Commit Graph

213 Commits

Author SHA1 Message Date
Nico Weber 5d53aed419 Consistently sort add_subdirectory calls in lib/Target/*/CMakeLists.txt
llvm-svn: 330584
2018-04-23 12:49:34 +00:00
Yonghong Song 149d4d3730 bpf: signal error instead of silent drop for certain invalid asm insn
Currently, an invalid asm insn, either in an asm file or
in an inline asm format, might be silently dropped. This patch
fixed two places where this may happen by
signaling the error so user knows what goes wrong.

The following is an example to demonstrate error messages:

    -bash-4.2$ cat t.c
    int test(void *ctx) {
    #if defined(NO_ERROR)
      asm volatile("r0 = *(u16 *)skb[%0]" : : "i"(2));
    #elif defined(ERROR_1)
      asm volatile("r20 = *(u16 *)skb[%0]" : : "i"(2));
    #elif defined(ERROR_2)
      asm volatile("r0 = *(u16 *)(r1 + ?)" : :);
    #endif
      return 0;
    }
    -bash-4.2$ cat run.sh
    for macro in NO_ERROR ERROR_1 ERROR_2; do
      echo "===== compile for macro" $macro
      clang -D${macro} -O2 -target bpf -emit-llvm -S t.c
      echo "==llc=="
      llc -march=bpf -filetype=obj t.ll
    done
    -bash-4.2$ ./run.sh
    ===== compile for macro NO_ERROR
    ==llc==
    ===== compile for macro ERROR_1
    ==llc==
    <inline asm>:1:2: error: invalid register/token name
            r20 = *(u16 *)skb[2]
            ^
    note: !srcloc = 135
    ===== compile for macro ERROR_2
    ==llc==
    <inline asm>:1:21: error: unexpected token
            r0 = *(u16 *)(r1 + ?)
                               ^
    note: !srcloc = 210
    -bash-4.2$

Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Yonghong Song <yhs@fb.com>
llvm-svn: 329849
2018-04-11 20:24:52 +00:00
Nico Weber 1cbd096914 Sort targetgen calls in lib/Target/*/CMakeLists.
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
2018-04-04 12:37:44 +00:00
Yonghong Song d3b522f519 bpf: fix incorrect SELECT_CC lowering
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
2018-04-03 03:56:37 +00:00
Fangrui Song 956ee79795 Fix a bunch of typoes. NFC
llvm-svn: 328907
2018-03-30 22:22:31 +00:00
Craig Topper 2fa1436206 [IR][CodeGen] Remove dependency on EVT from IR/Function.cpp. Move EVT to CodeGen layer.
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
2018-03-29 17:21:10 +00:00
David Blaikie b3f471a4bd Remove some unused includes to fix layering.
llvm-svn: 328745
2018-03-29 00:29:45 +00:00
David Blaikie 36a0f226b1 Fix layering by moving ValueTypes.h from CodeGen to IR
ValueTypes.h is implemented in IR already.

llvm-svn: 328397
2018-03-23 23:58:31 +00:00
Yonghong Song 82bf8bcb4f bpf: Enhance debug information for peephole optimization passes
Add more debug information for peephole optimization passes.

These would only be enabled for debug version binary and could help
analyzing why some optimization opportunities were missed.

Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
llvm-svn: 327371
2018-03-13 06:47:07 +00:00
Yonghong Song e91802f336 bpf: New post-RA peephole optimization pass to eliminate bad RA codegen
This new pass eliminate identical move:

  MOV rA, rA

This is particularly possible to happen when sub-register support
enabled. The special type cast insn MOV_32_64 involves different
register class on src (i32) and dst (i64), RA could generate useless
instruction due to this.

This pass also could serve as the bast for further post-RA optimization.

Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
llvm-svn: 327370
2018-03-13 06:47:06 +00:00
Yonghong Song 80b882ecc5 bpf: Don't expand BSWAP on i32, promote it
Currently, there is no ALU32 bswap support in eBPF ISA.

BSWAP on i32 was set to EXPAND which would need about eight instructions
for single BSWAP.

It would be more efficient to promote it to i64, then doing BSWAP on i64.
For eBPF programs, most of the promotion are zero extensions which are
likely be elimiated later by peephole optimizations.

Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
llvm-svn: 327369
2018-03-13 06:47:05 +00:00
Yonghong Song 1d28a759d9 bpf: Support subregister definition check on PHI node
This patch relax the subregister definition check on Phi node.
Previously, we just cancel the optimizatoin when the definition is Phi
node while actually we could further check the definitions of incoming
parameters of PHI node.

This helps catch more elimination opportunities.

Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
llvm-svn: 327368
2018-03-13 06:47:04 +00:00
Yonghong Song c88bcdec43 bpf: Extends zero extension elimination beyond comparison instructions
The current zero extension elimination was restricted to operands of
comparison. It actually could be extended to more cases.

For example:

  int *inc_p (int *p, unsigned a)
  {
    return p + a;
  }

'a' will be promoted to i64 during addition, and the zero extension could
be eliminated as well.

For the elimination optimization, it should be much better to start
recognizing the candidate sequence from the SRL instruction instead of J*
instructions.

This patch makes it an generic zero extension elimination pass instead of
one restricted with comparison.

Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
llvm-svn: 327367
2018-03-13 06:47:03 +00:00
Yonghong Song 905d13c123 bpf: J*_RR should check both operands
There is a mistake in current code that we "break" out the optimization
when the first operand of J*_RR doesn't qualify the elimination. This
caused some elimination opportunities missed, for example the one in the
testcase.

The code should just fall through to handle the second operand.

Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
llvm-svn: 327366
2018-03-13 06:47:02 +00:00
Yonghong Song 89e47ac671 bpf: Tighten subregister definition check
The current subregister definition check stops after the MOV_32_64
instruction.

This means we are thinking all the following instruction sequences
are safe to be eliminated:

  MOV_32_64 rB, wA
  SLL_ri    rB, rB, 32
  SRL_ri    rB, rB, 32

However, this is *not* true. The source subregister wA of MOV_32_64 could
come from a implicit truncation of 64-bit register in which case the high
bits of the 64-bit register is not zeroed, therefore we can't eliminate
above sequence.

For example, for i32_val, we shouldn't do the elimination:

  long long bar ();

  int foo (int b, int c)
  {
    unsigned int i32_val = (unsigned int) bar();

    if (i32_val < 10)
      return b;
    else
      return c;
  }

Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
llvm-svn: 327365
2018-03-13 06:47:00 +00:00
Yonghong Song 03e1c8b8f9 bpf: introduce -mattr=dwarfris to disable DwarfUsesRelocationsAcrossSections
Commit e4507fb8c94b ("bpf: disable DwarfUsesRelocationsAcrossSections")
disables MCAsmInfo DwarfUsesRelocationsAcrossSections unconditionally
so that dwarf will not use cross section (between dwarf and symbol table)
relocations. This new debug format enables pahole to dump structures
correctly as libdwarves.so does not have BPF backend support yet.

This new debug format, however, breaks bcc (https://github.com/iovisor/bcc)
source debug output as llvm in-memory Dwarf support has some issues to
handle it. More specifically, with DwarfUsesRelocationsAcrossSections
disabled, JIT compiler does not generate .debug_abbrev and Dwarf
DIE (debug info entry) processing is not happy about this.

This patch introduces a new flag -mattr=dwarfris
(dwarf relocation in section) to disable DwarfUsesRelocationsAcrossSections.
DwarfUsesRelocationsAcrossSections is true by default.

Signed-off-by: Yonghong Song <yhs@fb.com>
llvm-svn: 326505
2018-03-01 23:04:59 +00:00
Yonghong Song 60fed1fef0 bpf: New optimization pass for eliminating unnecessary i32 promotions
This pass performs peephole optimizations to cleanup ugly code sequences at
MachineInstruction layer.

Currently, the only optimization in this pass is to eliminate type
promotion
sequences for zero extending 32-bit subregisters to 64-bit registers.

If the compiler could prove the zero extended source come from 32-bit
subregistere then it is safe to erase those promotion sequece, because the
upper half of the underlying 64-bit registers were zeroed implicitly
already.

Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Reviewed-by: Yonghong Song <yhs@fb.com>
llvm-svn: 325991
2018-02-23 23:49:32 +00:00
Yonghong Song ae961bb061 bpf: New decoder namespace for 32-bit subregister load/store
When -mattr=+alu32 passed to the disassembler, use decoder namespace for
32-bit subregister.

