the IR going into it and to clean up the IR produced by the vectorizers.
Note that these are *off by default* right now while folks collect data
on whether the performance tradeoff is reasonable.
In a build of the 'opt' binary, I see about 2% compile time regression
due to this change on average. This is in my mind essentially the worst
expected case: very little of the opt binary is going to *benefit* from
these extra passes.
I've seen several benchmarks improve in performance my small amounts due
to running these passes, and there are certain (rare) cases where these
passes make a huge difference by either enabling the vectorizer at all
or by hoisting runtime checks out of the outer loop. My primary
motivation is to prevent people from seeing runtime check overhead in
benchmarks where the existing passes and optimizers would be able to
eliminate that.
I've chosen the sequence of passes based on the kinds of things that
seem likely to be relevant for the code at each stage: rotaing loops for
the vectorizer, finding correlated values, loop invariants, and
unswitching opportunities from any runtime checks, and cleaning up
commonalities exposed by the SLP vectorizer.
I'll be pinging existing threads where some of these issues have come up
and will start new threads to get folks to benchmark and collect data on
whether this is the right tradeoff or we should do something else.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219644 91177308-0d34-0410-b5e6-96231b3b80d8
This goes with the earlier commit to remove the static destructor from ManagedStatic.cpp by controlling the allocation and de-allocation of the mutex.
Summary: This is part of the ongoing work to remove static constructors and destructors.
Reviewers: chandlerc, rnk
Reviewed By: rnk
Subscribers: rnk, llvm-commits
Differential Revision: http://reviews.llvm.org/D5473
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219640 91177308-0d34-0410-b5e6-96231b3b80d8
We assumed that negation operations of the form (0 - %Z) resulted in a
negative number. This isn't true if %Z was originally negative.
Substituting the negative number into the remainder operation may result
in undefined behavior because the dividend might be INT_MIN.
This fixes PR21256.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219639 91177308-0d34-0410-b5e6-96231b3b80d8
This patch adds a new llvm_call_once function which is used by the ManagedStatic implementation to safely initialize a global to avoid static construction and destruction.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219638 91177308-0d34-0410-b5e6-96231b3b80d8
We have a transform that changes:
(x lshr C1) udiv C2
into:
x udiv (C2 << C1)
However, it is unsafe to do so if C2 << C1 discards any of C2's bits.
This fixes PR21255.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219634 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Make Mips fast-isel track the form of AArch64 where practical.
This makes it easier for people to review the code, to borrow similar code, and to see how to eventually move a lot of this
target code for fast-isels into target independent code.
These are just cosmetic changes. Should be no functional difference.
Test Plan:
make check
test-suite for 4 flavors mips32 r1/r2 , -O0/-O2
Reviewers: dsanders
Reviewed By: dsanders
Subscribers: aemerson, llvm-commits, rfuhler
Differential Revision: http://reviews.llvm.org/D5595
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219633 91177308-0d34-0410-b5e6-96231b3b80d8
Broken parent scope pointers in inlined DIVariables can cause
ensureAbstractVariableIsCreated to insert new abstract scopes, thus
invalidating the iterator in this loop and leading to hard-to-debug
crashes. Useful when manually reducing IR for testcases.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219628 91177308-0d34-0410-b5e6-96231b3b80d8
Some early revisions of the Cortex-A53 have an erratum (835769) whereby it is
possible for a 64-bit multiply-accumulate instruction in AArch64 state to
generate an incorrect result. The details are quite complex and hard to
determine statically, since branches in the code may exist in some
circumstances, but all cases end with a memory (load, store, or prefetch)
instruction followed immediately by the multiply-accumulate operation.
The safest work-around for this issue is to make the compiler avoid emitting
multiply-accumulate instructions immediately after memory instructions and the
simplest way to do this is to insert a NOP.
This patch implements such work-around in the backend, enabled via the option
-aarch64-fix-cortex-a53-835769.
The work-around code generation is not enabled by default.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219603 91177308-0d34-0410-b5e6-96231b3b80d8
has been modular since r206822, and excluding it was leading to workarounds
such as the one in r219592, which this change removes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219593 91177308-0d34-0410-b5e6-96231b3b80d8
This patch improves support for commutative instructions in the x86 memory folding implementation by attempting to fold a commuted version of the instruction if the original folding fails - if that folding fails as well the instruction is 're-commuted' back to its original order before returning.
This mainly helps the stack inliner better fold reloads of 3 (or more) operand instructions (VEX encoded SSE etc.) but by performing this in the lowest foldMemoryOperandImpl implementation it also replaces the X86InstrInfo::optimizeLoadInstr version and is now used by FastISel too.
