minus-1:
https://rise4fun.com/Alive/plKAH
This is another step towards improving select-of-constants codegen (see D48970).
x86 is the motivating target, and those diffs all appear to be wins. PPC and AArch64 look neutral.
I've limited this to early combining (!LegalOperations) in case a target wants to reverse it, but
I think canonicalizing to 'add' is more likely to produce further transforms because we have more
folds for 'add'.
Differential Revision: https://reviews.llvm.org/D49924
llvm-svn: 338317
The tests with a constant sub operand were added with rL338143,
but the potential transform doesn't have that requirement, so
adding more tests with variable operands.
llvm-svn: 338150
This is a follow-up suggested in D48970.
Alive proofs:
https://rise4fun.com/Alive/sII
We can eliminate an instruction in the usual select-of-constants
to bit hack transform by adjusting the add/sub with constant.
This is always a win.
There are more transforms that are likely wins, but they may need
target hooks in case some targets do not benefit.
This is another step towards making up for canonicalizing to
select-of-constants in rL331486.
llvm-svn: 338132
If the DAGCombiner's rotate matching was working as expected,
I don't think we'd see any test diffs here.
This sidesteps the issue of custom lowering for rotates raised in PR38243:
https://bugs.llvm.org/show_bug.cgi?id=38243
...by only dealing with legal operations.
llvm-svn: 337966
As we already return true from needsAggressiveScheduling() for the most recent
hardware it would be cleaner to just return true for all PowerPC hardware.
Differential Revision: https://reviews.llvm.org/D48663
llvm-svn: 337488
Summary:
The Signal Processing Engine (SPE) is found on NXP/Freescale e500v1,
e500v2, and several e200 cores. This adds support targeting the e500v2,
as this is more common than the e500v1, and is in SoCs still on the
market.
This patch is very intrusive because the SPE is binary incompatible with
the traditional FPU. After discussing with others, the cleanest
solution was to make both SPE and FPU features on top of a base PowerPC
subset, so all FPU instructions are now wrapped with HasFPU predicates.
Supported by this are:
* Code generation following the SPE ABI at the LLVM IR level (calling
conventions)
* Single- and Double-precision math at the level supported by the APU.
Still to do:
* Vector operations
* SPE intrinsics
As this changes the Callee-saved register list order, one test, which
tests the precise generated code, was updated to account for the new
register order.
Reviewed by: nemanjai
Differential Revision: https://reviews.llvm.org/D44830
llvm-svn: 337347
As discussed here:
http://lists.llvm.org/pipermail/llvm-dev/2018-May/123292.htmlhttp://lists.llvm.org/pipermail/llvm-dev/2018-July/124400.html
We want to add rotate intrinsics because the IR expansion of that pattern is 4+ instructions,
and we can lose pieces of the pattern before it gets to the backend. Generalizing the operation
by allowing 2 different input values (plus the 3rd shift/rotate amount) gives us a "funnel shift"
operation which may also be a single hardware instruction.
Initially, I thought we needed to define new DAG nodes for these ops, and I spent time working
on that (much larger patch), but then I concluded that we don't need it. At least as a first
step, we have all of the backend support necessary to match these ops...because it was required.
And shepherding these through the IR optimizer is the primary concern, so the IR intrinsics are
likely all that we'll ever need.
There was also a question about converting the intrinsics to the existing ROTL/ROTR DAG nodes
(along with improving the oversized shift documentation). Again, I don't think that's strictly
necessary (as the test results here prove). That can be an efficiency improvement as a small
follow-up patch.
So all we're left with is documentation, definition of the IR intrinsics, and DAG builder support.
Differential Revision: https://reviews.llvm.org/D49242
llvm-svn: 337221
This is almost the same as an existing IR canonicalization in instcombine,
so I'm assuming this is a good early generic DAG combine too.
The motivation comes from reduced bit-hacking for select-of-constants in IR
after rL331486. We want to restore that functionality in the DAG as noted in
the commit comments for that change and the llvm-dev discussion here:
http://lists.llvm.org/pipermail/llvm-dev/2018-July/124433.html
The PPC and AArch tests show that those targets are already doing something
similar. x86 will be neutral in the minimal case and generally better when
this pattern is extended with other ops as shown in the signbit-shift.ll tests.