This is to disassemble load and store instructions in preferred B format
as described in previous commit:

      w = *(u8 *) (r + off) // BPF_LDX | BPF_B
      w = *(u16 *)(r + off) // BPF_LDX | BPF_H
      w = *(u32 *)(r + off) // BPF_LDX | BPF_W

      *(u8 *) (r + off) = w // BPF_STX | BPF_B
      *(u16 *)(r + off) = w // BPF_STX | BPF_H
      *(u32 *)(r + off) = w // BPF_STX | BPF_W

NOTE: all other instructions should still use the default decoder
      namespace.

Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Reviewed-by: Yonghong Song <yhs@fb.com>
llvm-svn: 325990
2018-02-23 23:49:31 +00:00
Yonghong Song ca31c3bb3f bpf: Enable 32-bit subregister support for -mattr=+alu32
After all those preparation patches, now we could enable 32-bit subregister
support once -mattr=+alu32 specified.

Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Reviewed-by: Yonghong Song <yhs@fb.com>
llvm-svn: 325989
2018-02-23 23:49:30 +00:00
Yonghong Song fcd1e0f625 bpf: Support 32-bit subregister in various InstrInfo hooks
This patch support 32-bit subregister in three InstrInfo hooks, i.e.
copyPhysReg, loadRegFromStackSlot and storeRegToStackSlot,

Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Reviewed-by: Yonghong Song <yhs@fb.com>
llvm-svn: 325988
2018-02-23 23:49:29 +00:00
Yonghong Song b1a52bd756 bpf: New instruction patterns for 32-bit subregister load and store
The instruction mapping between eBPF/arm64/x86_64 are:

         eBPF              arm64        x86_64
LD1   BPF_LDX | BPF_B       ldrb        movzbl
LD2   BPF_LDX | BPF_H       ldrh        movzwl
LD4   BPF_LDX | BPF_W       ldr         movl

movzbl/movzwl/movl on x86_64 accept 32-bit sub-register, for example %eax,
the same for ldrb/ldrh on arm64 which accept 32-bit "w" register. And
actually these instructions only accept sub-registers. There is no point
to have LD1/2/4 (unsigned) for 64-bit register, because on these arches,
upper 32-bits are guaranteed to be zeroed by hardware or VM, so load into
the smallest available register class is the best choice for maintaining
type information.

For eBPF we should adopt the same philosophy, to change current
format (A):

  r = *(u8 *) (r + off) // BPF_LDX | BPF_B
  r = *(u16 *)(r + off) // BPF_LDX | BPF_H
  r = *(u32 *)(r + off) // BPF_LDX | BPF_W

  *(u8 *) (r + off) = r // BPF_STX | BPF_B
  *(u16 *)(r + off) = r // BPF_STX | BPF_H
  *(u32 *)(r + off) = r // BPF_STX | BPF_W

into B:

  w = *(u8 *) (r + off) // BPF_LDX | BPF_B
  w = *(u16 *)(r + off) // BPF_LDX | BPF_H
  w = *(u32 *)(r + off) // BPF_LDX | BPF_W

  *(u8 *) (r + off) = w // BPF_STX | BPF_B
  *(u16 *)(r + off) = w // BPF_STX | BPF_H
  *(u32 *)(r + off) = w // BPF_STX | BPF_W

There is no change on encoding nor how should they be interpreted,
everything is as it is, load the specified length, write into low bits of
the register then zeroing all remaining high bits.

The only change is their associated register class and how compiler view
them.

Format A still need to be kept, because eBPF LLVM backend doesn't support
sub-registers at default, but once 32-bit subregister is enabled, it should
use format B.

This patch implemented this together with all those necessary extended load
and truncated store patterns.

Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Reviewed-by: Yonghong Song <yhs@fb.com>
llvm-svn: 325987
2018-02-23 23:49:28 +00:00
Yonghong Song 63cf273f55 bpf: Support i32 in getScalarShiftAmountTy method
getScalarShiftAmount method should be implemented for eBPF backend to make
sure shift amount could still get correct type once 32-bit subregisters
support are enabled.

Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Reviewed-by: Yonghong Song <yhs@fb.com>
llvm-svn: 325986
2018-02-23 23:49:26 +00:00
Yonghong Song 59fc805c7e bpf: Support condition comparison on i32
We need to support condition comparison on i32. All these comparisons are
supposed to be combined into BPF_J* instructions which only support i64.

For ISD::BR_CC we need to promote it to i64 first, then do custom lowering.

