Commit Graph

29 Commits

Author SHA1 Message Date
Arthur Eubanks
8a584da153 [FunctionAttrs] Rename functionattrs -> function-attrs
To match NewPM pass name, and also for readability.
Also rename rpo-functionattrs -> rpo-function-attrs while we're here.

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D84694
2020-07-28 09:09:13 -07:00
Arthur Eubanks
ad84da6d6d Reland [X86] Codegen for preallocated
See https://reviews.llvm.org/D74651 for the preallocated IR constructs
and LangRef changes.

In X86TargetLowering::LowerCall(), if a call is preallocated, record
each argument's offset from the stack pointer and the total stack
adjustment. Associate the call Value with an integer index. Store the
info in X86MachineFunctionInfo with the integer index as the key.

This adds two new target independent ISDOpcodes and two new target
dependent Opcodes corresponding to @llvm.call.preallocated.{setup,arg}.

The setup ISelDAG node takes in a chain and outputs a chain and a
SrcValue of the preallocated call Value. It is lowered to a target
dependent node with the SrcValue replaced with the integer index key by
looking in X86MachineFunctionInfo. In
X86TargetLowering::EmitInstrWithCustomInserter() this is lowered to an
%esp adjustment, the exact amount determined by looking in
X86MachineFunctionInfo with the integer index key.

The arg ISelDAG node takes in a chain, a SrcValue of the preallocated
call Value, and the arg index int constant. It produces a chain and the
pointer fo the arg. It is lowered to a target dependent node with the
SrcValue replaced with the integer index key by looking in
X86MachineFunctionInfo. In
X86TargetLowering::EmitInstrWithCustomInserter() this is lowered to a
lea of the stack pointer plus an offset determined by looking in
X86MachineFunctionInfo with the integer index key.

Force any function containing a preallocated call to use the frame
pointer.

Does not yet handle a setup without a call, or a conditional call.
Does not yet handle musttail. That requires a LangRef change first.

Tried to look at all references to inalloca and see if they apply to
preallocated. I've made preallocated versions of tests testing inalloca
whenever possible and when they make sense (e.g. not alloca related,
inalloca edge cases).

Aside from the tests added here, I checked that this codegen produces
correct code for something like

```
struct A {
        A();
        A(A&&);
        ~A();
};

void bar() {
        foo(foo(foo(foo(foo(A(), 4), 5), 6), 7), 8);
}
```

by replacing the inalloca version of the .ll file with the appropriate
preallocated code. Running the executable produces the same results as
using the current inalloca implementation.

Reverted due to unexpectedly passing tests, added REQUIRES: asserts for reland.

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D77689
2020-05-20 11:25:44 -07:00
Arthur Eubanks
0671bbc792 Revert "[X86] Codegen for preallocated"
This reverts commit 810567dc691a57c8c13fef06368d7549f7d9c064.

Some tests are unexpectedly passing
2020-05-20 10:04:55 -07:00
Arthur Eubanks
a4df99a7cb [X86] Codegen for preallocated
See https://reviews.llvm.org/D74651 for the preallocated IR constructs
and LangRef changes.

In X86TargetLowering::LowerCall(), if a call is preallocated, record
each argument's offset from the stack pointer and the total stack
adjustment. Associate the call Value with an integer index. Store the
info in X86MachineFunctionInfo with the integer index as the key.

This adds two new target independent ISDOpcodes and two new target
dependent Opcodes corresponding to @llvm.call.preallocated.{setup,arg}.

The setup ISelDAG node takes in a chain and outputs a chain and a
SrcValue of the preallocated call Value. It is lowered to a target
dependent node with the SrcValue replaced with the integer index key by
looking in X86MachineFunctionInfo. In
X86TargetLowering::EmitInstrWithCustomInserter() this is lowered to an
%esp adjustment, the exact amount determined by looking in
X86MachineFunctionInfo with the integer index key.

The arg ISelDAG node takes in a chain, a SrcValue of the preallocated
call Value, and the arg index int constant. It produces a chain and the
pointer fo the arg. It is lowered to a target dependent node with the
SrcValue replaced with the integer index key by looking in
X86MachineFunctionInfo. In
X86TargetLowering::EmitInstrWithCustomInserter() this is lowered to a
lea of the stack pointer plus an offset determined by looking in
X86MachineFunctionInfo with the integer index key.

