The following code pattern:
mov %rax, %rcx
test %rax, %rax
%rax = ....
je throw_npe
mov(%rcx), %r9
mov(%rax), %r10
gets transformed into the following incorrect code after implicit null check pass:
mov %rax, %rcx
%rax = ....
faulting_load_op("movl (%rax), %r10", throw_npe)
mov(%rcx), %r9
For implicit null check pass, if the register that is checked for null value (ie, the register used in the 'test' instruction) is written into before the condition jump, we should avoid doing the optimization.
Patch by Surya Kumari Jangala!
Differential Revision: https://reviews.llvm.org/D48627
Reviewed By: skatkov
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@336241 91177308-0d34-0410-b5e6-96231b3b80d8
Now that D45806 has landed, we can re-enable support for MIN_SIGNED_VALUE in the sdiv by pow2-constant code
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@336198 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Replace use of a SmallPtrSet with a SmallSetVector to make the worklist
iteration order deterministic. This is done as the order the blocks are
removed may affect whether or not PHI nodes in successor blocks are
removed.
For example, consider the following case where %bb1 and %bb2 are
removed:
bb1:
br i1 undef, label %bb3, label %bb4
bb2:
br i1 undef, label %bb4, label %bb3
bb3:
pv1 = phi type [ undef, %bb1 ], [ undef, %bb2], [ v0, %other ]
br label %bb4
bb4:
pv2 = phi type [ undef, %bb1 ], [ undef, %bb2 ],
[ pv1, %bb3 ], [ v0, %other ]
If %bb2 is removed before %bb1, the incoming values from %bb1 and %bb2
to pv1 will be removed before %bb1 is removed as a predecessor to %bb4.
The pv1 node will thus be optimized out (to v0) at the time %bb1 is
removed as a predecessor to %bb4, leaving the blocks as following when
the incoming value from %bb1 has been removed:
bb3: ; pv1 optimized out, incoming value to pv2 is v0
br label %bb4
bb4:
pv2 = phi type [ v0, %bb3 ], [ v0, %other ]
The pv2 PHI node will be optimized away by removePredecessor() as all
incoming values are identical.
In case %bb2 is removed after %bb1, pv1 will not be optimized out at the
time %bb2 is removed as a predecessor to %bb4, leaving the blocks as
following when the incoming value from %bb2 to pv2 has been removed:
bb3:
pv1 = phi type [ undef, %bb2 ], [ v0, %other ]
br label %bb4
bb4:
pv2 = phi type [ pv1, %bb3 ], [ v0, %other ]
The pv2 PHI node will thus not be removed in this case, ultimately
leading to the following output
bb3: ; pv1 optimized out, incoming value to pv2 is v0
br label %bb4
bb4:
pv2 = phi type [ v0, %bb3 ], [ v0, %other ]
I have not looked into changing DeleteDeadBlock() so that the redundant
PHI nodes are removed.
I have not added a test case, as I was not able to create a particularly
small and (not messy) reproducer. This is likely due to SmallPtrSet
behaving deterministically when in small mode.
Reviewers: void, dexonsmith, spatel, skatkov, fhahn, bkramer, nhaehnle
Reviewed By: fhahn
Subscribers: mgrang, llvm-commits
Differential Revision: https://reviews.llvm.org/D48369
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@336109 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This patch introduce new intrinsic -
strip.invariant.group that was described in the
RFC: Devirtualization v2
Reviewers: rsmith, hfinkel, nlopes, sanjoy, amharc, kuhar
Subscribers: arsenm, nhaehnle, JDevlieghere, hiraditya, xbolva00, llvm-commits
Differential Revision: https://reviews.llvm.org/D47103
Co-authored-by: Krzysztof Pszeniczny <krzysztof.pszeniczny@gmail.com>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@336073 91177308-0d34-0410-b5e6-96231b3b80d8
The combine added in commit 329525 overlooked the case where one, but not all, of the divisor elements is -1, -1 is the only power of two value for which the sdiv expansion recipe breaks.
Thanks to @zvi for the original patch.
Differential Revision: https://reviews.llvm.org/D45806
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@336048 91177308-0d34-0410-b5e6-96231b3b80d8
This adds functionality to the outliner that allows targets to
specify certain functions that should be outlined from by default.