For ISD::SET_CC, just expand to SELECT_CC like what's been done for i64.

For ISD::SELECT_CC, we also want to do custom lower for i32. However, after
32-bit subregister support enabled, it is possible the comparison operands
are i32 while the selected value are i64, or the comparison operands are
i64 while the selected value are i32. We need to define extra instruction
pattern and support them in custom instruction inserter.

Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Reviewed-by: Yonghong Song <yhs@fb.com>
llvm-svn: 325985
2018-02-23 23:49:25 +00:00
Yonghong Song 219156cff0 bpf: Handle i32 for ALU operations without ISA support
There is no eBPF ISA support for BSWAP, ROTR, ROTL, SREM, SDIVREM, MULHU,
ADDC, ADDE etc on i32.

They could be emulated by other basic BPF_ALU operations, we'd set their
lowering action the same as i64.

Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Reviewed-by: Yonghong Song <yhs@fb.com>
llvm-svn: 325984
2018-02-23 23:49:24 +00:00
Yonghong Song 07a7a41753 bpf: New calling convention for 32-bit subregisters
This patch add new calling conventions to allow GPR32RegClass as valid
register class for arguments and return types.

New calling convention will only be choosen when -mattr=+alu32 specified.

Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Reviewed-by: Yonghong Song <yhs@fb.com>
llvm-svn: 325983
2018-02-23 23:49:23 +00:00
Yonghong Song 42389377d8 bpf: New target attribute "alu32" for 32-bit subregister support
This new attribute aims to control the enablement of 32-bit subregister
support on eBPF backend.

Name the interface as "alu32" is because we in particular want to enable
the generation of BPF_ALU32 instructions by enable subregister support.

This attribute could be used in the following format with llc:

  llc -mtriple=bpf -mattr=[+|-]alu32

It is disabled at default.

Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Reviewed-by: Yonghong Song <yhs@fb.com>
llvm-svn: 325982
2018-02-23 23:49:22 +00:00
Yonghong Song 0252f35362 bpf: Define instruction patterns for extensions and truncations between i32 to i64
For transformations between i32 and i64, if it is explicit signed extension:
  - first cast the operand to i64
  - then use SLL + SRA to finish the extension.

if it is explicit zero extension:
  - first cast the operand to i64
  - then use SLL + SRL to finish the extension.

if it is explicit any extension:
  - just refer to 64-bit register.

if it is explicit truncation:
  - just refer to 32-bit subregister.

NOTE: Some of the zero extension sequences might be unnecessary, they will be
removed by an peephole pass on MachineInstruction layer.

Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Reviewed-by: Yonghong Song <yhs@fb.com>
llvm-svn: 325981
2018-02-23 23:49:21 +00:00
Yonghong Song 3a564a8f6e bpf: Tighten the immediate predication for 32-bit alu instructions
These 32-bit ALU insn patterns which takes immediate as one operand were
initially added to enable AsmParser support, and the AsmMatcher uses "ins"
and "outs" fields to deduct the operand constraint.

However, the instruction selector doesn't work the same as AsmMatcher. The
selector will use the "pattern" field for which we are not setting the
predication for immediate operands correctly.

Without this patch, i32 would eventually means all i32 operands are valid,
both imm and gpr, while these patterns should allow imm only.

Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Reviewed-by: Yonghong Song <yhs@fb.com>
llvm-svn: 325980
2018-02-23 23:49:19 +00:00
Yonghong Song ec84e2f1b0 bpf: Use markSuperRegs to mark reserved registers
markSuperRegs is the canonical helper function used to mark reserved
registers. It could mark any overlapping sub-registers automatically.

Reviewed-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
llvm-svn: 325979
2018-02-23 23:49:18 +00:00
Yonghong Song 9fdd139b41 bpf: disable DwarfUsesRelocationsAcrossSections
The pahole does not work with BPF backend properly:

  -bash-4.2$ cat test.c
  struct test_t {
    int a;
    int b;
  };
  int test(struct test_t *s) {
    return s->a;
  }
  -bash-4.2$ clang -g -O2 -target bpf -c test.c
  -bash-4.2$ pahole test.o
  struct clang version 7.0.0 (trunk 325446) (llvm/trunk 325464) {
          clang version 7.0.0 (trunk 325446) (llvm/trunk 325464) clang version 7.0.0 (trunk 325446) (llvm/trunk 325464); /*     0     4 */
          clang version 7.0.0 (trunk 325446) (llvm/trunk 325464) clang version 7.0.0 (trunk 325446) (llvm/trunk 325464); /*     4     4 */

          /* size: 8, cachelines: 1, members: 2 */
          /* last cacheline: 8 bytes */
  };
  -bash-4.2$

The reason is that BPF backend is not yet implemented in elfutils backend
  https://github.com/threatstack/elfutils/tree/master/backends
and pahole depends on elfutils for dwarf parsing and resolving relocation.

