Commit Graph

70 Commits

Author SHA1 Message Date
Daniel Berlin 3c1432fecf Implement intrinsic mangling for literal struct types.
Fixes PR 31921

Summary:
Predicateinfo requires an ugly workaround to try to avoid literal
struct types due to the intrinsic mangling not being implemented.
This workaround actually does not work in all cases (you can hit the
assert by bootstrapping with -print-predicateinfo), and can't be made
to work without DFS'ing the type (IE copying getMangledStr and using a
version that detects if it would crash).

Rather than do that, i just implemented the mangling.  It seems
simple, since they are unified structurally.

Looking at the overloaded-mangling testcase we have, it actually turns
out the gc intrinsics will *also* crash if you try to use a literal
struct.  Thus, the testcase added fails before this patch, and works
after, without needing to resort to predicateinfo.

Reviewers: chandlerc, davide

Subscribers: llvm-commits, sanjoy

Differential Revision: https://reviews.llvm.org/D29925

llvm-svn: 295253
2017-02-15 23:16:20 +00:00
Davide Italiano 1e30b3d7be [LTO] Simplify this test quite a bit, @func2 is unused/unneeded.
llvm-svn: 294884
2017-02-12 03:47:54 +00:00
Davide Italiano 95a8707de8 [tests] Be explicit about the files we want to remove.
Hopefully Windows will stop whining after this change.

llvm-svn: 294801
2017-02-10 22:55:37 +00:00
Davide Italiano 62092aeb42 [LTO] Make these tests robust across multiple iterations.
Same as r294784, but for regular LTO.

llvm-svn: 294789
2017-02-10 22:11:06 +00:00
Adrian Prantl 1eadba1c8c Renumber testcase metadata nodes after r290153.
This patch renumbers the metadata nodes in debug info testcases after
https://reviews.llvm.org/D26769. This is a separate patch because it
causes so much churn. This was implemented with a python script that
pipes the testcases through llvm-as - | llvm-dis - and then goes
through the original and new output side-by side to insert all
comments at a close-enough location.

Differential Revision: https://reviews.llvm.org/D27765

llvm-svn: 290292
2016-12-22 00:45:21 +00:00
Adrian Prantl bceaaa9643 [IR] Remove the DIExpression field from DIGlobalVariable.
This patch implements PR31013 by introducing a
DIGlobalVariableExpression that holds a pair of DIGlobalVariable and
DIExpression.

Currently, DIGlobalVariables holds a DIExpression. This is not the
best way to model this:

(1) The DIGlobalVariable should describe the source level variable,
    not how to get to its location.

(2) It makes it unsafe/hard to update the expressions when we call
    replaceExpression on the DIGLobalVariable.

(3) It makes it impossible to represent a global variable that is in
    more than one location (e.g., a variable with multiple
    DW_OP_LLVM_fragment-s).  We also moved away from attaching the
    DIExpression to DILocalVariable for the same reasons.

This reapplies r289902 with additional testcase upgrades and a change
to the Bitcode record for DIGlobalVariable, that makes upgrading the
old format unambiguous also for variables without DIExpressions.

<rdar://problem/29250149>
https://llvm.org/bugs/show_bug.cgi?id=31013
Differential Revision: https://reviews.llvm.org/D26769

llvm-svn: 290153
2016-12-20 02:09:43 +00:00
Adrian Prantl 73ec065604 Revert "[IR] Remove the DIExpression field from DIGlobalVariable."
This reverts commit 289920 (again).
I forgot to implement a Bitcode upgrade for the case where a DIGlobalVariable
has not DIExpression. Unfortunately it is not possible to safely upgrade
these variables without adding a flag to the bitcode record indicating which
version they are.
My plan of record is to roll the planned follow-up patch that adds a
unit: field to DIGlobalVariable into this patch before recomitting.
This way we only need one Bitcode upgrade for both changes (with a
version flag in the bitcode record to safely distinguish the record
formats).

Sorry for the churn!

llvm-svn: 289982
2016-12-16 19:39:01 +00:00
Adrian Prantl 74a835cda0 [IR] Remove the DIExpression field from DIGlobalVariable.
This patch implements PR31013 by introducing a
DIGlobalVariableExpression that holds a pair of DIGlobalVariable and
DIExpression.