Force any function containing a preallocated call to use the frame
pointer.

Does not yet handle a setup without a call, or a conditional call.
Does not yet handle musttail. That requires a LangRef change first.

Tried to look at all references to inalloca and see if they apply to
preallocated. I've made preallocated versions of tests testing inalloca
whenever possible and when they make sense (e.g. not alloca related,
inalloca edge cases).

Aside from the tests added here, I checked that this codegen produces
correct code for something like

```
struct A {
        A();
        A(A&&);
        ~A();
};

void bar() {
        foo(foo(foo(foo(foo(A(), 4), 5), 6), 7), 8);
}
```

by replacing the inalloca version of the .ll file with the appropriate
preallocated code. Running the executable produces the same results as
using the current inalloca implementation.

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D77689
2020-05-20 09:20:38 -07:00
Hideto Ueno
e4b20675f9 [Attributor] Copy or port test cases related to Attributor to Attributor test folder
Summary:
This patch moves the test cases related to Attributor to `Transforms/Attributor` folder.
We have used `Transforms/FunctionAttrs` as the primary folder for Attributor test but we need to change testing way now.

For the test cases which I think functionattrs doesn't infer anything something like (willreturn, nosync, value-simplify, h2s ..etc), I moved them with the command `git mv`.

For the test cases in which functoinattrs and attributor are tested, I copied the test to the folder and remove the check only used by functoinattrs.

Reviewers: jdoerfert, sstefan1

Reviewed By: jdoerfert

Subscribers: jfb, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D70843
2019-12-02 15:36:29 +00:00
Stefan Stipanovic
4e04be8943 NoFree argument attribute.
Summary: Deducing nofree atrribute for function arguments.

Reviewers: jdoerfert

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D67886
2019-11-02 19:40:48 +01:00
Stefan Stipanovic
8973a4b594 Revert "NoFree argument attribute."
This reverts commit c12efa2ed0547f7f9f8fba0ad7a76a4cb08bf53a.
2019-11-02 17:31:02 +01:00
Stefan Stipanovic
e0f934d786 NoFree argument attribute.
Summary: Deducing nofree atrribute for function arguments.

Reviewers: jdoerfert

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D67886
2019-11-02 16:35:38 +01:00
Johannes Doerfert
bbcb73bcef [Attributor][NFCI] Avoid unnecessary work except for testing
Trying to deduce information for declarations and calls sites of
declarations is not useful in practice but only for testing. Add a flag
that disables this by default but also enable it in the tests.

The misc.ll test will verify the flag "works" as expected.
2019-11-02 00:28:24 -05:00
Johannes Doerfert
c49313343a [Attributor][MemBehavior] Fallback to the function state for arguments
Even if an argument is captured, we cannot have an effect the function
does not have. This is fine except for the special case of `inalloca` as
it does not behave by the rules.

TODO: Maybe the special rule for `inalloca` is wrong after all.
llvm-svn: 374736
2019-10-13 20:47:16 +00:00
Hideto Ueno
5316b0125f [Attributor][MustExec] Deduce dereferenceable and nonnull attribute using MustBeExecutedContextExplorer
Summary:
In D65186 and related patches, MustBeExecutedContextExplorer is introduced. This enables us to traverse instructions guaranteed to execute from function entry. If we can know the argument is used as `dereferenceable` or `nonnull` in these instructions, we can mark `dereferenceable` or `nonnull` in the argument definition:

1. Memory instruction (similar to D64258)
Trace memory instruction pointer operand. Currently, only inbounds GEPs are traced.
```
define i64* @f(i64* %a) {
entry:
  %add.ptr = getelementptr inbounds i64, i64* %a, i64 1
; (because of inbounds GEP we can know that %a is at least dereferenceable(16))
  store i64 1, i64* %add.ptr, align 8
  ret i64* %add.ptr ; dereferenceable 8 (because above instruction stores into it)
}
```

