Summary:
The InlineAsm::AsmDialect is only required for X86; no architecture
makes use of it and as such it gets passed around between arch-specific
and general code while being unused for all architectures but X86.
Since the AsmDialect is queried from a MachineInstr, which we also pass
around, remove the additional AsmDialect parameter and query for it deep
in the X86AsmPrinter only when needed/as late as possible.
This refactor should help later planned refactors to AsmPrinter, as this
difference in the X86AsmPrinter makes it harder to make AsmPrinter more
generic.
Reviewers: craig.topper
Subscribers: jholewinski, arsenm, dschuff, jyknight, dylanmckay, sdardis, nemanjai, jvesely, nhaehnle, javed.absar, sbc100, jgravelle-google, eraman, hiraditya, aheejin, kbarton, fedor.sergeev, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, PkmX, jocewei, jsji, llvm-commits, peter.smith, srhines
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60488
llvm-svn: 358101
For multi-dimensional array like below
int a[2][3];
the previous implementation generates BTF_KIND_ARRAY type
like below:
. element_type: int
. index_type: unsigned int
. number of elements: 6
This is not the best way to represent arrays, esp.,
when converting BTF back to headers and users will see
int a[6];
instead.
This patch generates proper support for multi-dimensional arrays.
For "int a[2][3]", the two BTF_KIND_ARRAY types will be
generated:
Type #n:
. element_type: int
. index_type: unsigned int
. number of elements: 3
Type #(n+1):
. element_type: #n
. index_type: unsigned int
. number of elements: 2
The linux kernel already supports such a multi-dimensional
array representation properly.
Signed-off-by: Yonghong Song <yhs@fb.com>
Differential Revision: https://reviews.llvm.org/D59943
llvm-svn: 357215
The .BTF.ext FuncInfoTable and LineInfoTable contain
information organized per ELF section. Current definition
of FuncInfoTable/LineInfoTable is:
std::unordered_map<uint32_t, std::vector<BTFFuncInfo>> FuncInfoTable
std::unordered_map<uint32_t, std::vector<BTFLineInfo>> LineInfoTable
where the key is the section name off in the string table.
The unordered_map may cause the order of section output
different for different platforms.
The same for unordered map definition of
std::unordered_map<std::string, std::unique_ptr<BTFKindDataSec>>
DataSecEntries
where BTF_KIND_DATASEC entries may have different ordering
for different platforms.
This patch fixed the issue by using std::map.
Test static-var-derived-type.ll is modified to generate two
DataSec's which will ensure the ordering is the same for all
supported platforms.
Signed-off-by: Yonghong Song <yhs@fb.com>
llvm-svn: 357077
Currently, the type id for a derived type is computed incorrectly.
For example,
type #1: int
type #2: ptr to #1
For a global variable "int *a", type #1 will be attributed to variable "a".
This is due to a bug which assigns the type id of the basetype of
that derived type as the derived type's type id. This happens
to "const", "volatile", "restrict", "typedef" and "pointer" types.
This patch fixed this bug, fixed existing test cases and added
a new one focusing on pointers plus other derived types.
Signed-off-by: Yonghong Song <yhs@fb.com>
llvm-svn: 356727
Two new kinds, BTF_KIND_VAR and BTF_KIND_DATASEC, are added.
BTF_KIND_VAR has the following specification:
btf_type.name: var name
btf_type.info: type kind
btf_type.type: var type
// btf_type is followed by one u32
u32: varinfo (currently, only 0 - static, 1 - global allocated in elf sections)
Not all globals are supported in this patch. The following globals are supported:
. static variables with or without section attributes
. global variables with section attributes
The inclusion of globals with section attributes
is for future potential extraction of key/value
type id's from map definition.
BTF_KIND_DATASEC has the following specification:
btf_type.name: section name associated with variable or
one of .data/.bss/.readonly
btf_type.info: type kind and vlen for # of variables
btf_type.size: 0
#vlen number of the following:
u32: id of corresponding BTF_KIND_VAR
u32: in-session offset of the var
u32: the size of memory var occupied
At the time of debug info emission, the data section
size is unknown, so the btf_type.size = 0 for
BTF_KIND_DATASEC. The loader can patch it during
loading time.
The in-session offseet of the var is only available
for static variables. For global variables, the
loader neeeds to assign the global variable symbol value in
symbol table to in-section offset.
