[DAGCombiner][X86][ARM] Teach visitMULO to fold multiplies with 0 to 0 and no carry.

I modified the ARM test to use two inputs instead of 0 so the
test hopefully still tests what was intended.

llvm

[DAGCombiner][X86][ARM] Teach visitMULO to fold multiplies with 0 to 0 and no carry.

I modified the ARM test to use two inputs instead of 0 so the
test hopefully still tests what was intended.

llvm-svn: 371344

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[ARM] Favour PL/MI over GE/LT when possible

The arm condition codes for GE is N==V (and for LT is N!=V). If the source of
flags cannot set V (overflow), such as a cmp against #0, then we can use the

[ARM] Favour PL/MI over GE/LT when possible

The arm condition codes for GE is N==V (and for LT is N!=V). If the source of
flags cannot set V (overflow), such as a cmp against #0, then we can use the
simpler PL and MI conditions that only check N. As these PL/MI conditions are
simpler than GE/LT, other passes like the peephole optimiser can have a better
time optimising away the redundant CMPs.

The exception is the VSEL instruction, which cannot take the PL code, so there
the transform favours GE.

Differential Revision: https://reviews.llvm.org/D64160

llvm-svn: 365117

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ARM: use target-specific SUBS node when combining cmp with cmov.

This has two positive effects. First, using a custom node prevents
recombination leading to an infinite loop since the output DAG is

ARM: use target-specific SUBS node when combining cmp with cmov.

This has two positive effects. First, using a custom node prevents
recombination leading to an infinite loop since the output DAG is notionally a
little more complex than the input one. Using a flag-setting instruction also
allows the subtraction to be folded with the related comparison more easily.

https://reviews.llvm.org/D53190

llvm-svn: 348122

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[SchedModel] Fix for read advance cycles with implicit pseudo operands.

The SchedModel allows the addition of ReadAdvances to express that certain
operands of the instructions are needed at a later

[SchedModel] Fix for read advance cycles with implicit pseudo operands.

The SchedModel allows the addition of ReadAdvances to express that certain
operands of the instructions are needed at a later point than the others.

RegAlloc may add pseudo operands that are not part of the instruction
descriptor, and therefore cannot have any read advance entries. This meant
that in some cases the desired read advance was nullified by such a pseudo
operand, which still had the original latency.

This patch fixes this by making sure that such pseudo operands get a zero
latency during DAG construction.

Review: Matthias Braun, Ulrich Weigand.
https://reviews.llvm.org/D49671

llvm-svn: 345606

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Revert "[ARM] Lower lower saturate to 0 and lower saturate to -1 using bit-operations"

Miscompiles code. Testcase pending.

This reverts commit r323869.

llvm-svn: 323929

[ARM] Lower lower saturate to 0 and lower saturate to -1 using bit-operations

Summary:
Expressions of the form x < 0 ? 0 : x; and x < -1 ? -1 : x can be lowered using bit-operations instead of bran

[ARM] Lower lower saturate to 0 and lower saturate to -1 using bit-operations

Summary:
Expressions of the form x < 0 ? 0 : x; and x < -1 ? -1 : x can be lowered using bit-operations instead of branching or conditional moves

In thumb-mode this results in a two-instruction sequence, a shift followed by a bic or or while in ARM/thumb2 mode that has flexible second operand the shift can be folded into a single bic/or instructions. In most cases this results in smaller code and possibly less branches, and in no case larger than before.

Patch by Marten Svanfeldt.

Reviewers: fhahn, pbarrio

Reviewed By: pbarrio

Subscribers: efriedma, rogfer01, aemerson, javed.absar, kristof.beyls, llvm-commits

Differential Revision: https://reviews.llvm.org/D42574

llvm-svn: 323869

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ARM: fixup more tests to specify the target more explicitly

This changes the tests that were targeting ARM EABI to explicitly specify the
environment rather than relying on the default. This breaks

ARM: fixup more tests to specify the target more explicitly

This changes the tests that were targeting ARM EABI to explicitly specify the
environment rather than relying on the default. This breaks with the new
Windows on ARM support when running the tests on Windows where the default
environment is no longer EABI.

Take the opportunity to avoid a pointless redirect (helps when trying to debug
with providing a command line invocation which can be copy and pasted) and
removing a few greps in favour of FileCheck.

llvm-svn: 205541

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Revert "Tests: Be less dependent on a specific schedule/regalloc"

This reverts r192454

Apparently FileCheck isn't as smart as I though and does not enforce a
topological order between variable defs

Revert "Tests: Be less dependent on a specific schedule/regalloc"

This reverts r192454

Apparently FileCheck isn't as smart as I though and does not enforce a
topological order between variable defs+uses.

llvm-svn: 192472

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Tests: Be less dependent on a specific schedule/regalloc

llvm-svn: 192454

Tests: Use CHECK-LABEL where possible

llvm-svn: 192403

ARM: use TableGen patterns to select CMOV operations.

Back in the mists of time (2008), it seems TableGen couldn't handle the
patterns necessary to match ARM's CMOV node that we convert select opera

ARM: use TableGen patterns to select CMOV operations.

Back in the mists of time (2008), it seems TableGen couldn't handle the
patterns necessary to match ARM's CMOV node that we convert select operations
to, so we wrote a lot of fairly hairy C++ to do it for us.