More specifically, the unsupported relocation in .debug_info for type/member name
against symbol table caused the incorrect result above. The following is
the raw .rel.debug_info for the above example,
  Hex dump of section '.rel.debug_info':
    0x00000000 06000000 00000000 0a000000 0b000000 ................
    0x00000010 0c000000 00000000 0a000000 01000000 ................
    0x00000020 12000000 00000000 0a000000 02000000 ................
    0x00000030 16000000 00000000 0a000000 0e000000 ................
    0x00000040 1a000000 00000000 0a000000 03000000 ................
               ----------------- -------- --------
                reloc location     type   symtab index

  Hex dump of section '.debug_info':
    0x00000000 7b000000 04000000 00000801 00000000 {...............
    0x00000010 0c000000 00000000 00000000 00000000 ................
    0x00000020 00000000 00001000 00000200 00000000 ................

Based on "type", the proper value will be extracted from symbol table
and filled in .debug_info so later on .debug_info can be properly
resolved against debug strings.

There are two ways to fix this problem. One is to fix elfutils by adding
BPF support which is desirable. This could take a long time and won't work
with already deployed pahole. For a short term workaround, we can disable
dwarf cross-section relation which specifically avoids debug_info and
symbol table cross relocation. This should help any dwarf-related tool
which has not implement BPF specific relocations yet.

Now .rel.debug_info does not have any relocation for symbol table and
.debug_info itself contains necessary relocation information by itself.
  Hex dump of section '.debug_info':
    0x00000000 7b000000 04000000 00000801 00000000 {...............
    0x00000010 0c003700 00000000 00003e00 00000000 ..7.......>.....
    0x00000020 00000000 00001000 00000200 00000000 ................
  location 0xc has 0, 0x12 has 0x37, 0x1a has 0x3e in place which
  will be used in relocation resolution. Here, the values of 0, 0x37 and 0x3e
  are offset in .debug_str section.
Please note the difference between two above .debug_info dumps.

With the fix, pahole works properly with BPF backend:
  -bash-4.2$ clang -O2 -g -target bpf -c test.c
  -bash-4.2$ pahole test.o
  struct test_t {
          int                        a;                    /*     0     4 */
          int                        b;                    /*     4     4 */

          /* size: 8, cachelines: 1, members: 2 */
          /* last cacheline: 8 bytes */
  };

Signed-off-by: Yonghong Song <yhs@fb.com>
llvm-svn: 325735
2018-02-21 22:59:14 +00:00
Jonas Paulsson 891789c299 [BPF] Return true in enableMultipleCopyHints().
Enable multiple COPY hints to eliminate more COPYs during register allocation.

Note that this is something all targets should do, see
https://reviews.llvm.org/D38128.

Review: Yonghong Song
llvm-svn: 325457
2018-02-18 10:09:54 +00:00
Yonghong Song 920df52a93 bpf: fix a bug in dag2dag optimization for loads from readonly section
The reference '&' is missing in the function parameter. If there are
back-to-back optimizations in terms of dag node list like below:
  t29: i64,ch = load<LD4[bitcast (%struct.test_t* @test.t to i8*)+12](dereferenceable), zext from i32> t3, t43, undef:i64
  t34: i64,ch = load<LD4[bitcast (%struct.test_t* @test.t to i8*)](dereferenceable), zext from i32> t3, t41, undef:i64
The bug will trigger a segfault for the added test case remove_truncate_5.ll:
  LLVMSymbolizer: error reading file: No such file or directory
  #0 0x000000000241c4d9 (llc+0x241c4d9)
  #1 0x000000000241c56a (llc+0x241c56a)
  #2 0x000000000241aa50 (llc+0x241aa50)
  ...
  #22 0x0000000000fd5edf (llc+0xfd5edf)
  #23 0x00007f0fe03bec05 __libc_start_main (/lib64/libc.so.6+0x21c05)
  #24 0x0000000000fd3e69 (llc+0xfd3e69)
  ...
  Segmentation fault

Signed-off-by: Yonghong Song <yhs@fb.com>
llvm-svn: 325267
2018-02-15 17:06:45 +00:00
Yonghong Song f2075aef68 bpf: Improve expanding logic in LowerSELECT_CC
LowerSELECT_CC is not generating optimal Select_Ri pattern at the moment. It
is not guaranteed to place ConstantNode at RHS which would miss matching
Select_Ri.