The size of memory is used to specify the amount of the
memory a variable occupies. Typically, it equals to
the type size, but for certain structures, e.g.,
struct tt {
int a;
int b;
char c[];
};
static volatile struct tt s2 = {3, 4, "abcdefghi"};
The static variable s2 has size of 20.
Note that for BTF_KIND_DATASEC name, the section name
does not contain object name. The compiler does have
input module name. For example, two cases below:
. clang -target bpf -O2 -g -c test.c
The compiler knows the input file (module) is test.c
and can generate sec name like test.data/test.bss etc.
. clang -target bpf -O2 -g -emit-llvm -c test.c -o - |
llc -march=bpf -filetype=obj -o test.o
The llc compiler has the input file as stdin, and
would generate something like stdin.data/stdin.bss etc.
which does not really make sense.
For any user specificed section name, e.g.,
static volatile int a __attribute__((section("id1")));
static volatile const int b __attribute__((section("id2")));
The DataSec with name "id1" and "id2" does not contain
information whether the section is readonly or not.
The loader needs to check the corresponding elf section
flags for such information.
A simple example:
-bash-4.4$ cat t.c
int g1;
int g2 = 3;
const int g3 = 4;
static volatile int s1;
struct tt {
int a;
int b;
char c[];
};
static volatile struct tt s2 = {3, 4, "abcdefghi"};
static volatile const int s3 = 4;
int m __attribute__((section("maps"), used)) = 4;
int test() { return g1 + g2 + g3 + s1 + s2.a + s3 + m; }
-bash-4.4$ clang -target bpf -O2 -g -S t.c
Checking t.s, 4 BTF_KIND_VAR's are generated (s1, s2, s3 and m).
4 BTF_KIND_DATASEC's are generated with names
".data", ".bss", ".rodata" and "maps".
Signed-off-by: Yonghong Song <yhs@fb.com>
Differential Revision: https://reviews.llvm.org/D59441
llvm-svn: 356326
Previous commit 6bc58e6d3dbd ("[BPF] do not generate unused local/global types")
tried to exclude global variable from type generation. The condition is:
if (Global.hasExternalLinkage())
continue;
This is not right. It also excluded initialized globals.
The correct condition (from AssemblyWriter::printGlobal()) is:
if (!GV->hasInitializer() && GV->hasExternalLinkage())
Out << "external ";
Let us do the same in BTF type generation. Also added a test for it.
Signed-off-by: Yonghong Song <yhs@fb.com>
llvm-svn: 356279
The kernel currently has a limit for # of types to be 64KB and
the size of string subsection to be 64KB. A simple bcc tool
runqlat.py generates:
. the size of ~33KB type section, roughly ~10K types
. the size of ~17KB string section
The majority type is from the types referenced by local
variables in the bpf program. For example, the kernel "task_struct"
itself recursively brings in ~900 other types.
This patch did the following optimization to avoid generating
unused types:
. do not generate types for local variables unless they are
function arguments.
. do not generate types for external globals.
If an external global is not used in the program, llvm
already removes it from IR, so global variable saving is
typical small. For runqlat.py, only one variable "llvm.used"
is the external global.
The types for locals and external globals can be added back
once there is a usage for them.
After the above optimization, the runqlat.py generates:
. the size of ~1.5KB type section, roughtly 500 types
. the size of ~0.7KB string section
UPDATE:
resubmitted the patch after previous revert with
the following fix:
use Global.hasExternalLinkage() to test "external"
linkage instead of using Global.getInitializer(),
which will assert on external variables.
Signed-off-by: Yonghong Song <yhs@fb.com>
llvm-svn: 356234
The kernel currently has a limit for # of types to be 64KB and
the size of string subsection to be 64KB. A simple bcc tool
runqlat.py generates:
. the size of ~33KB type section, roughly ~10K types
. the size of ~17KB string section
The majority type is from the types referenced by local
variables in the bpf program. For example, the kernel "task_struct"
itself recursively brings in ~900 other types.
This patch did the following optimization to avoid generating
unused types:
. do not generate types for local variables unless they are
function arguments.
. do not generate types for external globals.
If an external global is not used in the program, llvm
already removes it from IR, so global variable saving is
typical small. For runqlat.py, only one variable "llvm.used"
is the external global.
The types for locals and external globals can be added back
once there is a usage for them.
