Mehdi Amini [Thu, 6 Oct 2016 23:26:29 +0000 (23:26 +0000)]
Add a static_assert to enforce that parameters to llvm::format() are not totally unsafe
Summary:
I had for the second time today a bug where llvm::format("%s", Str)
was called with Str being a StringRef. The Linux and MacOS bots were
fine, but windows having different calling convention, it printed
garbage.
Instead we can catch this at compile-time: it is never expected to
call a C vararg printf-like function with non scalar type I believe.
Rong Xu [Thu, 6 Oct 2016 20:38:13 +0000 (20:38 +0000)]
[PGO] Create weak alias for the renamed Comdat function
Add a weak alias to the renamed Comdat function in IR level instrumentation,
using it's original name. This ensures the same behavior w/ and w/o IR
instrumentation, even for non standard conforming code.
When replacing FrameIndex with BasePtr, we must preserve BasePtr for
LEA64_32r since BasePtr is used later for stack adjustment if it is
the same as StackPtr.
[DAG] Generalize build_vector -> vector_shuffle combine for more than 2 inputs
This generalizes the build_vector -> vector_shuffle combine to support any
number of inputs. The idea is to create a binary tree of shuffles, where
the first layer performs pairwise shuffles of the input vectors placing each
input element into the correct lane, and the rest of the tree blends these
shuffles together.
This doesn't try to be smart and create any sort of "optimal" shuffles.
The assumption is that even a "poor" shuffle sequence is better than extracting
and inserting the elements one by one.
Michael Ilseman [Thu, 6 Oct 2016 17:58:38 +0000 (17:58 +0000)]
Add -strip-nonlinetable-debuginfo capability
This adds a new function to DebugInfo.cpp that takes an llvm::Module
as input and removes all debug info metadata that is not directly
needed for line tables, thus effectively stripping all type and
variable information from the module.
The primary motivation for this feature was the bitcode work flow
(cf. http://lists.llvm.org/pipermail/llvm-dev/2016-June/100643.html
for more background). This is not wired up yet, but will be in
subsequent patches. For testing, the new functionality is exposed to
opt with a -strip-nonlinetable-debuginfo option.
The secondary use-case (and one that works right now!) is as a
reduction pass in bugpoint. I added two new bugpoint options
(-disable-strip-debuginfo and -disable-strip-debug-types) to control
the new features. By default it will first attempt to remove all debug
information, then only the type info, and then proceed to hack at any
remaining MDNodes.
Matt Arsenault [Thu, 6 Oct 2016 17:54:30 +0000 (17:54 +0000)]
AMDGPU: Remove leftover implicit operands when folding immediates
When constant folding an operation to a copy or an immediate
mov, the implicit uses/defs of the old instruction were left behind,
e.g. replacing v_or_b32 left the implicit exec use on the new copy.
Hal Finkel [Thu, 6 Oct 2016 11:58:52 +0000 (11:58 +0000)]
[llvm-opt-report] Record VF, etc. correctly for multiple opts on one line
When there are multiple optimizations on one line, record the vectorization
factors, etc. correctly (instead of incorrectly substituting default values).
Reid Kleckner [Wed, 5 Oct 2016 22:36:07 +0000 (22:36 +0000)]
[codeview] Truncate records to maximum record size near 64KB
If we don't truncate, LLVM asserts when the label difference doesn't fit
in a 16 bit field. This patch truncates two kinds of data: trailing null
terminated names in symbol records, and inline line tables. The inline
line table test that I have is too large (many MB), so I'm not checking
it in.
Hal Finkel [Wed, 5 Oct 2016 22:25:33 +0000 (22:25 +0000)]
[llvm-opt-report] Distinguish inlined contexts when optimizations differ
How code is optimized sometimes, perhaps often, depends on the context into
which it was inlined. This change allows llvm-opt-report to track the
differences between the optimizations performed, or not, in different contexts,
and when these differ, display those differences.
For example, this code:
$ cat /tmp/q.cpp
void bar();
void foo(int n) {
for (int i = 0; i < n; ++i)
bar();
}
void quack() {
foo(4);
}
void quack2() {
foo(4);
}
will now produce this report:
< /home/hfinkel/src/llvm/test/tools/llvm-opt-report/Inputs/q.cpp
2 | void bar();
3 | void foo(int n) {
[[
> foo(int):
4 | for (int i = 0; i < n; ++i)
> quack(), quack2():
4 U4 | for (int i = 0; i < n; ++i)
]]
5 | bar();
6 | }
7 |
8 | void quack() {
9 I | foo(4);
10 | }
11 |
12 | void quack2() {
13 I | foo(4);
14 | }
15 |
Note that the tool has demangled the function names, and grouped the reports
associated with line 4. This shows that the loop on line 4 was unrolled by a
factor of 4 when inlined into the functions quack() and quack2(), but not in
the function foo(int) itself.
