[RA] Split a virtual register in cold blocks if it is not assigned preferred physical register

If a virtual register is not assigned preferred physical register, it means some
COPY instructions will

[RA] Split a virtual register in cold blocks if it is not assigned preferred physical register

If a virtual register is not assigned preferred physical register, it means some
COPY instructions will be changed to real register move instructions. In this
case we can try to split the virtual register in colder blocks, if success, the
original COPY instructions can be deleted, and the new COPY instructions in
colder blocks will be generated as register move instructions. It results in
fewer dynamic register move instructions executed.

The new test case split-reg-with-hint.ll gives an example, the hot path contains
24 instructions without this patch, now it is only 4 instructions with this
patch.

Differential Revision: https://reviews.llvm.org/D156491

show more ...

ARM: use divmod libcalls on embedded MachO platforms too.

The separated libcalls are implemented in terms of __divmodsi4 and __udivmodsi4
anyway, so we should always use them if possible.

llvm-svn:

ARM: use divmod libcalls on embedded MachO platforms too.

The separated libcalls are implemented in terms of __divmodsi4 and __udivmodsi4
anyway, so we should always use them if possible.

llvm-svn: 302462

show more ...

[ARM] Reapply: Use __rt_div functions for divrem on Windows

Reapplying r283383 after revert in r283442. The additional fix
is a getting rid of a stray space in a function name, in the
refactoring pa

[ARM] Reapply: Use __rt_div functions for divrem on Windows

Reapplying r283383 after revert in r283442. The additional fix
is a getting rid of a stray space in a function name, in the
refactoring part of the commit.

This avoids falling back to calling out to the GCC rem functions
(__moddi3, __umoddi3) when targeting Windows.

The __rt_div functions have flipped the two arguments compared
to the __aeabi_divmod functions. To match MSVC, we emit a
check for division by zero before actually calling the library
function (even if the library function itself also might do
the same check).

Not all calls to __rt_div functions for division are currently
merged with calls to the same function with the same parameters
for the remainder. This is more wasteful than a div + mls as before,
but avoids calls to __moddi3.

Differential Revision: https://reviews.llvm.org/D25332

llvm-svn: 283550

show more ...

Revert "[ARM] Use __rt_div functions for divrem on Windows"

This reverts commit r283383 because it broke some of the bots:
undefined reference to ` __aeabi_uldivmod'

It affected (at least) clang-cm

Revert "[ARM] Use __rt_div functions for divrem on Windows"

This reverts commit r283383 because it broke some of the bots:
undefined reference to ` __aeabi_uldivmod'

It affected (at least) clang-cmake-armv7-a15-selfhost,
clang-cmake-armv7-a15-selfhost and clang-native-arm-lnt.

llvm-svn: 283442

show more ...

[ARM] Use __rt_div functions for divrem on Windows

This avoids falling back to calling out to the GCC rem functions
(__moddi3, __umoddi3) when targeting Windows.

The __rt_div functions have flipped

[ARM] Use __rt_div functions for divrem on Windows

This avoids falling back to calling out to the GCC rem functions
(__moddi3, __umoddi3) when targeting Windows.

The __rt_div functions have flipped the two arguments compared
to the __aeabi_divmod functions. To match MSVC, we emit a
check for division by zero before actually calling the library
function (even if the library function itself also might do
the same check).

Not all calls to __rt_div functions for division are currently
merged with calls to the same function with the same parameters
for the remainder. This is more wasteful than a div + mls as before,
but avoids calls to __moddi3.

Differential Revision: https://reviews.llvm.org/D24076

llvm-svn: 283383

show more ...

[ARM] Honour ABI for rem under -O0 for EABI, GNUEABI, Android and Musl

At higher optimization levels, we generate the libcall for DIVREM_Ix, which is
fine: aeabi_{u|i}divmod. At -O0 we generate the

[ARM] Honour ABI for rem under -O0 for EABI, GNUEABI, Android and Musl

At higher optimization levels, we generate the libcall for DIVREM_Ix, which is
fine: aeabi_{u|i}divmod. At -O0 we generate the one for REM_Ix, which is the
default {u}mod{q|h|s|d}i3.