Note the asymmetry: we don't include the (extend (ifneg X)) transform because
it already exists in SimplifySelectCC(), and that is verified in the later
unchanged tests in the signbit-shift.ll files. Without the 'not' op, the
general transform to use a shift is always a win because that's a single
instruction.
Alive proofs:
https://rise4fun.com/Alive/ysli
Name: if pos, get -1
%c = icmp sgt i16 %x, -1
%r = sext i1 %c to i16
=>
%n = xor i16 %x, -1
%r = ashr i16 %n, 15
Name: if pos, get 1
%c = icmp sgt i16 %x, -1
%r = zext i1 %c to i16
=>
%n = xor i16 %x, -1
%r = lshr i16 %n, 15
Differential Revision: https://reviews.llvm.org/D48970
llvm-svn: 337130
Revision r322373 fixed a bug in how we materialize constants when the CR-field
needs to be set.
However the fix is overly conservative. It will only do the transform if
AND-ing the input with the new constant produces the same new constant.
This is of course correct, but not necessarily required.
If there are no futher uses of the constant, the constant can be changed.
If there are no uses of the GPR result, the final result of the materialization
isn't important other than it needs to compare to zero correctly (lt, gt, eq).
Differential revision: https://reviews.llvm.org/D42109
llvm-svn: 337008
See https://reviews.llvm.org/D47106 for details.
Reviewed By: probinson
Differential Revision: https://reviews.llvm.org/D47171
This commit drops that patch's changes to:
llvm/test/CodeGen/NVPTX/f16x2-instructions.ll
llvm/test/CodeGen/NVPTX/param-load-store.ll
For some reason, the dos line endings there prevent me from commiting
via the monorepo. A follow-up commit (not via the monorepo) will
finish the patch.
llvm-svn: 336843
Added __float128 support for a number of rounding operations:
trunc
rint
nearbyint
round
floor
ceil
Differential Revision: https://reviews.llvm.org/D48415
llvm-svn: 336601
Power 9 does not have a hardware instruction for frem but we can call fmodf128.
Differential Revision: https://reviews.llvm.org/D48552
llvm-svn: 336406
Map the following instructions to the proper float128 lib calls:
pow[i], exp[2], log[2|10], sin, cos, fmin, fmax
Differential Revision: https://reviews.llvm.org/D48544
llvm-svn: 336361
Optimize code sequences for integer conversion to fp128 when the integer is a result of:
* float->int
* float->long
* double->int
* double->long
Differential Revision: https://reviews.llvm.org/D48429
llvm-svn: 336316
Tests to verify that we are passing fp128 via VSX registers as per ABI.
These are related to clang commit rL336308.
Differential Revision: https://reviews.llvm.org/D48310
llvm-svn: 336314
Legalize and emit code for quad-precision floating point operation conversion of
single-precision value to quad-precision.
Differential Revision: https://reviews.llvm.org/D47569
llvm-svn: 336307
This patch enable parameter passing and return by value for float128 types.
Passing aggregate/union which contain float128 members will be submitted in
subsequent patches.
Differential Revision: https://reviews.llvm.org/D47552
llvm-svn: 336306
Legalize and emit code for round & convert float128 to double precision and
single precision.
Differential Revision: https://reviews.llvm.org/D46997
llvm-svn: 336299
We want to run the Machine Scheduler instead of the List Scheduler after RA.
Checked with a performance run on a Power 9 machine with SPEC 2006 and while
some benchmarks improved and others degraded the geomean was slightly improved
with the Machine Scheduler.
Differential Revision: https://reviews.llvm.org/D45265
llvm-svn: 336295
For the below case, pre-inc prep think it's a good candidate to use pre-inc for the bucket, but 64bit integer load/store update (pre-inc) instruction on Power requires the displacement field should be DS-form (4's multiple). Since it can't satisfy the constraint, we have to do some fix ups later. As below, the original load/stores could be well-form, it makes things worse.
unsigned long long result = 0;
unsigned long long foo(char *p, unsigned long long n) {
for (unsigned long long i = 0; i < n; i++) {
unsigned long long x1 = *(unsigned long long *)(p - 50000 + i);
unsigned long long x2 = *(unsigned long long *)(p - 61024 + i);
unsigned long long x3 = *(unsigned long long *)(p - 62048 + i);
unsigned long long x4 = *(unsigned long long *)(p - 64096 + i);
result *= x1 * x2 * x3 * x4;
}
return result;
}
Patch by jedilyn(Kewen Lin).