2. Propagation from callsite (similar to D27855)
If `deref` or `nonnull` are known in call site parameter attributes we can also say that argument also that attribute.

```
declare void @use3(i8* %x, i8* %y, i8* %z);
declare void @use3nonnull(i8* nonnull %x, i8* nonnull %y, i8* nonnull %z);

define void @parent1(i8* %a, i8* %b, i8* %c) {
  call void @use3nonnull(i8* %b, i8* %c, i8* %a)
; Above instruction is always executed so we can say that@parent1(i8* nonnnull %a, i8* nonnull %b, i8* nonnull %c)
  call void @use3(i8* %c, i8* %a, i8* %b)
  ret void
}
```

Reviewers: jdoerfert, sstefan1, spatel, reames

Reviewed By: jdoerfert

Subscribers: xbolva00, hiraditya, jfb, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D65402

llvm-svn: 374063
2019-10-08 15:25:56 +00:00
Johannes Doerfert
9b814421f3 [Attributor] Deduce memory behavior of functions and arguments
Deduce the memory behavior, aka "read-none", "read-only", or
"write-only", for functions and arguments.

Reviewers: sstefan1, uenoku

Subscribers: hiraditya, bollu, jfb, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D67384

llvm-svn: 373965
2019-10-07 21:07:57 +00:00
Johannes Doerfert
7637f84f45 [NFC][FnAttrs] Stress tests for attribute deduction
This commit is a preparation of upcoming patches on attribute deduction.
It will shorten the diffs and make it clear what we inferred before.

Reviewers: chandlerc, homerdin, hfinkel, fedor.sergeev, sanjoy, spatel, nlopes

Subscribers: bollu, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D59903

llvm-svn: 362577
2019-06-05 03:00:06 +00:00
Eric Christopher
a62270de2c Revert "Temporarily Revert "Add basic loop fusion pass.""
The reversion apparently deleted the test/Transforms directory.

Will be re-reverting again.

llvm-svn: 358552
2019-04-17 04:52:47 +00:00
Eric Christopher
71d1cca7ef Temporarily Revert "Add basic loop fusion pass."
As it's causing some bot failures (and per request from kbarton).

This reverts commit r358543/ab70da07286e618016e78247e4a24fcb84077fda.

llvm-svn: 358546
2019-04-17 02:12:23 +00:00
Elad Cohen
3908e15a8b Support arbitrary address space pointers in masked gather/scatter intrinsics.
Fixes PR31789 - When loop-vectorize tries to use these intrinsics for a
non-default address space pointer we fail with a "Calling a function with a
bad singature!" assertion. This patch solves this by adding the 'vector of
pointers' argument as an overloaded type which will determine the address
space.

Differential revision: https://reviews.llvm.org/D31490

llvm-svn: 302018
2017-05-03 12:28:54 +00:00
David Majnemer
61cc232b2d [FunctionAttrs] Correct the safety analysis for inference of 'returned'
We skipped over ReturnInsts which didn't return an argument which would
lead us to incorrectly conclude that an argument returned by another
ReturnInst was 'returned'.

This reverts commit r275756.

This fixes PR28610.

llvm-svn: 276008
2016-07-19 18:50:26 +00:00
NAKAMURA Takumi
5d74ab33c6 Revert r275678, "Revert "Revert r275027 - Let FuncAttrs infer the 'returned' argument attribute""
This reverts also r275029, "Update Clang tests after adding inference for the returned argument attribute"

It broke LTO build. Seems miscompilation.

llvm-svn: 275756
2016-07-18 03:23:25 +00:00
Hal Finkel
138dfcb551 Revert "Revert r275027 - Let FuncAttrs infer the 'returned' argument attribute"
This reverts commit r275042; the initial commit triggered self-hosting failures
on ARM/AArch64. James Molloy identified the problematic backend code, which has
been disabled in r275677. Trying again...

