Someday we'd like to remove old autoupgrade code so it helps to annotate how long its been there so we don't have to go digging through commit history.
llvm-svn: 348728
Previously we had to take the carry in and add -1 to it to set the carry flag so we could use it with ADC/SBB. But if we know its 0 then we don't need to bother.
This should go a long way towards fixing PR24545.
llvm-svn: 348727
The dependency was added in r213995 in response to r213986 which did make
X86/Utils depend on IR, but r256680 later removed that dependency again.
llvm-svn: 348724
The existing code tries to handle an undef operand while transforming an add to an LEA,
but it's incomplete because we will crash on the i16 test with the debug output shown below.
It's better to just give up instead. Really, GlobalIsel should have folded these before we
could get into trouble.
# Machine code for function add_undef_i16: NoPHIs, TracksLiveness, Legalized, RegBankSelected, Selected
bb.0 (%ir-block.0):
liveins: $edi
%1:gr32 = COPY killed $edi
%0:gr16 = COPY %1.sub_16bit:gr32
%5:gr64_nosp = IMPLICIT_DEF
%5.sub_16bit:gr64_nosp = COPY %0:gr16
%6:gr64_nosp = IMPLICIT_DEF
%6.sub_16bit:gr64_nosp = COPY %2:gr16
%4:gr32 = LEA64_32r killed %5:gr64_nosp, 1, killed %6:gr64_nosp, 0, $noreg
%3:gr16 = COPY killed %4.sub_16bit:gr32
$ax = COPY killed %3:gr16
RET 0, implicit killed $ax
# End machine code for function add_undef_i16.
*** Bad machine code: Reading virtual register without a def ***
- function: add_undef_i16
- basic block: %bb.0 (0x7fe6cd83d940)
- instruction: %6.sub_16bit:gr64_nosp = COPY %2:gr16
- operand 1: %2:gr16
LLVM ERROR: Found 1 machine code errors.
Differential Revision: https://reviews.llvm.org/D54710
llvm-svn: 348722
Extension to rL348617, turns out llvm-exegesis doesn't need to match the perf counter name against a scheduler model resource name - so I've added a few more counters that I could find in the libpfm4 source code (and fix a typo in the knl/knm retired_uops counter - which uses 'all' instead of 'any').
llvm-svn: 348721
The test file shows a case where the avoid store forwarding block
pass misses to copy a range (-1..1) when the load displacement
changes sign.
Baseline test for D55485.
llvm-svn: 348712
PE/COFF sections can have section names truncated to 8 chars, in order to
have the name available at runtime. (The string table, where long untruncated
names are stored, isn't loaded at runtime.)
This allows various llvm tools to dump the .eh_frame section from such
executables.
Patch by Peiyuan Song!
Differential Revision: https://reviews.llvm.org/D55407
llvm-svn: 348708
This is effectively re-committing the changes from:
rL347917 (D54640)
rL348195 (D55126)
...which were effectively reverted here:
rL348604
...because the code had a bug that could induce infinite looping
or eventual out-of-memory compilation.
The bug was that this code did not guard against transforming
opaque constants. More details are in the post-commit mailing
list thread for r347917. A reduced test for that is included
in the x86 bool-math.ll file. (I wasn't able to reduce a PPC
backend test for this, but it was almost the same pattern.)
Original commit message for r347917:
The motivating case for this is shown in:
https://bugs.llvm.org/show_bug.cgi?id=32023
and the corresponding rot16.ll regression tests.
Because x86 scalar shift amounts are i8 values, we can end up with trunc-binop-trunc
sequences that don't get folded in IR.
As the TODO comments suggest, there will be regressions if we extend this (for x86,
we mostly seem to be missing LEA opportunities, but there are likely vector folds
missing too). I think those should be considered existing bugs because this is the
same transform that we do as an IR canonicalization in instcombine. We just need
more tests to make those visible independent of this patch.
llvm-svn: 348706
Summary:
WasmSignature used to use its `WasmSignature` member variable only for
function types, but now it also can be used for events as well.
Reviewers: sbc100
Subscribers: dschuff, jgravelle-google, sunfish, llvm-commits
Differential Revision: https://reviews.llvm.org/D55247
llvm-svn: 348702
Summary:
This anoymous function actually has same logic with `Obj->toMappedAddr`.
Besides, I have a question on resolving illegal value. `gnu-readelf`, `gnu-objdump` and `llvm-objdump` could parse the test file 'test/tools/llvm-objdump/Inputs/private-headers-x86_64.elf', but `llvm-readobj` will fail when parse `DT_RELR` segment. Because, the value is 0x87654321 which is illegal. So, shall we do this clean up rather then remove the checking statements inside anoymous function?