This commit makes sure that we don't generate REM_Ix calls for ABIs that
don't support them (i.e. where we need to use DIVREM_Ix instead). This is
achieved by bailing out of FastISel, which can't handle non-double multi-reg
returns, and letting the legalization infrastructure expand the REM_Ix calls.

It also updates the divmod-eabi.ll test to run under -O0 as well, and adds some
Windows checks to it to make sure we don't break things for it.

Fixes PR27068

Differential Revision: https://reviews.llvm.org/D21926

llvm-svn: 275773

show more ...

Add support for musl-libc on ARM Linux.

Patch by Lei Zhang!

llvm-svn: 273726

[ARM] Merging 64-bit divmod lib calls into one

When div+rem calls on the same arguments are found, the ARM back-end merges the
two calls into one __aeabi_divmod call for up to 32-bits values. Howeve

[ARM] Merging 64-bit divmod lib calls into one

When div+rem calls on the same arguments are found, the ARM back-end merges the
two calls into one __aeabi_divmod call for up to 32-bits values. However,
for 64-bit values, which also have a lib call (__aeabi_ldivmod), it wasn't
merging the calls, and thus calling ldivmod twice and spilling the temporary
results, which generated pretty bad code.

This patch legalises 64-bit lib calls for divmod, so that now all the spilling
and the second call are gone. It also relaxes the DivRem combiner a bit on the
legal type check, since it was already checking for isLegalOrCustom on every
value, so the extra check for isTypeLegal was redundant.

Second attempt, creating TLI.isOperationCustom like isOperationExpand, to make
sure we only emit valid types or the ones that were explicitly marked as custom.
Now, passing check-all and test-suite on x86, ARM and AArch64.

This patch fixes PR17193 (and a long time FIXME in the tests).

llvm-svn: 262738

show more ...

Revert "[ARM] Merging 64-bit divmod lib calls into one"

This reverts commit r262507, which broke some ARM buildbots.

llvm-svn: 262594

[ARM] Merging 64-bit divmod lib calls into one

When div+rem calls on the same arguments are found, the ARM back-end merges the
two calls into one __aeabi_divmod call for up to 32-bits values. Howeve

[ARM] Merging 64-bit divmod lib calls into one

When div+rem calls on the same arguments are found, the ARM back-end merges the
two calls into one __aeabi_divmod call for up to 32-bits values. However,
for 64-bit values, which also have a lib call (__aeabi_ldivmod), it wasn't
merging the calls, and thus calling ldivmod twice and spilling the temporary
results, which generated pretty bad code.

This patch legalises 64-bit lib calls for divmod, so that now all the spilling
and the second call are gone. It also relaxes the DivRem combiner a bit on the
legal type check, since it was already checking for isLegalOrCustom on every
value, so the extra check for isTypeLegal was redundant.

This patch fixes PR17193 (and a long time FIXME in the tests).

llvm-svn: 262507

show more ...

[ARM] Move GNUEABI divmod to __aeabi_divmod*

The GNU toolchain emits __aeabi_divmod for soft-divide on ARM cores
which happens to be a lot faster than __divsi3/__modsi3 when the core
has hardware di

[ARM] Move GNUEABI divmod to __aeabi_divmod*

The GNU toolchain emits __aeabi_divmod for soft-divide on ARM cores
which happens to be a lot faster than __divsi3/__modsi3 when the core
has hardware divide instructions. Do the same here.

Fixes PR26450.

llvm-svn: 259657

show more ...

Adding support for TargetLoweringBase::LibCall

Summary:
TargetLoweringBase::Expand is defined as "Try to expand this to other ops,
otherwise use a libcall." For ISD::UDIV and ISD::SDIV, the choice b

Adding support for TargetLoweringBase::LibCall

Summary:
TargetLoweringBase::Expand is defined as "Try to expand this to other ops,
otherwise use a libcall." For ISD::UDIV and ISD::SDIV, the choice between
the two possibilities was defined in a rather convoluted way:

- if DIVREM is legal, expand to DIVREM
- if DIVREM has a custom lowering, expand to DIVREM
- if DIVREM libcall is defined and a remainder from the same division is
computed elsewhere, expand to a DIVREM libcall
- else, expand to a DIV libcall

This had the undesirable effect that if both DIV and DIVREM are implemented
as libcalls, then ISD::UDIV and ISD::SDIV are expanded to the heavier DIVREM
libcall, even when the remainder isn't used.