After the above optimization, the runqlat.py generates:
. the size of ~1.5KB type section, roughtly 500 types
. the size of ~0.7KB string section
Signed-off-by: Yonghong Song <yhs@fb.com>
llvm-svn: 356232
AMDGPU target run out of Subtarget feature flags hitting the limit of 64.
AssemblerPredicates uses at most uint64_t for their representation.
At the same time CodeGen has exhausted this a long time ago and switched
to a FeatureBitset with the current limit of 192 bits.
This patch completes transition to the bitset for feature bits extending
it to asm matcher and MC code emitter.
Differential Revision: https://reviews.llvm.org/D59002
llvm-svn: 355839
If There is no types/non-empty strings, do not generate
.BTF section. If there is no func_info/line_info, do
not generate .BTF.ext section.
Signed-off-by: Yonghong Song <yhs@fb.com>
Differential Revision: https://reviews.llvm.org/D58936
llvm-svn: 355360
Like the other load/store instructions, "w" register is preferred when
disassembling BPF_STX | BPF_W | BPF_XADD.
v1 -> v2:
- Updated testcase insn-unit.s (Yonghong)
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
llvm-svn: 355127
Support sub-register code-gen for XADD is like supporting any other Load
and Store patterns.
No new instruction is introduced.
lock *(u32 *)(r1 + 0) += w2
has exactly the same underlying insn as:
lock *(u32 *)(r1 + 0) += r2
BPF_W width modifier has guaranteed they behave the same at runtime. This
patch merely teaches BPF back-end that BPF_W width modifier could work
GPR32 register class and that's all needed for sub-register code-gen
support for XADD.
test/CodeGen/BPF/xadd.ll updated to include sub-register code-gen tests.
A new testcase test/CodeGen/BPF/xadd_legal.ll is added to make sure the
legal case could pass on all code-gen modes. It could also test dead Def
check on GPR32. If there is no proper handling like what has been done
inside BPFMIChecking.cpp:hasLivingDefs, then this testcase will fail.
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
llvm-svn: 355126
BPF XADD semantics require all Defs of XADD are dead, meaning any result of
XADD insn is not used.
However, BPF backend hasn't enabled sub-register liveness track, so when
the source and destination operands of XADD are GPR32, there is no
sub-register dead info. If we rely on the generic
MachineInstr::allDefsAreDead, then we will raise false alarm on GPR32 Def.
This was fine as there was no sub-register code-gen support for XADD which
will be added by the next patch.
To support GPR32 Def, ideally we could just enable sub-registr liveness
track on BPF backend, then allDefsAreDead could work on GPR32 Def. This
requires implementing TargetSubtargetInfo::enableSubRegLiveness on BPF.
However, sub-register liveness tracking module inside LLVM is actually
designed for the situation where one register could be split into more
than one sub-registers for which case each sub-register could have their
own liveness and kill one of them doesn't kill others. So, tracking
liveness for each make sense.
For BPF, each 64-bit register could only have one 32-bit sub-register. This
is exactly the case which LLVM think brings no benefits for doing
sub-register tracking, because the live range of sub-register must always
equal to its parent register, therefore liveness tracking is disabled even
the back-end has implemented enableSubRegLiveness. The detailed information
is at r232695:
Author: Matthias Braun <matze@braunis.de>
Date: Thu Mar 19 00:21:58 2015 +0000
Do not track subregister liveness when it brings no benefits
Hence, for BPF, we enhance MachineInstr::allDefsAreDead. Given the solo
sub-register always has the same liveness as its parent register, LLVM is
already attaching a implicit 64-bit register Def whenever the there is
a sub-register Def. The liveness of the implicit 64-bit Def is available.
For example, for "lock *(u32 *)(r0 + 4) += w9", the MachineOperand info
could be:
$w9 = XADDW32 killed $r0, 4, $w9(tied-def 0),
implicit killed $r9, implicit-def dead $r9
Even though w9 is not marked as Dead, the parent register r9 is marked as
Dead correctly, and it is safe to use such information or our purpose.
v1 -> v2:
- Simplified code logic inside hasLiveDefs. (Yonghong)
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
llvm-svn: 355124
Currently, the LLVM will print an error like
Unsupported relocation: try to compile with -O2 or above,
or check your static variable usage
if user defines more than one static variables in a single
ELF section (e.g., .bss or .data).