Currently, DIGlobalVariables holds a DIExpression. This is not the
best way to model this:

(1) The DIGlobalVariable should describe the source level variable,
    not how to get to its location.

(2) It makes it unsafe/hard to update the expressions when we call
    replaceExpression on the DIGLobalVariable.

(3) It makes it impossible to represent a global variable that is in
    more than one location (e.g., a variable with multiple
    DW_OP_LLVM_fragment-s).  We also moved away from attaching the
    DIExpression to DILocalVariable for the same reasons.

This reapplies r289902 with additional testcase upgrades.

<rdar://problem/29250149>
https://llvm.org/bugs/show_bug.cgi?id=31013
Differential Revision: https://reviews.llvm.org/D26769

llvm-svn: 289920
2016-12-16 04:25:54 +00:00
Adrian Prantl 03c6d31a3b Revert "[IR] Remove the DIExpression field from DIGlobalVariable."
This reverts commit 289902 while investigating bot berakage.

llvm-svn: 289906
2016-12-16 01:00:30 +00:00
Adrian Prantl ce13935776 [IR] Remove the DIExpression field from DIGlobalVariable.
This patch implements PR31013 by introducing a
DIGlobalVariableExpression that holds a pair of DIGlobalVariable and
DIExpression.

Currently, DIGlobalVariables holds a DIExpression. This is not the
best way to model this:

(1) The DIGlobalVariable should describe the source level variable,
    not how to get to its location.

(2) It makes it unsafe/hard to update the expressions when we call
    replaceExpression on the DIGLobalVariable.

(3) It makes it impossible to represent a global variable that is in
    more than one location (e.g., a variable with multiple
    DW_OP_LLVM_fragment-s).  We also moved away from attaching the
    DIExpression to DILocalVariable for the same reasons.

<rdar://problem/29250149>
https://llvm.org/bugs/show_bug.cgi?id=31013
Differential Revision: https://reviews.llvm.org/D26769

llvm-svn: 289902
2016-12-16 00:36:43 +00:00
Davide Italiano 2ceb628f36 [LTO] Reject modules without datalayout.
Also, udpate the ~60 failing tests in the tree which did
not contain a valid datalayout.
This fixes PR31123. lld will be updated in a following patch,
immediately after this is committed.

Differential Revision:  https://reviews.llvm.org/D27082

llvm-svn: 289719
2016-12-14 21:57:04 +00:00
Adam Nemet 4c207a6a1f [LTOs] Allow generation of hotness information
The flag is passed by the clang driver.

Differential Revision: https://reviews.llvm.org/D27331

llvm-svn: 288519
2016-12-02 17:53:56 +00:00
Adam Nemet 4df50e1fb0 Make LTO opt-remarks tests matching stricter
This ensures that we don't generate the hotness attribute by default.

llvm-svn: 288518
2016-12-02 17:53:49 +00:00
Adam Nemet de33651bd9 Rename option to -lto-pass-remarks-output
The new option -pass-remarks-output broke LLVM_LINK_LLVM_DYLIB because
of the duplicate option name with opt.

llvm-svn: 287627
2016-11-22 07:35:14 +00:00
Hans Wennborg 105e05a2a4 Fix test from r287353: don't use /dev/null
llvm-svn: 287360
2016-11-18 18:27:31 +00:00
Adam Nemet e9bd022c41 [LTO] Add option to generate optimization records
It is used to drive this from the clang driver via -mllvm.

Same option name is used as in opt.

Differential Revision: https://reviews.llvm.org/D26832

llvm-svn: 287356
2016-11-18 18:06:28 +00:00
Hans Wennborg aeacdc258b IRMover: Avoid accidentally mapping types from the destination module (PR30799)
During Module linking, it's possible for SrcM->getIdentifiedStructTypes();
to return types that are actually defined in the destination module
(DstM). Depending on how the bitcode file was read,
getIdentifiedStructTypes() might do a walk over all values, including
metadata nodes, looking for types. In my case, a debug info metadata
node was shared between the two modules, and it referred to a type
defined in the destination module (see test case).