```
if (Delta >= Phdr.p_filesz)
return createError("Virtual address is not in any segment");
```
Reviewers: rupprecht, jhenderson
Reviewed By: jhenderson
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D55329
llvm-svn: 348701
These nodes should have two results. A real VT and a Glue. But this code would have returned Undef which would only be a single result. But we're in the single result version of getNode so these opcodes should never be seen by this function anyway.
llvm-svn: 348670
It seems to be unexpectedly passing on some bots probably because it requires asserts to fail, but doesn't say that. But we already have a patch in review to make it not xfail so I'd rather just focus on getting it passing rather than trying to figure out an unexpected pass.
llvm-svn: 348661
We were still using the rounded down offset and alignment even though
they aren't handled because you can't trivially bitcast the loaded
value.
llvm-svn: 348658
`Saver` is a StringSaver, which has a few overloads of `save` that all
ultimately just call `StringRef save(StringRef)`. Just take a StringRef
here instead of building up a std::string to convert it to a StringRef.
llvm-svn: 348650
Summary:
- LLVM clang-format style doesn't allow one-line ifs.
- LLVM clang-tidy style says method names should start with a lowercase
letter. But currently WebAssemblyAsmParser's parent class
MCTargetAsmParser is mixing lowercase and uppercase method names
itself so overridden methods cannot be renamed now.
- Changed else ifs after returns to ifs.
- Added some newlines for readability.
Reviewers: aardappel, sbc100
Subscribers: dschuff, jgravelle-google, sunfish, llvm-commits
Differential Revision: https://reviews.llvm.org/D55350
llvm-svn: 348648
Currently memcpyopt optimizes cases like
memset(a, byte, N);
memcpy(b, a, M);
to
memset(a, byte, N);
memset(b, byte, M);
if M <= N. Often this allows further simplifications down the line,
which drop the first memset entirely.
This patch extends this optimization for the case where M > N, but we
know that the bytes a[N..M] are undef due to alloca/lifetime.start.
This situation arises relatively often for Rust code, because Rust does
not initialize trailing structure padding and loves to insert redundant
memcpys. This also fixes https://bugs.llvm.org/show_bug.cgi?id=39844.
For the implementation, I'm reusing a bit of code for a similar existing
optimization (direct memcpy of undef). I've also added memset support to
MemDepAnalysis GetLocation -- Instead, getPointerDependencyFrom could be
used, but it seems to make more sense to add this to GetLocation and thus
make the computation cachable.
Differential Revision: https://reviews.llvm.org/D55120
llvm-svn: 348645
The splitting pass uses its 'unlikelyExecuted' predicate to statically
decide which blocks are cold.
- Do not treat noreturn calls as if they are cold unless they are actually
marked cold. This is motivated by functions like exit() and longjmp(), which
are not beneficial to outline.
- Do not treat inline asm as an outlining barrier. In practice asm("") is
frequently used to inhibit basic block merging; enabling outlining in this case
results in substantial memory savings.
- Treat invokes of cold functions as cold.
As a drive-by, remove the 'exceptionHandlingFunctions' predicate, because it's
no longer needed. The pass can identify & outline blocks dominated by EH pads,
so there's no need to special-case __cxa_begin_catch etc.
Differential Revision: https://reviews.llvm.org/D54244
llvm-svn: 348640
Algorithm: Identify maximal cold regions and put them in a worklist. If
a candidate region overlaps with another, discard it. While the worklist
is full, remove a single-entry sub-region from the worklist and attempt
to outline it. By the non-overlap property, this should not invalidate
parts of the domtree pertaining to other outlining regions.
Testing: LNT results on X86 are clean. With test-suite + externals, llvm
outlines 134KB pre-patch, and 352KB post-patch (+ ~2.6x). The file
483.xalancbmk/src/Constants.cpp stands out as an extreme case where llvm
outlines over 100 times in some functions (mostly EH paths). There was
not a significant performance impact pre vs. post-patch.
Differential Revision: https://reviews.llvm.org/D53887
llvm-svn: 348639
Previously we would create an lldb::Function object for each function
parsed, but we would not add these to the clang AST. This is a first
step towards getting local variable support working, as we first need an
AST decl so that when we create local variable entries, they have the
proper DeclContext.
Differential Revision: https://reviews.llvm.org/D55384
llvm-svn: 348631
We were overcounting the number of arithmetic operations needed at each level before we reach a legal type. We were using the full vector type for that level, but we are going to split the input vector at that level in half. So the effective arithmetic operation cost at that level is half the width.
So for example on 8i32 on an sse target. Were were calculating the cost of an 8i32 op which is likely 2 for basic integer. Then after the loop we count 2 more v4i32 ops. For a total arith cost of 4. But if you look at the assembly there would only be 3 arithmetic ops.
There are still more bugs in this code that I'm going to work on next. The non pairwise code shouldn't count extract subvectors in the loop. There are no extracts, the types are split in registers. For pairwise we need to use 2 two src permute shuffles.