Hal Finkel [Wed, 5 Oct 2016 22:10:35 +0000 (22:10 +0000)]
Add an llvm-opt-report tool to generate basic source-annotated optimization summaries
LLVM now has the ability to record information from optimization remarks in a
machine-consumable YAML file for later analysis. This can be enabled in opt
(see r282539), and D25225 adds a Clang flag to do the same. This patch adds
llvm-opt-report, a tool to generate basic optimization "listing" files
(annotated sources with information about what optimizations were performed)
from one of these YAML inputs.
D19678 proposed to add this capability directly to Clang, but this more-general
YAML-based infrastructure was the direction we decided upon in that review
thread.
For this optimization report, I focused on making the output as succinct as
possible while providing information on inlining and loop transformations. The
goal here is that the source code should still be easily readable in the
report. My primary inspiration here is the reports generated by Cray's tools
(http://docs.cray.com/books/S-2496-4101/html-S-2496-4101/z1112823641oswald.html).
These reports are highly regarded within the HPC community. Intel's compiler,
for example, also has an optimization-report capability
(https://software.intel.com/sites/default/files/managed/55/b1/new-compiler-optimization-reports.pdf).
$ cat /tmp/v.c
void bar();
void foo() { bar(); }
void Test(int *res, int *c, int *d, int *p, int n) {
int i;
#pragma clang loop vectorize(assume_safety)
for (i = 0; i < 1600; i++) {
res[i] = (p[i] == 0) ? res[i] : res[i] + d[i];
}
for (i = 0; i < 16; i++) {
res[i] = (p[i] == 0) ? res[i] : res[i] + d[i];
}
foo();
foo(); bar(); foo();
}
D25225 adds -fsave-optimization-record (and
-fsave-optimization-record=filename), and this would be used as follows:
< /tmp/v.c
2 | void bar();
3 | void foo() { bar(); }
4 |
5 | void Test(int *res, int *c, int *d, int *p, int n) {
6 | int i;
7 |
8 | #pragma clang loop vectorize(assume_safety)
9 V4,2 | for (i = 0; i < 1600; i++) {
10 | res[i] = (p[i] == 0) ? res[i] : res[i] + d[i];
11 | }
12 |
13 U16 | for (i = 0; i < 16; i++) {
14 | res[i] = (p[i] == 0) ? res[i] : res[i] + d[i];
15 | }
16 |
17 I | foo();
18 |
19 | foo(); bar(); foo();
I | ^
I | ^
20 | }
Each source line gets a prefix giving the line number, and a few columns for
important optimizations: inlining, loop unrolling and loop vectorization. An
'I' is printed next to a line where a function was inlined, a 'U' next to an
unrolled loop, and 'V' next to a vectorized loop. These are printed on the
relevant code line when that seems unambiguous, or on subsequent lines when
multiple potential options exist (messages, both positive and negative, from
the same optimization with different column numbers are taken to indicate
potential ambiguity). When on subsequent lines, a '^' is output in the relevant
column.
Annotated source for all relevant input files are put into the listing file
(each starting with '<' and then the file name).
You can disable having the unrolling/vectorization factors appear by using the
-s flag.
David Callahan [Wed, 5 Oct 2016 21:36:16 +0000 (21:36 +0000)]
Modify df_iterator to support post-order actions
Summary: This makes a change to the state used to maintain visited information for depth first iterator. We know assume a method "completed(...)" which is called after all children of a node have been visited. In all existing cases, this method does nothing so this patch has no functional changes. It will however allow a client to distinguish back from cross edges in a DFS tree.
Lang Hames [Wed, 5 Oct 2016 21:20:00 +0000 (21:20 +0000)]
[Object] Fix a crash in Archive::child_iterator's default constructor.
To be default constructible, Archive::child_iterator needs to be able to
construct an Archive::Child with a null parent, however Archive::Child's
constructor always dereferenced its Parent argument to compute the remaining
archive size. This commit fixes Archive::Child's constructor to only do the
size calculation when the parent is non-null.
