Commit Graph

1303 Commits

Author SHA1 Message Date
Scott Douglass
f8560e5a5b [ARM] Handle commutativity when converting to tADDhirr in Thumb2
Also, run thumb_rewrite.s tests in Thumb2 now that they pass.

Differential Revision: http://reviews.llvm.org/D11132

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242036 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-13 15:31:48 +00:00
Scott Douglass
ffc51593c8 [ARM] Add Thumb2 ADD with SP narrowing from 3 operand to 2
Differential Revision: http://reviews.llvm.org/D11131

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242035 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-13 15:31:40 +00:00
Scott Douglass
f716895679 [ARM] Small refactor of tryConvertingToTwoOperandForm (nfc)
Also, add more Thumb2 ADD tests requested during review of
http://reviews.llvm.org/D11053.

Differential Revision: http://reviews.llvm.org/D11130

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242034 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-13 15:31:33 +00:00
Scott Douglass
0e714c7efa [ARM] Thumb1 3 to 2 operand convertion for commutative operations
Differential Revision: http://reviews.llvm.org/D11057

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@241802 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-09 14:13:55 +00:00
Scott Douglass
7b8defda79 [ARM] Don't be overzealous converting Thumb1 3 to 2 operands
Differential Revision: http://reviews.llvm.org/D11056

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@241801 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-09 14:13:48 +00:00
Scott Douglass
3ca1884ba8 [ARM] Add Thumb2 ADD with PC narrowing from 3 operand to 2
Differential Revision: http://reviews.llvm.org/D11055

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@241800 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-09 14:13:41 +00:00
Scott Douglass
ab17c04abe [ARM] Refactor converting Thumb1 from 3 to 2 operand (nfc)
Also adds some test cases.

Differential Revision: http://reviews.llvm.org/D11054

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@241799 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-09 14:13:34 +00:00
Scott Douglass
c221d448c7 [ARM] Add ADD tests for Thumb2 narrowing (nfc)
Differential Revision: http://reviews.llvm.org/D11053

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@241798 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-09 14:13:22 +00:00
Gabor Ballabas
4e0f6008b9 Reworking the test part of r241149
The test part of r241149 has been reverted in r241451, due to misplaced test cases.
This patch splits those test cases among the appropriate targets.

Differential Revision: http://reviews.llvm.org/D10897


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@241283 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-02 16:53:23 +00:00
Javed Absar
263dd533ee [ARM]: Extend -mfpu options for half-precision and vfpv3xd
Some of the the permissible ARM -mfpu options, which are supported in GCC,
are currently not present in llvm/clang.This patch adds the options:
'neon-fp16', 'vfpv3-fp16', 'vfpv3-d16-fp16', 'vfpv3xd' and 'vfpv3xd-fp16.
These are related to half-precision floating-point and single precision.

Reviewers: rengolin, ranjeet.singh

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D10645



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240930 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-29 09:32:29 +00:00
Daniel Jasper
b7f5b8b4b2 Revert r240302 ("Bring r240130 back.").
This causes errors like:

  ld: error: blah.o: requires dynamic R_X86_64_PC32 reloc against '' which
  may overflow at runtime; recompile with -fPIC
  blah.cc:function f(): error: undefined reference to ''
  blah.o:g(): error: undefined reference to ''

I have not yet come up with an appropriate reproduction.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240394 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-23 11:31:32 +00:00
Pete Cooper
54d0bc35fe Change .thumb_set to have the same error checks as .set.
According to the documentation, .thumb_set is 'the equivalent of a .set directive'.

We didn't have equivalent behaviour in terms of all the errors we could throw, for
example, when a symbol is redefined.

This change refactors parseAssignment so that it can be used by .set and .thumb_set
and implements tests for .thumb_set for all the errors thrown by that method.

Reviewed by Rafael Espíndola.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240318 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-22 19:35:57 +00:00
Rafael Espindola
afd779f72d Bring r240130 back.
Now that pr23900 is fixed, we can bring it back with no changes.

Original message:

Make all temporary symbols unnamed.

What this does is make all symbols that would otherwise start with a .L
(or L on MachO) unnamed.

Some of these symbols still show up in the symbol table, but we can just
make them unnamed.

In order to make sure we produce identical results when going thought assembly,
all .L (not just the compiler produced ones), are now unnamed.

