to be extended to a full register. This is modeled in the IR by marking
the return value (or argument) with a signext or zeroext attribute.
However, while these attributes are respected for function arguments,
they are currently ignored for function return values by the PowerPC
back-end. This patch updates PPCCallingConv.td to ask for the promotion
to i64, and fixes LowerReturn and LowerCallResult to implement it.
The new test case verifies that both arguments and return values are
properly extended when passing them; and also that the optimizers
understand incoming argument and return values are in fact guaranteed
by the ABI to be extended.
The patch caused a spurious breakage in CodeGen/PowerPC/coalesce-ext.ll,
since the test case used a "ret" instruction to create a use of an i32
value at the end of the function (to set up data flow as required for
what the test is intended to test). Since there's now an implicit
promotion to i64, that data flow no longer works as expected. To fix
this, this patch now adds an extra "add" to ensure we have an appropriate
use of the i32 value.
llvm-svn: 167396
The Z constraint specifies an r+r memory address, and the y modifier expands
to the "r, r" in the asm string. For this initial implementation, the base
register is forced to r0 (which has the special meaning of 0 for r+r addressing
on PowerPC) and the full address is taken in the second register. In the
future, this should be improved.
llvm-svn: 167388
getIntPtrType support for multiple address spaces via a pointer type,
and also introduced a crasher bug in the constant folder reported in
PR14233.
These commits also contained several problems that should really be
addressed before they are re-committed. I have avoided reverting various
cleanups to the DataLayout APIs that are reasonable to have moving
forward in order to reduce the amount of churn, and minimize the number
of commits that were reverted. I've also manually updated merge
conflicts and manually arranged for the getIntPtrType function to stay
in DataLayout and to be defined in a plausible way after this revert.
Thanks to Duncan for working through this exact strategy with me, and
Nick Lewycky for tracking down the really annoying crasher this
triggered. (Test case to follow in its own commit.)
After discussing with Duncan extensively, and based on a note from
Micah, I'm going to continue to back out some more of the more
problematic patches in this series in order to ensure we go into the
LLVM 3.2 branch with a reasonable story here. I'll send a note to
llvmdev explaining what's going on and why.
Summary of reverted revisions:
r166634: Fix a compiler warning with an unused variable.
r166607: Add some cleanup to the DataLayout changes requested by
Chandler.
r166596: Revert "Back out r166591, not sure why this made it through
since I cancelled the command. Bleh, sorry about this!
r166591: Delete a directory that wasn't supposed to be checked in yet.
r166578: Add in support for getIntPtrType to get the pointer type based
on the address space.
llvm-svn: 167221
parameters. Examples of these are:
struct { } a;
union { } b[256];
int a[0];
An empty aggregate has an address, although dereferencing that address is
pointless. When passed as a parameter, an empty aggregate does not consume
a protocol register, nor does it consume a doubleword in the parameter save
area. Passing an empty aggregate by reference passes an address just as
for any other aggregate. Returning an empty aggregate uses GPR3 as a hidden
address of the return value location, just as for any other aggregate.
The patch modifies PPCTargetLowering::LowerFormalArguments_64SVR4 and
PPCTargetLowering::LowerCall_64SVR4 to properly skip empty aggregate
parameters passed by value. The handling of return values and by-reference
parameters was already correct.
Built on powerpc64-unknown-linux-gnu and tested with no new regressions.
A test case is included to test proper handling of empty aggregate
parameters on both sides of the function call protocol.
llvm-svn: 167090
This patch adds more support for vector type comparisons using altivec.
It adds correct support for v16i8, v8i16, v4i32, and v4f32 vector
types for comparison operators ==, !=, >, >=, <, and <=.
llvm-svn: 167015
ELF ABI.
A varargs parameter consisting of a single-precision floating-point value,
or of a single-element aggregate containing a single-precision floating-point
value, must be passed in the low-order (rightmost) four bytes of the
doubleword stack slot reserved for that parameter. If there are GPR protocol
registers remaining, the parameter must also be mirrored in the low-order
four bytes of the reserved GPR.
Prior to this patch, such parameters were being passed in the high-order
four bytes of the stack slot and the mirrored GPR.
The patch adds a new test case to verify the correct code generation.
llvm-svn: 166968
structs having size 3, 5, 6, or 7. Such a struct must be passed and received
as right-justified within its register or memory slot. The problem is only
present for structs that are passed in registers.
Previously, as part of a patch handling all structs of size less than 8, I
added logic to rotate the incoming register so that the struct was left-
justified prior to storing the whole register. This was incorrect because
the address of the parameter had already been adjusted earlier to point to
the right-adjusted value in the storage slot. Essentially I had accidentally
accounted for the right-adjustment twice.