A new testcase added into the existing select_ri.ll, also there is an
existing case in cmp.ll which would be improved to use Select_Ri after this
patch, it is adjusted accordingly.

Reported-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Reviewed-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
llvm-svn: 324560
2018-02-08 04:37:49 +00:00
Craig Topper 8f324bb1a4 [SelectionDAGISel] Add a debug print before call to Select. Adjust where blank lines are printed during isel process to make things more sensibly grouped.
Previously some targets printed their own message at the start of Select to indicate what they were selecting. For the targets that didn't, it means there was no print of the root node before any custom handling in the target executed. So if the target did something custom and never called SelectNodeCommon, no print would be made. For the targets that did print a message in Select, if they didn't custom handle a node SelectNodeCommon would reprint the root node before walking the isel table.

It seems better to just print the message before the call to Select so all targets behave the same. And then remove the root node printing from SelectNodeCommon and just leave a message that says we're starting the table search.

There were also some oddities in blank line behavior. Usually due to a \n after a call to SelectionDAGNode::dump which already inserted a new line.

llvm-svn: 323551
2018-01-26 19:34:20 +00:00
Yonghong Song 035dd256d5 [BPF] Mark pseudo insn patterns as isCodeGenOnly
These pseudos are not supposed to be visible to user.

This patch reduced the auto-generated instruction matcher. For example,
the following words are removed from keyword list of LLVM BPF assembler.

-  MCK__35_, // '#'
-  MCK__COLON_, // ':'
-  MCK__63_, // '?'
-  MCK_ADJCALLSTACKDOWN, // 'ADJCALLSTACKDOWN'
-  MCK_ADJCALLSTACKUP, // 'ADJCALLSTACKUP'
-  MCK_PSEUDO, // 'PSEUDO'
-  MCK_Select, // 'Select'

Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
llvm-svn: 322535
2018-01-16 07:27:20 +00:00
Yonghong Song b42c7c7863 [BPF] Teach DAG2DAG AND elimination about load intrinsics
As commented on the existing code:

  // The Reg operand should be a virtual register, which is defined
  // outside the current basic block. DAG combiner has done a pretty
  // good job in removing truncating inside a single basic block.

However, when the Reg operand comes from bpf_load_[byte | half | word]
intrinsics, the generic optimizer doesn't understand their results are
zero extended, so these single basic block elimination opportunities were
missed.

Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
llvm-svn: 322534
2018-01-16 07:27:19 +00:00
Alex Bradbury b22f751fa7 Thread MCSubtargetInfo through Target::createMCAsmBackend
Currently it's not possible to access MCSubtargetInfo from a TgtMCAsmBackend. 
D20830 threaded an MCSubtargetInfo reference through 
MCAsmBackend::relaxInstruction, but this isn't the only function that would 
benefit from access. This patch removes the Triple and CPUString arguments 
from createMCAsmBackend and replaces them with MCSubtargetInfo.

This patch just changes the interface without making any intentional 
functional changes. Once in, several cleanups are possible:
* Get rid of the awkward MCSubtargetInfo handling in ARMAsmBackend
* Support 16-bit instructions when valid in MipsAsmBackend::writeNopData
* Get rid of the CPU string parsing in X86AsmBackend and just use a SubtargetFeature for HasNopl
* Emit 16-bit nops in RISCVAsmBackend::writeNopData if the compressed instruction set extension is enabled (see D41221)

This change initially exposed PR35686, which has since been resolved in r321026.

Differential Revision: https://reviews.llvm.org/D41349

llvm-svn: 321692
2018-01-03 08:53:05 +00:00
Yonghong Song 25bf825961 bpf: add support for objdump -print-imm-hex
Add support for 'objdump -print-imm-hex' for imm64, operand imm
and branch target. If user programs encode immediate values
as hex numbers, such an option will make it easy to correlate
asm insns with source code. This option also makes it easy
to correlate imm values with insn encoding.