TableGen can deal with it now: there were a few minor differences to CodeGen
(see tests), but nothing obviously worse that I could see, so we should
probably address anything that *does* come up in a localised manner.

llvm-svn: 188995

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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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Use predication instead of pseudo-opcodes when folding into MOVCC.

Now that it is possible to dynamically tie MachineInstr operands,
predicated instructions are possible in SSA form:

%vreg3<def>

Use predication instead of pseudo-opcodes when folding into MOVCC.

Now that it is possible to dynamically tie MachineInstr operands,
predicated instructions are possible in SSA form:

%vreg3<def> = SUBri %vreg1, -2147483647, pred:14, pred:%noreg, %opt:%noreg
%vreg4<def,tied1> = MOVCCr %vreg3<tied0>, %vreg1, %pred:12, pred:%CPSR

Becomes a predicated SUBri with a tied imp-use:

SUBri %vreg1, -2147483647, pred:13, pred:%CPSR, opt:%noreg, %vreg1<imp-use,tied0>

This means that any instruction that is safe to move can be folded into
a MOVCC, and the *CC pseudo-instructions are no longer needed.

The test case changes reflect that Thumb2SizeReduce recognizes the
predicated instructions. It didn't understand the pseudos.

llvm-svn: 163274

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Add ADD and SUB to the predicable ARM instructions.

It is not my plan to duplicate the entire ARM instruction set with
predicated versions. We need a way of representing predicated
instructions in S

Add ADD and SUB to the predicable ARM instructions.

It is not my plan to duplicate the entire ARM instruction set with
predicated versions. We need a way of representing predicated
instructions in SSA form without requiring a separate opcode.

Then the pseudo-instructions can go away.

llvm-svn: 162061

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Teach the DAG combiner to turn sitofp/uitofp from i1 into a conditional move, since there are only two possible values.
Previously, this would become an integer extension operation, followed by a rea

Teach the DAG combiner to turn sitofp/uitofp from i1 into a conditional move, since there are only two possible values.
Previously, this would become an integer extension operation, followed by a real integer->float conversion.

llvm-svn: 159957

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Allocate virtual registers in ascending order.

This is just the fallback tie-breaker ordering, the main allocation
order is still descending size.

Patch by Shamil Kurmangaleev!

llvm-svn: 153904

Fix SimplifySelectCC to add newly created nodes to the DAGCombiner
worklist, as it may be possible to perform further optimization on them.

llvm-svn: 140349

Thumb assembly parsing and encoding for ADR.

llvm-svn: 137864

Fix a compiler crash where a Glue value had multiple uses. Radar 9049552.

llvm-svn: 127198

These tests are looking for library function names that
appear to differ on Linux. Try to make them pass on Linux.
Would be good for a Linux person to review this.

llvm-svn: 119572

- Add TargetInstrInfo::getOperandLatency() to compute operand latencies. This
allow target to correctly compute latency for cases where static scheduling
itineraries isn't sufficient. e.g. variab

- Add TargetInstrInfo::getOperandLatency() to compute operand latencies. This
allow target to correctly compute latency for cases where static scheduling
itineraries isn't sufficient. e.g. variable_ops instructions such as
ARM::ldm.
This also allows target without scheduling itineraries to compute operand
latencies. e.g. X86 can return (approximated) latencies for high latency
instructions such as division.
- Compute operand latencies for those defined by load multiple instructions,
e.g. ldm and those used by store multiple instructions, e.g. stm.

llvm-svn: 115755

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Consider this code snippet:

float t1(int argc) {
return (argc == 1123) ? 1.234f : 2.38213f;
}

We would generate truly awful code on ARM (those with a weak stomach should look
away):

_t1:
movw

Consider this code snippet:

float t1(int argc) {
return (argc == 1123) ? 1.234f : 2.38213f;
}

We would generate truly awful code on ARM (those with a weak stomach should look
away):

_t1:
movw r1, #1123
movs r2, #1
movs r3, #0
cmp r0, r1
mov.w r0, #0
it eq
moveq r0, r2
movs r1, #4
cmp r0, #0
it ne
movne r3, r1
adr r0, #LCPI1_0
ldr r0, [r0, r3]
bx lr

The problem was that legalization was creating a cascade of SELECT_CC nodes, for
for the comparison of "argc == 1123" which was fed into a SELECT node for the ?:
statement which was itself converted to a SELECT_CC node. This is because the
ARM back-end doesn't have custom lowering for SELECT nodes, so it used the
default "Expand".

I added a fairly simple "LowerSELECT" to the ARM back-end. It takes care of this
testcase, but can obviously be expanded to include more cases.

Now we generate this, which looks optimal to me:

_t1:
movw r1, #1123
movs r2, #0
cmp r0, r1
adr r0, #LCPI0_0
it eq
moveq r2, #4
ldr r0, [r0, r2]
bx lr
.align 2
LCPI0_0:
.long 1075344593 @ float 2.382130e+00
.long 1067316150 @ float 1.234000e+00

llvm-svn: 110799

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Use Unified Assembly Syntax for the ARM backend.

llvm-svn: 86494

Convert some ARM tests with lots of greps to use FileCheck.

llvm-svn: 83651

Eliminate more uses of llvm-as and llvm-dis.

llvm-svn: 81293