Differential Revision: https://reviews.llvm.org/D48813
--This line, and those below, will be ignored--
M lib/Target/PowerPC/PPCLoopPreIncPrep.cpp
A test/CodeGen/PowerPC/preincprep-i64-check.ll
llvm-svn: 336074
As noted in the D44909 review, the transform from (fptosi+sitofp) to ftrunc
can produce -0.0 where the original code does not:
#include <stdio.h>
int main(int argc) {
float x;
x = -0.8 * argc;
printf("%f\n", (float)((int)x));
return 0;
}
$ clang -O0 -mavx fp.c ; ./a.out
0.000000
$ clang -O1 -mavx fp.c ; ./a.out
-0.000000
Ideally, we'd use IR/node flags to predicate the transform, but the IR parser
doesn't currently allow fast-math-flags on the cast instructions. So for now,
just use the function attribute that corresponds to clang's "-fno-signed-zeros"
option.
Differential Revision: https://reviews.llvm.org/D48085
llvm-svn: 335761
This patch has the same motivating example as D48466:
define void @foo(i64 %x, i32 %c.0282.in, i32 %d.0280, i32* %ptr0, i32* %ptr1) {
%c.0282 = and i32 %c.0282.in, 268435455
%a16 = lshr i64 32508, %x
%a17 = and i64 %a16, 1
%tobool = icmp eq i64 %a17, 0
%. = select i1 %tobool, i32 1, i32 2
%.286 = select i1 %tobool, i32 27, i32 26
%shr97 = lshr i32 %c.0282, %.
%shl98 = shl i32 %c.0282.in, %.286
%or99 = or i32 %shr97, %shl98
%shr100 = lshr i32 %d.0280, %.
%shl101 = shl i32 %d.0280, %.286
%or102 = or i32 %shr100, %shl101
store i32 %or99, i32* %ptr0
store i32 %or102, i32* %ptr1
ret void
}
...but I'm trying to kill the setcc bool math sooner rather than later.
By matching a larger pattern that includes both the low-bit mask and the trailing add/sub,
we can create a universally good fold because we always eliminate the condition code
intermediate value.
Here are Alive proofs for these (currently instcombine folds the 'add' variants, but
misses the 'sub' patterns):
https://rise4fun.com/Alive/Gsyp
Name: sub of zext cmp mask
%a = and i8 %x, 1
%c = icmp eq i8 %a, 0
%z = zext i1 %c to i32
%r = sub i32 C1, %z
=>
%optional_cast = zext i8 %a to i32
%r = add i32 %optional_cast, C1-1
Name: add of zext cmp mask
%a = and i32 %x, 1
%c = icmp eq i32 %a, 0
%z = zext i1 %c to i8
%r = add i8 %z, C1
=>
%optional_cast = trunc i32 %a to i8
%r = sub i8 C1+1, %optional_cast
All of the tests look like improvements or neutral to me. But it is possible that x86
test+set+bitop is better than what we now show here. I suspect we could do better by
adding another fold for the 'sub' variants.
We start with select-of-constant in IR in the larger motivating test, so that's why I
included tests with selects. Proofs for those variants:
https://rise4fun.com/Alive/Bx1
Name: true const is bigger
Pre: C2 == (C1 + 1)
%a = and i8 %x, 1
%c = icmp eq i8 %a, 0
%r = select i1 %c, i64 C2, i64 C1
=>
%z = zext i8 %a to i64
%r = sub i64 C2, %z
Name: false const is bigger
Pre: C2 == (C1 + 1)
%a = and i8 %x, 1
%c = icmp eq i8 %a, 0
%r = select i1 %c, i64 C1, i64 C2
=>
%z = zext i8 %a to i64
%r = add i64 C1, %z
Differential Revision: https://reviews.llvm.org/D48466
llvm-svn: 335433
We likely gave up on folding some select-of-constants patterns in
IR with rL331486, and we need to recover those in the DAG.