If a target supports default outlining, then it specifies that in
its TargetOptions. In the case that it does, and the user hasn't
specified that they *never* want to outline, the outliner will
be added to the pass pipeline and will run on those default functions.
This is a preliminary patch for turning the outliner on by default
under -Oz for AArch64.
https://reviews.llvm.org/D48776
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@336040 91177308-0d34-0410-b5e6-96231b3b80d8
This is a recommit of r335887, which was erroneously committed earlier.
To enable the MachineOutliner by default on AArch64, we need to be able to
disable the MachineOutliner and also provide an option to "always" enable the
outliner.
This adds that capability. It allows the user to still use the old
-enable-machine-outliner option, which defaults to "always". This is building
up to allowing the user to specify "always" versus the target default
outlining behaviour.
https://reviews.llvm.org/D48682
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335986 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
.debug_loc section is not supported for NVPTX target. If there is an
object whose location can change during its lifetime, we do not generate
debug location info for this variable.
Reviewers: echristo
Subscribers: jholewinski, JDevlieghere, llvm-commits
Differential Revision: https://reviews.llvm.org/D48730
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335976 91177308-0d34-0410-b5e6-96231b3b80d8
This is a recommit of r335879.
We shouldn't add the outliner when compiling at -O0 even if
-enable-machine-outliner is passed in. This makes sure that we
don't add it in this case.
This also removes -O0 from the outliner DWARF test.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335930 91177308-0d34-0410-b5e6-96231b3b80d8
This fixes a regression since SVN r334523, where the object files
built targeting MinGW were rejected by GNU binutils tools. Prior to
that commit, we only put constants in comdat for MSVC configurations.
Differential Revision: https://reviews.llvm.org/D48567
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335918 91177308-0d34-0410-b5e6-96231b3b80d8
Targets should be able to define whether or not they support the outliner
without the outliner being added to the pass pipeline. Before this, the
outliner pass would be added, and ask the target whether or not it supports the
outliner.
After this, it's possible to query the target in TargetPassConfig, before the
outliner pass is created. This ensures that passing -enable-machine-outliner
will not modify the pass pipeline of any target that does not support it.
https://reviews.llvm.org/D48683
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335887 91177308-0d34-0410-b5e6-96231b3b80d8
We could get away with it for constant folded cases, but not for rL335719.
Thanks to Krzysztof Parzyszek for noticing.
Reapply original commit rL335821 which was reverted at rL335871 due to a WebAssembly bug that was fixed at rL335884.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335886 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts commit 9c7c10e407.
It relies on r335872 since that introduces the machine outliner
flags test. I meant to commit D48683 in that commit, but got mixed
up and committed D48682 instead. So, I'm reverting this and
r335872, since D48682 hasn't made it through review yet.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335882 91177308-0d34-0410-b5e6-96231b3b80d8
We shouldn't add the outliner when compiling at -O0 even if
-enable-machine-outliner is passed in. This makes sure that we
don't add it in this case.
This also updates machine-outliner-flags to reflect the change
and improves the comment describing what that test does.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335879 91177308-0d34-0410-b5e6-96231b3b80d8
Add NoTrapAfterNoreturn target option which skips emission of traps
behind noreturn calls even if TrapUnreachable is enabled.
Enable the feature on Mach-O to save code size; Comments suggest it is
not possible to enable it for the other users of TrapUnreachable.
rdar://41530228
DifferentialRevision: https://reviews.llvm.org/D48674
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335877 91177308-0d34-0410-b5e6-96231b3b80d8
To enable the MachineOutliner by default on AArch64, we need to be able to
disable the MachineOutliner and also provide an option to "always" enable the
outliner.
This adds that capability. It allows the user to still use the old
-enable-machine-outliner option, which defaults to "always". This is building
up to allowing the user to specify "always" versus the target-default
outlining behaviour.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335872 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts commit r335821.
This crashes the webassembly test, run "ninja check-llvm-codegen-webassembly" to reproduce.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335871 91177308-0d34-0410-b5e6-96231b3b80d8
We could get away with it for constant folded cases, but not for rL335719.
Thanks to Krzysztof Parzyszek for noticing.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335821 91177308-0d34-0410-b5e6-96231b3b80d8
=== Generating the CG Profile ===
The CGProfile module pass simply gets the block profile count for each BB and scans for call instructions. For each call instruction it adds an edge from the current function to the called function with the current BB block profile count as the weight.