Differential Revision: https://reviews.llvm.org/D26212

llvm-svn: 287353
2016-11-18 17:33:05 +00:00
Teresa Johnson 3624bdf60a Restore "[ThinLTO] Prevent exporting of locals used/defined in module level asm"
This restores the rest of r286297 (part was restored in r286475).
Specifically, it restores the part requiring adding a dependency from
the Analysis to Object library (downstream use changed to correctly
model split BitReader vs BitWriter libraries).

Original description of this part of patch follows:

Module level asm may also contain defs of values. We need to prevent
export of any refs to local values defined in module level asm (e.g. a
ref in normal IR), since that also requires renaming/promotion of the
local. To do that, the summary index builder looks at all values in the
module level asm string that are not marked Weak or Global, which is
exactly the set of locals that are defined. A summary is created for
each of these local defs and flagged as NoRename.

This required adding handling to the BitcodeWriter to look at GV
declarations to see if they have a summary (rather than skipping them
all).

Finally, added an assert to IRObjectFile::CollectAsmUndefinedRefs to
ensure that an MCAsmParser is available, otherwise the module asm parse
would silently fail. Initialized the asm parser in the opt tool for use
in testing this fix.

Fixes PR30610.

llvm-svn: 286844
2016-11-14 17:12:32 +00:00
Mehdi Amini b6a11a7879 Revert "[ThinLTO] Prevent exporting of locals used/defined in module level asm"
This reverts commit r286297.
Introduces a dependency from libAnalysis to libObject, which I missed
during the review.

llvm-svn: 286329
2016-11-09 01:45:13 +00:00
Teresa Johnson 6955feebf3 [ThinLTO] Prevent exporting of locals used/defined in module level asm
Summary:
This patch uses the same approach added for inline asm in r285513 to
similarly prevent promotion/renaming of locals used or defined in module
level asm.

All static global values defined in normal IR and used in module level asm
should be included on either the llvm.used or llvm.compiler.used global.
The former were already being flagged as NoRename in the summary, and
I've simply added llvm.compiler.used values to this handling.

Module level asm may also contain defs of values. We need to prevent
export of any refs to local values defined in module level asm (e.g. a
ref in normal IR), since that also requires renaming/promotion of the
local. To do that, the summary index builder looks at all values in the
module level asm string that are not marked Weak or Global, which is
exactly the set of locals that are defined. A summary is created for
each of these local defs and flagged as NoRename.

This required adding handling to the BitcodeWriter to look at GV
declarations to see if they have a summary (rather than skipping them
all).

Finally, added an assert to IRObjectFile::CollectAsmUndefinedRefs to
ensure that an MCAsmParser is available, otherwise the module asm parse
would silently fail. Initialized the asm parser in the opt tool for use
in testing this fix.

Fixes PR30610.

Reviewers: mehdi_amini

Subscribers: johanengelen, krasin, llvm-commits

Differential Revision: https://reviews.llvm.org/D26146

llvm-svn: 286297
2016-11-08 21:53:35 +00:00
Peter Collingbourne 46aafc16e8 LTO: Use the correct mangler function in LTOCodeGenerator::applyScopeRestrictions().
We need to use the overload of Mangler::getNameWithPrefix that takes a
GlobalValue in order to mangle in the stdcall stack byte count for Windows
targets.

Differential Revision: https://reviews.llvm.org/D25529

llvm-svn: 284040
2016-10-12 20:12:19 +00:00
Mehdi Amini e470927187 Fix auto-upgrade of TBAA tags in Bitcode Reader
If TBAA is on an intrinsic and it gets upgraded, it'll delete the call
instruction that we collected in a vector. Even if we were to use
WeakVH, it'll drop the TBAA and we'll hit the assert on the upgrade
path.

r263673 gave a shot to make sure the TBAA upgrade happens before
intrinsics upgrade, but failed to account for all cases.

Instead of collecting instructions in a vector, this patch makes it
just upgrade the TBAA on the fly, because metadata are always
already loaded at this point.