Running llc on llvm-as.opt.bc, the peak memory usage goes from 208.24MB to
205.57MB.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240302 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-22 17:52:52 +00:00
Nico Weber
7081f6fc99 Revert 240130, it caused crashes (repro in PR23900).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240193 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-19 23:43:47 +00:00
Rafael Espindola
ec77d9ad83 Make all temporary symbols unnamed.
What this does is make all symbols that would otherwise start with a .L
(or L on MachO) unnamed.

Some of these symbols still show up in the symbol table, but we can just
make them unnamed.

In order to make sure we produce identical results when going thought assembly,
all .L (not just the compiler produced ones), are now unnamed.

Running llc on llvm-as.opt.bc, the peak memory usage goes from 208.24MB to
205.57MB.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240130 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-19 12:16:55 +00:00
Rafael Espindola
f314160e32 Convert a few tests to use llvm-mc.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240017 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-18 13:39:07 +00:00
John Brawn
272d7fdf42 [ARM] Add support for -sp- FPUs and FPU none to TargetParser
These are added mainly for the benefit of clang, but this also means that they
are now allowed in .fpu directives and we emit the correct .fpu directive when
single-precision-only is used.

Differential Revision: http://reviews.llvm.org/D10238


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239151 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-05 13:31:19 +00:00
Rafael Espindola
9f299abc05 Omit unused section symbols from the symbol table.
Section symbols exist as an optimization: instead of having multiple relocations
point to different symbols, many of them can point to a single section symbol.

When that optimization is unused, a section symbol is also unused and adds no
extra information to the object file.

This saves a bit of space on the object files and makes the output of
llvm-objdump -t easier to read and consequently some tests get quite a bit
simpler.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239045 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-04 15:33:30 +00:00
Rafael Espindola
0f898d59f8 No need to check the raw relocation bytes if checking the parsed dump.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239042 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-04 15:21:17 +00:00
Rafael Espindola
201a551929 Fix the interpretation of a 0 st_name.
The ELF spec is very clear:

-----------------------------------------------------------------------------
If the value is non-zero, it represents a string table index that gives the
symbol name. Otherwise, the symbol table entry has no name.
--------------------------------------------------------------------------

In particular, a st_name of 0 most certainly doesn't mean that the symbol has
the same name as the section.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238899 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-03 05:14:22 +00:00
Rafael Espindola
fb48de619e Don't special case undefined symbol when deciding the symbol order.
ELF has no restrictions on where undefined symbols go relative to other defined
symbols. In fact, gas just sorts them together. Do the same.

This was there since r111174 probably just because the MachO writer has it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238513 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-28 21:59:34 +00:00
Renato Golin
a052a77187 ARMTargetParser: Normalising build attributes
Now that most of the methods in Clang and LLVM that were parsing arch/cpu/fpu
strings are using ARMTargetParser, it's time to make it a bit more conforming
with what the ABI says.

This commit adds some clarification on what build attributes are accepted and
which are "non-standard". It also makes clear that the "defaultCPU" and
"defaultArch" methods were really just build attribute getters.

It also diverges from GCC's behaviour to say that armv2/armv3 are really an
ARMv4 in the build attributes, when the ABI has a clear state for that: Pre-v4.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238344 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-27 18:15:37 +00:00
Benjamin Kramer
083d79a583 [AArch64] Clean up the ELF streamer a bit.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238102 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-23 16:39:10 +00:00
John Brawn
8a95a5095d [ARM] Fix typo in subtarget feature list for 7em triple
The list of subtarget features for the 7em triple contains 't2xtpk',
which actually disables that subtarget feature. Correct that to
'+t2xtpk' and test that the instructions enabled by that feature do
actually work.

Differential Revision: http://reviews.llvm.org/D9936


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238022 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-22 14:16:22 +00:00
Keith Walker
09f089a39e [DWARF] Add CIE header fields address_size and segment_size when generating dwarf-4
The DWARF-4 specification added 2 new fields in the CIE header called
address_size and segment_size.
Create these 2 new fields when generating dwarf-4 CIE entries, print out
the new fields when dumping the CIE and update tests

Differential Revision: http://reviews.llvm.org/D9558


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237145 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-12 15:25:08 +00:00
Rafael Espindola
76e71bd66e Write sections mostly in one pass.
During ELF writing, there is no need to further relax the sections, so we
should not be creating fragments. This patch avoids doing so in all cases
but debug section compression (that is next).

Also, the ELF format is fairly simple to write. We can do a single pass over
the sections to write them out and compute the section header table.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236235 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-30 14:21:49 +00:00
Rafael Espindola
7fc9422362 Don't check for offsets in tests where it is not relevant.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236233 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-30 13:57:06 +00:00
Rafael Espindola
c846f35a04 Check the entire content of the comdat group.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236230 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-30 13:08:09 +00:00
Rafael Espindola
58a854d447 Write the section header string table directly to the output stream.
Instead of accumulating the content in a fragment first, just write it
to the output stream.