There is one changed behavior in this patch. In old way, we
print the 64bit imm as u64:
  O << (uint64_t)Op.getImm();
and the new way is:
  O << formatImm(Op.getImm());

The formatImm is defined in llvm/MC/MCInstPrinter.h as
  format_object<int64_t> formatImm(int64_t Value)

So the new way to print 64bit imm is i64 type.
If a 64bit value has the highest bit set, the old way
will print the value as a positive value and the
new way will print as a negative value. The new way
is consistent with x86_64.
For the code (see the test program):
 ...
 if (a == 0xABCDABCDabcdabcdULL)
 ...
x86_64 objdump, with and without -print-imm-hex, looks like:
 48 b8 cd ab cd ab cd ab cd ab   movabsq $-6067004223159161907, %rax
 48 b8 cd ab cd ab cd ab cd ab   movabsq $-0x5432543254325433, %rax

Signed-off-by: Yonghong Song <yhs@fb.com>
llvm-svn: 321215
2017-12-20 19:39:58 +00:00
Matthias Braun f1caa2833f MachineFunction: Return reference from getFunction(); NFC
The Function can never be nullptr so we can return a reference.

llvm-svn: 320884
2017-12-15 22:22:58 +00:00
Francis Visoiu Mistrih a8a83d150f [CodeGen] Use MachineOperand::print in the MIRPrinter for MO_Register.
Work towards the unification of MIR and debug output by refactoring the
interfaces.

For MachineOperand::print, keep a simple version that can be easily called
from `dump()`, and a more complex one which will be called from both the
MIRPrinter and MachineInstr::print.

Add extra checks inside MachineOperand for detached operands (operands
with getParent() == nullptr).

https://reviews.llvm.org/D40836

* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/kill: ([^ ]+) ([^ ]+)<def> ([^ ]+)/kill: \1 def \2 \3/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/kill: ([^ ]+) ([^ ]+) ([^ ]+)<def>/kill: \1 \2 def \3/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/kill: def ([^ ]+) ([^ ]+) ([^ ]+)<def>/kill: def \1 \2 def \3/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/<def>//g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<kill>/killed \1/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<imp-use,kill>/implicit killed \1/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<dead>/dead \1/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<def[ ]*,[ ]*dead>/dead \1/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<imp-def[ ]*,[ ]*dead>/implicit-def dead \1/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<imp-def>/implicit-def \1/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<imp-use>/implicit \1/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<internal>/internal \1/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<undef>/undef \1/g'

llvm-svn: 320022
2017-12-07 10:40:31 +00:00
Francis Visoiu Mistrih 25528d6de7 [CodeGen] Unify MBB reference format in both MIR and debug output
As part of the unification of the debug format and the MIR format, print
MBB references as '%bb.5'.

The MIR printer prints the IR name of a MBB only for block definitions.

* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#" << ([a-zA-Z0-9_]+)->getNumber\(\)/" << printMBBReference(*\1)/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#" << ([a-zA-Z0-9_]+)\.getNumber\(\)/" << printMBBReference(\1)/g'
* find . \( -name "*.txt" -o -name "*.s" -o -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#([0-9]+)/%bb.\1/g'
* grep -nr 'BB#' and fix

Differential Revision: https://reviews.llvm.org/D40422

llvm-svn: 319665
2017-12-04 17:18:51 +00:00
Francis Visoiu Mistrih c71cced0aa [CodeGen] Always use `printReg` to print registers in both MIR and debug
output

As part of the unification of the debug format and the MIR format,
always use `printReg` to print all kinds of registers.

Updated the tests using '_' instead of '%noreg' until we decide which
one we want to be the default one.

Differential Revision: https://reviews.llvm.org/D40421

llvm-svn: 319445
2017-11-30 16:12:24 +00:00
Francis Visoiu Mistrih 93ef145862 [CodeGen] Print "%vreg0" as "%0" in both MIR and debug output
As part of the unification of the debug format and the MIR format, avoid
printing "vreg" for virtual registers (which is one of the current MIR
possibilities).