The tests without select are based on our current DAGCombiner
optimizations for select-of-constants.
llvm-svn: 335390
Summary:
In some cases, these operands lacked the IsDebug property, which is meant to signal that
they should not affect codegen. This patch adds a check for this property in the
MachineVerifier and adds it where it was missing.
This includes refactorings to use MachineInstrBuilder construction functions instead of
manually setting up the intrinsic everywhere.
Patch by: JesperAntonsson
Reviewers: aprantl, rnk, echristo, javed.absar
Reviewed By: aprantl
Subscribers: qcolombet, sdardis, nemanjai, JDevlieghere, atanasyan, llvm-commits
Differential Revision: https://reviews.llvm.org/D48319
llvm-svn: 335214
Summary:
Two utils methods have essentially the same functionality. This is an attempt to merge them into one.
1. lib/Transforms/Utils/Local.cpp : MergeBasicBlockIntoOnlyPred
2. lib/Transforms/Utils/BasicBlockUtils.cpp : MergeBlockIntoPredecessor
Prior to the patch:
1. MergeBasicBlockIntoOnlyPred
Updates either DomTree or DeferredDominance
Moves all instructions from Pred to BB, deletes Pred
Asserts BB has single predecessor
If address was taken, replace the block address with constant 1 (?)
2. MergeBlockIntoPredecessor
Updates DomTree, LoopInfo and MemoryDependenceResults
Moves all instruction from BB to Pred, deletes BB
Returns if doesn't have a single predecessor
Returns if BB's address was taken
After the patch:
Method 2. MergeBlockIntoPredecessor is attempting to become the new default:
Updates DomTree or DeferredDominance, and LoopInfo and MemoryDependenceResults
Moves all instruction from BB to Pred, deletes BB
Returns if doesn't have a single predecessor
Returns if BB's address was taken
Uses of MergeBasicBlockIntoOnlyPred that need to be replaced:
1. lib/Transforms/Scalar/LoopSimplifyCFG.cpp
Updated in this patch. No challenges.
2. lib/CodeGen/CodeGenPrepare.cpp
Updated in this patch.
i. eliminateFallThrough is straightforward, but I added using a temporary array to avoid the iterator invalidation.
ii. eliminateMostlyEmptyBlock(s) methods also now use a temporary array for blocks
Some interesting aspects:
- Since Pred is not deleted (BB is), the entry block does not need updating.
- The entry block was being updated with the deleted block in eliminateMostlyEmptyBlock. Added assert to make obvious that BB=SinglePred.
- isMergingEmptyBlockProfitable assumes BB is the one to be deleted.
- eliminateMostlyEmptyBlock(BB) does not delete BB on one path, it deletes its unique predecessor instead.
- adding some test owner as subscribers for the interesting tests modified:
test/CodeGen/X86/avx-cmp.ll
test/CodeGen/AMDGPU/nested-loop-conditions.ll
test/CodeGen/AMDGPU/si-annotate-cf.ll
test/CodeGen/X86/hoist-spill.ll
test/CodeGen/X86/2006-11-17-IllegalMove.ll
3. lib/Transforms/Scalar/JumpThreading.cpp
Not covered in this patch. It is the only use case using the DeferredDominance.
I would defer to Brian Rzycki to make this replacement.
Reviewers: chandlerc, spatel, davide, brzycki, bkramer, javed.absar
Subscribers: qcolombet, sanjoy, nemanjai, nhaehnle, jlebar, tpr, kbarton, RKSimon, wmi, arsenm, llvm-commits
Differential Revision: https://reviews.llvm.org/D48202
llvm-svn: 335183
Previously this folding was done only if select is a first operand.
However, for non-commutative operations constant may go before
select.
Differential Revision: https://reviews.llvm.org/D48223
llvm-svn: 335167
and expand it post RA basing on the register pressure. However, we miss to do the add-imm peephole for these pseudo instruction.
Differential Revision: https://reviews.llvm.org/D47568
Reviewed By: Nemanjai
llvm-svn: 335024
Summary: This patch originated from D47388 and is a proper subset of the originating changes, containing only the fmf optimization guard extensions.