There is ongoing effort to support static and global
variables in libbpf and kernel. This patch removed the
assertion so user programs with static variables won't
fail compilation.
The static variable in-section offset is written to
the "imm" field of the corresponding to-be-relocated
bpf instruction. Below is an example to show how the
application (e.g., libbpf) can relate variable to relocations.
-bash-4.4$ cat g1.c
static volatile long a = 2;
static volatile int b = 3;
int test() { return a + b; }
-bash-4.4$ clang -target bpf -O2 -c g1.c
-bash-4.4$ llvm-readelf -r g1.o
Relocation section '.rel.text' at offset 0x158 contains 2 entries:
Offset Info Type Symbol's Value Symbol's Name
0000000000000000 0000000400000001 R_BPF_64_64 0000000000000000 .data
0000000000000018 0000000400000001 R_BPF_64_64 0000000000000000 .data
-bash-4.4$ llvm-readelf -s g1.o
Symbol table '.symtab' contains 6 entries:
Num: Value Size Type Bind Vis Ndx Name
0: 0000000000000000 0 NOTYPE LOCAL DEFAULT UND
1: 0000000000000000 0 FILE LOCAL DEFAULT ABS g1.c
2: 0000000000000000 8 OBJECT LOCAL DEFAULT 4 a
3: 0000000000000008 4 OBJECT LOCAL DEFAULT 4 b
4: 0000000000000000 0 SECTION LOCAL DEFAULT 4
5: 0000000000000000 64 FUNC GLOBAL DEFAULT 2 test
-bash-4.4$ llvm-objdump -d g1.o
g1.o: file format ELF64-BPF
Disassembly of section .text:
0000000000000000 test:
0: 18 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r1 = 0 ll
2: 79 11 00 00 00 00 00 00 r1 = *(u64 *)(r1 + 0)
3: 18 02 00 00 08 00 00 00 00 00 00 00 00 00 00 00 r2 = 8 ll
5: 61 20 00 00 00 00 00 00 r0 = *(u32 *)(r2 + 0)
6: 0f 10 00 00 00 00 00 00 r0 += r1
7: 95 00 00 00 00 00 00 00 exit
-bash-4.4$
. from symbol table, static variable "a" is in section #4, offset 0.
. from symbol table, static variable "b" is in section #4, offset 8.
. the first relocation is against symbol #4:
4: 0000000000000000 0 SECTION LOCAL DEFAULT 4
and in-section offset 0 (see llvm-objdump result)
. the second relocation is against symbol #4:
4: 0000000000000000 0 SECTION LOCAL DEFAULT 4
and in-section offset 8 (see llvm-objdump result)
. therefore, the first relocation is for variable "a", and
the second relocation is for variable "b".
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Yonghong Song <yhs@fb.com>
llvm-svn: 354954
JMP32 instructions has been added to eBPF ISA. They are 32-bit variants of
existing BPF conditional jump instructions, but the comparison happens on
low 32-bit sub-register only, therefore some unnecessary extensions could
be saved.
JMP32 instructions will only be available for -mcpu=v3. Host probe hook has
been updated accordingly.
JMP32 instructions will only be enabled in code-gen when -mattr=+alu32
enabled, meaning compiling the program using sub-register mode.
For JMP32 encoding, it is a new instruction class, and is using the
reserved eBPF class number 0x6.
This patch has been tested by compiling and running kernel bpf selftests
with JMP32 enabled.
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
llvm-svn: 353384
In IR, sometimes the following attributes for DIFile may be
generated:
filename: /home/yhs/test.c
directory: /tmp
The /tmp may represent the working directory of the compilation
process.
In such cases, since filename is with absolute path,
the directory should be ignored by BTF. The filename alone is
enough to get the source.
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Yonghong Song <yhs@fb.com>
llvm-svn: 352952
In IR, sometimes the following attributes for DIFile may be
generated:
filename: /home/yhs/test.c
directory: /tmp
The /tmp may represent the working directory of the compilation
process.
In such cases, since filename is with absolute path,
the directory should be ignored by BTF. The filename alone is
enough to get the source.
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Yonghong Song <yhs@fb.com>
llvm-svn: 352939
to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351636
Commit f1db33c5c1a9 ("[BPF] Disable relocation for .BTF.ext section")
assigned relocation type R_BPF_NONE if the fixup type
is FK_Data_4 and the symbol is temporary.
