[DAGCombine][X86][AArch64][MIPS][LANAI] (C - x) - y -> C - (x + y) fold (PR41952)

Summary:
This *might* be the last fold for `sink-addsub-of-const.ll`, but i'm not sure yet.

As far as i can tell,

[DAGCombine][X86][AArch64][MIPS][LANAI] (C - x) - y -> C - (x + y) fold (PR41952)

Summary:
This *might* be the last fold for `sink-addsub-of-const.ll`, but i'm not sure yet.

As far as i can tell, there are no regressions here (ignoring x86-32),
all changes are either good or neutral.

This, almost surprisingly to me, fixes the motivational tests (in `shift-amount-mod.ll`)
`@reg32_lshr_by_sub_from_negated` from [[ https://bugs.llvm.org/show_bug.cgi?id=41952 | PR41952 ]].

https://rise4fun.com/Alive/vMd3

Reviewers: RKSimon, t.p.northover, craig.topper, spatel, efriedma

Reviewed By: RKSimon

Subscribers: sdardis, javed.absar, arichardson, kristof.beyls, jrtc27, atanasyan, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62774

llvm-svn: 362488

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[mips] Always check that `shift and add` optimization is efficient.

The D45316 introduced the `shouldTransformMulToShiftsAddsSubs` function
to check that breaking down constant multiplications into

[mips] Always check that `shift and add` optimization is efficient.

The D45316 introduced the `shouldTransformMulToShiftsAddsSubs` function
to check that breaking down constant multiplications into a series
of shifts, adds, and subs is efficient. Unfortunately, this function
does not check maximum number of steps on all paths of the algorithm.
This patch fixes this bug.

Fix for PR41929.

Differential Revision: https://reviews.llvm.org/D62166

llvm-svn: 361606

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[DAGCombiner] Teach DAG combiner that A-(B-C) can be folded to A+(C-B)

This can be useful since addition is commutable, and subtraction is not.

This matches a transform that is also done by InstCom

[DAGCombiner] Teach DAG combiner that A-(B-C) can be folded to A+(C-B)

This can be useful since addition is commutable, and subtraction is not.

This matches a transform that is also done by InstCombine.

llvm-svn: 338181

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[mips] Materialize constants for multiplication

Previously, the MIPS backend would alwyas break down constant multiplications
into a series of shifts, adds, and subs. This patch changes that so the

[mips] Materialize constants for multiplication

Previously, the MIPS backend would alwyas break down constant multiplications
into a series of shifts, adds, and subs. This patch changes that so the cost of
doing so is estimated.

The cost is estimated against worst case constant materialization and retrieving
the results from the HI/LO registers.

For cases where the value type of the multiplication is not legal, the cost of
legalization is estimated and is accounted for before performing the
optimization of breaking down the constant

This resolves PR36884.

Thanks to npl for reporting the issue!

Reviewers: abeserminji, smaksimovic

Differential Revision: https://reviews.llvm.org/D45316

llvm-svn: 330037

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[mips] Regenerate test before posting patch for constant multiplication (NFC)

llvm-svn: 329268

[CodeGen] Always use `printReg` to print registers in both MIR and debug
output

As part of the unification of the debug format and the MIR format,
always use `printReg` to print all kinds of registe

[CodeGen] Always use `printReg` to print registers in both MIR and debug
output

As part of the unification of the debug format and the MIR format,
always use `printReg` to print all kinds of registers.

Updated the tests using '_' instead of '%noreg' until we decide which
one we want to be the default one.

Differential Revision: https://reviews.llvm.org/D40421

llvm-svn: 319445

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[mips] Improve genConstMult() to work with arbitrary precision

APInt is now used instead of uint64_t in function genConstMult() allowing
multiplication optimizations with constants of arbitrary leng

[mips] Improve genConstMult() to work with arbitrary precision

APInt is now used instead of uint64_t in function genConstMult() allowing
multiplication optimizations with constants of arbitrary length.

Patch by Milos Stojanovic.

Differential Revision: https://reviews.llvm.org/D38130

llvm-svn: 318296

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[mips] Use --check-prefixes where appropriate. NFC.

llvm-svn: 273669

[LLVM] Remove unwanted --check-prefix=CHECK from unit tests. NFC.

Summary: Removed unwanted --check-prefix=CHECK from numerous unit tests.