After scanning all the functions, it generates an appending module flag containing the data. The format looks like:
```
!llvm.module.flags = !{!0}
!0 = !{i32 5, !"CG Profile", !1}
!1 = !{!2, !3, !4} ; List of edges
!2 = !{void ()* @a, void ()* @b, i64 32} ; Edge from a to b with a weight of 32
!3 = !{void (i1)* @freq, void ()* @a, i64 11}
!4 = !{void (i1)* @freq, void ()* @b, i64 20}
```
Differential Revision: https://reviews.llvm.org/D48105
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335794 91177308-0d34-0410-b5e6-96231b3b80d8
Now that we have the ability to legalize based on MMO's. Add support for
legalizing based on AtomicOrdering and use it to correct the legalization
of the atomic instructions.
Also extend all() to be a variadic template as this ruleset now requires
3 and 4 argument versions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335767 91177308-0d34-0410-b5e6-96231b3b80d8
As noted in the D44909 review, the transform from (fptosi+sitofp) to ftrunc
can produce -0.0 where the original code does not:
#include <stdio.h>
int main(int argc) {
float x;
x = -0.8 * argc;
printf("%f\n", (float)((int)x));
return 0;
}
$ clang -O0 -mavx fp.c ; ./a.out
0.000000
$ clang -O1 -mavx fp.c ; ./a.out
-0.000000
Ideally, we'd use IR/node flags to predicate the transform, but the IR parser
doesn't currently allow fast-math-flags on the cast instructions. So for now,
just use the function attribute that corresponds to clang's "-fno-signed-zeros"
option.
Differential Revision: https://reviews.llvm.org/D48085
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335761 91177308-0d34-0410-b5e6-96231b3b80d8
Temporary fix until I've managed to get D45806 updated - both +1 and -1 special cases need to be properly supported.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335637 91177308-0d34-0410-b5e6-96231b3b80d8
It is legal for a PHI node not to have a live value in a predecessor
as long as the end of the predecessor is jointly dominated by an undef
value.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335607 91177308-0d34-0410-b5e6-96231b3b80d8
This removes debug locations from ConstantSDNode and ConstantSDFPNode.
When this kind of node is materialized we no longer create a line table
entry which jumps back to the constant's first point of use. This makes
single-stepping behavior smoother, and it matches the model used by IR,
where Constants have no locations. See this thread for more context:
http://lists.llvm.org/pipermail/llvm-dev/2018-June/124164.html
I'd like to handle constant BuildVectorSDNodes and to try to eliminate
passing SDLocs to SelectionDAG::getConstant*() in follow-up commits.
Differential Revision: https://reviews.llvm.org/D48468
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335497 91177308-0d34-0410-b5e6-96231b3b80d8
I thought I fixed this in r308673, but that fix was
very broken. The assumption that any frame index can be used
in place of another was more widespread than I realized.
Even when stack slot sharing was disabled, this was still
replacing frame index uses with a different ID with a different
stack slot.
Really fix this by doing the coloring per-stack ID, so all of
the coloring logically done in a separate namespace. This is a lot
simpler than trying to figure out how to change the color if
the stack ID is different.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335488 91177308-0d34-0410-b5e6-96231b3b80d8
This patch has the same motivating example as D48466:
define void @foo(i64 %x, i32 %c.0282.in, i32 %d.0280, i32* %ptr0, i32* %ptr1) {
%c.0282 = and i32 %c.0282.in, 268435455
%a16 = lshr i64 32508, %x
%a17 = and i64 %a16, 1
%tobool = icmp eq i64 %a17, 0
%. = select i1 %tobool, i32 1, i32 2
%.286 = select i1 %tobool, i32 27, i32 26
%shr97 = lshr i32 %c.0282, %.
%shl98 = shl i32 %c.0282.in, %.286
%or99 = or i32 %shr97, %shl98
%shr100 = lshr i32 %d.0280, %.
%shl101 = shl i32 %d.0280, %.286
%or102 = or i32 %shr100, %shl101
store i32 %or99, i32* %ptr0
store i32 %or102, i32* %ptr1
ret void
}
...but I'm trying to kill the setcc bool math sooner rather than later.
By matching a larger pattern that includes both the low-bit mask and the trailing add/sub,
we can create a universally good fold because we always eliminate the condition code
intermediate value.