The reason is we use FK_Data_4 as a fixup type
for insn offsets in .BTF.ext section.
Just checking whether the symbol is temporary is not enough.
For example, .debug_info may reference some strings whose
fixup is FK_Data_4 with a temporary symbol as well.
To truely reflect the case for .BTF.ext section,
this patch further checks that the section associateed with the symbol
must be SHF_ALLOC and SHF_EXECINSTR, i.e., in the text section.
This fixed the above-mentioned problem.
Signed-off-by: Yonghong Song <yhs@fb.com>
llvm-svn: 350637
Build llvm with assertion on, and then build bcc against this llvm.
Run any bcc tool with debug=8 (turning on -g for clang compilation),
you will get the following assertion errors,
/home/yhs/work/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp:888:
void llvm::RuntimeDyldELF::resolveBPFRelocation(const llvm::SectionEntry&, uint64_t,
uint64_t, uint32_t, int64_t): Assertion `Value <= (4294967295U)' failed.
The .BTF.ext ELF section uses Fixup's to get the instruction
offsets. The data width of the Fixup is 4 bytes since we only need
the insn offset within the section.
This caused the above error though since R_BPF_64_32 expects
4-byte value and the Runtime Dyld tried to resolve the actual
insn address which is 8 bytes.
Actually the offset within the section is all what we need.
Therefore, there is no need to perform any kind of relocation
for .BTF.ext section and such relocation will actually cause
incorrect result.
This patch changed BPFELFObjectWriter::getRelocType() such that
for Fixup Kind FK_Data_4, if the relocation Target is a temporary
symbol, let us skip the relocation (ELF::R_BPF_NONE).
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Yonghong Song <yhs@fb.com>
llvm-svn: 349778
Adds fatal errors for any target that does not support the Tiny or Kernel
codemodels by rejigging the getEffectiveCodeModel calls.
Differential Revision: https://reviews.llvm.org/D50141
llvm-svn: 348585
This patch should not introduce any behavior changes. It consists of
mostly one of two changes:
1. Replacing fall through comments with the LLVM_FALLTHROUGH macro
2. Inserting 'break' before falling through into a case block consisting
of only 'break'.
We were already using this warning with GCC, but its warning behaves
slightly differently. In this patch, the following differences are
relevant:
1. GCC recognizes comments that say "fall through" as annotations, clang
doesn't
2. GCC doesn't warn on "case N: foo(); default: break;", clang does
3. GCC doesn't warn when the case contains a switch, but falls through
the outer case.
I will enable the warning separately in a follow-up patch so that it can
be cleanly reverted if necessary.
Reviewers: alexfh, rsmith, lattner, rtrieu, EricWF, bollu
Differential Revision: https://reviews.llvm.org/D53950
llvm-svn: 345882
Finally all targets are enabling multiple regalloc hints, so the hook to
disable this can now be removed.
NFC.
Review: Simon Pilgrim
https://reviews.llvm.org/D52316
llvm-svn: 343851
Currently, BPF has XADD (locked add) insn support and the
asm looks like:
lock *(u32 *)(r1 + 0) += r2
lock *(u64 *)(r1 + 0) += r2
The instruction itself does not have a return value.
At the source code level, users often use
__sync_fetch_and_add()
which eventually translates to XADD. The return value of
__sync_fetch_and_add() is supposed to be the old value
in the xadd memory location. Since BPF::XADD insn does not
support such a return value, this patch added a PreEmit
phase to check such a usage. If such an illegal usage
pattern is detected, a fatal error will be reported like
line 4: Invalid usage of the XADD return value
if compiled with -g, or
Invalid usage of the XADD return value
if compiled without -g.
Signed-off-by: Yonghong Song <yhs@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
llvm-svn: 342692
Clang-compiled object files currently don't include the symbol sizes and
types. Some tools however need that information. For example, ctfconvert
uses that information to generate FreeBSD's CTF representation from ELF
files.
With this patch, symbol sizes and types are included in object files.
Signed-off-by: Paul Chaignon <paul.chaignon@orange.com>
Reported-by: Yutaro Hayakawa <yhayakawa3720@gmail.com>
llvm-svn: 342556
Disassemblers cannot depend on main target headers. The same is true for
MCTargetDesc, but there's a lot more cleanup needed for that.
llvm-svn: 341822
Fix bug https://bugs.llvm.org/show_bug.cgi?id=38643
In BPFAsmBackend applyFixup(), there is an assertion for FixedValue to be 0.