Reviewers: spatel, hfinkel, wristow, arsenm, javed.absar, rampitec, nhaehnle, nemanjai
Reviewed By: rampitec, nhaehnle
Subscribers: tpr, nemanjai, wdng
Differential Revision: https://reviews.llvm.org/D47918
llvm-svn: 334876
Summary: This change uses fmf subflags to guard fma optimizations as well as unsafe. These changes originated from D46483 and have been simplified via getNode.
Reviewers: spatel, arsenm, hfinkel, javed.absar
Reviewed By: spatel
Subscribers: nemanjai, wdng
Differential Revision: https://reviews.llvm.org/D47388
llvm-svn: 334242
BitPermutationSelector sets Repl32 flag for bit groups which can be (potentially) benefit from 32-bit rotate-and-mask instructions with bit replication, i.e. rlwinm/rlwimi copies lower 32 bits into upper 32 bits on 64-bit PowerPC before rotation.
However, enforcing 32-bit instruction sometimes results in redundant generated code.
For example, the following simple code is compiled into rotldi + rlwimi while it can be compiled into only rldimi instruction if Repl32 flag is not set on the bit group for (a & 0xFFFFFFFF).
uint64_t func(uint64_t a, uint64_t b) {
return (a & 0xFFFFFFFF) | (b << 32) ;
}
To avoid such problem, this patch checks the potential benefit of Repl32 flag before setting it. If a bit group does not require rotation (i.e. RLAmt == 0) and won't be merged into another group, we do not benefit from Repl32 flag on this group.
Differential Revision: https://reviews.llvm.org/D47867
llvm-svn: 334195
Summary:
This change uses fmf subflags to guard optimizations as well as unsafe. These changes originated from D46483.
It contains only context for fsqrt.
Reviewers: spatel, hfinkel, arsenm
Reviewed By: spatel
Subscribers: hfinkel, wdng, andrew.w.kaylor, wristow, efriedma, nemanjai
Differential Revision: https://reviews.llvm.org/D47749
llvm-svn: 334113
Summary: This change uses fmf subflags to guard optimizations as well as unsafe. These changes originated from D46483.
Reviewers: spatel, hfinkel
Reviewed By: spatel
Subscribers: nemanjai
Differential Revision: https://reviews.llvm.org/D47389
llvm-svn: 334037
BitPermutationSelector builds the output value by repeating rotate-and-mask instructions with input registers.
Here, we may avoid one rotate instruction if we start building from an input register that does not require rotation.
For example of the test case bitfieldinsert.ll, it first rotates left r4 by 8 bits and then inserts some bits from r5 without rotation.
This can be executed by one rlwimi instruction, which rotates r4 by 8 bits and inserts its bits into r5.
This patch adds a check for rotation amounts in the comparator used in sorting to process the input without rotation first.
Differential Revision: https://reviews.llvm.org/D47765
llvm-svn: 334011
Instruction selection can insert nodes into the underlying list after the root
node so iterating will thereby miss it. We should NOT assume that, the root node
is the last element in the DAG nodelist.
Patch by: steven.zhang (Qing Shan Zhang)
Differential Revision: https://reviews.llvm.org/D47437
llvm-svn: 333415
Implemente patterns to extract HWord and Byte vector elements and convert to
quad-precision.
Differential Revision: https://reviews.llvm.org/D46774
llvm-svn: 333377
The match pattern in the definition of LXSDX is xoaddr, so the Pseudo
instruction XFLOADf64 never gets selected. XFLOADf64 expands to LXSDX/LFDX post
RA based on the register pressure. To avoid ambiguity, we need to remove the
select pattern for LXSDX, same as what was done for LXSD. STXSDX also have
the same issue.
Patch by Qing Shan Zhang (steven.zhang).
Differential Revision: https://reviews.llvm.org/D47178
llvm-svn: 333150
Implemente patterns to extract [Un]signed Word vector element and convert to
quad-precision.
Differential Revision: https://reviews.llvm.org/D46536
llvm-svn: 333115
Implemente patterns to extract [Un]signed DWord vector element and convert to
quad-precision.
Differential Revision: https://reviews.llvm.org/D46333
llvm-svn: 333112
We need to clean up the DAG floating-point undef logic.