Differential Revision: https://reviews.llvm.org/D24533

llvm-svn: 281549
2016-09-14 22:29:59 +00:00
Mehdi Amini e75aa6f674 Add a libLTO API to query a memory buffer and check if it contains ObjC categories
The linker supports a feature to force load an object from a static
archive if it defines an Objective-C category.
This API supports this feature by looking at every section in the
module to find if a category is defined in the module.

llvm-svn: 275125
2016-07-11 23:10:18 +00:00
Nicolai Haehnle 84c9f9919a Add writeonly IR attribute
Summary:
This complements the earlier addition of IntrWriteMem and IntrWriteArgMem
LLVM intrinsic properties, see D18291.

Also start using the attribute for memset, memcpy, and memmove intrinsics,
and remove their special-casing in BasicAliasAnalysis.

Reviewers: reames, joker.eph

Subscribers: joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D18714

llvm-svn: 274485
2016-07-04 08:01:29 +00:00
Artur Pilipenko 6c7a8abf5c Remangle intrinsics names when types are renamed
This is a resubmittion of previously reverted rL273568.

This is a fix for the problem mentioned in "LTO and intrinsics mangling" llvm-dev mail thread:
http://lists.llvm.org/pipermail/llvm-dev/2016-April/098387.html

Reviewers: mehdi_amini, reames

Differential Revision: http://reviews.llvm.org/D19373

llvm-svn: 273686
2016-06-24 15:10:29 +00:00
Hans Wennborg a63b50afb8 Revert r273568 "Remangle intrinsics names when types are renamed"
It broke 2008-07-15-Bswap.ll and 2009-09-01-PostRAProlog.ll

llvm-svn: 273574
2016-06-23 16:13:23 +00:00
Artur Pilipenko f0c9f81379 Remangle intrinsics names when types are renamed
This is a fix for the problem mentioned in "LTO and intrinsics mangling" llvm-dev mail thread:
http://lists.llvm.org/pipermail/llvm-dev/2016-April/098387.html

Reviewers: mehdi_amini, reames

Differential Revision: http://reviews.llvm.org/D19373

llvm-svn: 273568
2016-06-23 15:25:09 +00:00
Peter Collingbourne 96efdd6107 IR: Introduce local_unnamed_addr attribute.
If a local_unnamed_addr attribute is attached to a global, the address
is known to be insignificant within the module. It is distinct from the
existing unnamed_addr attribute in that it only describes a local property
of the module rather than a global property of the symbol.

This attribute is intended to be used by the code generator and LTO to allow
the linker to decide whether the global needs to be in the symbol table. It is
possible to exclude a global from the symbol table if three things are true:
- This attribute is present on every instance of the global (which means that
  the normal rule that the global must have a unique address can be broken without
  being observable by the program by performing comparisons against the global's
  address)
- The global has linkonce_odr linkage (which means that each linkage unit must have
  its own copy of the global if it requires one, and the copy in each linkage unit
  must be the same)
- It is a constant or a function (which means that the program cannot observe that
  the unique-address rule has been broken by writing to the global)

Although this attribute could in principle be computed from the module
contents, LTO clients (i.e. linkers) will normally need to be able to compute
this property as part of symbol resolution, and it would be inefficient to
materialize every module just to compute it.

See:
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20160509/356401.html
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20160516/356738.html
for earlier discussion.

Part of the fix for PR27553.

Differential Revision: http://reviews.llvm.org/D20348

llvm-svn: 272709
2016-06-14 21:01:22 +00:00
Adrian Prantl fe7a382453 Allow the LTO code generator to strip invalid debug info from the input.
This patch introduces a new option -lto-strip-invalid-debug-info, which
drops malformed debug info from the input.

The problem I'm trying to solve with this sequence of patches is that
historically we've done a really bad job at verifying debug info. We want
to be able to make the verifier stricter without having to worry about
breaking bitcode compatibility with existing producers. For example, we
don't necessarily want IR produced by an older version of clang to be
rejected by an LTO link just because of malformed debug info, and rather
provide an option to strip it. Note that merely outdated (but well-formed)
debug info would continue to be auto-upgraded in this scenario.

rdar://problem/25818489
http://reviews.llvm.org/D19987

This reapplies 268936 with a test case fix for Linux (-exported-symbol foo)

llvm-svn: 268965
2016-05-09 19:57:15 +00:00
Adrian Prantl 6d80100c6a Revert "Allow the LTO code generator to strip invalid debug info from the input."
This reverts commit 268936 while investigating buildbot breakage.

llvm-svn: 268940
2016-05-09 17:43:30 +00:00
Adrian Prantl 4a9292b127 Allow the LTO code generator to strip invalid debug info from the input.
This patch introduces a new option -lto-strip-invalid-debug-info, which
drops malformed debug info from the input.