Reviewers: t.p.northover, dblaikie, uweigand, MatzeB, tste

[LLVM] Remove unwanted --check-prefix=CHECK from unit tests. NFC.

Summary: Removed unwanted --check-prefix=CHECK from numerous unit tests.

Reviewers: t.p.northover, dblaikie, uweigand, MatzeB, tstellarAMD, mcrosier

Subscribers: mcrosier, dsanders

Differential Revision: http://reviews.llvm.org/D19279

llvm-svn: 266834

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[mips] Promote i32 arguments to i64 for the N32/N64 ABI and fix <64-bit structs...

Summary:
... and after all that refactoring, it's possible to distinguish softfloat
floating point values from inte

[mips] Promote i32 arguments to i64 for the N32/N64 ABI and fix <64-bit structs...

Summary:
... and after all that refactoring, it's possible to distinguish softfloat
floating point values from integers so this patch no longer breaks softfloat to
do it.

Remove direct handling of i32's in the N32/N64 ABI by promoting them to
i64. This more closely reflects the ABI documentation and also fixes
problems with stack arguments on big-endian targets.

We now rely on signext/zeroext annotations (already generated by clang) and
the Assert[SZ]ext nodes to avoid the introduction of unnecessary sign/zero
extends.

It was not possible to convert three tests to use signext/zeroext. These tests
are bswap.ll, ctlz-v.ll, ctlz-v.ll. It's not possible to put signext on a
vector type so we just accept the sign extends here for now. These tests don't
pass the vectors the same way clang does (clang puts multiple elements in the
same argument, these map 1 element to 1 argument) so we don't need to worry too
much about it.

With this patch, all known N32/N64 bugs should be fixed and we now pass the
first 10,000 tests generated by ABITest.py.

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D6117

llvm-svn: 221534

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[mips] Make mips64 the default CPU for the mips64 architecture

Summary:
This is consistent with the integrated assembler.
All mips64 codegen tests previously passed -mcpu. Removed -mcpu from
blez_bg

[mips] Make mips64 the default CPU for the mips64 architecture

Summary:
This is consistent with the integrated assembler.
All mips64 codegen tests previously passed -mcpu. Removed -mcpu from
blez_bgez.ll and const-mult.ll to cover the default case.

Ideally, the two implementations of selectMipsCPU() will be merged but it's
proven difficult to find a home for the function that doesn't cause link errors.
For now, we'll hoist the common functionality into a function and mark it with
FIXME's.

Reviewers: jacksprat, matheusalmeida

Reviewed By: matheusalmeida

Differential Revision: http://llvm-reviews.chandlerc.com/D2830

llvm-svn: 201782

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[mips] Use multiple FileCheck prefixes rather than run the test multiple times

llvm-svn: 201695

Mass update to CodeGen tests to use CHECK-LABEL for labels corresponding to function definitions for more informative error messages. No functionality change and all updated tests passed locally.

Th

Mass update to CodeGen tests to use CHECK-LABEL for labels corresponding to function definitions for more informative error messages. No functionality change and all updated tests passed locally.

This update was done with the following bash script:

find test/CodeGen -name "*.ll" | \
while read NAME; do
echo "$NAME"
if ! grep -q "^; *RUN: *llc.*debug" $NAME; then
TEMP=`mktemp -t temp`
cp $NAME $TEMP
sed -n "s/^define [^@]*@\([A-Za-z0-9_]*\)(.*$/\1/p" < $NAME | \
while read FUNC; do
sed -i '' "s/;\(.*\)\([A-Za-z0-9_-]*\):\( *\)$FUNC: *\$/;\1\2-LABEL:\3$FUNC:/g" $TEMP
done
sed -i '' "s/;\(.*\)-LABEL-LABEL:/;\1-LABEL:/" $TEMP
sed -i '' "s/;\(.*\)-NEXT-LABEL:/;\1-NEXT:/" $TEMP
sed -i '' "s/;\(.*\)-NOT-LABEL:/;\1-NOT:/" $TEMP
sed -i '' "s/;\(.*\)-DAG-LABEL:/;\1-DAG:/" $TEMP
mv $TEMP $NAME
fi
done

llvm-svn: 186280

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[mips] Fix test case to check that mips64 instructions are generated.

llvm-svn: 185371

[mips] Improve code generation for constant multiplication using shifts, adds and
subs.

llvm-svn: 185011