This process is similar to how we handled integer undef
logic in D43141.
And as we did there, I'm trying to reduce the patch by
changing tests that would probably become meaningless
once we correct FP undef folding.
llvm-svn: 332549
This is a simple hack based on what's proposed in D37686, but we can extend it if needed in follow-ups.
It gets us most of the FMF functionality that we want without adding any state bits to the flags. It
also intentionally leaves out non-FMF flags (nsw, etc) to minimize the patch.
It should provide a superset of the functionality from D46563 - the extra tests show propagation and
codegen diffs for fcmp, vecreduce, and FP libcalls.
The PPC log2() test shows the limits of this most basic approach - we only applied 'afn' to the last
node created for the call. AFAIK, there aren't any libcall optimizations based on the flags currently,
so that shouldn't make any difference.
Differential Revision: https://reviews.llvm.org/D46854
llvm-svn: 332358
In order to set breakpoints on labels and list source code around
labels, we need collect debug information for labels, i.e., label
name, the function label belong, line number in the file, and the
address label located. In order to keep these information in LLVM
IR and to allow backend to generate debug information correctly.
We create a new kind of metadata for labels, DILabel. The format
of DILabel is
!DILabel(scope: !1, name: "foo", file: !2, line: 3)
We hope to keep debug information as much as possible even the
code is optimized. So, we create a new kind of intrinsic for label
metadata to avoid the metadata is eliminated with basic block.
The intrinsic will keep existing if we keep it from optimized out.
The format of the intrinsic is
llvm.dbg.label(metadata !1)
It has only one argument, that is the DILabel metadata. The
intrinsic will follow the label immediately. Backend could get the
label metadata through the intrinsic's parameter.
We also create DIBuilder API for labels to be used by Frontend.
Frontend could use createLabel() to allocate DILabel objects, and use
insertLabel() to insert llvm.dbg.label intrinsic in LLVM IR.
Differential Revision: https://reviews.llvm.org/D45024
Patch by Hsiangkai Wang.
llvm-svn: 331841
Legalize and emit code for truncate and convert float128 to (un)signed short
and (un)signed char.
Differential Revision: https://reviews.llvm.org/D46194
llvm-svn: 331797
Existing DAG combine only handles conversions for FP_TO_SINT:
"{f32, f64} x { i32, i16 }"
This patch simplifies the code to handle:
"{ FP_TO_SINT, FP_TO_UINT } x { f64, f32 } x { i64, i32, i16, i8 }"
Differential Revision: https://reviews.llvm.org/D46102
llvm-svn: 331778
Summary: Adding support for Fast flags in the SDNode to leverage fast math sub flag usage.
Reviewers: spatel, arsenm, jbhateja, hfinkel, escha, qcolombet, echristo, wristow, javed.absar
Reviewed By: spatel
Subscribers: llvm-commits, rampitec, nhaehnle, tstellar, FarhanaAleen, nemanjai, javed.absar, jbhateja, hfinkel, wdng
Differential Revision: https://reviews.llvm.org/D45710
llvm-svn: 331547
We can't see all of the problems currently unless
we look at debug output when the global 'unsafe' is
on. It's a mess. This is another attempt to make
sure that D45710 is not making changes unintentionally.
llvm-svn: 331476
I'm choosing PPC out of convenience because it does
all of the transforms of interest in these tests by
default. There are multiple FMF problems shown in the
current checks. D45710 is proposing to fix part of
that.
llvm-svn: 331471
Sinking the and closer to a compare against zero is beneficial on PPC as it
allows us to emit record-form instructions. In the future, we may expand this
to a larger set of operations that feed compares against zero since PPC has
lots of record-form instructions.
Differential revision: https://reviews.llvm.org/D46060
llvm-svn: 331416
The CTR loops pass will insert the decrementing branch instruction in an exiting
block for the loop being transformed. However if that block is part of another
loop as well (whether a nested loop or with irreducible CFG), it is not valid
to use that exiting block. In fact, if the loop hass irreducible CFG, we don't
bother analyzing it and we just bail on the transformation. In practice, this
doesn't lead to a noticeable reduction in the number of loops transformed by
this pass.
