In setInsertionPoint if the value is not a PHI, Instruction or
Argument it should be a Constant, not a ConstantExpr.
Original commit message:
[InstCombine] Look through PHIs, GEPs, IntToPtrs and PtrToInts to expose more constants when comparing GEPs
Summary:
When comparing two GEP instructions which have the same base pointer
and one of them has a constant index, it is possible to only compare
indices, transforming it to a compare with a constant. This removes
one use for the GEP instruction with the constant index, can reduce
register pressure and can sometimes lead to removing the comparisson
entirely.
InstCombine was already doing this when comparing two GEPs if the base
pointers were the same. However, in the case where we have complex
pointer arithmetic (GEPs applied to GEPs, PHIs of GEPs, conversions to
or from integers, etc) the value of the original base pointer will be
hidden to the optimizer and this transformation will be disabled.
This change detects when the two sides of the comparison can be
expressed as GEPs with the same base pointer, even if they don't
appear as such in the IR. The transformation will convert all the
pointer arithmetic to arithmetic done on indices and all the relevant
uses of GEPs to GEPs with a common base pointer. The GEP comparison
will be converted to a comparison done on indices.
Reviewers: majnemer, jmolloy
Subscribers: hfinkel, jevinskie, jmolloy, aadg, llvm-commits
Differential Revision: http://reviews.llvm.org/D15146
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@257164 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
When comparing two GEP instructions which have the same base pointer
and one of them has a constant index, it is possible to only compare
indices, transforming it to a compare with a constant. This removes
one use for the GEP instruction with the constant index, can reduce
register pressure and can sometimes lead to removing the comparisson
entirely.
InstCombine was already doing this when comparing two GEPs if the
base pointers were the same. However, in the case where we have
complex pointer arithmetic (GEPs applied to GEPs, PHIs of GEPs,
conversions to or from integers, etc) the value of the original
base pointer will be hidden to the optimizer and this transformation
will be disabled.
This change detects when the two sides of the comparison can be
expressed as GEPs with the same base pointer, even if they don't
appear as such in the IR. The transformation will convert all the
pointer arithmetic to arithmetic done on indices and all the
relevant uses of GEPs to GEPs with a common base pointer. The
GEP comparison will be converted to a comparison done on indices.
Reviewers: majnemer, jmolloy
Subscribers: hfinkel, jevinskie, jmolloy, aadg, llvm-commits
Differential Revision: http://reviews.llvm.org/D15146
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@257064 91177308-0d34-0410-b5e6-96231b3b80d8
Summary: This patch fixes a bug in prepareICWorklistFromFunction, where the loop becomes infinite with instructions of token type. The patch checks if the instruction is token type, and if so it updates EndInst with the current instruction.
Reviewers: reames, majnemer
Subscribers: llvm-commits, sanjoy
Differential Revision: http://reviews.llvm.org/D15859
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@256792 91177308-0d34-0410-b5e6-96231b3b80d8
a standalone pass.
There is no call graph or even interesting analysis for this part of
function attributes -- it is literally inferring attributes based on the
target library identification. As such, we can do it using a much
simpler module pass that just walks the declarations. This can also
happen much earlier in the pass pipeline which has benefits for any
number of other passes.
In the process, I've cleaned up one particular aspect of the logic which
was necessary in order to separate the two passes cleanly. It now counts
inferred attributes independently rather than just counting all the
inferred attributes as one, and the counts are more clearly explained.
The two test cases we had for this code path are both ... woefully
inadequate and copies of each other. I've kept the superset test and
updated it. We need more testing here, but I had to pick somewhere to
stop fixing everything broken I saw here.