Here are Alive proofs for these (currently instcombine folds the 'add' variants, but
misses the 'sub' patterns):
https://rise4fun.com/Alive/Gsyp
Name: sub of zext cmp mask
%a = and i8 %x, 1
%c = icmp eq i8 %a, 0
%z = zext i1 %c to i32
%r = sub i32 C1, %z
=>
%optional_cast = zext i8 %a to i32
%r = add i32 %optional_cast, C1-1
Name: add of zext cmp mask
%a = and i32 %x, 1
%c = icmp eq i32 %a, 0
%z = zext i1 %c to i8
%r = add i8 %z, C1
=>
%optional_cast = trunc i32 %a to i8
%r = sub i8 C1+1, %optional_cast
All of the tests look like improvements or neutral to me. But it is possible that x86
test+set+bitop is better than what we now show here. I suspect we could do better by
adding another fold for the 'sub' variants.
We start with select-of-constant in IR in the larger motivating test, so that's why I
included tests with selects. Proofs for those variants:
https://rise4fun.com/Alive/Bx1
Name: true const is bigger
Pre: C2 == (C1 + 1)
%a = and i8 %x, 1
%c = icmp eq i8 %a, 0
%r = select i1 %c, i64 C2, i64 C1
=>
%z = zext i8 %a to i64
%r = sub i64 C2, %z
Name: false const is bigger
Pre: C2 == (C1 + 1)
%a = and i8 %x, 1
%c = icmp eq i8 %a, 0
%r = select i1 %c, i64 C1, i64 C2
=>
%z = zext i8 %a to i64
%r = add i64 C1, %z
Differential Revision: https://reviews.llvm.org/D48466
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335433 91177308-0d34-0410-b5e6-96231b3b80d8
With compilation fix.
Original commit message:
D39788 added a '.stack-size' section containing metadata on function stack sizes
to output ELF files behind the new -stack-size-section flag.
This change does following two things on top:
1) Imagine the case when there are -ffunction-sections flag given and there are text sections in COMDATs.
The patch adds a '.stack-size' section into corresponding COMDAT group, so that linker will be able to
eliminate them fast during resolving the COMDATs.
2) Patch sets a SHF_LINK_ORDER flag and links '.stack-size' with the corresponding .text.
With that linker will be able to do -gc-sections on dead stack sizes sections.
Differential revision: https://reviews.llvm.org/D46874
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335336 91177308-0d34-0410-b5e6-96231b3b80d8
D39788 added a '.stack-size' section containing metadata on function stack sizes
to output ELF files behind the new -stack-size-section flag.
This change does following two things on top:
1) Imagine the case when there are -ffunction-sections flag given and there are text sections in COMDATs.
The patch adds a '.stack-size' section into corresponding COMDAT group, so that linker will be able to
eliminate them fast during resolving the COMDATs.
2) Patch sets a SHF_LINK_ORDER flag and links '.stack-size' with the corresponding .text.
With that linker will be able to do -gc-sections on dead stack sizes sections.
Differential revision: https://reviews.llvm.org/D46874
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335332 91177308-0d34-0410-b5e6-96231b3b80d8
This is the first pass in the main pipeline to use the legacy PM's
ability to run function analyses "on demand". Unfortunately, it turns
out there are bugs in that somewhat-hacky approach. At the very least,
it leaks memory and doesn't support -debug-pass=Structure. Unclear if
there are larger issues or not, but this should get the sanitizer bots
back to green by fixing the memory leaks.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335320 91177308-0d34-0410-b5e6-96231b3b80d8
This patch adds support for generating a call graph profile from Branch Frequency Info.
The CGProfile module pass simply gets the block profile count for each BB and scans for call instructions. For each call instruction it adds an edge from the current function to the called function with the current BB block profile count as the weight.
After scanning all the functions, it generates an appending module flag containing the data. The format looks like:
!llvm.module.flags = !{!0}
!0 = !{i32 5, !"CG Profile", !1}
!1 = !{!2, !3, !4} ; List of edges
!2 = !{void ()* @a, void ()* @b, i64 32} ; Edge from a to b with a weight of 32
!3 = !{void (i1)* @freq, void ()* @a, i64 11}
!4 = !{void (i1)* @freq, void ()* @b, i64 20}
Differential Revision: https://reviews.llvm.org/D48105
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335306 91177308-0d34-0410-b5e6-96231b3b80d8
