support notionally const queries even though they may trigger DFS
numbering updates.
The updating of DFS numbers and tracking of slow queries do not mutate
the observable state of the domtree. They should be const to
differentiate them from the APIs which mutate the tree directly to do
incremental updates.
This will make it possible in a world where the DominatorTree is not
a pass but merely the result of running a pass to derive DominatorTree
from the base class as it was originally designed, removing a huge
duplication of API in DominatorTree.
llvm-svn: 199101
trees into the Support library.
These are all expressed in terms of the generic GraphTraits and CFG,
with no reliance on any concrete IR types. Putting them in support
clarifies that and makes the fact that the static analyzer in Clang uses
them much more sane. When moving the Dominators.h file into the IR
library I claimed that this was the right home for it but not something
I planned to work on. Oops.
So why am I doing this? It happens to be one step toward breaking the
requirement that IR verification can only be performed from inside of
a pass context, which completely blocks the implementation of
verification for the new pass manager infrastructure. Fixing it will
also allow removing the concept of the "preverify" step (WTF???) and
allow the verifier to cleanly flag functions which fail verification in
a way that precludes even computing dominance information. Currently,
that results in a fatal error even when you ask the verifier to not
fatally error. It's awesome like that.
The yak shaving will continue...
llvm-svn: 199095
Very sorry, this was a premature patch that I still need to investigate and
finish off (for some reason beyond me at the moment it doesn't actually fix the
issue in all cases).
This reverts commit r199091.
llvm-svn: 199093
There are two attempted optimisations in reMaterializeTrivialDef, trying to
avoid promoting the size of a register too much when rematerializing.
Unfortunately, both appear to be flawed. First, we see if the original register
would have worked, but this is inadequate. Consider:
v1 = SOMETHING (v1 is QQ)
v2:Q0 = COPY v1:Q1 (v1, v2 are QQ)
...
uses of v2
In this case even though v2 *could* be used directly as the output of
SOMETHING, this would set the wrong bits of the QQ register involved. The
correct rematerialization must be:
v2:Q0_Q1 = SOMETHING (v2 promoted to QQQ)
...
uses of v2:Q1_Q2
For the second optimisation, if the correct remat is "v2:idx = SOMETHING" then
we can't necessarily expect v2 itself to be valid for SOMETHING, but we do try
to hunt for a class between v1 and v2 that works. Unfortunately, this is also
wrong:
v1 = SOMETHING (v1 is QQ)
v2:Q0_Q1 = COPY v1 (v1 is QQ, v2 is QQQ)
...
uses of v2 as a QQQ
The canonical rematerialization here is "v2:Q0_Q1 = SOMETHING". However current
logic would decide that v2 could be a QQ (no interest is taken in later uses).
This patch, therefore, always accepts the widened register class without trying
to be clever. Generally there is no penalty to this (e.g. in the common GR32 <
GR64 case, expanding the width doesn't matter because it's not like you were
going to do anything else with the high bits of a GR32 register). It can
increase register pressure in cases like the ARM VFP regs though (multiple
non-overlapping but equivalent subregisters). Hopefully this situation is rare
enough that it won't matter.
Unfortunately, no in-tree targets actually expose this as far as I can tell
(there are so few isAsCheapAsAMove instructions for it to trigger on) so I've
been unable to produce a test. It was exposed in our ARM64 SPEC tests though,
and I will be adding a test there that we should be able to contribute
soon(TM).
llvm-svn: 199091
style, and remove some unnecessary comments (the code is perfectly
self-documenting here). Also clang-format the function declarations as
they wrap cleanly now.
llvm-svn: 199084
directory. These passes are already defined in the IR library, and it
doesn't make any sense to have the headers in Analysis.
Long term, I think there is going to be a much better way to divide
these matters. The dominators code should be fully separated into the
abstract graph algorithm and have that put in Support where it becomes
obvious that evn Clang's CFGBlock's can use it. Then the verifier can
manually construct dominance information from the Support-driven
interface while the Analysis library can provide a pass which both
caches, reconstructs, and supports a nice update API.
But those are very long term, and so I don't want to leave the really
confusing structure until that day arrives.
llvm-svn: 199082
This moves the old pass creation functionality to its own header and
updates the callers of that routine. Then it adds a new PM supporting
bitcode writer to the header file, and wires that up in the opt tool.
A test is added that round-trips code into bitcode and back out using
the new pass manager.
llvm-svn: 199078
It was too late to set BUG_REPORT_URL after configure_file(config.h).
BUG_REPORT_URL in config.h.cmake would be updated at 2nd run of cmake.