Differential Revision: http://reviews.llvm.org/D15676
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@256466 91177308-0d34-0410-b5e6-96231b3b80d8
Summary: This patch changes gc.statepoint intrinsic's return type to token type instead of i32 type. Using token types could prevent LLVM to merge different gc.statepoint nodes into PHI nodes and cause further problems with gc relocations. The patch also changes the way on how gc.relocate and gc.result look for their corresponding gc.statepoint on unwind path. The current implementation uses the selector value extracted from a { i8*, i32 } landingpad as a hook to find the gc.statepoint, while the patch directly uses a token type landingpad (http://reviews.llvm.org/D15405) to find the gc.statepoint.
Reviewers: sanjoy, JosephTremoulet, pgavlin, igor-laevsky, mjacob
Subscribers: reames, mjacob, sanjoy, llvm-commits
Differential Revision: http://reviews.llvm.org/D15662
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@256443 91177308-0d34-0410-b5e6-96231b3b80d8
This is an extension of the shuffle combining from r203229:
http://reviews.llvm.org/rL203229
The idea is to widen a short input vector with undef elements so the
existing shuffle transform for extract/insert can kick in.
The motivation is to finally solve PR2109:
https://llvm.org/bugs/show_bug.cgi?id=2109
For that example, the IR becomes:
%1 = bitcast <2 x i32>* %P to <2 x float>*
%ld1 = load <2 x float>, <2 x float>* %1, align 8
%2 = shufflevector <2 x float> %ld1, <2 x float> undef, <4 x i32> <i32 0, i32 1, i32 undef, i32 undef>
%i2 = shufflevector <4 x float> %A, <4 x float> %2, <4 x i32> <i32 0, i32 1, i32 4, i32 5>
ret <4 x float> %i2
And x86 SSE output improves from:
movq (%rdi), %xmm1 ## xmm1 = mem[0],zero
movdqa %xmm1, %xmm2
shufps $229, %xmm2, %xmm2 ## xmm2 = xmm2[1,1,2,3]
shufps $48, %xmm0, %xmm1 ## xmm1 = xmm1[0,0],xmm0[3,0]
shufps $132, %xmm1, %xmm0 ## xmm0 = xmm0[0,1],xmm1[0,2]
shufps $32, %xmm0, %xmm2 ## xmm2 = xmm2[0,0],xmm0[2,0]
shufps $36, %xmm2, %xmm0 ## xmm0 = xmm0[0,1],xmm2[2,0]
retq
To the almost optimal:
movhpd (%rdi), %xmm0
Note: There's a tension in the existing transform related to generating
arbitrary shufflevector masks. We avoid that in other places in InstCombine
because we're scared that codegen can't handle strange masks, but it looks
like we're ok with producing those here. I purposely chose weird insert/extract
indexes for the regression tests to see the effect in these cases.
For PowerPC+Altivec, AArch64, and X86+SSE/AVX, I think the codegen is equal or
better for these examples.
Differential Revision: http://reviews.llvm.org/D15096
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@256394 91177308-0d34-0410-b5e6-96231b3b80d8
For non padded structs, we can just proceed and deaggregate them.
We don't want ot do this when there is padding in the struct as to not
lose information about this padding (the subsequents passes would then
try hard to preserve the padding, which is undesirable).
Also update extractvalue.ll and cast.ll so that they use structs with padding.
Remove the FIXME in the extractvalue of laod case as the non padded case is
handled when processing the load, and we don't want to do it on the padded
case.
Patch by: Amaury SECHET <deadalnix@gmail.com>
Differential Revision: http://reviews.llvm.org/D14483
From: Mehdi Amini <mehdi.amini@apple.com>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@255600 91177308-0d34-0410-b5e6-96231b3b80d8
This patch adds optional fast-math-flags (the same that apply to fmul/fadd/fsub/fdiv/frem/fcmp)
to call instructions in IR. Follow-up patches would use these flags in LibCallSimplifier, add
support to clang, and extend FMF to the DAG for calls.