The problem I'm trying to solve with this sequence of patches is that
historically we've done a really bad job at verifying debug info. We want
to be able to make the verifier stricter without having to worry about
breaking bitcode compatibility with existing producers. For example, we
don't necessarily want IR produced by an older version of clang to be
rejected by an LTO link just because of malformed debug info, and rather
provide an option to strip it. Note that merely outdated (but well-formed)
debug info would continue to be auto-upgraded in this scenario.

rdar://problem/25818489
http://reviews.llvm.org/D19987

llvm-svn: 268936
2016-05-09 17:37:33 +00:00
Peter Collingbourne edf8432480 LTO: Don't bother trying to mangle unnamed globals, as they can't be preserved with MustPreserveSymbols.
Summary: Should fix sanitizer-windows bot.

Reviewers: joker.eph

Subscribers: llvm-commits, joker.eph

Differential Revision: http://reviews.llvm.org/D19635

llvm-svn: 267820
2016-04-27 23:48:11 +00:00
Mehdi Amini c7b950171d Revert "Support "preserving" the summary information when using setModule() API in LTOCodeGenerator"
This reverts commit r267665.
ASAN shows that there is a use of undefined value.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 267668
2016-04-27 05:11:44 +00:00
Mehdi Amini 360ed847bc Support "preserving" the summary information when using setModule() API in LTOCodeGenerator
Another attempt at r267655...

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 267665
2016-04-27 04:24:10 +00:00
Mehdi Amini a1b8b6cd56 Revert "Support "preserving" the summary information when using setModule() API in LTOCodeGenerator"
This reverts commit r267657, r267656, and r267655.
The test does not pass on multiple bots, I'm unsure why yet but let's unbreak them.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 267664
2016-04-27 03:34:28 +00:00
Mehdi Amini 4960919723 Fix the test from r267656: Support "preserving" the summary information when using setModule() API in LTOCodeGenerator
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 267657
2016-04-27 01:49:11 +00:00
Mehdi Amini 1f65039f06 Add a test for r267655: Support "preserving" the summary information when using setModule() API in LTOCodeGenerator
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 267656
2016-04-27 01:47:46 +00:00
Mehdi Amini 24d3414f06 Refactor the InternalizePass into a helper class, and expose it through a public free function (NFC)
There is really no reason to require to instanciate a pass manager to
internalize.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266167
2016-04-13 05:25:08 +00:00
Mehdi Amini f59f2bb1b5 Refactor the Internalize stage of libLTO in a separate file (NFC)
This is intended to be shared by the ThinLTOCodeGenerator.

Note that there is a change in the way the verifier is run, previously
it was ran as a Pass on the merged module during internalization.
While now the verifier is called explicitely on the merged module
outside of the internalize "pass pipeline".

What remains strange in the API is the fact that `DisableVerify` in
the API does not disable this initial verifier.

Differential Revision: http://reviews.llvm.org/D19000

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266047
2016-04-12 06:34:10 +00:00
Colin LeMahieu efe3732883 Revert r265817
lld tests need to be addressed.

llvm-svn: 265822
2016-04-08 18:15:37 +00:00
Akira Hatanaka e9148dd62f [LoopVectorize] Don't unconditionally print vectorization diagnostics
when compiling with LTO.

r244523 a new class DiagnosticInfoOptimizationRemarkAnalysisAliasing for
optimization analysis remarks related to pointer aliasing without
guarding it in isDiagnosticEnabled in LLVMContext.cpp. This caused the
diagnostic message to be printed unconditionally when compiling with
LTO.

This commit cleans up isDiagnosticEnabled and makes sure all the
vectorization optimization remarks are guarded.

rdar://problem/25382153

llvm-svn: 265084
2016-04-01 00:34:39 +00:00
Steven Wu f2fe0141ca Rename embedded bitcode section in MachO
Summary:
Rename the section embeds bitcode from ".llvmbc,.llvmbc" to "__LLVM,__bitcode".
The new name matches MachO section naming convention.