Martin Storsjo [Wed, 5 Oct 2016 21:08:02 +0000 (21:08 +0000)]
[ARM] Use __rt_div functions for divrem on Windows
This avoids falling back to calling out to the GCC rem functions
(__moddi3, __umoddi3) when targeting Windows.
The __rt_div functions have flipped the two arguments compared
to the __aeabi_divmod functions. To match MSVC, we emit a
check for division by zero before actually calling the library
function (even if the library function itself also might do
the same check).
Not all calls to __rt_div functions for division are currently
merged with calls to the same function with the same parameters
for the remainder. This is more wasteful than a div + mls as before,
but avoids calls to __moddi3.
Yunzhong Gao [Wed, 5 Oct 2016 20:26:29 +0000 (20:26 +0000)]
Improve the debug-info test created in r274263.
This patch is related to r274263 or Phabricator/D21818.
This patch aims to improve the test case added in the previous commit to verify
specifically that the stack protector pass is adding the debug line info as
intended. Before, the test only verified that the verifier pass does not crash.
The current approach is to generate the assembly output and then look for the
.loc directive.
Matthew Simpson [Wed, 5 Oct 2016 20:23:46 +0000 (20:23 +0000)]
[LV] Pass profitability analysis in vectorizer constructor (NFC)
The vectorizer already holds a pointer to one cost model artifact in a member
variable (i.e., MinBWs). As we add more, it will be easier to communicate these
artifacts to the vectorizer if we simply pass a pointer to the cost model
instead.
Matthew Simpson [Wed, 5 Oct 2016 19:11:54 +0000 (19:11 +0000)]
[LV] Use getScalarizationOverhead in memory instruction costs (NFC)
This patch refactors the cost estimation of scalarized loads and stores to
reuse getScalarizationOverhead for the cost of the extractelement and
insertelement instructions we might create. The existing code accounted for
this cost, but it was functionally equivalent to the helper function.
Reid Kleckner [Wed, 5 Oct 2016 18:36:02 +0000 (18:36 +0000)]
Improve DEBUG_VALUE assembly comments for spilled bitpieces
Previously we would give up when we saw the bitpiece DWARF expression
and print "[complex expression]" when actually we handled bitpiece
expressions outside the loop.
Matthew Simpson [Wed, 5 Oct 2016 18:30:36 +0000 (18:30 +0000)]
[LV] Add helper function for predicated block probability (NFC)
The cost model has to estimate the probability of executing predicated blocks.
However, we currently always assume predicated blocks have a 50% chance of
executing (this value is hardcoded in several places throughout the code).
Since we always use the same value, this patch adds a helper function for
getting this uniform probability. The function simplifies some comments and
makes our assumptions more clear. In the future, we may want to extend this
with actual block probability information if it's available.
Simon Dardis [Wed, 5 Oct 2016 18:26:19 +0000 (18:26 +0000)]
[mips][ias] fix li macro when values are negated with ~
The integrated assembler evaluates the expressions such as ~0x80000000 to
0xffffffff7fffffff early in the parsing process. This patch adds compatibility
with gas so that li loads the expected value (0x7fffffff) in those cases. This
only occurs iff all the upper 32bits are set and maintains existing checks by
not truncating the result down to 32 bits if any of the the upper bits are not
set.
Matthew Simpson [Wed, 5 Oct 2016 17:52:34 +0000 (17:52 +0000)]
[LV] Add isScalarWithPredication helper function (NFC)
This patch adds a single helper function for checking if an instruction will be
scalarized with predication. Such instructions include conditional stores and
instructions that may divide by zero. Existing checks have been updated to use
the new function.
[DAG] Teach computeKnownBits and ComputeNumSignBits in SelectionDAG to look through EXTRACT_VECTOR_ELT.
Summary: Both computeKnownBits and ComputeNumSignBits can now do a simple
look-through of EXTRACT_VECTOR_ELT. It will compute the result based
on the known bits (or known sign bits) for the vector that the element
is extracted from.
James Molloy [Wed, 5 Oct 2016 14:52:13 +0000 (14:52 +0000)]
[Thumb] Don't try and emit LDRH/LDRB from the constant pool
This is not a valid encoding - these instructions cannot do PC-relative addressing.
The underlying problem here is of whitelist in ARMISelDAGToDAG that unwraps ARMISD::Wrappers during addressing-mode selection. This didn't realise TargetConstantPool was actually possible, so didn't handle it.
projects / llvm / log