Motivating example:
%y = fmul fast float %x, %x
%z = tail call float @sqrtf(float %y)
We'd like to be able to optimize sqrt(x*x) into fabs(x). We do this today using a function-wide
attribute for unsafe-math, but we really want to trigger on the instructions themselves:
%z = tail call fast float @sqrtf(float %y)
because in an LTO build it's possible that calls with fast semantics have been inlined into a
function with non-fast semantics.
The code changes and tests are based on the recent commits that added "notail":
http://reviews.llvm.org/rL252368
and added FMF to fcmp:
http://reviews.llvm.org/rL241901
Differential Revision: http://reviews.llvm.org/D14707
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@255555 91177308-0d34-0410-b5e6-96231b3b80d8
This change was discussed in D15392. It allows us to remove the fold that was added
in:
http://reviews.llvm.org/r255261
...and it will allow us to generalize this fold:
http://reviews.llvm.org/rL112232
while preserving the order of bitcast + extract that it produces and testing shows
is better handled by the backend.
Note that the existing check for "isVectorTy()" wasn't strong enough in general
and specifically because: x86_mmx. It's not a vector, but it's not vectorizable
either. So here we check VectorType::isValidElementType() directly before
proceeding with the transform.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@255433 91177308-0d34-0410-b5e6-96231b3b80d8
While we have successfully implemented a funclet-oriented EH scheme on
top of LLVM IR, our scheme has some notable deficiencies:
- catchendpad and cleanupendpad are necessary in the current design
but they are difficult to explain to others, even to seasoned LLVM
experts.
- catchendpad and cleanupendpad are optimization barriers. They cannot
be split and force all potentially throwing call-sites to be invokes.
This has a noticable effect on the quality of our code generation.
- catchpad, while similar in some aspects to invoke, is fairly awkward.
It is unsplittable, starts a funclet, and has control flow to other
funclets.
- The nesting relationship between funclets is currently a property of
control flow edges. Because of this, we are forced to carefully
analyze the flow graph to see if there might potentially exist illegal
nesting among funclets. While we have logic to clone funclets when
they are illegally nested, it would be nicer if we had a
representation which forbade them upfront.
Let's clean this up a bit by doing the following:
- Instead, make catchpad more like cleanuppad and landingpad: no control
flow, just a bunch of simple operands; catchpad would be splittable.
- Introduce catchswitch, a control flow instruction designed to model
the constraints of funclet oriented EH.
- Make funclet scoping explicit by having funclet instructions consume
the token produced by the funclet which contains them.
- Remove catchendpad and cleanupendpad. Their presence can be inferred
implicitly using coloring information.
N.B. The state numbering code for the CLR has been updated but the
veracity of it's output cannot be spoken for. An expert should take a
look to make sure the results are reasonable.
Reviewers: rnk, JosephTremoulet, andrew.w.kaylor
Differential Revision: http://reviews.llvm.org/D15139
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@255422 91177308-0d34-0410-b5e6-96231b3b80d8
MatchBSwap has most of the functionality to match bit reversals already. If we switch it from looking at bytes to individual bits and remove a few early exits, we can extend the main recursive function to match any sequence of ORs, ANDs and shifts that assemble a value from different parts of another, base value. Once we have this bit->bit mapping, we can very simply detect if it is appropriate for a bswap or bitreverse.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@255334 91177308-0d34-0410-b5e6-96231b3b80d8
This is a redo of r255137 (reverted at r255227) which was a redo of
r255124 (reverted at r255126) with a fixed check for a scalar source
type and an added test for the failure that caused the revert.
Original commit message:
Example:
bitcast (extractelement (bitcast <2 x float> %X to <2 x i32>), 1) to float
--->
extractelement <2 x float> %X, i32 1
This is part of fixing PR25543:
https://llvm.org/bugs/show_bug.cgi?id=25543
The next step will be to generalize this fold:
trunc ( lshr ( bitcast X) ) -> extractelement (X)
Ie, I'm hoping to replace the existing transform of:
bitcast ( trunc ( lshr ( bitcast X)))
added by:
http://reviews.llvm.org/rL112232
with 2 less specific transforms to catch the case in the bug report.