This may not be true, esp. for optimiation level 0.
For example, in the above bug, for the following two
static variables:
@bpf_map_lookup_elem = internal global i8* (i8*, i8*)*
inttoptr (i64 1 to i8* (i8*, i8*)*), align 8
@bpf_map_update_elem = internal global i32 (i8*, i8*, i8*, i64)*
inttoptr (i64 2 to i32 (i8*, i8*, i8*, i64)*), align 8
The static variable @bpf_map_update_elem will have a symbol
offset of 8 and a FK_SecRel_8 with FixupValue 8 will cause
the assertion if llvm is built with -DLLVM_ENABLE_ASSERTIONS=ON.
The above relocations will not exist if the program is compiled
with optimization level -O1 and above as the compiler optimizes
those static variables away. In the below error message, -O2
is suggested as this is the common practice.
Note that FixedValue = 0 in applyFixup() does exist and is valid,
e.g., for the global variable my_map in the above bug. The bpf
loader will process them properly for map_id's before loading
the program into the kernel.
The static variables, which are not optimized away by compiler,
may have FK_SecRel_8 relocation with non-zero FixedValue.
The patch removed the offending assertion and will issue
a hard error as below if the FixedValue in applyFixup()
is not 0.
$ llc -march=bpf -filetype=obj fixup.ll
LLVM ERROR: Unsupported relocation: try to compile with -O2 or above,
or check your static variable usage
Signed-off-by: Yonghong Song <yhs@fb.com>
llvm-svn: 340455
Errors like the following are reported by:
https://urldefense.proofpoint.com/v2/url?u=http-3A__lab.llvm.org-3A8011_builders_llvm-2Dclang-2Dx86-5F64-2Dexpensive-2Dchecks-2Dwin_builds_11261&d=DwIBAg&c=5VD0RTtNlTh3ycd41b3MUw&r=DA8e1B5r073vIqRrFz7MRA&m=929oWPCf7Bf2qQnir4GBtowB8ZAlIRWsAdTfRkDaK-g&s=9k-wbEUVpUm474hhzsmAO29VXVvbxJPWD9RTgCD71fQ&e=
*** Bad machine code: Explicit definition marked as use ***
- function: cal_align1
- basic block: %bb.0 entry (0x47edd98)
- instruction: LDB $r3, $r2, 0
- operand 0: $r3
This is because RegState info was missing for ScratchReg inside
expandMEMCPY. This caused incomplete register usage information to
MachineInstr verifier which then would complain as there could be potential
code-gen issue if the complained MachineInstr is used in place where
register usage information matters even though the memcpy expanding is not
in such case as it happens at the last stage of IR optimization pipeline.
We should always specify those register usage information which compiler
couldn't deduct automatically whenever we add a hardware register manually.
Reported-by: Builder llvm-clang-x86_64-expensive-checks-win Build #11261
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Reviewed-by: Yonghong Song <yhs@fb.com>
llvm-svn: 338134
Some BPF JIT backends would want to optimize memcpy in their own
architecture specific way.
However, at the moment, there is no way for JIT backends to see memcpy
semantics in a reliable way. This is due to LLVM BPF backend is expanding
memcpy into load/store sequences and could possibly schedule them apart from
each other further. So, BPF JIT backends inside kernel can't reliably
recognize memcpy semantics by peephole BPF sequence.
This patch introduce new intrinsic expand infrastructure to memcpy.
To get stable in-order load/store sequence from memcpy, we first lower
memcpy into BPF::MEMCPY node which then expanded into in-order load/store
sequences in expandPostRAPseudo pass which will happen after instruction
scheduling. By this way, kernel JIT backends could reliably recognize
memcpy through scanning BPF sequence.
This new memcpy expand infrastructure is gated by a new option:
-bpf-expand-memcpy-in-order
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
llvm-svn: 337977
On targets like Arm some relaxations may only be performed when certain
architectural features are available. As functions can be compiled with
differing levels of architectural support we must make a judgement on
whether we can relax based on the MCSubtargetInfo for the function. This
change passes through the MCSubtargetInfo for the function to
fixupNeedsRelaxation so that the decision on whether to relax can be made
per function. In this patch, only the ARM backend makes use of this
information. We must also pass the MCSubtargetInfo to applyFixup because
some fixups skip error checking on the assumption that relaxation has
occurred, to prevent code-generation errors applyFixup must see the same
MCSubtargetInfo as fixupNeedsRelaxation.