Differential Revision: https://reviews.llvm.org/D55397
llvm-svn: 348621
To make X86CondBrFoldingPass can be run with --run-pass option, this can test one wrong assertion on analyzeCompare function for SUB32ri when its operand is not imm
Patch by Jianping Chen
Differential Revision: https://reviews.llvm.org/D55412
llvm-svn: 348620
This patch attempts to improve pfm perf counter coverage for all the x86 CPUs that libpfm4 supports.
Intel/AMD CPU families tend to share names for cycle/uops counters so even if they don't have a scheduler model yet they can at least use the default values (checked against the libpfm4 source code).
The remaining CPUs (where their port/pipe resource counters are known) I've tried to add to the existing model mappings.
These are untested but don't represent a regression to current llvm-exegesis behaviour for these CPUs.
Differential Revision: https://reviews.llvm.org/D55432
llvm-svn: 348617
As discussed in the post-commit thread of r347917, this
transform is fighting with an existing transform causing
an infinite loop or out-of-memory, so this is effectively
reverting r347917 and its follow-up r348195 while we
investigate the bug.
llvm-svn: 348604
DemandedBits and BDCE currently only support scalar integers. This
patch extends them to also handle vector integer operations. In this
case bits are not tracked for individual vector elements, instead a
bit is demanded if it is demanded for any of the elements. This matches
the behavior of computeKnownBits in ValueTracking and
SimplifyDemandedBits in InstCombine.
Unlike the previous iteration of this patch, getDemandedBits() can now
again be called on arbirary (sized) instructions, even if they don't
have integer or vector of integer type. (For vector types the size of the
returned mask will now be the scalar size in bits though.)
The added LoopVectorize test case shows a case which triggered an
assertion failure with the previous attempt, because getDemandedBits()
was called on a pointer-typed instruction.
Differential Revision: https://reviews.llvm.org/D55297
llvm-svn: 348602
This change attempts to shrink scalar AND, OR and XOR instructions which take an immediate that isn't inlineable.
It performs:
AND s0, s0, ~(1 << n) -> BITSET0 s0, n
OR s0, s0, (1 << n) -> BITSET1 s0, n
AND s0, s1, x -> ANDN2 s0, s1, ~x
OR s0, s1, x -> ORN2 s0, s1, ~x
XOR s0, s1, x -> XNOR s0, s1, ~x
In particular, this catches setting and clearing the sign bit for fabs (and x, 0x7ffffffff -> bitset0 x, 31 and or x, 0x80000000 -> bitset1 x, 31).
llvm-svn: 348601
This patch introduces a new instinsic `@llvm.experimental.widenable_condition`
that allows explicit representation for guards. It is an alternative to using
`@llvm.experimental.guard` intrinsic that does not contain implicit control flow.
We keep finding places where `@llvm.experimental.guard` is not supported or
treated too conservatively, and there are 2 reasons to that:
- `@llvm.experimental.guard` has memory write side effect to model implicit control flow,
and this sometimes confuses passes and analyzes that work with memory;
- Not all passes and analysis are aware of the semantics of guards. These passes treat them
as regular throwing call and have no idea that the condition of guard may be used to prove
something. One well-known place which had caused us troubles in the past is explicit loop
iteration count calculation in SCEV. Another example is new loop unswitching which is not
aware of guards. Whenever a new pass appears, we potentially have this problem there.
Rather than go and fix all these places (and commit to keep track of them and add support
in future), it seems more reasonable to leverage the existing optimizer's logic as much as possible.
The only significant difference between guards and regular explicit branches is that guard's condition
can be widened. It means that a guard contains (explicitly or implicitly) a `deopt` block successor,
and it is always legal to go there no matter what the guard condition is. The other successor is
a guarded block, and it is only legal to go there if the condition is true.
This patch introduces a new explicit form of guards alternative to `@llvm.experimental.guard`
intrinsic. Now a widenable guard can be represented in the CFG explicitly like this:
%widenable_condition = call i1 @llvm.experimental.widenable.condition()
%new_condition = and i1 %cond, %widenable_condition
br i1 %new_condition, label %guarded, label %deopt
guarded:
; Guarded instructions
deopt:
call type @llvm.experimental.deoptimize(<args...>) [ "deopt"(<deopt_args...>) ]
The new intrinsic `@llvm.experimental.widenable.condition` has semantics of an
`undef`, but the intrinsic prevents the optimizer from folding it early. This form
should exploit all optimization boons provided to `br` instuction, and it still can be
widened by replacing the result of `@llvm.experimental.widenable.condition()`
with `and` with any arbitrary boolean value (as long as the branch that is taken when
it is `false` has a deopt and has no side-effects).
For more motivation, please check llvm-dev discussion "[llvm-dev] Giving up using
implicit control flow in guards".
This patch introduces this new intrinsic with respective LangRef changes and a pass
that converts old-style guards (expressed as intrinsics) into the new form.
The naming discussion is still ungoing. Merging this to unblock further items. We can
later change the name of this intrinsic.
Reviewed By: reames, fedor.sergeev, sanjoy
Differential Revision: https://reviews.llvm.org/D51207
llvm-svn: 348593
