10 Commits

Author SHA1 Message Date
Roman Lebedev
0aef747b84
[NFC][X86][Codegen] Megacommit: mass-regenerate all check lines that were already autogenerated
The motivation is that the update script has at least two deviations
(`<...>@GOT`/`<...>@PLT`/ and not hiding pointer arithmetics) from
what pretty much all the checklines were generated with,
and most of the tests are still not updated, so each time one of the
non-up-to-date tests is updated to see the effect of the code change,
there is a lot of noise. Instead of having to deal with that each
time, let's just deal with everything at once.

This has been done via:
```
cd llvm-project/llvm/test/CodeGen/X86
grep -rl "; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py" | xargs -L1 <...>/llvm-project/llvm/utils/update_llc_test_checks.py --llc-binary <...>/llvm-project/build/bin/llc
```

Not all tests were regenerated, however.
2021-06-11 23:57:02 +03:00
Craig Topper
0248e24071 [X86][update_llc_test_checks] Use a less greedy regular expression for replacing constant pool labels in tests.
While working on D97208 I noticed that these greedy regular
expressions prevent tests from failing when (%rip) appears after
a constant pool label when it didn't before.

Reviewed By: RKSimon, pengfei

Differential Revision: https://reviews.llvm.org/D99460
2021-03-28 11:39:46 -07:00
Fangrui Song
a084c0388e [TargetMachine] Don't imply dso_local on function declarations in Reloc::Static model for ELF/wasm
clang/lib/CodeGen/CodeGenModule sets dso_local on applicable function declarations,
we don't need to duplicate the work in TargetMachine:shouldAssumeDSOLocal.
(Actually the long-term goal (started by r324535) is to drop TargetMachine::shouldAssumeDSOLocal.)

By not implying dso_local, we will respect dso_local/dso_preemptable specifiers
set by the frontend. This allows the proposed -fno-direct-access-external-data
option to work with -fno-pic and prevent a canonical PLT entry (SHN_UNDEF with non-zero st_value)
when taking the address of a function symbol.

This patch should be NFC in terms of the Clang emitted assembly because the case
we don't set dso_local is a case Clang sets dso_local. However, some tests don't
set dso_local on some function declarations and expose some differences. Most
tests have been fixed to be more robust in the previous commit.
2020-12-05 14:54:37 -08:00
Fangrui Song
961f31d8ad [TargetMachine] Don't imply dso_local on global variable declarations in Reloc::Static model
clang/lib/CodeGen/CodeGenModule sets dso_local on applicable global variables,
we don't need to duplicate the work in TargetMachine:shouldAssumeDSOLocal.
(Actually the long-term goal (started by r324535) is to remove as much
additional implied dso_local in TargetMachine:shouldAssumeDSOLocal as possible.)

By not implying dso_local, we will respect dso_local/dso_preemptable specifiers
set by the frontend. This allows the proposed -fno-direct-access-external-data
option to work with -fno-pic and prevent copy relocations.

This patch should be NFC in terms of the Clang behavior because the case we
don't set dso_local is a case Clang sets dso_local. However, some tests don't
set dso_local on some `external global` and expose some differences. Most tests
have been fixed to be more robust in previous commits.
2020-12-04 19:03:41 -08:00
Craig Topper
8c050070fb [X86] Fix a nullptr dereference in X86Subtarget::classifyLocalReference when compiling with -mcmodel=medium -fpic and using a constant pool
LowerConstantPool passes a nullptr into classifyLocalReference. The medium code model handling for PIC will try to deference it using isa. This patch switches to isa_and_nonnull.

Differential Revision: https://reviews.llvm.org/D80763
2020-05-28 17:20:42 -07:00
Fangrui Song
872c5fb143 [AsmPrinter] Don't generate .Lfoo$local for -fno-PIC and -fPIE
-fno-PIC and -fPIE code generally cannot be linked in -shared mode and there is no benefit accessing via local aliases.

