Treat signed icmps as 'sinks', allowing them to be in the use-def
tree, enabling more promotions to be performed. As a sink, any
promoted incoming values need to be truncated before being used by
the signed icmp.
Differential Revision: https://reviews.llvm.org/D50067
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@339755 91177308-0d34-0410-b5e6-96231b3b80d8
Add pointers to the list of allowed types, but don't try to promote
them. Also fixed a bug with the promotion of undef values, so a new
value is now created instead of mutating in place. We also now only
promote if there's an instruction in the use-def chains other than
the icmp, sinks and sources.
Differential Revision: https://reviews.llvm.org/D50054
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@339754 91177308-0d34-0410-b5e6-96231b3b80d8
LLVM normally prefers to minimize the number of bits set in an AND
immediate, but that doesn't always match the available ARM instructions.
In Thumb1 mode, prefer uxtb or uxth where possible; otherwise, prefer
a two-instruction sequence movs+ands or movs+bics.
Some potential improvements outlined in
ARMTargetLowering::targetShrinkDemandedConstant, but seems to work
pretty well already.
The ARMISelDAGToDAG fix ensures we don't generate an invalid UBFX
instruction due to a larger-than-expected mask. (It's orthogonal, in
some sense, but as far as I can tell it's either impossible or nearly
impossible to reproduce the bug without this change.)
According to my testing, this seems to consistently improve codesize by
a small amount by forming bic more often for ISD::AND with an immediate.
Differential Revision: https://reviews.llvm.org/D50030
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@339472 91177308-0d34-0410-b5e6-96231b3b80d8
Enabling ARMCodeGenPrepare by default caused a whole load of
failures. This is due to zexts and truncs not being handled properly.
ZExts are messy so it's just easier to disable for now and truncs
are allowed only as 'sinks'. I still need to figure out why allowing
them as 'sources' causes so many failures. The other main changes are
that we are explicit in the types that we converting to, it's now
always 'TypeSize'. Type support is also now performed while checking
for valid opcodes as it unnecessarily complicated having the checks
are different stages.
I've moved the tests around too, so we have the zext and truncs in
their own file as well as the overflowing opcode tests.
Differential Revision: https://reviews.llvm.org/D50518
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@339432 91177308-0d34-0410-b5e6-96231b3b80d8
Add new feature, `FeatureUseWideStrideVFP`, that replaces the need for a
processor check. Otherwise, NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@339354 91177308-0d34-0410-b5e6-96231b3b80d8
LLVM triple normalization is handling "unknown" and empty components
differently; for example given "x86_64-unknown-linux-gnu" and
"x86_64-linux-gnu" which should be equivalent, triple normalization
returns "x86_64-unknown-linux-gnu" and "x86_64--linux-gnu". autoconf's
config.sub returns "x86_64-unknown-linux-gnu" for both
"x86_64-linux-gnu" and "x86_64-unknown-linux-gnu". This changes the
triple normalization to behave the same way, replacing empty triple
components with "unknown".
This addresses PR37129.
Differential Revision: https://reviews.llvm.org/D50219
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@339294 91177308-0d34-0410-b5e6-96231b3b80d8
Normally, if any registers are spilled, we prefer to spill lr on Thumb1
so we can fold the "bx lr" into the "pop". However, if there are tail
calls involved, restoring lr is expensive, so skip the optimization in
that case.
The spill of r7 in the new test also isn't necessary, but that's
mostly orthogonal to this patch. (It's the same code in
ARMFrameLowering, but it's not related to tail calls.)
Differential Revision: https://reviews.llvm.org/D49459
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@339283 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Currently, in line with GCC, when specifying reserved registers like sp or pc on an inline asm() clobber list, we don't always preserve the original value across the statement. And in general, overwriting reserved registers can have surprising results.