Reviewers: rafael, pcc

Subscribers: davide, llvm-commits, joker.eph

Differential Revision: http://reviews.llvm.org/D17388

llvm-svn: 262245
2016-02-29 19:40:10 +00:00
Tobias Edler von Koch 8ecaf69291 [LTO] Restore original linkage of externals prior to splitting
Summary:
This is a companion patch for http://reviews.llvm.org/D16124.

Internalized symbols increase the size of strongly-connected components in
SCC-based module splitting and thus reduce the amount of parallelism. This
patch records the original linkage of non-local symbols prior to
internalization and then restores it just before splitting/CodeGen. This is
also useful for cases where the linker requires symbols to remain external, for
instance, so they can be placed according to linker script rules.

It's currently under its own flag (-restore-globals) but should eventually
share a common flag with D16124.

Reviewers: joker.eph, pcc

Subscribers: slarin, llvm-commits, joker.eph

Differential Revision: http://reviews.llvm.org/D16229

llvm-svn: 258100
2016-01-18 23:24:54 +00:00
Rafael Espindola 79db917139 Don't try to check all uses if lazy loading.
This means that LTO_SYMBOL_SCOPE_DEFAULT_CAN_BE_HIDDEN will not be set
in a few cases.

This should have no impact in ld64 since it doesn't use lazy loading
when merging modules and that is when it checks
LTO_SYMBOL_SCOPE_DEFAULT_CAN_BE_HIDDEN.

llvm-svn: 257915
2016-01-15 18:23:46 +00:00
Vaivaswatha Nagaraj fb3f4907c0 Add InaccessibleMemOnly and inaccessibleMemOrArgMemOnly attributes
Summary:
This patch introduces two new function attributes 

InaccessibleMemOnly: This attribute indicates that the function may only access memory that is not accessible by the program/IR being compiled. This is a weaker form of ReadNone.
inaccessibleMemOrArgMemOnly: This attribute indicates that the function may only access memory that is either not accessible by the program/IR being compiled, or is pointed to by its pointer arguments. This is a weaker form of  ArgMemOnly

Test cases have been updated. This revision uses this (d001932f3a) as reference.

Reviewers: jmolloy, hfinkel

Subscribers: reames, joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D15499

llvm-svn: 255778
2015-12-16 16:16:19 +00:00
Tobias Edler von Koch 49c9a6e802 [LTO] Add options to llvm-lto to select output format and dump merged module
This introduces two new options:
- "llvm-lto -save-merged-module -o outfile" dumps the LTO Module to
  outfile.merged.bc prior to CodeGen and after LTO optimizations have been run.
- "llvm-lto -filetype=asm -o outfile" makes llvm-lto emit assembly instead of
  object code in outfile.

Both are intended for use in lit tests.

llvm-svn: 253624
2015-11-20 00:13:05 +00:00
James Molloy 9ad4f22538 [LTO] Add an early run of functionattrs
Because we internalize early, we can potentially mark a bunch of functions as norecurse. Do this before globalopt.

llvm-svn: 253451
2015-11-18 11:24:42 +00:00
Yunzhong Gao ea7b3a2320 Add a libLTO diagnostic handler that supports lto_get_error_message API
This is a follow-up from the previous discussion on the thread:
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20151019/307763.html

The LibLTO lto_get_error_message() API reads error messages from a std::string
sLastErrorString. Instead of passing this string around as an argument, this
patch creates a diagnostic handler and then sends this handler to the
constructor of LTOCodeGenerator.

Differential Revision: http://reviews.llvm.org/D14313

llvm-svn: 252791
2015-11-11 19:59:08 +00:00
Yunzhong Gao ef436f068c llvm-lto: trivial spelling changes to distinguish custom diagnostic handler and
default diagnostic handler.

Differential Revision: http://reviews.llvm.org/D14520

llvm-svn: 252633
2015-11-10 18:52:48 +00:00
James Molloy e6f87ca812 Add a new attribute: norecurse
This attribute allows the compiler to assume that the function never recurses into itself, either directly or indirectly (transitively). This can be used among other things to demote global variables to locals.

llvm-svn: 252282
2015-11-06 10:32:53 +00:00