Fixes https://bugs.llvm.org/show_bug.cgi?id=37229
Differential Revision: https://reviews.llvm.org/D46162
llvm-svn: 331410
Debug var, expr and loc were only supported for non-fixed stack objects.
This patch adds the following fields to the "fixedStack:" entries, and
renames the ones from "stack:" to:
* debug-info-variable
* debug-info-expression
* debug-info-location
Differential Revision: https://reviews.llvm.org/D46032
llvm-svn: 330859
Vectorized loops with abs() returns incorrect results on POWER9. This patch fixes it.
For example the following code returns negative result if input values are negative though it sums up the absolute value of the inputs.
int vpx_satd_c(const int16_t *coeff, int length) {
int satd = 0;
for (int i = 0; i < length; ++i) satd += abs(coeff[i]);
return satd;
}
This problem causes test failures for libvpx.
For vector absolute and vector absolute difference on POWER9, LLVM generates VABSDUW (Vector Absolute Difference Unsigned Word) instruction or variants.
Since these instructions are for unsigned integers, we need adjustment for signed integers.
For abs(sub(a, b)), we generate VABSDUW(a+0x80000000, b+0x80000000). Otherwise, abs(sub(-1, 0)) returns 0xFFFFFFFF(=-1) instead of 1. For abs(a), we generate VABSDUW(a+0x80000000, 0x80000000).
Differential Revision: https://reviews.llvm.org/D45522
llvm-svn: 330497
This was originally committed at rL328921 and reverted at rL329920 to
investigate failures in Chrome. This time I've added to the ReleaseNotes
to warn users of the potential of exposing UB and let me repeat that
here for more exposure:
Optimization of floating-point casts is improved. This may cause surprising
results for code that is relying on undefined behavior. Code sanitizers can
be used to detect affected patterns such as this:
int main() {
float x = 4294967296.0f;
x = (float)((int)x);
printf("junk in the ftrunc: %f\n", x);
return 0;
}
$ clang -O1 ftrunc.c -fsanitize=undefined ; ./a.out
ftrunc.c:5:15: runtime error: 4.29497e+09 is outside the range of
representable values of type 'int'
junk in the ftrunc: 0.000000
Original commit message:
fptosi / fptoui round towards zero, and that's the same behavior as ISD::FTRUNC,
so replace a pair of casts with the equivalent node. We don't have to account for
special cases (NaN, INF) because out-of-range casts are undefined.
Differential Revision: https://reviews.llvm.org/D44909
llvm-svn: 330437
Legalize and emit code for converting unsigned HWord/Char to QP:
xscvsdqp
xscvudqp
Only covering patterns for unsigned forms cause we don't have part-word
sign-extending integer loads into VSX registers.
Differential Revision: https://reviews.llvm.org/D45494
llvm-svn: 330278
Legalize and emit code for converting (Un)Signed Word to quad-precision via:
xscvsdqp
xscvudqp
Differential Revision: https://reviews.llvm.org/D45389
llvm-svn: 330273
Duplicating this intrinsic is not generally valid because it has the side-effect
of decrementing the CTR. Any passes that duplicate it would need to be taught to
keep the regions formed completely disjoint.
This patch should be NFC for typical uses as CTRLoops runs after the remaining
loop passes. It only affects situations where the loop passes are scheduled on
the IR after the codegen passes (as is the case with some JIT pipelines).
Fixes https://bugs.llvm.org/show_bug.cgi?id=37050
llvm-svn: 330186
This is a transform that I limited in instcombine in rL329821 because it was
creating more instructions in IR when the cast has multiple uses.
But if the cast is free, then we can do the transform regardless of other
uses because it improves the potential throughput of the calculation by
removing a dependency on the fneg.
Differential Revision: https://reviews.llvm.org/D45598
llvm-svn: 330098
This is a test for a transform that was suggested in the post-commit
mailing list thread for rL329821. The target in question is not in
trunk, so PPC gets to stand in for it because it's the only in-tree
target that sets 'isFPExtFree()' to 'true'.
llvm-svn: 329963
This change is exposing UB in source code - as was warned/predicted. :)
See D44909 for discussion. Reverting while we figure out how to fix things.
llvm-svn: 329920
This patch fixes https://bugs.llvm.org/show_bug.cgi?id=37039
The condition only covers one of the two 64-bit rotate instructions. This just
adds the second (RLDICLo).