Actually, a .Lfoo$local reference will be converted to a STT_SECTION (if no section relaxation) reference which will cause the section symbol (sizeof(Elf64_Sym)=24) to be generated.
2020-05-25 23:35:49 -07:00
Fangrui Song
5b22bcc2b7 [X86][ELF] Prefer to lower MC_GlobalAddress operands to .Lfoo$local
For a MC_GlobalAddress reference to a dso_local external GlobalValue with a definition, emit .Lfoo$local to avoid a relocation.

-fno-pic and -fpie can infer dso_local but -fpic cannot.  In the future,
we can explore the possibility of inferring dso_local with -fpic. As the
description of D73228 says, LLVM's existing IPO optimization behaviors
(like -fno-semantic-interposition) and a previous assembly behavior give
us enough license to be aggressive here.

Reviewed By: rnk

Differential Revision: https://reviews.llvm.org/D73230
2020-01-30 17:52:35 -08:00
Craig Topper
3fe4bd464c [X86] Fix tls variable lowering issue with large code model
Summary:
The problem here is the lowering for tls variable. Below is the DAG for the code.
SelectionDAG has 11 nodes:

t0: ch = EntryToken
      t8: i64,ch = load<(load 8 from `i8 addrspace(257)* null`, addrspace 257)> t0, Constant:i64<0>, undef:i64
        t10: i64 = X86ISD::WrapperRIP TargetGlobalTLSAddress:i64<i32* @x> 0 [TF=10]
      t11: i64,ch = load<(load 8 from got)> t0, t10, undef:i64
    t12: i64 = add t8, t11
  t4: i32,ch = load<(dereferenceable load 4 from @x)> t0, t12, undef:i64
t6: ch = CopyToReg t0, Register:i32 %0, t4
And when mcmodel is large, below instruction can NOT be folded.

  t10: i64 = X86ISD::WrapperRIP TargetGlobalTLSAddress:i64<i32* @x> 0 [TF=10]
t11: i64,ch = load<(load 8 from got)> t0, t10, undef:i64
So "t11: i64,ch = load<(load 8 from got)> t0, t10, undef:i64" is lowered to " Morphed node: t11: i64,ch = MOV64rm<Mem:(load 8 from got)> t10, TargetConstant:i8<1>, Register:i64 $noreg, TargetConstant:i32<0>, Register:i32 $noreg, t0"

When llvm start to lower "t10: i64 = X86ISD::WrapperRIP TargetGlobalTLSAddress:i64<i32* @x> 0 [TF=10]", it fails.

The patch is to fold the load and X86ISD::WrapperRIP.

Fixes PR26906

Patch by LuoYuanke

Reviewers: craig.topper, rnk, annita.zhang, wxiao3

Reviewed By: rnk

Subscribers: llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D58336

llvm-svn: 354756
2019-02-24 19:33:37 +00:00
Reid Kleckner
49a24278ba [ELF] Fix large code model MIR verifier errors
Instead of using the MOVGOT64r pseudo, use the existing
MO_PIC_BASE_OFFSET support on symbol operands. Now I don't have to
create a "scratch register operand" for the pseudo to use, and the
register allocator can make better decisions.

Fixes some X86 verifier errors tracked in PR27481.

llvm-svn: 345219
2018-10-24 22:57:28 +00:00
Reid Kleckner
980c4df037 Re-land r335297 "[X86] Implement more of x86-64 large and medium PIC code models"
Don't try to generate large PIC code for non-ELF targets. Neither COFF
nor MachO have relocations for large position independent code, and
users have been using "large PIC" code models to JIT 64-bit code for a
while now. With this change, if they are generating ELF code, their
JITed code will truly be PIC, but if they target MachO or COFF, it will
contain 64-bit immediates that directly reference external symbols. For
a JIT, that's perfectly fine.

llvm-svn: 337740
2018-07-23 21:14:35 +00:00