For example:
```
extern int bar(int[]);
int foo(int i) {
int a[i]; // VLA
asm volatile(
"mov r7, #1"
:
:
: "r7"
);
return 1 + bar(a);
}
```
Compiled for thumb, this gives:
```
$ clang --target=arm-arm-none-eabi -march=armv7a -c test.c -o - -S -O1 -mthumb
...
foo:
.fnstart
@ %bb.0: @ %entry
.save {r4, r5, r6, r7, lr}
push {r4, r5, r6, r7, lr}
.setfp r7, sp, #12
add r7, sp, #12
.pad #4
sub sp, #4
movs r1, #7
add.w r0, r1, r0, lsl #2
bic r0, r0, #7
sub.w r0, sp, r0
mov sp, r0
@APP
mov.w r7, #1
@NO_APP
bl bar
adds r0, #1
sub.w r4, r7, #12
mov sp, r4
pop {r4, r5, r6, r7, pc}
...
```
r7 is used as the frame pointer for thumb targets, and this function needs to restore the SP from the FP because of the variable-length stack allocation a. r7 is clobbered by the inline assembly (and r7 is included in the clobber list), but LLVM does not preserve the value of the frame pointer across the assembly block.
This type of behavior is similar to GCC's and has been discussed on the bugtracker: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=11807 . No consensus seemed to have been reached on the way forward. Clang behavior has briefly been discussed on the CFE mailing (starting here: http://lists.llvm.org/pipermail/cfe-dev/2018-July/058392.html). I've opted for following Eli Friedman's advice to print warnings when there are reserved registers on the clobber list so as not to diverge from GCC behavior for now.
The patch uses MachineRegisterInfo's target-specific knowledge of reserved registers, just before we convert the inline asm string in the AsmPrinter.
If we find a reserved register, we print a warning:
```
repro.c:6:7: warning: inline asm clobber list contains reserved registers: R7 [-Winline-asm]
"mov r7, #1"
^
```
Reviewers: eli.friedman, olista01, javed.absar, efriedma
Reviewed By: efriedma
Subscribers: efriedma, eraman, kristof.beyls, llvm-commits
Differential Revision: https://reviews.llvm.org/D49727
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@339257 91177308-0d34-0410-b5e6-96231b3b80d8
Summary: Extend fix for PR34170 to support inline assembly with multiple output operands that do not naturally go in the register class it is constrained to (eg. double in a 32-bit GPR as in the PR).
Reviewers: bogner, t.p.northover, lattner, javed.absar, efriedma
Reviewed By: efriedma
Subscribers: efriedma, tra, eraman, javed.absar, llvm-commits
Differential Revision: https://reviews.llvm.org/D45437
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@339225 91177308-0d34-0410-b5e6-96231b3b80d8
Clang support for the Armv8.2-A FP16 vector intrinsic was committed in
rC328277, but this was never followed up, i.e. the LLVM part is missing.
I've raised PR38404, and this is the first step to address this. I.e.,
this adds tests for the Armv8.2-A FP16 vector intrinsic, and thus shows
which intrinsics already work, and which need further work.
Differential Revision: https://reviews.llvm.org/D50142
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@338568 91177308-0d34-0410-b5e6-96231b3b80d8
Disable ARMCodeGenPrepare by default again. It is causing verifier
failues in V8 that look like:
Duplicate integer as switch case
switch i32 %trunc, label %if.end13 [
i32 0, label %cleanup36
i32 0, label %if.then8
], !dbg !4981
i32 0
fatal error: error in backend: Broken function found, compilation aborted!
I will continue reducing the test case and send it along.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@338452 91177308-0d34-0410-b5e6-96231b3b80d8
Re-enabling ARMCodeGenPrepare by default after failing to reproduce
the bootstrap issues that I was concerned it was causing.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@338354 91177308-0d34-0410-b5e6-96231b3b80d8
This reapplies commit r338206 reverted by r338214 since the bug that
r338206 uncovered has been fixed in r338268.
Add support for inline assembly with matching input operand that do not
naturally go in the register class it is constrained to (eg. double in a
32-bit GPR). Note that regular input is already handled by existing
code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@338269 91177308-0d34-0410-b5e6-96231b3b80d8
Code in `CC_ARM_AAPCS_Custom_Aggregate()` is responsible for handling
homogeneous aggregates for `CC_ARM_AAPCS_VFP`. When an aggregate ends up
fully on stack, the function tries to pack all resulting items of the
aggregate as tightly as possible according to AAPCS.