It caused many recompilations.
FYI, configure handles BUG_REPORT_URL in llvm side.
llvm-svn: 199076
that through the interface rather than a simple bool. This should allow
starting to wire up real output to round-trip IR through opt with the
new pass manager.
llvm-svn: 199071
This patch covered 2 more scenarios:
1. Two operands of shuffle_vector are the same, like
%shuffle.i = shufflevector <8 x i8> %a, <8 x i8> %a, <8 x i32> <i32 0, i32 2, i32 4, i32 6, i32 8, i32 10, i32 12, i32 14>
2. One of operands is undef, like
%shuffle.i = shufflevector <8 x i8> %a, <8 x i8> undef, <8 x i32> <i32 0, i32 2, i32 4, i32 6, i32 8, i32 10, i32 12, i32 14>
After this patch, perm instructions will have chance to be emitted instead of lots of INS.
llvm-svn: 199069
The target specific parser should return `false' if the target AsmParser handles
the directive, and `true' if the generic parser should handle the directive.
Many of the target specific directive handlers would `return Error' which does
not follow these semantics. This change simply changes the target specific
routines to conform to the semantis of the ParseDirective correctly.
Conformance to the semantics improves diagnostics emitted for the invalid
directives. X86 is taken as a sample to ensure that multiple diagnostics are
not presented for a single error.
llvm-svn: 199068
Targets like SPARC and MIPS have delay slots and normally bundle the
delay slot instruction with the corresponding terminator.
Teach isBlockOnlyReachableByFallthrough to find any MBB operands on
bundled terminators so SPARC doesn't need to specialize this function.
llvm-svn: 199061
This implements the legacy passes in terms of the new ones. It adds
basic testing using explicit runs of the passes. Next up will be wiring
the basic output mechanism of opt up when the new pass manager is
engaged unless bitcode writing is requested.
llvm-svn: 199049
API is exposed.
This removes the support for deleting the ostream, switches the member
and constructor order arround to be consistent with the creation
routines, and switches to using references.
llvm-svn: 199047
Nothing was using the ability of the pass to delete the raw_ostream it
printed to, and nothing was trying to pass it a pointer to the
raw_ostream. Also, the function variant had a different order of
arguments from all of the others which was just really confusing. Now
the interface accepts a reference, doesn't offer to delete it, and uses
a consistent order. The implementation of the printing passes haven't
been updated with this simplification, this is just the API switch.
llvm-svn: 199044
name to match the source file which I got earlier. Update the include
sites. Also modernize the comments in the header to use the more
recommended doxygen style.
llvm-svn: 199041
nests to the opt commandline support. This also showcases the
implicit-initial-manager support which will be most useful for testing.
There are several bugs that I spotted by inspection here that I'll fix
with test cases in subsequent commits.
llvm-svn: 199038
An improper qualifier would result in a superfluous error due to the parser not
consuming the remainder of the statement. Simply consume the remainder of the
statement to avoid the error.
llvm-svn: 199035
The implicit immediate 0 forms are assembly aliases, not distinct instruction
encodings. Fix the initial implementation introduced in r198914 to an alias to
avoid two separate instruction definitions for the same encoding.
An InstAlias is insufficient in this case as the necessary due to the need to
add a new additional operand for the implicit zero. By using the AsmPsuedoInst,
fall back to the C++ code to transform the instruction to the equivalent
_POST_IMM form, inserting the additional implicit immediate 0.
llvm-svn: 199032
This is different from the argument passing convention which puts the
first float argument in %f1.
With this patch, all returned floats are treated as if the 'inreg' flag
were set. This means multiple float return values get packed in %f0,
%f1, %f2, ...
Note that when returning a struct in registers, clang will set the
'inreg' flag on the return value, so that behavior is unchanged. This
also happens when returning a float _Complex.
llvm-svn: 199028
case when the lookup table doesn't have any holes.
This means we can build a lookup table for switches like this:
switch (x) {
case 0: return 1;
case 1: return 2;
case 2: return 3;
case 3: return 4;
default: exit(1);
}
The default case doesn't yield a constant result here, but that doesn't matter,
since a default result is only necessary for filling holes in the lookup table,
and this table doesn't have any holes.
This makes us transform 505 more switches in a clang bootstrap, and shaves 164 KB
off the resulting clang binary.
llvm-svn: 199025
A 32-bit immediate value can be formed from a constant expression and loaded
into a register. Add support to emit this into an object file. Because this
value is a constant, a relocation must *not* be produced for it.
llvm-svn: 199023
Chandler Carruth