Also put it first in the section table, so that we never have to worry
about its index being >= SHN_LORESERVE.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236145 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-29 20:25:24 +00:00
Duncan P. N. Exon Smith
e56023a059 IR: Give 'DI' prefix to debug info metadata
Finish off PR23080 by renaming the debug info IR constructs from `MD*`
to `DI*`.  The last of the `DIDescriptor` classes were deleted in
r235356, and the last of the related typedefs removed in r235413, so
this has all baked for about a week.

Note: If you have out-of-tree code (like a frontend), I recommend that
you get everything compiling and tests passing with the *previous*
commit before updating to this one.  It'll be easier to keep track of
what code is using the `DIDescriptor` hierarchy and what you've already
updated, and I think you're extremely unlikely to insert bugs.  YMMV of
course.

Back to *this* commit: I did this using the rename-md-di-nodes.sh
upgrade script I've attached to PR23080 (both code and testcases) and
filtered through clang-format-diff.py.  I edited the tests for
test/Assembler/invalid-generic-debug-node-*.ll by hand since the columns
were off-by-three.  It should work on your out-of-tree testcases (and
code, if you've followed the advice in the previous paragraph).

Some of the tests are in badly named files now (e.g.,
test/Assembler/invalid-mdcompositetype-missing-tag.ll should be
'dicompositetype'); I'll come back and move the files in a follow-up
commit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236120 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-29 16:38:44 +00:00
Rafael Espindola
e28f663f71 Don't constrain the section order in tests that don't depend on it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236102 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-29 13:55:07 +00:00
Ahmed Bougacha
e1f835ab59 [MC] Use LShr for constant evaluation of ">>" on ELF/arm64--darwin.
This matches other assemblers and is less unexpected (e.g. PR23227).
On ELF, I tried binutils gas v2.24 and nasm 2.10.09, and they both
agree on LShr.  On COFF, I couldn't get my hands on an assembler yet,
so don't change the behavior.  For now, don't change it on non-AArch64
Darwin either, as the other assembler is gas v1.38, which does an AShr.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235963 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-28 01:37:11 +00:00
Peter Collingbourne
f86c29ea2c ARM: When spilling extra registers for alignment, prefer low registers on all Thumb targets.
This makes it more likely that we can use the 16-bit push and pop instructions
on Thumb-2, saving around 4 bytes per function.

Differential Revision: http://reviews.llvm.org/D9165

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235637 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-23 20:31:26 +00:00
Peter Collingbourne
b28abbf98b ARM: Only enforce 4-byte alignment on Thumb-2 functions with constant pools.
This appears to have been introduced back in r76698 as part of an unrelated
change. I can find no official ARM documentation stating that Thumb-2 functions
require 4-byte alignment; in fact, ARM documentation appears to contradict
this (see, e.g., ARM Architecture Reference Manual Thumb-2 Supplement,
section 2.6.1: "Thumb-2 enforces 16-bit alignment on all instructions.").

Also remove code that sets alignment for ARM functions, which is redundant
with code in the MachineFunction constructor, and remove the hidden
-arm-align-constant-islands flag, which has been enabled by default since
r146739 (Dec 2011) and has probably received sufficient testing by now.

Differential Revision: http://reviews.llvm.org/D9138

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235636 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-23 20:31:22 +00:00
Hans Wennborg
defaf830f9 Re-commit r235560: Switch lowering: extract jump tables and bit tests before building binary tree (PR22262)
Third time's the charm. The previous commit was reverted as a
reverse for-loop in SelectionDAGBuilder::lowerWorkItem did 'I--'
on an iterator at the beginning of a vector, causing asserts
when using debugging iterators. This commit fixes that.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235608 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-23 16:45:24 +00:00
Aaron Ballman
5d538f71c2 Revert r235560; this commit was causing several failed assertions in Debug builds using MSVC's STL. The iterator is being used outside of its valid range.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235597 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-23 13:41:59 +00:00
Hans Wennborg
395f4f4b2a Switch lowering: extract jump tables and bit tests before building binary tree (PR22262)
This is a re-commit of r235101, which also fixes the problems with the previous patch:

- Switches with only a default case and non-fallthrough were handled incorrectly

- The previous patch tickled a bug in PowerPC Early-Return Creation which is fixed here.