In this patch, I removed the incorrect logic and reorganized the code to make
the flow clearer.
The removal of the rotates changes the expected code generation, so test case
structsinregs.ll has been modified to reflect this. I also added a new test
case, jaggedstructs.ll, to demonstrate that structs of these sizes can now
be properly received and passed.
I've built and tested the code on powerpc64-unknown-linux-gnu with no new
regressions. I also ran the GCC compatibility test suite and verified that
earlier problems with these structs are now resolved, with no new regressions.
llvm-svn: 166680
for the PowerPC target, and factoring the results. This will ease future
maintenance of both subtargets.
PPCTargetLowering::LowerCall_Darwin_Or_64SVR4() has grown a lot of special-case
code for the different ABIs, making maintenance difficult. This is getting
worse as we repair errors in the 64-bit ELF ABI implementation, while avoiding
changes to the Darwin ABI logic. This patch splits the routine into
LowerCall_Darwin() and LowerCall_64SVR4(), allowing both versions to be
significantly simplified. I've factored out chunks of similar code where it
made sense to do so. I also performed similar factoring on
LowerFormalArguments_Darwin() and LowerFormalArguments_64SVR4().
There are no functional changes in this patch, and therefore no new test
cases have been developed.
Built and tested on powerpc64-unknown-linux-gnu with no new regressions.
llvm-svn: 166480
test case on PowerPC caused by rounding errors when converting from a 64-bit
integer to a single-precision floating point. The reason for this are
double-rounding effects, since on PowerPC we have to convert to an
intermediate double-precision value first, which gets rounded to the
final single-precision result.
The patch fixes the problem by preparing the 64-bit integer so that the
first conversion step to double-precision will always be exact, and the
final rounding step will result in the correctly-rounded single-precision
result. The generated code sequence is equivalent to what GCC would generate.
When -enable-unsafe-fp-math is in effect, that extra effort is omitted
and we accept possible rounding errors (just like GCC does as well).
llvm-svn: 166178
For the PowerPC 64-bit ELF Linux ABI, aggregates of size less than 8
bytes are to be passed in the low-order bits ("right-adjusted") of the
doubleword register or memory slot assigned to them. A previous patch
addressed this for aggregates passed in registers. However, small
aggregates passed in the overflow portion of the parameter save area are
still being passed left-adjusted.
The fix is made in PPCTargetLowering::LowerCall_Darwin_Or_64SVR4 on the
caller side, and in PPCTargetLowering::LowerFormalArguments_64SVR4 on
the callee side. The main fix on the callee side simply extends
existing logic for 1- and 2-byte objects to 1- through 7-byte objects,
and correcting a constant left over from 32-bit code. There is also a
fix to a bogus calculation of the offset to the following argument in
the parameter save area.
On the caller side, again a constant left over from 32-bit code is
fixed. Additionally, some code for 1, 2, and 4-byte objects is
duplicated to handle the 3, 5, 6, and 7-byte objects for SVR4 only. The
LowerCall_Darwin_Or_64SVR4 logic is getting fairly convoluted trying to
handle both ABIs, and I propose to separate this into two functions in a
future patch, at which time the duplication can be removed.
The patch adds a new test (structsinmem.ll) to demonstrate correct
passing of structures of all seven sizes. Eight dummy parameters are
used to force these structures to be in the overflow portion of the
parameter save area.
As a side effect, this corrects the case when aggregates passed in
registers are saved into the first eight doublewords of the parameter
save area: Previously they were stored left-justified, and now are
properly stored right-justified. This requires changing the expected
output of existing test case structsinregs.ll.
llvm-svn: 166022
For function calls on the 64-bit PowerPC SVR4 target, each parameter
is mapped to as many doublewords in the parameter save area as
necessary to hold the parameter. The first 13 non-varargs
floating-point values are passed in registers; any additional
floating-point parameters are passed in the parameter save area. A
single-precision floating-point parameter (32 bits) must be mapped to
the second (rightmost, low-order) word of its assigned doubleword
slot.
Currently LLVM violates this ABI requirement by mapping such a
parameter to the first (leftmost, high-order) word of its assigned
doubleword slot. This is internally self-consistent but will not
interoperate correctly with libraries compiled with an ABI-compliant
compiler.
This patch corrects the problem by adjusting the parameter addressing
on both sides of the calling convention.
llvm-svn: 165714
We use the enums to query whether an Attributes object has that attribute. The
opaque layer is responsible for knowing where that specific attribute is stored.
llvm-svn: 165488
Vector compare using altivec 'vcmpxxx' instructions have as third argument
a vector register instead of CR one, different from integer and float-point
compares. This leads to a failure in code generation, where 'SelectSETCC'
expects a DAG with a CR register and gets vector register instead.