Basically:

* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E "s/%vreg([0-9]+)/%\1/g"
* grep -nr '%vreg' . and fix if needed
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E "s/ vreg([0-9]+)/ %\1/g"
* grep -nr 'vreg[0-9]\+' . and fix if needed

Differential Revision: https://reviews.llvm.org/D40420

llvm-svn: 319427
2017-11-30 12:12:19 +00:00
Alexei Starovoitov 9bd566f8c8 [bpf] remove unused variable
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
llvm-svn: 318615
2017-11-19 02:41:53 +00:00
Alexei Starovoitov 9a67245d88 [bpf] allow direct and indirect calls
kernel verifier is becoming smarter and soon will support
direct and indirect function calls.
Remove obsolete error from BPF backend.
Make call to use PCRel_4 fixup.
'bpf to bpf' calls are distinguished from 'bpf to kernel' calls
by insn->src_reg == BPF_PSEUDO_CALL == 1 which is used as relocation
indicator similar to ld_imm64->src_reg == BPF_PSEUDO_MAP_FD == 1
The actual 'call' instruction remains the same for both
'bpf to kernel' and 'bpf to bpf' calls.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
llvm-svn: 318614
2017-11-19 01:35:00 +00:00
David Blaikie b3bde2ea50 Fix a bunch more layering of CodeGen headers that are in Target
All these headers already depend on CodeGen headers so moving them into
CodeGen fixes the layering (since CodeGen depends on Target, not the
other way around).

llvm-svn: 318490
2017-11-17 01:07:10 +00:00
Yonghong Song ce96738dee bpf: print backward branch target properly
Currently, it prints the backward branch offset as unsigned value
like below:
       7:       7d 34 0b 00 00 00 00 00         if r4 s>= r3 goto 11 <LBB0_3>
       8:       b7 00 00 00 00 00 00 00         r0 = 0
LBB0_2:
       9:       07 00 00 00 01 00 00 00         r0 += 1
      ......
      17:       bf 31 00 00 00 00 00 00         r1 = r3
      18:       6d 32 f6 ff 00 00 00 00         if r2 s> r3 goto 65526 <LBB0_3+0x7FFB0>

The correct print insn 18 should be:
      18:       6d 32 f6 ff 00 00 00 00         if r2 s> r3 goto -10 <LBB0_2>

To provide better clarity and be consistent with kernel verifier output,
the insn 7 output is changed to the following with "+" added to
non-negative branch offset:
       7:       7d 34 0b 00 00 00 00 00         if r4 s>= r3 goto +11 <LBB0_3>

Signed-off-by: Yonghong Song <yhs@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
llvm-svn: 318442
2017-11-16 19:15:36 +00:00
Yonghong Song 4c3ce59e61 bpf: enable llvm-objdump to print out symbolized jmp target
Add hook in BPF backend so that llvm-objdump can print out
the jmp target with label names, e.g.,
  ...
  if r1 != 2 goto 6 <LBB0_2>
  ...
  goto 7 <LBB0_4>
  ...
 LBB0_2:
  ...
 LBB0_4:
  ...

Signed-off-by: Yonghong Song <yhs@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
llvm-svn: 318358
2017-11-16 00:52:30 +00:00
Daniel Sanders 725584e26d Add backend name to Target to enable runtime info to be fed back into TableGen
Summary:
Make it possible to feed runtime information back to tablegen to enable
profile-guided tablegen-eration, detection of untested tablegen definitions, etc.

Being a cross-compiler by nature, LLVM will potentially collect data for multiple
architectures (e.g. when running 'ninja check'). We therefore need a way for
TableGen to figure out what data applies to the backend it is generating at the
time. This patch achieves that by including the name of the 'def X : Target ...'
for the backend in the TargetRegistry.

Reviewers: qcolombet

Reviewed By: qcolombet

Subscribers: jholewinski, arsenm, jyknight, aditya_nandakumar, sdardis, nemanjai, ab, nhaehnle, t.p.northover, javed.absar, qcolombet, llvm-commits, fedor.sergeev

Differential Revision: https://reviews.llvm.org/D39742

llvm-svn: 318352
2017-11-15 23:55:44 +00:00
David Blaikie 3f833edc7c Target/TargetInstrInfo.h -> CodeGen/TargetInstrInfo.h to match layering
This header includes CodeGen headers, and is not, itself, included by
any Target headers, so move it into CodeGen to match the layering of its
implementation.

llvm-svn: 317647
2017-11-08 01:01:31 +00:00