The new code adds a new LegalizeAction, TargetLoweringBase::LibCall, so that
backends can directly control whether they prefer an expansion or a conversion
to a libcall. This makes the generic lowering code even more generic,
allowing its reuse in a wider range of target-specific configurations.

The useful effect is that ARM backend will now generate a call
to __aeabi_{i,u}div rather than __aeabi_{i,u}divmod in cases where
it doesn't need the remainder. There's no functional change outside
the ARM backend.

Reviewers: t.p.northover, rengolin

Subscribers: t.p.northover, llvm-commits, aemerson

Differential Revision: http://reviews.llvm.org/D13862

llvm-svn: 250826

show more ...

[ARM] Lower modulo operation to generate __aeabi_divmod on Android

For a modulo (reminder) operation,
clang -target armv7-none-linux-gnueabi generates "__modsi3"
clang -target armv7-none-eabi ge

[ARM] Lower modulo operation to generate __aeabi_divmod on Android

For a modulo (reminder) operation,
clang -target armv7-none-linux-gnueabi generates "__modsi3"
clang -target armv7-none-eabi generates "__aeabi_idivmod"
clang -target armv7-linux-androideabi generates "__modsi3"
Android bionic libc doesn't provide a __modsi3, instead it provides a
"__aeabi_idivmod". This patch fixes the LLVM ARMISelLowering to generate
the correct call when ever there is a modulo operation.

Differential Revision: http://reviews.llvm.org/D11661

llvm-svn: 243717

show more ...

Revert "ARM: improve RTABI 4.2 conformance on Linux"

This reverts commit r215862 due to nightly failures. Will work on getting a
reduced test case, but I wanted to get our bots green in the meantim

Revert "ARM: improve RTABI 4.2 conformance on Linux"

This reverts commit r215862 due to nightly failures. Will work on getting a
reduced test case, but I wanted to get our bots green in the meantime.

llvm-svn: 216325

show more ...

ARM: improve RTABI 4.2 conformance on Linux

The set of functions defined in the RTABI was separated for no real reason.
This brings us closer to proper utilisation of the functions defined by the
RT

ARM: improve RTABI 4.2 conformance on Linux

The set of functions defined in the RTABI was separated for no real reason.
This brings us closer to proper utilisation of the functions defined by the
RTABI. It also sets the ground for correctly emitting function calls to AEABI
functions on all AEABI conforming platforms.

The previously existing lie on the behaviour of __ldivmod and __uldivmod is
propagated as it is beyond the scope of the change.

The changes to the test are due to the fact that we now use the divmod functions
which return both the quotient and remainder and thus we no longer need to
invoke two functions on Linux (making it closer to EABI's behaviour).

llvm-svn: 215862

show more ...

Fix broken CHECK lines.

llvm-svn: 199016

ARM: keep special non-AEABIness of "-darwin-eabi" triples for now

Longer term, we want to move users to "*-*-*-macho" for embedded work, but for
now people are relying on the last thing we told them

ARM: keep special non-AEABIness of "-darwin-eabi" triples for now

Longer term, we want to move users to "*-*-*-macho" for embedded work, but for
now people are relying on the last thing we told them, which is unfortunately
"*-*-darwin-eabi".

rdar://problem/15703934

llvm-svn: 198602

show more ...

Recognize EABIHF as environment and use it for RTAPI + VFP.

llvm-svn: 197405

Update to CodeGen tests to use CHECK-LABEL for labels corresponding to function definitions for more informative error messages. No functionality change.

llvm-svn: 186594

ARM EABI divmod support

This patch enables calls to __aeabi_idivmod when in EABI mode,
by using the remainder value returned on registers (R1),
enabled by the ARM triple "none-eabi". Note that Darwi

ARM EABI divmod support

This patch enables calls to __aeabi_idivmod when in EABI mode,
by using the remainder value returned on registers (R1),
enabled by the ARM triple "none-eabi". Note that Darwin and
GNUEABI triples will continue lowering on GNU style, that is,
using the stack for the remainder.

Still need to add SREM/UREM support fix for 64-bit lowering.

llvm-svn: 186390

show more ...