Differential Revision: https://reviews.llvm.org/D44928
llvm-svn: 334078
Summary:
They've been deprecated in favor of UADDO/ADDCARRY or USUBO/SUBCARRY for a while.
Target that uses these opcodes are changed in order to ensure their behavior doesn't change.
Reviewers: efriedma, craig.topper, dblaikie, bkramer
Subscribers: jholewinski, arsenm, jyknight, sdardis, nemanjai, nhaehnle, kbarton, fedor.sergeev, asb, rbar, johnrusso, simoncook, jordy.potman.lists, apazos, sabuasal, niosHD, jrtc27, zzheng, edward-jones, mgrang, atanasyan, llvm-commits
Differential Revision: https://reviews.llvm.org/D47422
llvm-svn: 333748
With this we gain a little flexibility in how the generic object
writer is created.
Part of PR37466.
Differential Revision: https://reviews.llvm.org/D47045
llvm-svn: 332868
To make this work I needed to add an endianness field to MCAsmBackend
so that writeNopData() implementations know which endianness to use.
Part of PR37466.
Differential Revision: https://reviews.llvm.org/D47035
llvm-svn: 332857
Provide some free functions to reduce verbosity of endian-writing
a single value, and replace the endianness template parameter with
a field.
Part of PR37466.
Differential Revision: https://reviews.llvm.org/D47032
llvm-svn: 332757
The idea is that a client that wants split dwarf would create a
specific kind of object writer that creates two files, and use it to
create the streamer.
Part of PR37466.
Differential Revision: https://reviews.llvm.org/D47050
llvm-svn: 332749
The DEBUG() macro is very generic so it might clash with other projects.
The renaming was done as follows:
- git grep -l 'DEBUG' | xargs sed -i 's/\bDEBUG\s\?(/LLVM_DEBUG(/g'
- git diff -U0 master | ../clang/tools/clang-format/clang-format-diff.py -i -p1 -style LLVM
- Manual change to APInt
- Manually chage DOCS as regex doesn't match it.
In the transition period the DEBUG() macro is still present and aliased
to the LLVM_DEBUG() one.
Differential Revision: https://reviews.llvm.org/D43624
llvm-svn: 332240
Because we create a new kind of debug instruction, DBG_LABEL, we need to
check all passes which use isDebugValue() to check MachineInstr is debug
instruction or not. When expelling debug instructions, we should expel
both DBG_VALUE and DBG_LABEL. So, I create a new function,
isDebugInstr(), in MachineInstr to check whether the MachineInstr is
debug instruction or not.
This patch has no new test case. I have run regression test and there is
no difference in regression test.
Differential Revision: https://reviews.llvm.org/D45342
Patch by Hsiangkai Wang.
llvm-svn: 331844
Makes it easier to see mistakes such as the one fixed in r329178 and makes
the different target CMakeLists more consistent.
Also remove some stale-looking comments from the Nios2 target cmakefile.
No intended behavior change.
llvm-svn: 329181
Commit 37962a331c77 ("bpf: Improve expanding logic in LowerSELECT_CC")
intended to improve code quality for certain jmp conditions. The
commit, however, has a couple of issues:
(1). In code, just swap is not enough, ConditionalCode CC
should also be swapped, otherwise incorrect code will
be generated.
(2). The ConditionalCode swap should be subject to
getHasJmpExt(). If getHasJmpExt() is False, certain
conditional codes will not be supported and swap
may generate incorrect code.
The original goal for this patch is to optimize jmp operations
which does not have JmpExt turned on. If JmpExt is on,
better code could be generated. For example, the test
select_ri.ll is introduced to demonstrate the optimization.
The same result can be achieved with -mcpu=v2 flag.
Signed-off-by: Yonghong Song <yhs@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
llvm-svn: 329043
Currently EVT is in the IR layer only because of Function.cpp needing a very small piece of the functionality of EVT::getEVTString(). The rest of EVT is used in codegen making CodeGen a better place for it.
The previous code converted a Type* to EVT and then called getEVTString. This was only expected to handle the primitive types from Type*. Since there only a few primitive types, we can just print them as strings directly.
Differential Revision: https://reviews.llvm.org/D45017
llvm-svn: 328806