Differential Revision: http://reviews.llvm.org/D14879
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@255261 91177308-0d34-0410-b5e6-96231b3b80d8
This is a redo of r255124 (reverted at r255126) with an added check for a
scalar destination type and an added test for the failure seen in Clang's
test/CodeGen/vector.c. The extra test shows a different missing optimization.
Original commit message:
Example:
bitcast (extractelement (bitcast <2 x float> %X to <2 x i32>), 1) to float
--->
extractelement <2 x float> %X, i32 1
This is part of fixing PR25543:
https://llvm.org/bugs/show_bug.cgi?id=25543
The next step will be to generalize this fold:
trunc ( lshr ( bitcast X) ) -> extractelement (X)
Ie, I'm hoping to replace the existing transform of:
bitcast ( trunc ( lshr ( bitcast X)))
added by:
http://reviews.llvm.org/rL112232
with 2 less specific transforms to catch the case in the bug report.
Differential Revision: http://reviews.llvm.org/D14879
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@255137 91177308-0d34-0410-b5e6-96231b3b80d8
Example:
bitcast (extractelement (bitcast <2 x float> %X to <2 x i32>), 1) to float
--->
extractelement <2 x float> %X, i32 1
This is part of fixing PR25543:
https://llvm.org/bugs/show_bug.cgi?id=25543
The next step will be to generalize this fold:
trunc ( lshr ( bitcast X) ) -> extractelement (X)
Ie, I'm hoping to replace the existing transform of:
bitcast ( trunc ( lshr ( bitcast X)))
added by:
http://reviews.llvm.org/rL112232
with 2 less specific transforms to catch the case in the bug report.
Differential Revision: http://reviews.llvm.org/D14879
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@255124 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
There are `SelectPatternFlavor`s that don't represent min or max idioms,
and we should not be passing those to `getCmpPredicateForMinMax`.
Fixes PR25745.
Reviewers: majnemer
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D15249
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@254869 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
In order to avoid calling pow function we generate repeated fmul when n is a
positive or negative whole number.
For each exponent we pre-compute Addition Chains in order to minimize the no.
of fmuls.
Refer: http://wwwhomes.uni-bielefeld.de/achim/addition_chain.html
We pre-compute addition chains for exponents upto 32 (which results in a max of
7 fmuls).
For eg:
4 = 2+2
5 = 2+3
6 = 3+3 and so on
Hence,
pow(x, 4.0) ==> y = fmul x, x
x = fmul y, y
ret x
For negative exponents, we simply compute the reciprocal of the final result.
Note: This transformation is only enabled under fast-math.
Patch by Mandeep Singh Grang <mgrang@codeaurora.org>
Reviewers: weimingz, majnemer, escha, davide, scanon, joerg
Subscribers: probinson, escha, llvm-commits
Differential Revision: http://reviews.llvm.org/D13994
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@254776 91177308-0d34-0410-b5e6-96231b3b80d8
The compiler can take advantage of the allocation/deallocation
function's properties. We knew how to do this for Itanium but had no
support for MSVC-style functions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@254656 91177308-0d34-0410-b5e6-96231b3b80d8
This one is enabled only under -ffast-math. There are cases where the
difference between the value computed and the correct value is huge
even for ffast-math, e.g. as Steven pointed out:
x = -1, y = -4
log(pow(-1), 4) = 0
4*log(-1) = NaN
I checked what GCC does and apparently they do the same optimization
(which result in the dramatic difference). Future work might try to
make this (slightly) less worse.
Differential Revision: http://reviews.llvm.org/D14400
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We had two code paths. One would create names like "foo.1" and the other
names like "foo1".
For globals it is important to use "foo.1" to help C++ name demangling.
For locals there is no strong reason to go one way or the other so I
kept the most common mangling (foo1).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253804 91177308-0d34-0410-b5e6-96231b3b80d8