Differential Revision: http://reviews.llvm.org/D5701
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219584 91177308-0d34-0410-b5e6-96231b3b80d8
A helper routine, MultiplyOverflows, was a less efficient
reimplementation of APInt's smul_ov and umul_ov. While we are here,
clean up the code so it's more uniform.
No functionality change intended.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219583 91177308-0d34-0410-b5e6-96231b3b80d8
On x86_64 this brings it from 80 bytes to 64 bytes. Also make any member
variables private and clean up uses to go through the existing accessors.
NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219573 91177308-0d34-0410-b5e6-96231b3b80d8
Consider the case where X is 2. (2 <<s 31)/s-2147483648 is zero but we
would fold to X. Note that this is valid when we are in the unsigned
domain because we require NUW: 2 <<u 31 results in poison.
This fixes PR21245.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219568 91177308-0d34-0410-b5e6-96231b3b80d8
consider:
C1 = INT_MIN
C2 = -1
C1 * C2 overflows without a doubt but consider the following:
%x = i32 INT_MIN
This means that (%X /s C1) is 1 and (%X /s C1) /s C2 is -1.
N. B. Move the unsigned version of this transform to InstSimplify, it
doesn't create any new instructions.
This fixes PR21243.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219567 91177308-0d34-0410-b5e6-96231b3b80d8
consider:
mul i32 nsw %x, -2147483648
this instruction will not result in poison if %x is 1
however, if we transform this into:
shl i32 nsw %x, 31
then we will be generating poison because we just shifted into the sign
bit.
This fixes PR21242.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219566 91177308-0d34-0410-b5e6-96231b3b80d8
getSmallConstantTripCount even when it isn't the exiting block.
I missed this in my first audit, very sorry. This was found in LNT and
elsewhere. I don't have a test case, but it was completely obvious from
inspection that this was the problem. I'll see if I can reduce a test
case, but I'm not really hopeful, and the value seems quite low.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219562 91177308-0d34-0410-b5e6-96231b3b80d8
Summary: Implement the most basic form of conditional branches in Mips fast-isel.
Test Plan:
br1.ll
run 4 flavors of test-suite. mips32 r1/r2 and at -O0/O2
Reviewers: dsanders
Reviewed By: dsanders
Subscribers: llvm-commits, rfuhler
Differential Revision: http://reviews.llvm.org/D5583
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219556 91177308-0d34-0410-b5e6-96231b3b80d8
routines and fix all of the bugs they expose.
I hit a test case that crashed even without these asserts due to passing
a non-exiting latch to the ExitingBlock parameter of the trip count
computation machinery. However, when I add the nice asserts, it turns
out we have plenty of coverage of these bugs, they just didn't manifest
in crashers.
The core problem seems to stem from an assumption that the latch *is*
the exiting block. While this is often true, and somewhat the "normal"
way to think about loops, it isn't necessarily true. The correct way to
call the trip count routines in a *generic* fashion (that is, without
a particular exit in mind) is to just use the loop's single exiting
block if it has one. The trip count can't be computed generically unless
it does. This works great for the loop vectorizer. The loop unroller
actually *wants* to select the latch when it has to chose between
multiple exits because for unrolling it is the latch trips that matter.
But if this is the desire, it needs to explicitly guard for non-exiting
latches and check for the generic trip count in that case.
I've added the asserts, and added convenience APIs for querying the trip
count generically that check for a single exit block. I've kept the APIs
consistent between computing trip count and trip multiples.
Thansk to Mark for the help debugging and tracking down the *right* fix
here!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219550 91177308-0d34-0410-b5e6-96231b3b80d8
The LLVM Lang Ref states for signed/unsigned int to float conversions:
"If the value cannot fit in the floating point value, the results are undefined."
And for FP to signed/unsigned int:
"If the value cannot fit in ty2, the results are undefined."
This matches the C definitions.
The existing behavior pins to infinity or a max int value, but that may just
lead to more confusion as seen in:
http://llvm.org/bugs/show_bug.cgi?id=21130
Returning undef will hopefully lead to a less silent failure.
Differential Revision: http://reviews.llvm.org/D5603
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219542 91177308-0d34-0410-b5e6-96231b3b80d8
1) Explicitly provide important arguments to llvm-symbolizer,
not relying on defaults.
2) Be more defensive about symbolizer output.
This might fix weird failures on ninja-x64-msvc-RA-centos6 buildbot.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219541 91177308-0d34-0410-b5e6-96231b3b80d8