Original commit message:

Let FuncAttrs infer the 'returned' argument attribute

A function can have one argument with the 'returned' attribute, indicating that
the associated argument is always the return value of the function. Add
FuncAttrs inference logic.

llvm-svn: 275678
2016-07-16 07:21:28 +00:00
Hal Finkel
3aee15342e Revert r275027 - Let FuncAttrs infer the 'returned' argument attribute
Reverting r275027 and r275033. These seem to cause miscompiles on the AArch64 buildbot.

llvm-svn: 275042
2016-07-11 04:51:23 +00:00
Hal Finkel
6271874a51 Let FuncAttrs infer the 'returned' argument attribute
A function can have one argument with the 'returned' attribute, indicating that
the associated argument is always the return value of the function. Add
FuncAttrs inference logic.

Differential Revision: http://reviews.llvm.org/D22202

llvm-svn: 275027
2016-07-10 22:02:55 +00:00
Sean Silva
145ca3d2aa Remove dead TLI arg of isKnownNonNull and propagate deadness. NFC.
This actually uncovered a surprisingly large chain of ultimately unused
TLI args.
From what I can gather, this argument is a remnant of when
isKnownNonNull would look at the TLI directly.
The current approach seems to be that InferFunctionAttrs runs early in
the pipeline and uses TLI to annotate the TLI-dependent non-null
information as return attributes.

This also removes the dependence of functionattrs on TLI altogether.

llvm-svn: 274455
2016-07-02 23:47:27 +00:00
David Majnemer
3c41824d16 [FunctionAttrs] Volatile loads should disable readonly
A volatile load has side effects beyond what callers expect readonly to
signify.  For example, it is not safe to reorder two function calls
which each perform a volatile load to the same memory location.

llvm-svn: 270671
2016-05-25 05:53:04 +00:00
Chandler Carruth
d8a5b5b32e [PM] Port the PostOrderFunctionAttrs pass to the new pass manager and
convert one test to use this.

This is a particularly significant milestone because it required
a working per-function AA framework which can be queried over each
function from within a CGSCC transform pass (and additionally a module
analysis to be accessible). This is essentially *the* point of the
entire pass manager rewrite. A CGSCC transform is able to query for
multiple different function's analysis results. It works. The whole
thing appears to actually work and accomplish the original goal. While
we were able to hack function attrs and basic-aa to "work" in the old
pass manager, this port doesn't use any of that, it directly leverages
the new fundamental functionality.

For this to work, the CGSCC framework also has to support SCC-based
behavior analysis, etc. The only part of the CGSCC pass infrastructure
not sorted out at this point are the updates in the face of inlining and
running function passes that mutate the call graph.

The changes are pretty boring and boiler-plate. Most of the work was
factored into more focused preperatory patches. But this is what wires
it all together.

llvm-svn: 261203
2016-02-18 11:03:11 +00:00
Elena Demikhovsky
0600baa03e Vector of pointers in function attributes calculation
While setting function attributes we check all instructions that may access memory. For a call instruction we check all arguments. The special check is required for pointers.
I added vector-of-pointers to the call arguments types that should be checked.

Differential Revision: http://reviews.llvm.org/D14693

llvm-svn: 253363
2015-11-17 19:30:51 +00:00
David Blaikie
dfadb4e9ee [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))

llvm-svn: 235145
2015-04-16 23:24:18 +00:00
Nick Lewycky
cf5b9e086e When analyzing params/args for readnone/readonly, don't forget to consider that a pointer argument may be passed through a callsite to the return, and that we may need to analyze it. Fixes a bug reported on llvm-dev: http://lists.cs.uiuc.edu/pipermail/llvmdev/2014-May/073098.html
llvm-svn: 209870
2014-05-30 02:31:27 +00:00
Reid Kleckner
c9ab4a9a3b Update optimization passes to handle inalloca arguments
Summary:
I searched Transforms/ and Analysis/ for 'ByVal' and updated those call
sites to check for inalloca if appropriate.

I added tests for any change that would allow an optimization to fire on
inalloca.

Reviewers: nlewycky

Differential Revision: http://llvm-reviews.chandlerc.com/D2449

llvm-svn: 200281
2014-01-28 02:38:36 +00:00
Nick Lewycky
7b093a1c2f Extend 'readonly' and 'readnone' to work on function arguments as well as
functions. Make the function attributes pass add it to known library functions
and when it can deduce it.

llvm-svn: 185735
2013-07-06 00:29:58 +00:00