> This is a major rewrite of the SelectionDAG switch lowering. The previous code
> would lower switches as a binary tre, discovering clusters of cases
> suitable for lowering by jump tables or bit tests as it went along. To increase
> the likelihood of finding jump tables, the binary tree pivot was selected to
> maximize case density on both sides of the pivot.
>
> By not selecting the pivot in the middle, the binary trees would not always
> be balanced, leading to performance problems in the generated code.
>
> This patch rewrites the lowering to search for clusters of cases
> suitable for jump tables or bit tests first, and then builds the binary
> tree around those clusters. This way, the binary tree will always be balanced.
>
> This has the added benefit of decoupling the different aspects of the lowering:
> tree building and jump table or bit tests finding are now easier to tweak
> separately.
>
> For example, this will enable us to balance the tree based on profile info
> in the future.
>
> The algorithm for finding jump tables is quadratic, whereas the previous algorithm
> was O(n log n) for common cases, and quadratic only in the worst-case. This
> doesn't seem to be major problem in practice, e.g. compiling a file consisting
> of a 10k-case switch was only 30% slower, and such large switches should be rare
> in practice. Compiling e.g. gcc.c showed no compile-time difference.  If this
> does turn out to be a problem, we could limit the search space of the algorithm.
>
> This commit also disables all optimizations during switch lowering in -O0.
>
> Differential Revision: http://reviews.llvm.org/D8649

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235560 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-22 23:14:56 +00:00
Rafael Espindola
b4b0b34181 Write relocation sections contiguously.
Linkers normally read all the relocations upfront to compute the references
between sections. Putting them together is a bit more cache friendly.

I benchmarked linking a Release+Asserts clang with gold on a vm. I tried all
4 combinations of --gc-sections/no --gc-section hot and cold cache.

I cleared the cache with

echo 3 > /proc/sys/vm/drop_caches

and warmed it up by running the link once before timing the subsequent ones.

With cold cache and --gc-sections the time goes from

1.86130781665 +- 0.01713126697463843 seconds
to
1.82370735105 +- 0.014127522318814516 seconds

With cold cache and no --gc-sections the time goes from

1.6087245435500002 +- 0.012999066825178644 seconds
to
1.5687122041500001 +- 0.013145850126026619 seconds

With hot cache and no --gc-sections the time goes from

0.926200939 ( +-  0.33% ) seconds
to
0.907200079 ( +-  0.31% ) seconds

With hot cache and gc sections the time goes from

1.183038049 ( +-  0.34% ) seconds
to
1.147355862 ( +-  0.39% ) seconds

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235165 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-17 08:11:38 +00:00
David Blaikie
32b845d223 [opaque pointer type] Add textual IR support for explicit type parameter to the call instruction
See r230786 and r230794 for similar changes to gep and load
respectively.

Call is a bit different because it often doesn't have a single explicit
type - usually the type is deduced from the arguments, and just the
return type is explicit. In those cases there's no need to change the
IR.

When that's not the case, the IR usually contains the pointer type of
the first operand - but since typed pointers are going away, that
representation is insufficient so I'm just stripping the "pointerness"
of the explicit type away.

This does make the IR a bit weird - it /sort of/ reads like the type of
the first operand: "call void () %x(" but %x is actually of type "void
()*" and will eventually be just of type "ptr". But this seems not too
bad and I don't think it would benefit from repeating the type
("void (), void () * %x(" and then eventually "void (), ptr %x(") as has
been done with gep and load.

This also has a side benefit: since the explicit type is no longer a
pointer, there's no ambiguity between an explicit type and a function
that returns a function pointer. Previously this case needed an explicit
type (eg: a function returning a void() function was written as
"call void () () * @x(" rather than "call void () * @x(" because of the
ambiguity between a function returning a pointer to a void() function
and a function returning void).

No ambiguity means even function pointer return types can just be
written alone, without writing the whole function's type.

This leaves /only/ the varargs case where the explicit type is required.

Given the special type syntax in call instructions, the regex-fu used
for migration was a bit more involved in its own unique way (as every
one of these is) so here it is. Use it in conjunction with the apply.sh
script and associated find/xargs commands I've provided in rr230786 to
migrate your out of tree tests. Do let me know if any of this doesn't
cover your cases & we can iterate on a more general script/regexes to
help others with out of tree tests.