Once the first item was laid out, the alignment used for consecutive
items was the size of one item. This logic went wrong for 128-bit
vectors because their alignment is normally only 64 bits, and so could
result in inserting unexpected padding between the first and second
element.
The patch fixes the problem by updating the alignment with the item size
only if this results in reducing it.
Differential Revision: https://reviews.llvm.org/D49720
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@338233 91177308-0d34-0410-b5e6-96231b3b80d8
Add support for inline assembly with matching input operand that do not
naturally go in the register class it is constrained to (eg. double in a
32-bit GPR). Note that regular input is already handled by existing
code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@338206 91177308-0d34-0410-b5e6-96231b3b80d8
This can be useful since addition is commutable, and subtraction is not.
This matches a transform that is also done by InstCombine.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@338181 91177308-0d34-0410-b5e6-96231b3b80d8
This feature enables the fusion of such operations on Cortex A57 and Cortex
A72, as recommended in their Software Optimisation Guides, sections 4.14 and
4.11, respectively.
Differential revision: https://reviews.llvm.org/D49563
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@338147 91177308-0d34-0410-b5e6-96231b3b80d8
Add support for inline assembly with output operand that do not
naturally go in the register class it is constrained to (eg. double in a
32-bit GPR as in the PR).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@337903 91177308-0d34-0410-b5e6-96231b3b80d8
ARM Stage 2 builders have been suspiciously broken since the pass was
committed. Disabling to hopefully fix the bots and give me time to
debug.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@337821 91177308-0d34-0410-b5e6-96231b3b80d8
Arm specific codegen prepare is implemented to perform type promotion
on icmp operands, which can enable the removal of uxtb and uxth
(unsigned extend) instructions. This is possible because performing
type promotion before ISel alleviates this duty from the DAG builder
which has to perform legalisation, but has a limited view on data
ranges.
The pass visits any instruction operand of an icmp and creates a
worklist to traverse the use-def tree to determine whether the values
can simply be promoted. Our concern is values in the registers
overflowing the narrow (i8, i16) data range, so instructions marked
with nuw can be promoted easily. For add and sub instructions, we are
able to use the parallel dsp instructions to operate on scalar data
types and avoid overflowing bits. Underflowing adds and subs are also
permitted when the result is only used by an unsigned icmp.
Differential Revision: https://reviews.llvm.org/D48832
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@337687 91177308-0d34-0410-b5e6-96231b3b80d8
We were emitting incorrect calls to libm functions that LLVM had decided it
knew about because the default is soft-float.
Recommitted without breaking ELF this time.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@337450 91177308-0d34-0410-b5e6-96231b3b80d8
We were emitting incorrect calls to libm functions that LLVM had decided it
knew about because the default is soft-float.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@337385 91177308-0d34-0410-b5e6-96231b3b80d8
See https://reviews.llvm.org/D47106 for details.
Reviewed By: probinson
Differential Revision: https://reviews.llvm.org/D47171
This commit drops that patch's changes to:
llvm/test/CodeGen/NVPTX/f16x2-instructions.ll
llvm/test/CodeGen/NVPTX/param-load-store.ll
For some reason, the dos line endings there prevent me from commiting
via the monorepo. A follow-up commit (not via the monorepo) will
finish the patch.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@336843 91177308-0d34-0410-b5e6-96231b3b80d8
This fixes an issue that we were not properly supporting multiple reduction
stmts in a loop, and not generating SMLADs for these cases. The alias analysis
checks were done too early, making it too conservative.
Differential revision: https://reviews.llvm.org/D49125
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@336795 91177308-0d34-0410-b5e6-96231b3b80d8
The original code attempted to do this, but the std::abs() call didn't
actually do anything due to implicit type conversions. Fix the type
conversions, and perform the correct check for negative immediates.
This probably has very little practical impact, but it's worth fixing
just to avoid confusion in the future, I think.
Differential Revision: https://reviews.llvm.org/D48907
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@336742 91177308-0d34-0410-b5e6-96231b3b80d8