Patch by Josh Stone.
llvm-svn: 329852
Recommitting r329283, third time lucky...
If the SRL node is only used by an AND, we may be able to set the
ExtVT to the width of the mask, making the AND redundant. To support
this, another check has been added in isLegalNarrowLoad which queries
whether the load is valid.
Differential Revision: https://reviews.llvm.org/D41350
llvm-svn: 329551
Should fix UBSan bot by also checking there's no "uwtable" attribute
before skipping. Otherwise the unwind table will be useless since its
moves expect CSRs to actually be preserved.
A noreturn nounwind function can be expected to never return in any way, and by
never returning it will also never have to restore any callee-saved registers
for its caller. This makes it possible to skip spills of those registers during
function entry, saving some stack space and time in the process. This is rather
useful for embedded targets with limited stack space.
Should fix PR9970.
Patch mostly by myeisha (pmb).
llvm-svn: 329494
VSX D-form load/store instructions of POWER9 require the offset be a multiple of 16 and a helper`isOffsetMultipleOf` is used to check this.
So far, the helper handles FrameIndex + offset case, but not handling FrameIndex without offset case. Due to this, we are missing opportunities to exploit D-form instructions when accessing an object or array allocated on stack.
For example, x-form store (stxvx) is used for int a[4] = {0}; instead of d-form store (stxv). For larger arrays, D-form instruction is not used when accessing the first 16-byte. Using D-form instructions reduces register pressure as well as instructions.
Differential Revision: https://reviews.llvm.org/D45079
llvm-svn: 329377
A noreturn nounwind function can be expected to never return in any way, and by
never returning it will also never have to restore any callee-saved registers
for its caller. This makes it possible to skip spills of those registers during
function entry, saving some stack space and time in the process. This is rather
useful for embedded targets with limited stack space.
Should fix PR9970.
Patch by myeisha (pmb).
llvm-svn: 329287
fptosi / fptoui round towards zero, and that's the same behavior as ISD::FTRUNC,
so replace a pair of casts with the equivalent node. We don't have to account for
special cases (NaN, INF) because out-of-range casts are undefined.
Differential Revision: https://reviews.llvm.org/D44909
llvm-svn: 328921
On Hexagon "x = y" is a syntax used in most instructions, and is not
treated as a directive.
Differential Revision: https://reviews.llvm.org/D44256
llvm-svn: 328635
Legalize and emit code for quad-precision floating point operation xscvdpqp
and add option to guard the quad precision operation support.
Differential Revision: https://reviews.llvm.org/D44746
llvm-svn: 328558
A new function getOpcodeForSpill should now be the only place to get
the opcode for a given spilled register.
Differential Revision: https://reviews.llvm.org/D43086
llvm-svn: 328556
This patch adds functions to allow MachineLICM to hoist invariant stores.
Currently, MachineLICM does not hoist any store instructions, however
when storing the same value to a constant spot on the stack, the store
instruction should be considered invariant and be hoisted. The function
isInvariantStore iterates each operand of the store instruction and checks
that each register operand satisfies isCallerPreservedPhysReg. The store
may be fed by a copy, which is hoisted by isCopyFeedingInvariantStore.
This patch also adds the PowerPC changes needed to consider the stack
register as caller preserved.
Differential Revision: https://reviews.llvm.org/D40196
llvm-svn: 328326
I'm not entirely sure these hacks are still needed. If you remove the hacks completely, the name of the library call that gets generated doesn't match the grep the test previously had. So the test wasn't really checking anything.
If the hack is still needed it belongs in PPC specific code. I believe the FP_TO_SINT code here is the only place in the tree where a FP_ROUND_INREG node is created today. And I don't think its even being used correctly because the legalization returned a BUILD_PAIR with the same value twice. That doesn't seem right to me. By moving the code entirely to PPC we can avoid creating the FP_ROUND_INREG at all.
I replaced the grep in the existing test with full checks generated by hacking update_llc_test_check.py to support ppc32 just long enough to generate it.
Differential Revision: https://reviews.llvm.org/D44061
llvm-svn: 328017
Sanjay Patel