This patch changes the behavior by just returning a DAG with the
vector compare instruction based on the type. The patch also adds a testcase
for all vector types llvm defines.
It also included a fix on signed 5-bits predicates printing, where
signed values were not handled correctly as signed (char are unsigned by
default for PowerPC). This generates 'vspltisw' (vector splat)
instruction with SIM out of range.
llvm-svn: 165419
into separate versions for the Darwin and 64-bit SVR4 ABIs. This will
facilitate doing more major surgery on the 64-bit SVR4 ABI in the near future.
llvm-svn: 165336
lib/Target/PowerPC/PPCISelLowering.{h,cpp}
Rename LowerFormalArguments_Darwin to LowerFormalArguments_Darwin_Or_64SVR4.
Rename LowerFormalArguments_SVR4 to LowerFormalArguments_32SVR4.
Receive small structs right-justified in LowerFormalArguments_Darwin_Or_64SVR4.
Rename LowerCall_Darwin to LowerCall_Darwin_Or_64SVR4.
Rename LowerCall_SVR4 to LowerCall_32SVR4.
Pass small structs right-justified in LowerCall_Darwin_Or_64SVR4.
test/CodeGen/PowerPC/structsinregs.ll
New test.
llvm-svn: 164228
- BlockAddress has no support of BA + offset form and there is no way to
propagate that offset into machine operand;
- Add BA + offset support and a new interface 'getTargetBlockAddress' to
simplify target block address forming;
- All targets are modified to use new interface and X86 backend is enhanced to
support BA + offset addressing.
llvm-svn: 163743
[Tobias von Koch] What's happening here is that the CR6SET/CR6UNSET is breaking the chain of register copies glued to the function call (BL_SVR4 node). The scheduler then moves other instructions in between those and the function call, which isn't good!
Right. That's the case where there is no chain of register copies before the call, so InFlag == 0... Attached is a new revision of the patch which should fix this for good.
llvm-svn: 162916
The 32-bit ABI requires CR bit 6 to be set if the call has fp arguments and
unset if it doesn't. The solution up to now was to insert a MachineNode to
set/unset the CR bit, which produces a CR vreg. This vreg was then copied
into CR bit 6. When the register allocator saw a bunch of these in the same
function, it allocated the set/unset CR bit in some random CR register (1
extra instruction) and then emitted CR moves before every vararg function
call, rather than just setting and unsetting CR bit 6 directly before every
vararg function call. This patch instead inserts a PPCcrset/PPCcrunset
instruction which are then matched by a dedicated instruction pattern.
Patch by Tobias von Koch.
llvm-svn: 162725
On PPC64, this can be done with a simple TableGen pattern.
To enable this, I've added the (otherwise missing) readcyclecounter
SDNode definition to TargetSelectionDAG.td.
llvm-svn: 161302
Over the entire test-suite, this has an insignificantly negative average
performance impact, but reduces some of the worst slowdowns from the
anti-dep. change (r158294).
Largest speedups:
SingleSource/Benchmarks/Stanford/Quicksort - 28%
SingleSource/Benchmarks/Stanford/Towers - 24%
SingleSource/Benchmarks/Shootout-C++/matrix - 23%
MultiSource/Benchmarks/SciMark2-C/scimark2 - 19%
MultiSource/Benchmarks/MiBench/automotive-bitcount/automotive-bitcount - 15%
(matrix and automotive-bitcount were both in the top-5 slowdown list from the
anti-dep. change)
Largest slowdowns:
MultiSource/Benchmarks/McCat/03-testtrie/testtrie - 28%
MultiSource/Benchmarks/mediabench/gsm/toast/toast - 26%
MultiSource/Benchmarks/MiBench/automotive-susan/automotive-susan - 21%
SingleSource/Benchmarks/CoyoteBench/lpbench - 20%
MultiSource/Applications/d/make_dparser - 16%
llvm-svn: 158296
It seems that this no longer causes test suite failures on PPC64 (after r157159),
and often gives a performance benefit, so it can be enabled by default.
llvm-svn: 157911
to pass around a struct instead of a large set of individual values. This
cleans up the interface and allows more information to be added to the struct
for future targets without requiring changes to each and every target.
NV_CONTRIB
llvm-svn: 157479
(load only has one operand) and smuggle in some whitespace changes too
NB: I am obviously testing the water here, and believe that the unguarded
cast is still wrong, but why is the getZExtValue of the load's operand
tested against zero here? Any review is appreciated.
llvm-svn: 155190
This allows us to keep passing reduced masks to SimplifyDemandedBits, but
know about all the bits if SimplifyDemandedBits fails. This allows instcombine
to simplify cases like the one in the included testcase.
llvm-svn: 154011
Ulrich Weigand