About 9 test cases couldn't be automatically migrated - half of those
were functions returning function pointers, where I just had to manually
delete the function argument types now that we didn't need an explicit
function type there. The other half were typedefs of function types used
in calls - just had to manually drop the * from those.

import fileinput
import sys
import re

pat = re.compile(r'((?:=|:|^|\s)call\s(?:[^@]*?))(\s*$|\s*(?:(?:\[\[[a-zA-Z0-9_]+\]\]|[@%](?:(")?[\\\?@a-zA-Z0-9_.]*?(?(3)"|)|{{.*}}))(?:\(|$)|undef|inttoptr|bitcast|null|asm).*$)')
addrspace_end = re.compile(r"addrspace\(\d+\)\s*\*$")
func_end = re.compile("(?:void.*|\)\s*)\*$")

def conv(match, line):
  if not match or re.search(addrspace_end, match.group(1)) or not re.search(func_end, match.group(1)):
    return line
  return line[:match.start()] + match.group(1)[:match.group(1).rfind('*')].rstrip() + match.group(2) + line[match.end():]

for line in sys.stdin:
  sys.stdout.write(conv(re.search(pat, line), line))

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235145 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-16 23:24:18 +00:00
Hans Wennborg
e2711530de Revert the switch lowering change (r235101, r235103, r235106)
Looks like it broke the sanitizer-ppc64-linux1 build. Reverting for now.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235108 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-16 15:43:26 +00:00
Hans Wennborg
cc987d98bb Switch lowering: extract jump tables and bit tests before building binary tree (PR22262)
This is a major rewrite of the SelectionDAG switch lowering. The previous code
would lower switches as a binary tre, discovering clusters of cases
suitable for lowering by jump tables or bit tests as it went along. To increase
the likelihood of finding jump tables, the binary tree pivot was selected to
maximize case density on both sides of the pivot.

By not selecting the pivot in the middle, the binary trees would not always
be balanced, leading to performance problems in the generated code.

This patch rewrites the lowering to search for clusters of cases
suitable for jump tables or bit tests first, and then builds the binary
tree around those clusters. This way, the binary tree will always be balanced.

This has the added benefit of decoupling the different aspects of the lowering:
tree building and jump table or bit tests finding are now easier to tweak
separately.

For example, this will enable us to balance the tree based on profile info
in the future.

The algorithm for finding jump tables is O(n^2), whereas the previous algorithm
was O(n log n) for common cases, and quadratic only in the worst-case. This
doesn't seem to be major problem in practice, e.g. compiling a file consisting
of a 10k-case switch was only 30% slower, and such large switches should be rare
in practice. Compiling e.g. gcc.c showed no compile-time difference.  If this
does turn out to be a problem, we could limit the search space of the algorithm.

This commit also disables all optimizations during switch lowering in -O0.

Differential Revision: http://reviews.llvm.org/D8649

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235101 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-16 14:49:23 +00:00
Rafael Espindola
05da50f87b Don't depend on the order relocations are written to a .o file.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235092 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-16 12:59:30 +00:00
Vladimir Sukharev
5ade5fcee4 [ARM] Add v8.1a "Privileged Access Never" extension
Reviewers: jmolloy

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D8504


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235087 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-16 11:34:25 +00:00
Charlie Turner
fdb3720f58 Fix BXJ is undefined in AArch32.
BXJ was incorrectly said to be unsupported in ARMv8-A. It is not
supported in the A64 instruction set, but it is supported in the T32
and A32 instruction sets, because it's listed as an instruction in the
ARM ARM section F7.1.28.

Using SP as an operand to BXJ changed from UNPREDICTABLE to
PREDICTABLE in v8-A. This patch reflects that update as well.

This was found by MCHammer.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235024 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-15 17:28:23 +00:00
Rafael Espindola
11df480f67 Make it explicit which sections these relocations are in.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235022 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-15 17:24:06 +00:00
Rafael Espindola
70a987303a Make it clear in which sections these relocations are.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235020 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-15 16:59:47 +00:00
Rafael Espindola
6d9fd9bc70 Make it clear where the relocations we are CHECKING are from.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235018 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-15 16:45:03 +00:00
Rafael Espindola
f194367792 Update tests to not be as dependent on section numbers.
Many of these predate llvm-readobj. With elf-dump we had to match
a relocation to symbol number and symbol number to symbol name or
section number.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235015 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-15 15:59:37 +00:00
Rafael Espindola
50b935707f Write section and section table entries in the same order.
We had two different orders, which has no value.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235004 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-15 13:07:47 +00:00
Rafael Espindola
541279fdf9 Write the section header in the end.
One could make the argument for writing it immediately after the ELF header,
but writing it in the middle of the sections like we were doing just makes
it harder for no reason.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234400 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-08 11:41:24 +00:00